Syst Parasitol (2006) 65:235–249 DOI 10.1007/s11230-006-9052-8

ORIGINAL PAPER

Gilquiniid cestodes (Trypanorhyncha) from elasmobranch fishes off New Caledonia with descriptions of two new genera and a new species I. Beveridge Æ J.-L. Justine

Received: 22 November 2005 / Accepted: 16 January 2006 / Published online: 6 September 2006
Springer Science+Business Media B.V. 2006

Abstract Cestodes were collected from deepsea sharks caught off New Caledonia, South Pacific. Vittirhynchus squali n. g., n. sp. (Trypanorhyncha: Gilquiniidae) is described from the spiral valve of Squalus melanurus Fourmanoir & Rivaton. The new genus possesses four bothria and a typical heteroacanthous metabasal armature but has a file of three macrohooks forming a short chainette on the internal surface of the basal armature. Sagittirhynchus aculeatus n. g., n. sp., from the spiral valve of Centrophorus sp. (undescribed), also has four bothria and a typical heteroacanthous armature but lacks a distinctive basal swelling and has the final hooks of each principal row prominently enlarged. Gilquinia minor n. sp., from the spiral valve of Centrophorus sp. (undescribed), is distinguished by the presence of only five hooks per principal row compared with eight in congeners.

I. Beveridge (&) Department of Veterinary Science, University of Melbourne, Veterinary Clinical Centre, Werribee 3030 Victoria, Australia e-mail: [email protected] J.-L. Justine E´quipe Bioge´ographie Marine Tropicale, Unite´ ´ volution (CNRS, UPMC, Syste´matique, Adaptation, E MNHN, IRD), Institut de Recherche pour le De´veloppement, BP A5, 98848 Noume´a Cedex, Nouvelle Cale´donie

Gilquinia sp. is reported from Squalus melanurus. G. robertsoni Beveridge, 1990 is reported from S. megalops (Macleay). Re´sume´ Les cestodes ont e´te´ collecte´es de requins peˆche´s au large de la Nouvelle-Cale´donie, Pacifique Sud. Vittirhynchus squali n. g., n. sp. (Trypanorhyncha: Gilquiniidae) est de´crit de la valvule spirale de Squalus melanurus Fourmanoir & Rivaton. Le nouveau genre posse`de quatre bothries et une armature me´tabasale he´te´racanthe typique, mais a une file de trois grands crochets en forme de chaıˆnette courte sur la face interne de l’armature basale. Sagittirhynchus aculeatus n. g., n. sp., de la valvule spirale de Centrophorus sp. (non de´crit), a aussi quatre bothries et une armature he´te´racanthe typique, mais n’a pas d’e´paississement basal distinctif, et a les crochets finaux de chaque range´e principale plus grands. Gilquinia minor n. sp., de la valvule spirale de Centrophorus sp. (non de´crit), se distingue par la pre´sence de seulement cinq crochets par range´e principale, en comparaison avec huit chez ses conge´ne`res. Gilquinia sp. est mentionne´ de Squalus melanurus. G. robertsoni Beveridge, 1990 est mentionne´ de S. megalops (Macleay). Introduction The trypanorhynch family Gilquiniidae Dollfus, 1942 is a small family of cestodes currently

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comprising four genera (Gilquinia Guiart, 1927, Deanicola Beveridge, 1990, Plesiorhynchus Beveridge, 1990 and Aporhynchus Nybelin, 1918) and 10 species. The family was reviewed by Beveridge (1990), following which a single new species of Plesiorhynchus has been described by Palm (2004). Most of the known species are from squalid sharks generally collected from deep waters, which may account for the small number of cestode species known from these sharks, as they are not frequently obtained for parasitological examination. The current paper describes a new collection of gilquiniid cestodes from squalid sharks collected off the coast of New Caledonia and includes the description of two new genera, reports two new species of Gilquinia and a new geographical record for G. robertsoni Beveridge, 1990.

