Marine Biologyt7, 7--29 (t972) 9 by Springer-Verlag 1972
Bathymetric Distribution of Chaetognaths in the South Eastern Pacific Ocean E. Fagetti Departamento de Oceanologfa,Universidad de Chile; Vifia del Mar, Chile
Abstract
The bathymetrie distribution of chaetognath fauna observed at planktonic stations in the South Eastern Pacific Ocean during three different expeditions, is presented quantitatively. The material from the cruises IFOP-01 (October-December, 1964) and IFOP-04 (November--December, 1965) was collected by vertical closing net, at regular intervals, from 2000 and t 000 m depth, respectively; the l%.V. "A. Bruun" Cruise 13 data include vertical samples at usual depth intervals from 3000 m (see Table 12), Isaac-Xidd Midwater Trawl (IKMT) and surface collections. They allowed us to identify, for the first time, the meso and bathypelagic species of this region and to extend the longitudinal distribution of the epipelagic species, which had been previously limited to the coastal areas. Among the epiplanktonic species, it was shown that two, Sagitta serratodentata and S. bipunctata, do not penetrate into the Peru Coastal Current region, where the endemic S. bierri is to be found extending westwards to the west boundary of the Peru Coastal Current, and that both mesopelagic species, previously reported for the epipelagic level of this area, S. decipiens and Eukrohnia hamata, inhabit the upper mesopelagic level in the oceanic region, but also rise to the epipelagic level near the coast, where upwellings do occur. The lower mesopelagic levels (500 to t000 m) are occupied by E./owleri and S. macrvcephala, this latter species being reported for the first time in the South Eastern Pacific Ocean. The other mesopelagic species, S. zetesios and S. bathypelagica, also found for the first time in this region, were not found in large enough numbers to obtain a correct view of their stratification. Eukrohnia bathyantarctica, described for the Southern Ocean and previously reported only in the bathypelagic levels of the Gulf of Mexico and Caribbean Sea, was found at only bathypelagic levels. The faunistic data from the R.V. "A. Bruun" Cruise 13, were compared with the corresponding hydro. graphical profiles. Introduction
As no information was available in the literature about the vertical distribution of zooplankton in the South Eastern Pacific Ocean, nor about its specific composition and quantitative vertical stratification, deep vertical, plankton samples were collected during two national expeditions off the Chilean coast. The present paper presents data on vertical distribution of chaetognaths; our observations on the total biomass and group composition will be dealt with in a separate paper. Previous knowledge on the chaetognath fauna of Chilean waters pertained to the horizontal distribution of epiplanktonic species collected mainly by surface
and oblique hauls from approximately 150 m depth (Fagetti, i958b, i959, t968b). As a complete understanding of the species can only be obtained through the study of the two-dimensional distribution of each species and of its temporal and geographical variation, the second step of our research had, as its main objective, the identification of the species inhabiting the deep layers and the determination of their vertical ranges in this relatively unstudied region of the southern hemisphere. I n the present paper, data are presented for the chaetognath fauna from all deep collections so far made in Chilean waters: IFOP-01, IFOP-04 and R.V. "A. Bruun" Cruise t3. A more comprehensive picture on the vertical distribution of the species can be obtained only through the study of the complete deep collection series of the R. V. "A. Bruun" Cruise. Material and Methods
The material examined in this study comes from plankton samples collected off the Chilean coast, during 3 different expeditions: IFOP-01 (October--December, 1964): 25 vertical plankton stations, distributed along i2 transects perpendicular to the coast, from 30 ~to 43o30 ' S (Fig. l). IFOP-04 (October--November, i965): 5 vertical plankton stations off the northern Chilean coast, from about t8 ~ to 25 ~ S (Fig. f). R.V. "A. Bruun" Cruise 13 (January--February, 1966): l i vertical stations, 8 surface stations and 42 collections made with the Isaac-Kidd Midwater Trawl (IKMT) and distributed in a transect extending seaward from Valparaiso, for a distance of approximately 1000 nautical miles, between 33 ~ and 34~ S. The position of the IKMT and surface collections, and of the vertical plankton stations, are shown in Fig. 2. A full account of the cruise, as well as the basic hydrological data has been reported by Mead (i966). The IFOP-01, IFOP-04 and R.V. "A. Bruun" Cruise t3 vertical samples were collected with a NV 70 net. The depth intervals programmed for the IFOP-01 stations were: 2000 to 1000 m, 1000 to 500 m, 500 to 200 m, 200 to 0 m; unfortunately, it has not been possible, at each station, to accomplish the vertical
8
E. Fagetti: Bathymetrie Distribution of Chaetognaths
sampling at each fixed interval, due to the poor condition of the gear and closing apparatus available. The fishing depth intervals for each station are given in Table 10. The depths commonly sampled during the IFOP-04 were 2000 to Y000 m, t000 to 500 m, 500 to 200 m, 200 to t00 m and 100 to 0 m (Table tl). The vertical hauls of the R.V. "A. Bruun" Cruise t3 were made from 3000 m at regular depth intervals of 3000 to 2000m, 2000 to 1000m, 1000 to 500m, 500 to 200 m, 200 to t00 m and t00 to 0 m (Table t2). The IIs collections of the l%.V. "A. Bruun" cruise were made with a t0 ft Isaac-Kidd Midwater Trawl and the concurrent surface tows with a t m houston net (6 m long, No. 2 mesh). Out of the 42 XK1V[T collections examined, 25 were sampled within the upper 500 m, 5 at a m a x i m u m depth between 500 and 1000 m and the remaining i2 at greater depths, below 1000 m. No subsampling has been made, except for some of the I~.V. "A. Bruun" vertical samples of the upper level (100 to 0 m), which were particularly rich in ehaetognaths; in these cases, the specimens were counted in 2 or 3 subsamples obtained with the F o x , o n splitter. The actual number of specimens found in each I K M T collection is given in Table t3. The numerical results from the vertical samples were standardized to represent number for t000 m 8 of water. Only for the I~.V. "A. Brunn" vertical samples, were flowmeter readings available for most of the samples as well as data on the actual depth sampled (corrected depth) for each interval as determined from the depth recorder and filed at the Woods-ItoIe OeeanographieaI Institution, Woods Hole, USA. I n those instances where no flowmeter data were available (IFOP-0t and IFOP-04 samples and some of the l%V. "A. Bruun" vertical samples) we have used, in our computation, 80% of the theoretical value of water filtered, computed mathematically as suggested b y Grice and Hulsemann (t965). I n this paper, the vertical q u a n t i ~ i v e ranges of each species is given mainly on the basis of the vertical sampling; the surface samples as well as the I K M T material have been used only as a qualitative index of horizontal distribution and vertical stratification.
s
IFOP-01 St.~ IFOP-04 St.,
20"
2s~
30o
3so
40~
;2 2
,2# 4so
w ,
W
80 ~
75 ~
70 ~
Fig. 1. Vertical plankton stations of IFOI~-01 and iFOP-04= cruises. St: Stations
90 ~
92 ~ W
88 ~
86 ~
84 ~
Mar. Biol.
82 ~
80
~
78 ~
76*
752
7T
W
28T
~ T,s
7,,T V
2 ,s
| 2~s
~TS
l~vs
2 T,v,s T
t
1
}
l
t
i
~
T
1
l
T
;
T
~ ____--l----.
Fig. 2. Plankton stations of l%.V. "A. Bruun" Cruise 13. V: vertical samples; S: surface samples; T: B f W T collections
Vol. 17, 2go. 1, I972
E. Fagetti: Bathymetrie Disgribution of Chaetog~laths
Previous Investigations Only brief reference will be made here to the literature available to the author, including quantitative results on chaetognath fauna of meso and bathypelagie levels sampled with vertical closing nets. One of the earliest attempts was that of Steinhaus (1896), followed later by Fowler (1905), who collected plankton in the northeastern Atlantic Ocean at definite intervals clown to 2000 m depth. The same author (1906), studying the material of the "Siboga Expedition" which includes some samples taken with the mesoplanktonic closing net, presented a revision of all known previous data on the distribution of the species, giving the lowest depth for each one. Burfield and Harvey (1926) gave the vertical ranges down to i000 fathoms (1850m) for the Indian Ocean species. A more complete picture of the quantitative distribution of species at different levels was obtained only later; Thiel (!938) first plotted the density contours of the Atlantic Ocean species at different layers down to 1000 m depth. Tachindonova (t955) extended the vertical ranges of the deep species, to 5000 m depth in r Kurile-Kamchatka trench. The quantitative stratification from 1500m depth of the Southern Ocean chaetognaths species has been thouroughly presented by David (1955, t958a and t965). Matsudaira and Furuhashi (t955) and Furuhashi (1961) reported on the chaetognaths collected by divided hauls from 2500 m off the south eastern coast of Japan. Furnestin (t962) described the vertical distribution of chaetognaths from 2610m in the western Mediterranean Sea. The bathymetric distribution of the Pacific and Indian chaetognaths was presented by Alvarifio (1964), who also studied their nyctimeral stratification from 300 m depth off San Diego, California (Alvarifio, I967a); Kitou (1966b, 1967) reported on material collected in the Japan Trench and in the North West Pacific Ocean, off Hokkaido, from 5000 m depth. Finally, Dawson (1968) studied the quantitative distribution of the chaetognath species from the Arctic Basin, in collections made from 3800 m depth. The qualitative stratification of species at the mesopelagie level has been extensively studied in severaI oceanographical regions: the San Diego region (Michael, 1911 and t913), the eastern coast of Canada (Huntsman, 1919), the South Georgia whMing ground (Hardy and Gunther, 1935), the Scottish area (Fraser, t952), the west coast of South Africa (Heydorn, 1959), the Florida Current (Owre, 1960), the eastern tropical Pacific Ocean (Sund, 1961), the eastern Australian slope (Sheard, t965), and the equatorial and tropical African water (Ducret, 1968). Several new species have been described lately, as methods for the exploration of deeper layers have advanced: Eukrohnia bathypelagica Alvarifio (i962) and E. proboscidea Furnestin and Ducret (i965) for 2 3[arineBiology,Vol.17
9
the mesopelagic levels; E. bathyantarctica David (1958b), Sagitta izuensis Kitou (i966a), E. bathybia Marumo and Kitou (1966), Heterokrohnia involucrum Dawson (t968) and E. minuta Silas and Srinivasan (1968) for greater depths. The increasing knowledge of the deep fauna has also shown that the species inhabiting the deeper layers are mainly cosmopolitan. Very little is known on the meso and bathypelagic fauna of the South Eastern Pacific Ocean. The recent IKMT collections made by the US research vessels "Eltanin" and "A. Bruun" have contributed towards filling this important gap. Menzies (1963) presented general results on the biological investigation of deepsea fauna from Panama to Valparaiso, and Geiger (1966) reported on the biological oceanographic data of the Antarctic Ocean as collected by the R.V. "Eltanin" Cruises 4 to 13, which include data from the Chilean area. Data on the qualitative and quantitative distribution of the mesopelagic fauna from the Eastern South Pacific waters have been so far provided for: mid-water fishes (Bussing, t965; Craddock and Mead, t970) copepods (Grice and Hulsemann, t968); heteropod mollusks (Fagetti, 1968@ Nevertheless, more observations and data are still needed to achieve a generalized knowledge of the vertical distributio~ of zooplankton and micronekton from this area.
