Hydrobiologia 137, 3 - 7 (1986). O Dr W. Junk Publishers, Dordrecht. Printed in the Netherlands.

Some rotifers from Republic of Korea P. N. Turner Dept. Znv. Zool., Nat. Mus. Nat. Hist., Wash. D.C., 20560, USA

Keywords: rotifers, geographic distribution, Republic of Korea

Abstract The author gives account of rotifers found at ten locations in the Republic of Korea, and elaborates some detail of specimens encountered with remarks and drawings. Thirty-seven different rotifer species were found, mostly belonging to the Order Monogononta. llventy-two are new to the species list compiled by Yamamoto (1953). Keratella hiemalis was found for the first time in Asia. To date, one-hundred and two species of rotifers have been found in Korea. Introduction Zooplankton studies of Korean rotifers are scarce. Hada (1936) treats rotifers of Korea adequately, and his study may reflect the first venture of this kind to include rotifers. Sato (1939, 1941) also accounts for the rotifers of this area. Yamamoto (1941) details the rotifers of North Korea, and his later study, Yamamoto (1953) combines his own research with a comprehensive summary of previous efforts by other authors. This study adds 22 species to the list of Korean rotifers. One of the species found is new to the region. Limnological characteristics of the sample areas Samples were taken from ten locations in the Republic of Korea, betwen 14 March 1981 and 19 March 1981; then 23 March 1982 and 24 March 1982. Gross sampling (jar dipping) was augmented with several pulls of a 150 pm plankton net for the 1981 samplings. The March 1982 collections were taken with a 53 pm plankton net from as far out into the body of water as the net could be thrown. remperature was measured and pH taken using 1 - 12 Hydrion papers. All samples were preserved

on the spot with 10% formalin. Carbonated water was introduced to the samples first, to narcotize the rotifers, then formalin was introduced slowly in an attempt to preserve the non-loricated species undistorted shapes. Sample areas are shown in Fig. 1. Site 1. Roughly 0.8 km2, this man-made reservoir appeared free from the sewage pollution characteristic of many Korean bodies of water. Foliage grew down to the water's edge and semisubmerged vegetation was apparent along the shoreline. Temp. - air 1 9 ° C water ll°C, pH 6.0-6.5 23 March 1982. Site 2. This very small fishing pond offered little to the fishermen other than the few three or four inch fish caught. The pond was very shallow (1 m), and very organically polluted. No vegetation was visible either on shore or submerged. Temp. - air 15 "C, water '14"C, pH 6.0 23 March 1982. Site 3. Adjacent the city, this area on the Han River was extremely organically polluted. An organic waste dump site was located approximately 200 m up-river from this site. The water was very turbid and had a strong organic odor. The bank of the river was mostly very soft and odiferous mud, with very few rocks and no vegetation. Salinity can get as high as 109b this far up-river. (Dr. YI BoemJun, pers. commun.) Temp. - air 13"C, water

<',

REPUBLIC KOREA

0

,

100

2 go

kilometers

Fig. 1. Sample site locations in Republic of Korea.

12"C, pH 6.0 23 March 1982. Site 4. This area was a rapidly flowing portion of the Han River, just 20 m down-river from a highway bridge. The sample was taken from the rock stratum Iaid down to support the bridge piers. Temp. - air 9 "C, water 11 "C, pH 6.0-6.5 24 March 1982. Site 5. This pond measured 100 by 200 m and was about 3 m deep. No vegetation was visible in or near the pond except grass. The water appeared relatively clear, but was odiferous organically. This pond was fed by a small stream on its way to the Han River. Temp. - air 9 "C, water 11"C, pH 6.0-6.5 24 March 1982.

Site 6. This large freshwater reservoir backs up into the North and South Han Rivers. It is characterized by very clean, clear water; contrasting most bodies of standing waters in the country. Vegetation surrounding the lake was apparent, including submerged vegetation. Temp. - air 7 "C, water 9"C, pH 6.5 24 March 1982. Site 7. This stream, feeding into the South Han River, is used for washing clothes and general purposes by the local population. Apparently kept clean by its rapid flow, this stream fostered filamentous green algae along its shoreline and on the rocky bottom. Temp. - air 7 "C, water 9"C, pH 6.0 24 March 1982. Site 8. This is a temporary pond on Kimhae Air

Base, near the city of Pusan. It is apparently used to cultivate semi-submerged vegetation, harvested in the early spring for its tubor. The surface area was approximately 800 m2 and the water was from 0.2 to 0.6 m deep. Temp. - air 21 "C, water 15 "C, pH 5.0-5.5 19 March 1981. Site 9. This is a permanent pond serving as a moat around a building on Kimhae Air Base. The pond is no more than 1.5 m deep, with a surface area of approximately 5000 m2. Temp. - air 19"C, water 14"C, pH 5.0-5.5 19 March 1981. Site 10. This is a drainage ditch on Osan Air Force Base, Songton Si. Rain the night before sampling this site made the water turbid, and no doubt had an equal impact on the water chemistry. The ditch probably has a small continuous amount of water in it except for the hottest months of the year. Temp. - air 11 "C, water 11 "C, pH 7.0-7.5 14 March 1981.