Results Species F o u n d at Diferent Levels The material examined in this report has extended our knowledge on the chaetognath fauna off the Chilean coast from a descriptive point of view, as well as aiding in the determination of their latitudinal and vertical ranges. The species so far recorded for the South-Eastern Pacific waters are listed below, in order of abundance, and grouped according to vertical stratification. The numbers correspond to the specimens actually present in the vertical samples only. Ep@lanktonic 200--0 m Species No. % Sagitta minima 2513 40.92 Sagitta enflata 3031 33.07 Saffitta bierii 675 10.99 Sagitta tasmanica 366 23.83 Sagitta 8erratodentata t:l5 t.87 Perosagitta draco i08 i.75 Sagitta bipunctata 104 1.69 Sagitta pacifica 60 0.94 Sagitta gazellae 53 0.86 Sagi~ta maxima 48 0.78 Sagitta lyra 27 0.43 Krohnitta subtilis 22 0.35 Sagitta hexaptera 19 0.30 Nagitta planctonis } Krohnitta pacifica not found in ~he present materiM Total
6141
t0
E. Fagetti: Bathymetric Distribution of Chaetognaths
!!
200 E t I i 1
500
Mar. Biol.
?
=' 1 0 0 0
ul
Z
2000
300(
Ranges of vert. sclmp/es iDepth of positive Sis. of IMWF col{.
~o_~
_>j~_ ~.o,!.~
T
A
200
m 5o(~ I.u i-. i.u
:s
1000
~o,__E. _>.!~
"r" ~2000 Q
3000
B
20C 10~
z
>1 ~"
50C
1000
C Fig. 3. Vertical distribution of species collected, represented as percentage of total for all depths and computed on average number of specimens captured at each interval. Note change of scale at 500 and i000 m
Vol. 17, 1go. 1, 1972
E. Fagetti: Bathymetric Distribution of Chaetognaths
Mesoplanktonic
Sagitta bipunctata Quoy and Gaimard
1000--500 m Species
No.
Eukrohnia hamata Sagitta dec@lens Sagitta macrocephala Eukrohnia/owleri Sagitta zetesios Eukrohnia bathypelagica
929 4t4 33 2t ~3 4 Total
11
% 65.70 29.27 2.33 t.48 0.91 0.28
1414
F o u n d only in the R.V. "'A. Bruun" collections made west of 76~ W, this species does not extend eastwards beyond the west boundary of the Peru Coastal Current (Fig. 8). This explains the absence of Sagitta bipunctata in the material collected on the R.V. "Marchile I " Expedition (Fagetti, i968b) and from the I F O P - 0 t and IFOP-04 cruises, which covered only the Peru Coastal Current region. More abundant in the upper t00 m (Fig. 3 C), this species moves down sporadically to deeper levels than the epiplanktonic level.
JBathyplanktonic
Sagitta enflata Grassi
below t000 m Species
No.
Eukrohnia bathyantarctica
4
The more common species of this area, Sagitta enflata, has been found in the same latitudinal range
The quantitative vertical and horizontal distribution of each species found in the material examined for this study, as well as the biometric data of species not previously found or not common for this area, are presented below. Epiplanktonic Species
Sagitta bierii Alvarh]o This species, previously known as endemic to the California and Peru Currents (Alvarifio, 1965 ; Fagetti, 1968b) has been recently reported in the intertropieal region off the West African coast (Durcet, 1968). Its latitudinal distribution off the Chilean coast has been extended from 29 ~ S to 33 ~ S. Sagitta bierii lives at the epiplanktonic level, being found more abundantly in the upper 200 m (Fig. 3 A).
as previously given by Campodonieo (in preparation), extending west of Valparaiso to the outermost R.V. "A. Bruun" station at 92o30 ' W . S. enflata inhabits the epiplanktonie levels, only moving to deeper layers in very inconspicuous numbers (Fig. 3 A).
Sagitta gazellae ~i%er-Zahony The horizontal distribution of this species is given in Fig. 4, where the previous findings off the Chilean coast (Fagetti, i968 b; Campodonieo in preparation), are also indicated. The specimens found in this area correspond to the "small northern race" described by David (1955), as can be deduced by the measurements presented in Table i. The present material demonstrates that the intrusion of this subantarctie species into the Peru Current extends to 30~ the same is true also of the other subantarctie species, Sagitta tasmanica. I n this region, S. gazellae was found at 1000 m depth, being however more abundant in the upper 200 m (Fig. 3 B).
Table t. Sagitta gazellae. Collection data and measurements. IK.M T : Isaac-Kidd Midwater Trawl; sere. ves.: seminal vesicles Cruise
Net
Station Depth No. (m)
IFOP-01 "A. Bruun" XIII
Nansen IKMT
122 5
IFOP-01 Nansen "A. Bruun" XIII IKMT IFOP-0t Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-01 Nansen
94 5 1t8 124 t24 36 124 t24
2*
Total length (mm)
Percent Hooks tail~
Anterior Posterior Maturity stage teeth teeth
2000--t000 58.0 5000-+ 55.0
12.0 13.4
6~
80--0 5000-+ 150--0 200--0 200--0 500--0 200--0 200--0
1t.9 12.7 t0.8 tt.9 f3A 15.6 14.8 13.7
51.0 47.0 46.0 42.0 38.0 32.0 27.0 25.5
7 .
. 5/7
. 7/8 9-+ 10/1I 8/9 1t/11 11-+
. 5-~
.
. 5-+ 4-+ 4/5 4/5 4/5 4-+
7/8 .
Late II, sem. yes. present
7-+ . 8-+ 6 9 8/9 7 8
Late II, sere. yes. present II II Early II Early I I I I
12
Mar. Biol.
E. Fagetti: B+thymetric Distribution of Chaetognaths
e
9
0 20" 5 @ @
9
@
@
O@
@
25~
III
II
300
.+ .#i.J.. 35*
[] .. Ill Sagitta paci fica
[]
| 5oo ~ Fagetti,1968 No/1000m 3 $agitta gazellae I I
== i
NTT
[ ] >loo ~Cornpodonico,1969
[]
+ positive IKMTcoffections
[] ..i o
~5~ W
90"
85 ~
80 ~
75 ~
70"
Fig. 4. Sagitta gaz~llaeand S. pacifica. ~orizonbaI distribution
Sagitta hexaptera d'Orbigny This species has been found only in the vertical and I K M T samples of the I~.V. "A. B r a u n " Cruise 13, collected between 72~ ' and 92o30 ' W, in the same latitudinal ranges previously established for this area (Fagetti, t958b, 1959, i968b; Sund, 1964; Campodonieo, in preparation). Tts vertical distribution, ranging from 0 to 500 m, is mainly restricted to the lower epiplanktonie level, 200 to 100 m (Fig. 3 A). Sagitta lyra K r o h n Sagitta lyra, previously found only twice in Chilean waters (Fagetti, 1958 b ; Campodonico, in preparation)
between 28 ~ and 33 ~ S, was not considered as an inhabitant of South Pacific waters by Alvarifio (t965). The finding of this species at one station (Station i18) of the I F O P - 0 i , and in several vertical stations of the R.V. "A. B r a u n " Cruise 13, corroborates the presence of S. lyra in South Eastern Pacific waters, and extends its southern and western ranges to 42 ~ S and 92 ~ W, respectively. I n this region, the species has been found from 100 to 500 m depth, but occurred mainly in the deeper level of the epiplankton, 200 to 100 m (Fig. 3 C). The measurements of some Sagitta lyra specimens collected are given in Table 2.
E. Fagetti: Bathymetric Distribution of Chaetognaths
Vol 17, No. 1, 1972
t3
Table 2. Sagitta lyra. Collection data and measurements Cruise
"A. :Bruun" "A. Bruun" "A. :Bruun". "fl~. :Brllun". "~x. :Bruun" "A, ]3ruun" "A. ]~ruun'. "A. ]3ruun". "~. ]3ruun". "A. Bruun" "_4. :Brunn". '~fl.. ]~ruuIf'. "A. Bruun" 'A. Bruun".
Net
Station No.
Depth (m)
Total length (ram)
Percent tail
XIII XIII XIII XIII XIII XIII XIII XIII
Nansen Nansen Nansen Nansen Nansen Nansen Nansen Nansen
8 8 24
1000--500 1000--500 1000--500
31.6 30.0 29.9
16.7 15.3 16.8
24 44
1000--500 200--0
26.4 22.6
17.0 15.9
24 24 8
200--100 200--100 1000--500
22.0 21.7 21.1
15.9 17.9 15.6
XIII
Nansen
44
200--0
21.0
15.2
XIII XIII XIII XI!I XIII
Nansen Nansen Nansen Nansen Nansen
20 44 24 24 20
200--100 200--0 200--100 200--100 200--100
20.5 20.3 20.0 15.0 13.5
16.5 17.0 15.0 16.6 17.5
Table 3. Sagitta maxima. Collection data and meazurements, sam. yes.: seminal vesicles Cruise
IFOP-01 IFOP-01 IFOP-01 IFOP-01 IFOP-01 "A. Bruun" X I I I IFOP-01
Station Depth No. (m)
Total length
Percent tail
~Iooks
38 tl 1 66 43 8 66
41.0 41.0 35.0 31.0 29.0 25.0 23.0
2L9 19.5 20.0 25.8 20.6 23.9 23.9
5 5 6 9/8 6 6 6/7
500--0 1000--500 500--0 1000--500 500 0 500---200 1000--500
(ram)
Sagitta m a x i m a Conand The horizontal distribution previously k n o w n for Sagitta m a x i m a off the Chilean coast, from 19 ~ to 38 ~ S (Campodonico, in preparation), has been extended south to 43 ~ S and west from 82 ~ to 92 ~ 30' W. I)espite h a v i n g been f o u n d in the meso a n d deeper layers in other regions of ~he Pacific Ocean (Alvarifio, i964, t967 b), this species showed, in our samples, a m a x i m u m a b u n d a n c e in the upper 200 m, extending as far down as 1000 m (Fig. 3 B). Measurements a n d m a t u r i t y stages are presented in Table 3.
Anterior teeth
Posterior teeth
Ovary length
2/3 2/3 4/3 3/4 2 3 2/3
5 3 4 4/5 5 4/5 4
5.6 6.0 3.0 3.5 2.6 ---
Testes
(ram)
sere. yes. beginning sam. yes. empty sem. yes. not, visible sem. yes. not visible tail almost empty ---
been reported b y F a g e t t i (1958b); a few specimens were also collected further south (approximately 33 ~ S), in one vertical station of the t~.V. "A. B r u n n " Cruise i3, located at 7 6 ~ (Fig. 4). I t is the only species, a m o n g the epiplanktonie species reported here, which is distributed vertically only in the upper i00 m (Fig. 3 C).
Sagitta serratodentata K r o h n
Sagitta m i n i m a was found between the latitudinal ranges previously given for this area (Fagetti, i968 b), and extending westwards to 9 2 ~ in the l%.V. "A. B r u u n " Cruise 13 stations. I t inhabits almost exclusely the upper t00 m (Fig. 3 A).
This species was found only in the I{.V. "A. B r u n n " Cruise 13 samples collected west of the b o u n d a r y of the Peru Coastal Current (Fig. 8); it was not sampled b y the two other expeditions, which explored only the coastal region. Sagitta ssrratodentata was only once previously reported for Chilean waters (Fagetti, t958b) in oceanic regions. I t s vertical ranges lie between 500 and 0 m; it is more a b u n d a n t in the deeper epiplanktonie level of 200 to i00 m (Fig. 3 C}. Y[easnrements for S. 8erratodentata are given in Table 4.
Sagitta paci fica Tokioka
Sagitta tasmanica T h o m s o n
This species was found mainly in the same area (off the n o r t h e r n Chilean coast) where it h a d already
The specimens found in the southern p a r t of the explored region (from 43 ~ to 38 ~ S) correspond to the
Sagitta m i n i m a Grassi
E. Fagetti: Bathymetric Distribution of Chaetognaths
14
Mar. Biol.
Table 4. Sagitta serratodentata. Collection data and measurements. IKMT: Isaac.
Kidd Midwater Trawl
Cruise
l~et
Station No.
Total length (ram)
Percent tail
"A. Brunn" XIII "A. Brunn" XIII "A. Brunn" XIII "A. Bruun" XIII "A. Bruun" XIII "A. Bruun" XIII "A. Brunn" XIII "A. Bruun" XIII "A. Bruun" XIII
Nansen IKlViT IICMT Nansen IKMT IKMT IKMT IKMT IKMT
20 44 44 44 24 8 24 22 26
t4.0 13A 12.6 12.5 t2.5 12.2 t2.0 12.0 11.5
23.5 24.3 25.0 24.8 24.7 25.4 24.3 25.0 25.2
typical form (Fagetti, 1968b); the specimens from the northern stations (R.V. "A. Braun" Cruise 13 vertical and horizontal samples) belong to the small northern form, described by Fagetti (1958a) as Sagitta selkirki, and discussed in a later publication (Fagetti, 1968b). The horizontal distribution of the small northern form of S. tasmanica, as observed off Valparaiso (latitude 33 ~ S) from the R.V. "A. B r a u n " material and from material collected later ("Marehile V" Expedition, unpublished personal data) extends eastwards to 76~ W, but does not exceed the west boundary of the Peru Current (Fig. 8). Its vertical stratification in the whole explored area ranges from 500 to 0 m, with a greater density in the upper 200 m (Fig. 3 B).
Pterosagitta draco Krohn The previous records of Pterosagitta draco from this area have been summarized by Campodonieo (in preparation), who Mso quotes some new localities. The distribution of the sampled specimens conform to the latitudinal ranges already known, extending offshore to the outermost station of the R.V. "A. Bruun" Cruise i3 at 92~ ' W; this species was more frequently collected in the offshore stations. Its vertical range extends from 0 to 500 m, being found more abundantly in the upper t00 m (Fig. 3 C). Krohnitta subtills Grassi This species has been sampled between the latitudinal ranges 40 ~ N to 38 ~ S previously reported for the Pacific Ocean b y Alvarifio (1965) and Fagetti (1968b), and extending seaward off Valparaiso to 90~ ' W. Krohnitta subtilis is distributed vertically from 0 to 500 m, being more abundant at the epipelagic level (Fig. 3 C). ~esopelagie Species
Sagitta desipiens Fowler Sagitta decipiens has been sporadically found at the epipelagic level of this area, (Sand, i964 and
Fagetti, 1968b). During the present cruises, however, this species was collected in great numbers and at most stations, extending south to 43~ and west to 92~ (Fig. 6). These findings indicate, for this species, a uniform distribution in the Pacific; the previous information obtained b y Alvarifio (1965) did not include material from the Peru Current. S. decipiens inhabits mainly the upper mesoplanktonic level, from 500 to 200 m, rising also into the epiplankton layer, and reaching deeper strata down to 1000 m (Fig. 3 B).
Sagitta macrocephala Fowler Sagitta macrocephaIa is now recorded for the first time in the South Eastern Pacific Ocean, extending between 21 ~ and 38 ~ S and reaching offshore to 92 ~ W (Fig. 6). S. macrocephala inhabits mainly the deeper mesoplanktonic layers between ~000 and 500 m depth, sinking in the bathypclagic region down to 3000 m deep (Fig. 3 A). This species was collected also below 3000 m, by the deep IKMT catches (Fig. 10). Measurements for this species are given in Table 5. An orange or reddish color appears in the gut of recently preserved specimens, as previously observed by other authors. Sagitta zetesios Fowler This species is recorded for the first time in the South Eastern Pacific Ocean; Sagitta zetesios has been collected only in one station of the I F O P Expeditions but in most of the IKYIT and vertical samples of the R.V. "A. Brnun" Cruise t3 (Fig. 6). I t ranges vertically from 2000 to 200 m depth (Fig. 3 A) but, because of the small number of specimens found in the vertical closing samples, it has not been possible to determine its quantitative distribution at different levels. The lateral fins, beginning just at the posterior end of the ventral ganglion, as well as the measurements of some specimens (Table 6), assure the correct identification of the present material and separate it from its related subantaretie species, Sagitta planctonis,
Vol. 17, 2go. 1, 1972
E. Fagetti: Bathymetrie Distribution of Chaetogna~hs
15
Table 5. Sagitta macrocephala. Collection data and measurements Cruise
Net
"A. Braun" XIII Nansen "A. Braun" XIII Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-01 Nansen IFOP-0t Nansen IFOP-01 Nansen
Station No.
Depth (m)
Total length Percent (ram) tail
Hooks
Anterior teeth Posterior teeth
24 24 11 11 83 11 24 43
2000--1000 2000--1000 2000--1000 2000--t000 1000--0 1000---500 1000--500 1000--500
20.0 1.9.0 16.3 15.5 14.5 13.5 9.3 7.4
11 t0 11/12 11/12 13/12 12 t2 12
9 7 8 7/8 5 7 6 4
35.0 36.3 30.6 29.6 31.0 33.0 32.0 27.6
34 27 29 20/2t 20 24 14 t2
Table 6. Sagitta zetesios. Collection data and measurements. I K M T : Isaac-Kidd Midwater Trawl Cruise
"A. Braun" "A. Braun" "A. Braun" IFOP-01 "A. Braun" "A. Braun" "A. Braun" "A. Bruun" "A. Braun" "A. Braun" "A. Braun" "A. Braun" "A. Braun"
XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII
Net
Station No.