Table I. List of rotifers found in Republic of Korea; (* new to Republic of Korea).

Site #.

* * * *

*

* *

* *

* Results Table I is a list of rotifers found in Republic of Korea. Lindia (Halolindia) tecusa (Harring & Myers) was found in Site 4, a small fishing pond near the Han River. This uncharacteristic plankton catch was probably due to the extent of eutrophication and turbidity of the water, facilitating this rotifer's existence away from its typical substratum lair. Keratella tecta (Gosse) occurred at three sample sites. At Site 5 however, the animal's anterior spines were extremely reduced (Fig. 2a). The characteristic sculpturing on the anterior lorica was also mostly absent. The average animal size was 115 pm. Sudzuki (1964), also reports a similar form from a marsh in Japan. Notholca rotifers of the acuminata/labis group are variable and polytypical (Bjorklund, 1972; Ruttner-Kolisko, 1974). This variation is reflected in the species composition of Korea, with variations on the main morphological theme. I encountered Notholca labis with body sizes ranging from 140- 185 pm, and posterior extension lengths from 10- 20 pm respectively. These dimensions fall within the normal variation for this species. Polyarthra species encountered during this time also varied in physical dimensions. Variation in paddle lengths and animal length were noticable

=

* * * * *

* * * * * * *

Epiphanes senta EHR Brachionus angularis GOSSE B. calyciflorus PALLAS B. caudatus BARROIS + DADAY B. diversicornis (DADAY) B. leydigi COHN B. leydigi rotundus ROUSSELET B. urceolaris O.F.M. B. variabilis (HEMPEL) Keratella cochlearis (GOSSE) K. tecta (GOSSE) K. hiemalis CARLIN K. quadrata (O.F.M.) Notholca labis GOSSE Notholca squamula (O.F.M.) Euchlanis deflexa (GOSSE) Trichotria tetractis (EHR) Lepadella acuminata (EHR) Lecane (Monostyla) lunaris (EHR) Cephalodella auriculata (O.F.M.) C. catellina (O.F.M.) C. gibba (EHR) C . sp. BORY DE ST VINCENT Resticula gelida (HAR + MYERS) Itura aurifa (EHR) Lindia (Halolindia) tecusa HAR + MYERS Polyarthra vulgaris CARLIN P. vulgaris longiremis (CARLIN) P. dolichoptera IDELSON Synchaeta lakowitziana LUCKS S. oblonga EHR S. pectinata EHR S. sp. EHR Filinia longiseta passa ( 0 . F .M.) F. cornuta (WEISSE) F. terminalis (PLATE) Testudinella patina (HERMANN)

and typical. (Carlin, 1943; Pejler, 1956, from Ruttner-Kolisko, 1974). No doubt some species encountered were more appropriately transition or introgressive forms of the vulgaris/dolichoptera species group. At Site 1 however, Polyarthra vulgaris longiremis was abundant, and no transition forms were visible between it and the other Polyarthra present at this site, vulgaris and dolichoptera. The largest vulgaris at this site was 140/130/15 pm body/paddle length/paddle width; while the average vulgaris longiremis was 170/200/15 pm. Since the length and nature of caudal and skip-

was 1.27. Since Pejler (1957), after a very detailed study, has shown that terminal members of R terminalis series are well defined, the distinguishing ratios from Ruttner-Kolisko (1974) were used for identification - S:C = 1.2; D = 0 - 15 pm. In addition, the temperature at Site 5 was 11 OC, and R terminalis is most often found in water below 15 OC (cold stenothermous), (Pejler, 1957; Hutchinson, 1964; Ruttner - Kolisko, 1974; Stemberger, 1979). Remarks on a new record

Fig. 2. a: Keratella tecta (Gosse), left lateral & dorsal; b: Filinia longisetapassa (O.F.M.), left lateral; c: Filinia cornuta (Weisse), right lateral; d: Keratella hiemalis (Carlin) dorsal with pustulations.

ping bristles is one of the main species indicators, Filinia longiseta passa (O.F.M.) is thought of by many as a transitional species between Filinia longiseta/terminalis species group, and Filinia cornuta/brachiata species group (Ruttner-Kolisko, 1974). This study found the rare rotifers Filinia longiseta passa (O.F.M.) and Filinia cornuta Weisse (Figs 2b&2c) coincident in a small, shallow 'fishing' pond (Site 2). The differences between these species were apparent, and there was little difficulty determining their identity. Average body 1ength:ant. brist1e:post. bristle - - - 200:180:60 pm - - - Site 2 E cornuta - - - 150:30:40 pm - - - Site 2 & 5

R long. passa

At Site 5, the Filinia terminalis specimens reported had the added characteristic of spines on their bristles. These spines are often thought of as a characteristic of Filinia longiseta, its sister species. However, more accurate distinguishing features were used to determine this species. The distance [Dl of caudal bristle insertion from the end of the body was 15 pm, and the ratio of the length of skipping bristles: length of caudal bristles [S:C]

Keratella hiemalis (Fig. 2d) has been found for the first time in East Asia. It was found at several sites in abundance. Most specimens were cylindrical in shape, and looked like short balloons with spines. The left posterior spine on many specimens was reduced or absent. Pustulations was also animal dependent. Average specimen length was 140 pm. This encounter broadens the known range for this rotifer westward. This occurrence also supports the postulation by Pejler (1977b), that K. hiemalis seems to be restricted to the northern hemisphere, apd temperate waters. In addition, Republic of Korea may be the southernmost record (38"N latitude) for this rotifer (Pejler, 1977b). Summary Ten bodies of water were sampled in the Republic of Korea. Twenty-two new rotifers are added to the species list compiled by Yamarnoto (1953), bringing the number of species found in Korea to onehundred and two. No endemic species were found, but Keratella hiemalis was found for the first time in Asia. A list of rotifers found is included. Acknowledgements Many thanks to Dr. YI Beom-Jun of the University of Inha at Incheon, R.O.K., for his enormous equipment support and help in obtaining the collections. Also thanks to Dr. Birger Pejler and Eric Hollowday for their advice and encouragement.

References Bjorklund, B. G., 1972. Taxonomic and Ecological studies of species of Notholca found in sea and brackish water, with description of a new species, Sarsia 51: 25-66. Carlin, B., 1943. Die Planktonrotatorien des Motalastrom. Medd. Lunds Univ. Limnol. Inst. 5: 1-255. Dumont, H. J., 1983. Biogeography of rotifers. Hydrobiologia 104: 19-30. Hada, Y., 1936. The plankton of Lake Seiko, Suigen in autumn. Chosen Nat. Hist. Soc. J. 21: 1-11. Hutchinson, G. E., 1964. On Filinia terminalis and R Pejleri n. spp. (Rotatoria, Testudinellidae). Postilla 81: 1-8. Koste, W., 1978. Die Radertiere Mitteleuropas begriindet von Max Voight, 2. Gebriider Borntraeger, Berlin, Stuttgart, 637 pp. Pejler, B., 1956. Introgression in planktonic Rotatoria with some points of view on it's causes and conceivable results. Evolution 10: 246-261. Pejler, B., 1957. On variation and evolution in planctonic Rotatoria. Zool. Bidr. Upps. 32: 1-66. Pejler, B., 1977a. General problems on rotifer taxonomy and global distribution. Arch. Hydrobiol. Beih. 8: 212-220. Pejler, B., 1977b. On the global distribution of the family

Brachionidae (Rotatoria). Arch. Hydrobiol., Suppl. 53: 255-306. Ruttner-Kolisko, A., 1974. Plankton Rotifers, Biology and Taxonomy. Binnengewasser. Suppl. 26: 1- 146. Sato, T., 1939. Potamoplankton of the River Hang-gang in early winter. Jap. J. Limnol. 10: 128-130. Sato, T., 1941. Biological notes on the brackish water lake Kodoko on the Japan Sea coast of Korea. Jap. J. Limnol. 11: 85 - 88. Stemberger, R., 1979. A guide to Rotifers of the Laurentian Great Lakes. E.P.A. 600/4-79-021: 1-186. Sudzuki, M., 1964. New Systematical Approach to the Japanese Planktonic Rotatoria. Hydrobiologia 23(1/2): 1-24. Yamamoto, K., 1941. The plankton of lake Fusenko of Northern Chosen. Jap. J. Limnol. 11: 108-117. Yamamoto, K., 1953. Preliminary Studies on the Rotatorian Fauna of Korea. Pacif. Sci. 7: 151-164. Ueno, M., 1941. Introductory account of the biological survey of inland waters of northern Chosen (Korea). Jap. J. Limnol. 14: 96 - 107.

Received 4 December 1984; in revised form 3 December 1985; accepted 28 January 1986.