Depth (m)
Total length Tail length (mm) (ram) (%)
IKMT IKlVIT IKMT Nansen IKMT IKMT IKMT IK/cIT IKMT IKMT IKMT IKMT IK1VIT
18 18 18 24 18 20 18 18 18 18 18 18 18
2500--0 2500--0 2500--0 1000--500 2500--0 1000--500 2500--0 2500--0 2500--0 2500--0 2500--0 2500--0 2500--0
38.0 36.0 32.0 31.5 31.0 31.0 29.0 29.0 28.0 26.0 26.0 22.0 19.0
previously found in the epipelagie layers of this area (Fagetti, t958b, 1968b).
Eukrohnia bathypelagica Alvarifio This species, described by Alvarifio (t962) from North Pacific Ocean material, and found later by the same author (1965) also in the Indian Ocean, was recorded by Ducret (t965 and t968) in the tropical and equatorial waters off West Africa. I n this area E~krohnia bathypelagica has been found for the first time, in very small numbers, present in one of the vertical samples of Station 59 of the R.V. "A. Bruun" Cruise 13 (Fig. 5) between 1000 and 500 m depth and at about 2500 m in the I K M T Collection 18 (Fig. 3 A, Fig. 11). The flaccid and transparent body, the very narrow neck, the very close tmpigmented eyes, the shape of the ovary and of the genital papilla, as well as the percent of tail (higher than 25 %, see Table 7), confirm the correct identification of the few specimens found. Eukrohnia /owleri Ritter-Zahony Previously found only in the northern part of the explored area off 25~ (Sund, t964), the horizontal
8.0 7.5 7.0 7.5 6.5 8.0 7.0 7.3 7.0 6.0 5.5 5.0 4.9
21.0 20.8 21.9 23.8 20.9 25.8 24.1 25.1 25.0 23.0 21.5 22.7 25.8
range of this species has been extended now to 33 ~ S (Fig. 5). Eukrohnia [owleri inhabits the same vertical layer as Sagitta macrocephala, being mainly distributed between t000 and 500m deep, but also extending down to deeper layers (Fig. 3 A; Fig. 1t). Measurements of some of the specimens found are presented in Table 8. A reddish color appears in the gut of preserved specimens, as reported byAlvarifio (t967 a).
Eukrohnia hamata ~Sbius This species, represented by immature specimens, was previously recorded in the epiplanktonic layer of this area (Fagetti, i968b). The specimens collected in the deeper samples showed well developed gonads, the caudal segment being opaque and of a pale pink color. Eukrohnia hamata was distributed in most of the stations (Fig. 5), mainly at the upper mesopelagie level (1000 to 500 m), rising to the epiplankton level, and also occurring deeper down to 2000 m (Fig. 3 B). The quantitative vertical distribution of this species at Station ! t of the IFOP-01 Cruise (latitude 35 ~ S longitude 75 ~ W) is shown in Fig. 7. The species
t6
E. Fagetti: Bathymetric Distribution of 0hae~ognaths
Mar. Biol.
20~
[]
@
[] I
I
9
@
@
I
I
Ii
25~ t
9 O~176
S0~
Gee
|
~o
O E.ukrohnia hamata No./lO00 m3
r:. fowled No./lOOOm3
[] <10
go~
<100 Previous records 0_100-200 9 Sund, 196~ r--~ 10-so I
200-5
O0
e Fcigetti,1968Previousrecords:Sund,1964m
O
E.hathyanta rctica
O
5oo-looo
~ positivelKMTcoUs.
b.>1ooO
E.balhy pelagica 9 positive'vertical St.
T
45~ W
90 ~
85 ~
80"
75"
70 a
Fig. 5. Horizontal distribution of Eukhronia hamata and E. fowleri and occurrence of E. bathyantarctica and E. bathypelagica
Table 7. Eukrohnia bathypelagica. Collection data and measurements. I K M T : Isaac-Kidd Midwater Trawl Cruise
Net
Station No.
Depth (m)
Total length (ram)
Percent tail
Hooks
Teeth
Ovary Length Shape (ram)
"A. Braun" X l I I "A. Brulm" X I I I "A. Braun" X I I I "A. Braun" X H I "A. Braun" XIII
IKMT N~nsen Nansen Nansen Nansen
t8 59 59 59 59
0--2500--0 1000--500 1000--500 1000--500 ~[000--500
25.0 20.3 17.0 15.0 14.0
28.0 30,0 30.5 30.0 28,5
8 8 8 7 9/10
20 22 25 t9 4_0
-4_ -1 0.8
m
Curler Ourlet Outlet
Vol. 17, No. 1, 1972
E. Fagetti: Bathymetrie Distribution of Ohaetognaths
17
@
@
9
O
e 9
9
$agil'ta deeiple~s
e
No.tlOOOm"
e
~,r 100 100-200
e
S. macrocep~a Ja
No./lO00m 3
200-500
i'-'1< 10
9 soo
[ ] lo.so
Previous records 9 Sund, 1964 e Fagetti, 1968
e
S. zeteslos ~*,Positive sis. A.BRUUN C r.J3
,]0o so' ~5" so o Fig. 6. Horizontal distribution of Bagitta deci~oiens and ~. macrocephala and positive occurrence of S. zetesios No, of specimens of E.hamata per 1000m3olwater
100
200
300
400
was most abundant in the upper mesopelagie level between 500 and 200 m, its number decreases steadily in the epipelagie level and progressively in the deeper strata.
500
Bathypelagic Species
Eu]crohnia bathyantarctica David w 100C IE z
2000
3
~dZarineBiology, Vol. 17
Since its discovery in the Southern Ocean (David, i958b), this species has been recorded again only once (l~agetti, i968a), in the deep layers of the Gulf of Mexico and Caribbean Sea. I n this area Eukhronia
,- Fig. 7. Eukhronia hamata. Quantitative distribution of Station 11 of the IFOP-01 Cruise (latitude 35~S, longitude 75 ~ Note change of scale at 500 m
.Mar. Biol.
E. Fagetti: Bathymetrie Distribution of Chaetognaths
18
Table 8. Eukrohnia fowleri. Collection data and measurements. IKMT: Isaac-Kidd Midwater Trawl Cruise
"A. Brunn" IFOP 0-4 IFOP 0-4 "A. Brunn" "A. Brunn" "A. Braun" "A. Braun" "A. Brunn" "A. Brunn" IFOP-04 IFOP-04 "A. Brutm" "A. Brutm" IFOP-04 ~OP-01 "A. Brunn" "A. Brunn" "A. Brutm"
XIII XIII XFII XIII XIII XIIt XIII XIII XIII X~I XIII XIII
Net
Station No.
Depth (m)
Total length (mm)
1%rcent tail
Hooks
Teeth
IK1VIT Nansen Nansen IKMT IKMT IKMT IKMT IK~T II~r Nansen Nansen IKMT IKMT Nansen Iqansen Nansen Nansen Nansen
62 57 172 3 44 62 44 18 62 tt0 t72 41 16 t72 tt 59 59 59
t000 and 650 t000--500 1000--500 3750 and 670 2200 and 325 t000 and 650 2200 and 325 0--2500--0 1000 and 650 1000--500 7000--500 1000 t250 and 200 1000--500 2000--1000 1000--500 7000--500 1000--500
38.0 34.0 33.0 32.5 32.5 32.0 3t.0 28.0 26.2 25.0 24.0 24.0 24.0 17.5 15.3 13.0 10.0 9.0
23.6 20.8 24.2 23.0 24.0 28.t 25.8 26.0 23.7 22.0 22.9 21.7 22.9 22.8 22.2 26.9 25.0 24.0
12/13 t0 13 1t t2 t2 12 t2 12 11 t2 12 11 10 t0 t0 I0 ~ 9b
30 22 23 25 25 21 26 25 20 20 19 18 18 t5 10/11 11 4 5
:First 5 ventral hooks denticulate. b First 6 ventral hooks dentieulate.
Table 9. Eukrohnia bathyantareti~. Collection data and measurements. IKM T : Isaac-Kidd Midwater Trawl Cruise
"A. Brunn" "A. Brunn" "A. Bruun" "A. Braun" "A. Brunn" "A. Braun" "A. Bruun" "A. Braun" "A. Bruun" "A. Brutm" "A. Bruun" "A. Bruun"
XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII XIII
Net
Station No.
Depth (m)
Total length (ram)
Percent tail
I-Iooks
Teeth
IKMT IKMT IKMT IKMT IKIYIT IKMT Nansen IKMT IKMT Nansen Nansen Nansen
44 44 t6 16 t6 20 27 3 20 24 20 20
2200 and 325 2200 and 325 t250 an4 200 1250 and 200 t250 and 200 2900 2000--1000 3750 and 670 2900 2000--1000 1000--500 1000--500
32.0 29.0 29.0 26.5 26.5 26.0 26.0 23.2 23.0 20.0 15.2 tl.8
23.4 22.4 24.8 24.5 t9.6 25.0 23.0 24.6 26.0 25.0 21.3 22.0
12 12 t3 t3 13 1t 12 t2 tt t3 13 t2
16 16 15 13 t3 12 14 14 12 14/15 7 4
bathyantarctica has b e e n collected b y t h e v e r t i c a l a n d I K M T s a m p l e s (Fig. 5) a l w a y s below i000 m deep, being m o s t a b u n d a n t b e t w e e n 2000 a n d 1000 m (Fig. 3 A ; Fig. 10). M e a s u r e m e n t s a r e p r e s e n t e d in T a b l e 9. T h e orange color in t h e g u t of r e c e n t l y preserved specimens r e p o r t e d b y D a v i d ( i 9 5 8 b ) , has b e e n o b s e r v e d also in m o s t of o u r specimens. Horizontal Distribution o / E p i p l a n k t o n i c Species in the Peru Current Region and O#shore S t u d y of t h e p l a n k t o n i c m a t e r i a l collected d u r i n g t h e first Chilean e x p e d i t i o n s off our coast has e n a b l e d t h e d e t e r m i n a t i o n o f t h e e n d e m i c species o f this region as well as t h e n o r t h w a r d incursion o f s u b a n t a r c t i c spe-
cies into t h e P e r u C u r r e n t ( F a g e t t i , 1968 b). T h e w o r k of ]3ieri (1957) on t h e P e r u v i a n c h a e t o g n a t h f a u n a , as well as t h e d a t a of F a g e t t i (1958b) on t h e ehaetogn a t h s o f N o r t h e r n Chile a n d of Stmd (i964) on t h e P e r u region, including m a t e r i a l collected off 24 ~ a n d 18 ~ S, i n d i c a t e t h e s o u t h w a r d e x t e n s i o n of t h e t r o p i c a l e q u a t o r i a l species along t h e S o u t h A m e r i c a n coast. With the additional data provided by the present m a t e r i a l (Tables i 0 - - t 3 ) , i t has been possible to est a b l i s h t h e W e s t a n d E a s t w a r d extensions of t h e epip l a n k t o n i c species of t h e P e r u C u r r e n t region a n d t h e e a s t e r n S o u t h Pacific C e n t r a l w a t e r s respectively, a t 33 ~ S. Fig. 8 shows t h e offshore d i s t r i b u t i o n o f 4 epip l a n k t o n i c species in a t r a n s e c t off V a l p a r a i s o (33 ~ S),
Vol. 17, No. 1, 1972
E. Fagetti: Bathymetric Distribution of Chaetognaths
observed in the material of the l%.V. "A. ]~ruun" Cruise i3 (Table 12), as well as in the stations located at 33 ~ S during other Chilean expeditions. As can be seen, Sagitta bierii inhabits only the Peru Coastal Current, extending westward to its west boundary at approximately 76 ~ W, as pointed out by Gunther (1936) and by Sverdrup et al. (1942). S. tasmanica inhabits the coastal as well as the offshore region of the Current, extending westward to 80 ~ W. On the other hand, in the collections made west of this latitude, two other species are found, S. serratodentata and S. bipunctata, which are typical of the Central South Pacific waters; their distribution does not extend eastward behind the west boundary of the Peru Coastal Current. In the central region of the transect between 75 ~ and 80 ~ W, these two Central South Pacific species are found together with S. tasmanica. Craddock and Mead (i970) reported two species of fishes, collected only between 75 ~ and 80~ and concluded that "this cel~raI section of the transect m a y contain a characteristic fauna, but evidence of this is inadequate". The other epiplanktonie species found at this latitude are distributed indistinctly in the whole explored area and were already recorded for the South Eastern Pacific Ocean. Only a few of them are of numerical importance, listed here in order of abun. dance : Sagitta minima, S. enflata, S. bierii, S. tasmani. ca, S. serratodentata, Pe~vsagitta draco, S. bipunctata ; the others did not reach t % of the total. Only the presence of N. lyra in the South Pacific Ocean was still doubtful. Alvarifio (t965) considered this species as cosmopolitan to the warm and temperate regions of the Atlantic and Indian Oceans and of the Kuroshio region of the l)acific Ocean. The finding of S. lyra in the present material corroborates the presence of this species off Chile, as previously recorded by Fagetti (t958b) and Campodonico (in preparation); however, S. scrippsae, its corresponding species of the northern hemisphere, was not observed. Sagitta pacifica, which extends in the Pacific Ocean from 40 ~ to 35~ (Alvarifio, t965), was previously found off the Chilean coast extending to 29~ (Fagetti, 1958b); it has now been observed as far as 33 ~ 8, but only in one offshore station (Fig. 4), west of 75 ~ W, being absent, however, at the same latitude in the waters of the Peru Coastal Current. Also, the northward extension of the subantarctie species S. gazellae (Fig. 4), previously found only south of 35 ~ (Fagetti, i968b), has now been extended to latitude 30~ corresponding to the latitudinal incursion of the other subantarctie species, S. tasmanica, in the Peru Current region.
R. V. " A. B r u u n " Cruise 13 Transect The chaetognaths taken in the I K M T collections (Table i3) and in the vertical samples (Table 12) of the R.V. "A. B r a u n " Cruise 13, are considered here 3*
19
in relation to depth and physical environment. The hydrography of the region at 34 ~ S has been described by Craddock and Mead (i970) based on physicochemical information (salinity, oxygen, temperature)obtained from hydrographic casts made during the cruise. Our results on chaetognaths have been plotted in relation to the salinity and temperature profiles taken from their results, in order to establish possible relationships to the envh'onmental conditions. Species Diversity and Depth The quantitative specific distribution at different depths in three latitudinal sectors of the transect off Valparaiso (33~ 8) is shown diagrammatically in Fig. 9. I t is apparent that the highest number of species was found at the epiplanktonic level, a smaller number occurring below i000 m depth. Between these two depth intervals, there was a progressive reduction in diversity. The diversity of species at a given level, for the 3 regions sampled [(a) coastal, east of 75 ~ W, in water of high productivity; (b) area of m a ~ m m n water movement just to the west, between 75 ~ to 80 ~ W; (c) water of greater stability west of 80~ W] is apparent only in the epiplanktonic layer. The western boundary of Sagitta blerii, an endemic species of the Peru Coastal Current, and the eastern boundary of the two oceanic species S. bipunctata and S. serratodentata, overlap, as shown also in Fig. 8. Craddock and Mead (1970) found more species of fishes in collections west of the Peru Coastal Current than in collections east of 77 ~ W, and commented "this implies greater diversity offshore where productivity is less and greater dominance inshore." The same can be concluded also for the epiplanktonie chaetognath fauna, despite the low number of species. Species Distribution and I-Iydrographic Profiles In Figs. t0 and i t , the vertical stratification of some of the most significative species, together with the salinity and temperature profiles, is plotted. Among the epiplanktonic species, only two were found stratifying in two different ]ayers: (a) Sagitta bierii, which inhabits mainly the upper i00 m near the coast but extends downward, at the westernmost part of its distributional area, to a depth of 300 m; (b) ,.9. serratodentata, an oceanic species which does not penetrate into the Peru Coastal Current; it appears stratified between 200 and i00 m in the stations west of 80 ~ W, located in waters of greater stability, but extending to deeper layers in the region of its eastern boundary, following the isotherms (Fig. t0). The finding of these two species at a deeper level than usual and in a geographical location coincident with the west boundary of the Peru Coastal Current may indicate a convergence, as proved by the ascending isohalines
~
I1o
~
[[o I1o
Ilo
Iio
lllo
i[~
II]~
l[~ ll~
Ilo
llo
o
[[o
~[[
b~
I
Ioo
[l[o
Iooo
]1o
Ilo
oll
I[o
Io~
~ ~ooo~
I1o
I1o
I1o
o1[
~
9
I
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o
o
~-~ o
v~
~
c~
Q
0
Ilo
II1~
Io1~ rll~
1olo
JJ~
Jl~
I11o
oloo
11~
I1o
I1o
rl~
II1o
olo
o1~
rolo
I1o
rl~
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e~
II1~
Iolo
I1o
Ilo
I1~
II
ol
I
o
~
o
o
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!i ~ ~ ! ~ i ~~176176 !~
II1o
I~t~
I1o
If~
I1o
olo
II ~
II
I o
tl
tl
I o
I o~o
El
L ooo
o
o
o
o
o
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~ i ~! oo~ ~~ ~,ooo oo~ ~~ ~o~ ~. _~~~
II1o
ltlo
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~00o
b~
#
22
Mar. Biol.
E. FageSti: Bathymetric Distribution of Chaetognaths
Table 10 Species & depth of occurrence (m~
Station No. 9 11
12
24
34
36
38
4-3
50
5t
66
71 (90-0)
--0
0 0 --
0 0 0
0 0 0
0 -.
0 --
.
.
0 -. .
0 0
.
0 --.
64 127 25 .
0 --
.
0 -. .
32 0
.
516 --.
0 0 0
0 0 .
0 --
.
0 --.
Eukhronla]owleri 200--0 500--200 t000--500 2000--t000
0 0 0 --
0 0 0 6
0 --.
0 3t9 12 --
32 446 244 5t
63 --.
0 0 0 --
32 0 0 0
21 --.
.
.
.
.
.
.
Eukhroniahamata 200--0 500--200 t000--500 2000---t000
--294 .
258 425 -.
0 0 115 .
96 -. .
.
.
Perosagittadraco 200---0 500--200 1000--500 2000--1000
--0 .
0 0 -.
.
0 0 0 .
.
0 -. . .
0 -. .
.
IO~
32 ~
Epiplankonic
species of A.BRUUNcr.13 ~ ~V~ARCH!LEI* MARCHILE 6 +
and
IFOP-01
~)
Fig. 8. Sagitta bipunctata, S. ~erratodentata, S. bierii and S. tasmanica. Horizontal distribution of epiplanktonic species along transect of stations extending seaward from Valparaiso
(Fig. i 0 ) . A l v a r i f i o (t964) r e p o r t e d s i m i l a r b e h a v i o u r in t h e S o u t h C e n t r a l Pacific O c e a n for S. gazellae a n d S. pacifica, w h o s e r e s p e c t i v e n o r t h e r n a n d s o u t h e r n b o u n d a r i e s of d i s t r i b u t i o n c o i n c i d e a t a d e p t h of 200 m. S. bipunctata, t h e o t h e r o c e a n i c species w h i c h d o e s n o t e n t e r t h e w a t e r s of t h e P e r u C o a s t a l C u r r e n t , w a s f o u n d o n l y in t h e e p i p e l a g i c l a y e r o f t h e w h o l e a r e a o f its s e a w a r d d i s t r i b u t i o n (Fig. t l ) . The mesoplanktonie level can be subdivided into a n u p p e r a n d a l o w e r zone, e a c h w i t h its c h a r a c t e r i s t i c species: Sagitta decipiens, d i s t r i b u t e d b e t w e e n t h e i s o t h e r m s o f 6 ~ a n d 10 ~ C, a n d S. macroeephala, b e l o w t h e 6 ~ i s o t h e r m (Fig. 10). S. deeipiens i n h a b i t s t h e lower layer of the South Pacific Temperate Waters and t h e u p p e r l a y e r of t h e I n t e r m e d i a t e W a t e r s ; S. macro. cephala is d i s t r i b u t e d in t h e I n t e r m e d i a t e W a t e r s , w h o s e l o w e r b o u n d a r y , a c c o r d i n g t o W i r g k i (1966) c a n b e t a k e n as t h e d e p t h w h e r e s a l i n i t y is 34,6%~ ;
t h i s s a l i n i t y v a l u e is f o u n d , in t h i s area, a t a d e p t h of i 6 0 0 m. Eukrohnia hamata, t h e m o s t a b u n d a n t m e s o p l a n k t o n i c species o f t h i s area, s p r e a d s v e r t i c a l l y throughout the whole mesopelagie domain, from t000 t o 200 m , b e t w e e n v e r y w i d e t e m p e r a t u r e e x t r e m e s , r e a c h i n g also t h e epiplanl~tonic l e v e l in t h e c o a s t a l r e g i o n ; t h e s a m e is also t r u e for S. decipiens. T h e finding o f b o t h species in t h e e p i p e l a g i e l e v e l o f t h e c o a s t a l r e g i o n can, t h e r e f o r e , b e r e l a t e d t o t h e v e r t i c a l c i r c u l a t i o n t o w a r d t h e s u r f a c e in t h e p r o x i m i t y o f t h e coast, w h e r e u p w e l l i n g s occur. D e s p i t e t h e w i d e v e r t i c a l r a n g e o f Eukrohnia hamata, its q u a n t i t a t i v e v e r t i c a l d i s t r i b u t i o n a t S t a t i o n 11 o f t h e I F O P - 0 1 Cruise (at 30 ~ S a n d 75 ~ W ) s h o w s t h a t , i n t h e P e r u C o a s t a l C u r r e n t , t h e species is d i s t r i b u t e d m a i n l y t h r o u g h o u t t h e u p p e r m e s o p e l a gic l e v e l (Fig. 2). T h e I K M T c o l l e c t i o n s a d d e d m o r e r e c o r d s a t g r e a t e s t d e p t h for t h e d e e p - l i v i n g species
Vol. 17, No. 1, 1972
E. Fagetti: Bathymetric Distribution of Chaetognaths
23
(continued)
82
83
0 0 0
0 0 0
94 (80---0)
99
~02
~06 t13 (100--0)
0
0
Species & depth ~27 of occurre*~ce (m) (130--0)
ti8
t22
124
0
0
0
0
0
--
Eukhronia]owkri
.
.
0 --.
0
.
0
.
.
0 .
.
0 .
0 .
--
.
.
.
--
.
.
--
.
0
.
200--0 500--200 t000--500
.
.
2000--1000
~ukhroniahama~ 48 1t~ 45 .
~6 0 0
250 ---
.
0 0 0
.
.
147 . 0 .
66
~31
. .
.
0 . --
.
-.
-.
0
0
295 . 52
.
.
1526 . 0
itO0
0
0
200--0 500--200 1000--500 2000--~00~
--
.
Perosagitta draco 0 0 0 .
0 0
0 --
0 .
-.
.
NUMBER |
2
0 0 O
3
4
.
. 0
.
OF 5
0
.
.
--
.
.
0 . --
-.
.
.
0 . 0
7
8
9
10
11
12
13
14
15
16
'
J
~
0
--
1000--500
.
2000--~000
SPECIES 6
200--0 500--200
.
s+..
,
,
o t o , , p . . ./: g - x 1~ 3
'
,
2r
2~176 .
500
r
,
i
t
~,~
,
s
7
f
i
i
i
,~ .. ,6 577, ,
.... .~-~=. ~ . -":."~ , "' " I ~.... _ .:~__ ~ s~. . . .-0. . ~ . . ~ A--~4.30~ ~~ - - 3 ~ - -~+ ~ . ~ , - ."- ~
a~F-~p--:-
i
:
10
8 1000
4 0 o
st of 75"W
.--/I./'
~ ........
b. . . . . .
75"and SO'W
2
=~176176 IIllllllllllllIlll ll : , z
z
200(~
SoO
Q
4 1000
300C
t~ ....................
,
-~ooo
:Fig. 9. Quantitative specific distribution in depth of chaetognaths in three different latitudinal sections of a transect off Valparaiso, based on vertical, surface and Isaac-Kidd Midwater Trawl (IKWT) collections
93~
90"
85" denlat=
a n d E. bathypelagica, r e c o r d i n g s of which, in t h e vertical samples, were sporadic and not large enough to obtain a correct view of these species' vertical ranges. The two latter deepliving species were more frequently found in layers b e l o w 2000 m , i n P a c i f i c D e e p W a t e r , w i t h a s a l i n i t y o f
80~
(vert . . . . pies)
~/-~$.declpieni(vert.$=mples);
E. bathyantarctica
....... ~
e
+!+,1
~:~. ] ~
5000"
S. . . . . . . .
E. /owleri,
-. .......
,.75tJ-~-LL~. . . . _o___ [ ] ..............................
S, macroce p h a l o ~
[]
75" ~
TIW S; blerll
E.~athyantatctitct {IKWT)
yell, samples t 411 tKWTr
:Fig. 10. Hydrographic profile of I~.V. "A. Bruun" Cruise t3 off Valparaiso, with distribution in d e p t h of Sagltta bierii, S. serratodentata and other mesopelagic species
24
Table t l . Species and their occurrence in the vertical samplez
0
o] the IFOP-04 Cruise (October--November, 1965). The number o] each species is standardized to 1000 m ~ o] filtered water. Horizontal dash: sample missing or not made at proper interval Species & d e p t h of occurrenco (m)
Mar. Biol.
E. Fagetti: B a t h y m e t r i e Distribution of Chaetognaths
Station ~ o . 57 82
t10
t50
STA. 27 , I,
,
24 I ,
,
,
,
20 I ,
~emp ~.:.~.:-i~ .:-:::-~k~+v.~" <§ 9 ...
........
17 I J.
,
~5~57 1
3/d,I
. .~...:...:.:.~
,X 3~.5o . , \ .V ~q
172
('~ ,,,
,
Sagitta bierii 100--0 200--t00 500--200 1000---500
2564 1438 0 0
2938 94 0 0
-t719 -0
17t9 -0 --
~156 -0 0
.\ \ \ \ ,~
~oo ~
~agitta enflata 100--0 200--100 500--200 1000--500
2563 1469 0 0
1156 31 0 0
-839 -0
1625 -0 --
219 -0 0
0 0 0 32
0 0 0 6
-0 -6
0 -0 --
0 -0 38
100020003000-
i125 0 0 0
781 31 42 0
-0 -0
0 -0 --
0 -0 0
4000-
594 0 0 0
1156 63(?) 0
-0 --
0
0
0 0 0 38
0 0 0 0
-0 -0
0 0 0 38
0 0 0 0
-25
0 94 0 13
0 0 0 13
-0 -57
31 94 0 0
93 0 0 0
-0 -0
0 -0
0 -0
--
0
0 -0 --
E. | o w l e r i
(IKWT co|Is.)
75 ~
80 ~
~ []
?I~V
S. b i p u n c t a t a
E.~athype|aglca
Fig. t l . Hydrographic profile of R.V. "A. B r u u n " Cruise t 3 Valparaiso, with d e p t h distribution of Sagitta bizpunotata, S. dev~iens a n d other mess a n d bathypelagic species
-0
0 --
11 --
o f less t h a n 2 ~ C
S.mmary
0 -0 32 0
0
-21 --
0 44
0 -0
--
--
m o r e t h a n 3 4 . 6 %0 a n d a t e m p e r a t u r e ( W i r t k i , 1966).
i. The bathymetric distribution of the ehaetognath species collected during 3 expeditions in the South E a s t e r n P a c i f i c O c e a n is p r e s e n t e d q u a n t i t a t i v e l y . Analysis of the data obtained has enabled the extension of the geographical ranges of the epipelagie species already known for the region under consideration, as well as the identification, for the first time, of t h e m e s s - a n d b a t h y p e l a g i e species. 2. T h e h o r i z o n t a l a n d b a t h y m e t r i c distribution o f e a c h o f t h e 2 0 s p e c i e s f o u n d i n t h e a r e a is d i s c u s s e d and shown in distributional maps and graphs. Data on metric and meristie characteristics are given for the u n c o m m o n species. 3. A m o n g t h e t 3 e p i p e l a g i e species, i t w a s s h o w n t h a t Sagitta 8erratodentata a n d S. bilmnctata d o n o t penetrate into the Peru Coastal Current region, and t h a t t h e e n d e m i c s p e c i e s o f t h i s r e g i o n , S. bierii, extends westwards only to the west boundary of the Coastal Current. 4. A m o n g t h e 6 m e s o p e l a g i c s p e c i e s , i t w a s s h o w n t h a t t h e t w o s p e c i e s p r e v i o u s l y r e p o r t e d f o r t h e epi-
Krohnitta subtiIis 100---0 200--t00 500--200 1000--500
9
85 ~
(ver fica|,sQmple$}
0
Eubhronia hamata 100--0 200--100 50O---200 1000--500
90 ~
-'~ E. h area t a,.
-o 0
~ukhrtmia ]awleri t00--0 200--100 500--200 1000--500
93 ~
off
Sagitta zetesios lO0---O 200--100 500--200 t000---500
135
e_
50gO-
~a~itta Tacifica lO0--O 200--100 500--200 1 0 0 0 --500
@ 2 .........................
Sagltta minima 100--4) 200--100 500--200 1000--500
\<'$
\ ' , ", ~,~ f f ~ ,
Sagitta macrocephala 100---0 200--100 500--200 i000--500
~ \• {"\,', \~\"
0 0 0
VoI. 17, No. 1, 1972
25
E. F a g e t t i : B a t h y m e t r i c D i s t r i b u t i o n of C h a e t o g n a t h s
T a b l e '12. Species and their occurrence in the vertical samples o/ the " A . Bruun" Cruise (January--Februa~T,
1966). Stations are listed according to latitudinal location /tom coast seaward. The number o/ each species is standardized to 1000 m a o/ filtered water. Horizontal dash: sample missing or not made at proper interval Species & d e p t h of o c c u r r e n c e (m)
S t a t i o n No. ~1 59 (t60--0)
50 (300--100 500 300)
6
44
8
t7
20
24
27
Sagittabierii 100--0 200--100 500--200 1000--500 2000---1000 3000---2000
203t 4052 -----
977 426 82 0 ---
0 50 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 0 0 0
0 0 0 0 ---
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 -----
0 0 0 0 ---
0 0 0 0 0 0
0 0 0 0 0 0
250 -20 0 0 0
534 0 0 0
47 0 10 2
0 72 30 0 0 0
750 30 0 0 0 0
0 570 -----
0 0 53 0 ---
0 120 t0 0 0 0
0 0 0 0 0 0
0 -10 0 0 0
0 0 27 6 0 0
9150 33420 -----
829 24 0 0 0 0
992 420 76 0 0 0
5620 51 0 0 0 0
0 0 -----
0 0 0 0 0 0
0 0 0 0 0 0
0 0 -----
0 0 0 t6 ---
0 0 ----0 0 -----
Sag~tabipunctata 100--0 200--t00 500--200 1000---500 2000~1000 3000--2000
0
--
0
--
187 t2 0 0 0 0
0 0 242 25 0 0
0 0 38 0 ---
0 0 12 0 90 0
0 90 25 0 0 0
t333 -0 0 0 0
2383 754 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
4533 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 0 0 0
0 0 0 0 ---
0 0 0 0 0 0
0 18 0 0 0 0
530 21 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 1t 0 0
0 0 0 0 ---
0 0 0 2 0 0
0 0 0 4 4 4
0 0 0 t l 2
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 18 5 0 0
0 0 7 0 ---
0 25 0 0 0 0
0 200 0 8 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0
0 0 6 0 0 0
0 0 0 0 ---
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
Sagittadecipiens 100--0 200--t00 500--200 1000--500 2000--1000 3000--2000
Sagittaenflata 100--0 200--100 500--200 1000--500 2000--1000 3000--2000
Sagittahexap~ra 100--0 200--t00 500 200 1000--500 2000--1000 3000--2000
Sag~tamaeroeephala t00--0 200--100 500--200 t000--500 2000--t000 3000--2000
Sagittalyra 100--0 200--t00 500--200 t000--500 2000--1000 3000--2000
Sag~ta max~na t00--0 200---100 500--200 1000--500 2000--1000 3000--2000 4
~ r i n e Biology, Vol. 17
~ 3 0 0 0
26
Mar. Biol.
E. F a g e t t i : B a t h y m e t r i c D i s t r i b u t i o n of C h a e t o g n a t h s T a b l e 12. (continued) Species & d e p t h of o ccurrence (m)
S t a t i o n No. t 59 (160--0)
50 (300--t00 500--300)
6
44
8
t7
20
24
27
340 0 0 0 0 0
0 -0 0 0 g
2671 452 0 0 0 0
755 351 0 0 ---
12625 125 0 0 0 0
5333 t27 0 0 0 0
870 90 0 0 0 0
55 43 0 0 ---
0 37 0 0 0 0
0 36 0 0 0 0
0 90 0 0 0 0
Saf~taminima 100---0 200--100 500--200 1000--500 2000--1000 300O--2000
31 0 -----
Sag~tapa~ifica Sagittaserra~dentata
0 0 0 0
0 0 0 0 0 0
4 s p e c i m e n s a t S t a t i o n 44 f r o m 2 0 0 - - 0 m d e p t h
100--0 200---t00 500--200 t000--500 2000--1000 3000--2000
0 0 -----
Sagi~atasmanica Sagitta zetesios
0 0 0 0 ---
0 0 0 0 0 0
0 0 0 0 0 0
133 -22 0 0 0
205 339 18 0 0 0
9 s p e c i m e n s a t S t a t i o n 44 f r o m 2 0 0 - - 0 m d e p t h a n d 12 a t S t a t i o n 20, 2 0 0 - - 1 0 0 m
t00--0 200--100 500--200 1000--500 2000--1000 3000--2000
0 0 -----
0 0 0 4 ---
0 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 17 0 0
0 0 3 0 ---
0 0 0 4 31 0
0 36 5 0 0 0
0 0 0 0 2 0
t25 263 -----
0 8 4 0 ---
0 6 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 0 0 0
0 0 0 0 ---
0 18 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 -----
0 0 0 0 --
0 0 0 0 0 0
60 0 0 0 0 0
25 -0 0 0 0
54 9 0 0 0 0
377 131 7 0 -~
406 37 0 0 0 0
0 54 25 0 0 0
90 60 0 0 0 0
0 0 -----
0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 0 0 0
0 0 0 0 ---
0 0 0 0 0 2
0 0 0 0 0 3
0 0 0 0 2 0
Krohnittasubtilis t00--0 200--100 500--200 1000--500 2000--1000 3000--2000
Perosagittadraco 100--0 200--100 500--200 1000--500 2000--t000 3000--2000
Eukhroniabathyantarctica t00--0 200--100 500--200 t000--500 2000--t000 3000--2000
Eukhronia bathypelagica Eukhroniahamata 100--0 200--100 500~200 t000--500 2000--t000 3000~2000
Eukhroniafow~ri t00~0 200--t00 500--200 t000--500 2000--1000 3000--2000
--
4 s p e c i m e n s a t S t a t i o n 59 f r o m 1 0 0 0 - - 5 0 0 m d e p t h 64 ------
0 16 173 90 ---
0 t84 t5 0 0 0
0 0 0 0 0 0
0 -29 6 0 0
0 0 189 147 0 0
0 0 84 0 ---
0 0 4 29 35 4
0 0 0 53 8 0
0 0 22 10 0 0
0
0
0 -----
0 0 12 ---
0 0 0 0 0 0
0 0 0 0 0 0
0 -0 0 0 0
0 0 0 0 2 0
0 0 0 0 ---
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
o~
~'o
~ ~-.~ ~.
~
~ . . ~
~
o~"
~'~
~~
~
eM
o.~ .~ g
~ "
~.~ ~.~ r;
~ .~ ~' S'~
r
:~ ~
9
~
~ o ~ o
~ ~.~a -~ ~ ~ ~ ~
~
9 ~ ' < ~v
~
II[[I
~ll
ill
IlllJJl~l
Ill
I
~f
~l I I i I~l
lll~lllllt
I I
II
I I
II
IIIlllllllIIlll
-]]~]llltll]]]
t111II1
%
[ I t I I I I l
.111111t
" ~ b ~ O0 ~ '
Illl~lltillilll
bO~
I I I I I~l
JJlJlllr
I
I[l[[lllllll[ll[
f[llll[ll
Illtllll~
o
Perosagltta draco
Eukhronia /owleri
Eu~hronia hamata
Eukhronia bathyantarctica
Nagitta zetesios
Sagitta tasmanica
Sagitta se?'ratodentata
Sagitta minima
Nagitta maxima
Sagitta macrocephala
Sagitta hexaptera
Sagitta gazellae
Sagitta enflata
Sagitta decipiens
Sagitta bipunctata
Sagitta bierii
~.~.~
[ g ~
~~
"" e
28
E. Fagetti: Bathymetrie Distribution of Chaetognaths
and IFOP-04 cruises, respectively. My thanks are also due to m y colleague at the Department of Oceanology, Mr. T. Antezana, who participated in the IFOP-0I cruises mainly in order to take care of the deep, vertical, plankton sampling. I am particularly grateful to Dr. G. Mead, Chief Scientist, who kindly lent me material other than fishes and eopepods, from the IKMT and surface eellections of the I~.V. "A. Bruun" Cruise 13, and to Dr. G. Grice (Woods-Hole Oceanographical Laboratory, USA) who allowed me to study the ehaetognaths from the vertical samples of the same cruise. The quantitative analysis of the ehaetognaths from the vertical samples was carried out in the Laboratory of Dr. G. Griee at the WoodsHole Oceanographical Institution during a visit by the author to this Center at the invitation of Dr. G. Mead. I should also like to thank both Dr. Craddock and Dr. Mead, for sending me a copy of their manuscript on mid-water fishes, as well as the hydrographic profiles of the R.V. "A. Brnun" Cruise.
Literature
Cited
Alvarifo, A.: Two new Pacific ehaetognaths, their distribution and relationship to allied species. Bull. Scripps Instn oeeanogr. 8 (1), t - - 5 0 (1962). - - Bathymetric distribution of chaetognaths. Pacif. Sei. 18 (1), 64 82 ((1964). - - Chaetognaths. Oceanogr. mar. Biol. A. Rev. 8, 115---194 (1965). - - Bathymetric distribution of chaetognaths, Siphonophorae, Medusae and Ctenophorae off San Diego, California. Pacific Sci. 21 (4), 474~485 (19671). - - The ehaetognaths of the :NAGA Expedition (t959--1961) in the South China Sea and the Gulf of Thailand. P t 1. Systematics. :Naga Rep. 4 (2), 1 - - I 9 5 (1967b). Bieri, R.: The ehaetognath fauna off Peru in 1941. Pacif. Sci. 11 (3), 255--264 (1957). Bnrfield, S. T. and J. W. Harvey: The ehaetognatha of the Sealark Expedition. Trans. Linn. Soc. Lend, (2nd. Ser., Zool.) 19 (1), 93--t19 (1926). Bussing, W. A.: Studies of the midwater fishes of the PeruChile Trench. A_utaret. Res. Ser. (American Geophysical Union) 5, i 8 5 ~ 2 2 7 (t965). Campodonico, I.: Resultados voinm6tricos del zooplaneton eolectado frente a Chile per diferentes expediciones y analisis eualitativo partial. Tesis. (In preparation). Craddock, J. E. and G. W. Mead: Midwater fishes from the Eastern South Pacific Ocean. Aaron Bruun Rep. scient. Res. SE Pacif. Exped. 8, 3--46 (1970). David, P.: The distribution of Sagitta gazellae Ritter-Zahony. 'Discovery' Rep. 27, 235--278 (1955). - - The distribution of the chaetognatha of the Southern Ocean. 'Discovery' Rep. 29, 199---228 (19581). - - A new species of Eukrohnia from the Southern Ocean with a note on fertilization. Prec. zool. Soc. Lend. 131 (4), 597--606 (1958b). - - Biogeography and ecology in Antarctica. Monographiae biol. 15, 296--323 (1965). Dawson, J. K. : Chae~ognaths from the Arctic Basin, including the description of a new species of Heterokrohnia. B u l l S. Calif. Acad. Sci. 67 (2), 112--124 (t968). Ducret, F.: Les esp&ces du genre Eukrohnia dans les eaux 6quatoriales et tropicales afrieaines. Cah. O.R.S.T.O.M. s6r. Ocdanogr. 3 (2), 63--73 (1965). -Chaetognathes des campagnes de l'"Ombango" dans les eaux 6quatoriales et tropicales africaines. Cab. O.R.S.T.O.M s6r. Oc6anogr. 6 (1), 95--i41 (1968). Fagetti, E.: Quetognato nuevo procedente del arehipi6lago de J u a n Fernandez. l~ev. Biol. mar., Valparaiso 8, 125-t31 (19581). -Investigaeiones sobre quetognatos colectados especialmente frente a la costa central y norte de Chile. Rev. Biol. mar., Valparaiso 8, 25--82 (1958b).
Mar. Biol.
- - :Nueva eontribuci6n al estudio de los quetognatos de la costa central y norte de Chile. Aetas y trabajos I Congreso Sud-Americano de Zoologia 2, t 2 7 - - i 3 5 (1959). - - : N e w record of Eukrohnia bathyantarctica David 1958, from the Gulf of Mexico and Caribbean Sea. Bull. mar. Sei. 18 (2), 383--387 (19681). - - Quetognatos de la expediei6n "Marchile I" con observaciones acerca del posible valor de algunas especies come indicadoras de las masas de agua frente a Chile. Rev. Biol. mar., Valparaiso 18 (2), 85--17t (1968b). - - :Nueva localidad para dos espeeies de motuscos heteropodos, Pterotrachea scutata Gegenbaner 1855 y Cardiapoda richardi Vayssi6re 1904, encontrados per primera vez en el Pacifico Snr Oriental frente a Chile. I~ev. Biol. mar., Valparaiso 13, (3) 287--291 (i968c). Fowler, G. H.: Biskayan plankton collected during a cruise of H.M.S. Research, 1900, Part 3. The chaetognatha. Trans. Linn. See. Lend. 10 (2), 55--87 (1905). - - The chaetognatha of the Siboga Expedition. Siboga Expod. 21, 1--86 (1906). Fraser, J. H.: The chaetognatha and other zooplankton of the Scottish area and their value as biological indicators of hydrographical conditions. Mar. Res. 2, ~t--52 (([952). Fumestin, M. L.: P~ches planetoniques, superficielles et profondes, en M6diterran6e occidentale. (Campagne de la "Thalassa" - - jauvier t961 - - entre les ~les Bal~ares, ~a Sardaigne et l'Alg6rie). III. Chaetognathes. Revue Tray. Inst. (scient. tech.) P@ch. marit. 26, 357--368 (1962). - - e t F. Ducret: Eukrohnia proboscidea, nouvelle esp~ce de chaetognathe. Revue Tray. Inst. (seient. techn.) P@ch. marit. 29 (3), 271--273 (1965). Fnruhashi, K.: On the distribution of chaetognaths in the waters off the South eastern coast of Japan. Publs Seto mar. biol. Lab. 9, 17--30 (1961). Geiger, S. R.: Biological oceanography in the Antarctic: Eltanin cruises 4 to 13. Polar Rec. 13 (82), 29--36 (1966). Grice, G. and K. Hulsemann: Abundance, vertical distribution and texonomy of calanoid copepods at selected stations in the northeast Atlantic. J. Zool., London 146, 213--262 (1965). --Calanoid eopepods from midwater trawI collections made in the Southeastern Pacific Ocean. PaciL Sci. 12 (3), 322--355 (1968). Gunther, E. R.: A report on oceanographical investigations in the Peru Coastal Current. 'Discovery' Rep. 18, 107---276 (1936). Hardy, A. C. and E. I~. Gunther: The plankton of the South Georgia whaling ground and adjacent waters, 192@--1927. 'Discovery' ~ep. 11, I - - 4 5 6 (1935). Heydorn, _4. E. F.: The chaetognaths off the west coast of the Union of South Africa. Invest. Rep. Fish. mar. biol. Surv. Un. S. Afr. 86, 4--56 (1959). Huntsman, A. G.: Some quantitative and qualitative plankton studies of the eastern Canadian plankton. 3. A special study of the Canadian ehaetogaatha, their distribution, etc. in the waters of the eastern coast. In: Canadian Fisheries Expedition 1914--15, pp 421--485. Ed. by J. Hjort. Ottawa: Dept. of hTaval Services 19t9. Kitou, M.: A new species of Sagitta (ehaetognatha) collected off the Izu Peninsula. Mer, Tokyo 4 (4), 238--240 (19661). - - Chaetognaths collected on the fifth cruise of the Japanese Expedition of deep seas. Mer, Tokyo 4 (3), 169--t77 (~966b). - - Chaetognatha collected on the eighth cruise of the Japanese Expedition of deep seas. Mer, Tokyo 5 (2), 127--130 (1967). Marumo, R. and M. Kitou: A new species of Heterokrohnia (Chactognatha) from the Western :North Pacific. Mer, Tokyo 4 (3), 178--183 (1966).
Vol. 17, No. 1, 1972
E. Fagetti: Bathymetric Distribution of Chaetognaths
Matsudaira, Y. and K. Furuhashi: Notes on some animal plankton collected from the deep layers of~he Pacific waters off Southern Japan. [In Japanese]. Umi Sora 81, 1t--16 (t955). 5'feud, G.: Cruise l~eport, Research Vessel Anton Bruun Cruise XIII. Spee. Rep. 3, mar. Lab. Texas, A & IV[ University Galveston, Texas (t966). 3'Ienzies, R. J. : General results of biological investigations on the deep-sea fauna made on the USNS Eltanin (USARP) during Cruise 13 between Panams and Valparaiso, Chile, in t962. Int. Revue ges. Hydrobio]. 48 (2), 185--200 (1963). Michael, E. L.: Classification and vertical distribution of Chaetognatha of the San Diego region, including redescriptions of some doubtful species of the group. Univ. Calif., Publs Zoo|. 8 (3), 21--170 (19~t). - - Vertical distribution of the chaetognatha of the San Diego region in relation to the question of isolation vs. coincidence. Am. Na~. 47, i7--49 (1913). Owre, H. B. : Plankton of the Florida Current. Part VI. The ehaetognatha. Bull. mar. Sci. Gulf Caribb. 19, 255--322 (1960). Sheard, K.: Species groups in the zooplankton of eastern Australian slope waters, t938--41. Aust. J. mar. Freshwat. ~es. 16, 219--25~ (1965). Silas, E. G. and M. Srinivasan: A new species of Eukrohnia from the Indian Seas with notes on three species of chaetognatha. J. mar. biol. Ass. India 10 (i), 1--33 (1968).
29
Steinhans, 0.: Die Verbreitung der Chaetognathen im sfidatlantisehen und indischen Ozean. Inaugural Dissertation, Kiel t896. Sund, P. : Some features of the autecologsr and distribution of chaetognaths in the eastern-tropical Pacific. Bull. inter-Am. trop. Tuna Commn 5, 307--340 (1961). - - The chaetognaths of the waters of Peru Region. Bull. interAm. trop. Tuna Commn 9 (3), i15--t62 (1964). Sverdrup, H. U., M. W. Johnson and I~. H. Fleming: The oceans. Their physics, chemistry and general biology, 1087 pp. New York: Prentice-Hall, Inc. 1942. Tachindonova, J. G.: Chaetognatha of the Kurile-Kamchatka Trench. Trud:~ Inst. Okeanol. 12, 298--310 (1955). Thiel, M. E.: Die Chaetognathen-BevSlkerung des Sfidatlantischen Ozeans. Wiss. Ergebn. dr. atlant. Exped. 'N[eteor' t925--27 ]3 (l), l - - i t 0 (1938). Wirtki, K.: Summary of the physical oceanography of the eastern Pacific Ocean. Univ. Calif. San Diego, I.M.R. Ref. 65-i0, 69 pp. (1966). Author's address: Dr. E. Fagetti Departamento de Oceanologia Universidad de Chile Vifia del ~Iar Chile
Date of final manuscript acceptance: July 9, i972. Communicated by J. A. Petersen, S~o Paulo