Materials and methods Sharks were collected during the CHONDRICAL cruise of the N/O ‘Alis’ organised by the Institut de Recherche pour le De´veloppement (IRD) off New Caledonia in January and February, 2002. Sharks were examined on board immediately after capture. Spiral valves were dissected and cestode specimens were collected and fixed in 70% ethanol; sometimes spiral valves were fixed by injection of 4% formalin and kept in formalin before the dissection and the collection of cestodes. Shark specimens were deposited in the ichthyological collections of the Muse´um National d’Histoire Naturelle, Paris (MNHN). Specimens were stained in celestine blue, dehydrated in ethanol, cleared in methyl salicylate and mounted in Canada balsam. Serial sections were prepared from mature segments embedded in paraffin and sectioned at a thickness of 5lm. Sections were stained with haematoxylin and eosin. Tentacles were removed with a scalpel blade and mounted individually either on slides or between 2 coverslips for examination of opposite surfaces as described by Dollfus (1942). Morphological terminology for trypanorhynch cestodes follows Campbell and Beveridge (1994) except that the attachment organs are referred to

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as bothria following Jones, Beveridge, Campbell & Palm (2004). Drawings were made with the aid of a drawing tube attached to an Olympus BH microscope. In dorso-ventral views of segments, only the vitelline follicles in the lateral regions of the segment are shown. Measurements were made with an ocular micrometer. All measurements are presented in micrometres, unless otherwise stated, as the range followed, in parentheses, by the mean and the number of specimens measured. Specimens have been deposited in MNHN. Host nomenclature follows Eschmeyer (1998).

Vittirhynchus n. g. Diagnosis Small cestodes with numerous segments. Scolex acraspedote; four bothria; pars bothrialis shorter than pars vaginalis. Metabasal armature heteroacanthous, typical; hook rows begin on internal surface of tentacle, terminate on external surface of tentacle but do not overlap; hooks hollow. Basal swelling and basal armature present. Short file of three enlarged or macrohooks present on internal surface of base arranged similarly to chainette. Bulbs short, retractor originates at base of bulb. Prebulbar organ absent. Segments acraspedote; genitalia single; genital pores alternate irregularly. Testes numerous, scattered, not confluent posterior to ovary. Internal, external and accessory seminal vesicles present. Vagina tubiform; ovary tetra-lobed, situated at posterior margin of segment; uterus terminates at uterine pore in middle of segment. Vitelline follicles circum-medullary. Parasitic in spiral valves of squalid sharks. Type-species: V. squali n. sp. Etymology: The generic is name derived from the Latin vitta, meaning a band and referring to the small chainette.

Vittirhynchus squali n. sp. Type-host: Squalus melanurus Fourmanoir & Rivaton (Squalidae), fish specimen in ichthylogical collections, MNHN 2002–1197.

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Type-locality: CHONDRICAL cruise, Stn CH3, off Banc du Co¨etlogon, New Caledonia (2217¢S, 16712¢E), depth 385–401 m, 30 January, 2002. Site: Spiral valve. Type-material: Holotype and single paratype, MNHN; holotype, 1 slide JN37A1; single paratype, 5 slides JN37A2–A6, serial sections 9 slides JN37A7–A15. Cestodes fixed live in 70% ethanol. Etymology: The species name squali is derived from the generic name of the host. Description (Figs. 1–11) Total length 26–47 (34, n = 2) mm; maximum width 1,400–1,800 (1,600, n = 2); number of segments 60–82 (71, n = 2). Scolex acraspedote, 2,900–3,300 (3,100, n = 2) long, with maximum width in pars bulbosa 720–750 (735, n = 2); 4 bothria with distinct margins; pars bothrialis shorter than pars vaginalis, 680–720 (700, n = 2) long; sheaths sinuous anteriorly, straight in pars vaginalis, sinuous anterior to junction with bulbs; pars vaginalis 2,400–2,700 (2,550, n = 2) long. Bulbs short, prebulbar organ absent; bulbs 730– 800 (765) long, 220–330 (275, n = 2) wide, length:width ratio 1:2.2–3.6 (1:2.9, n = 2); retractor muscle originates at base of bulb; no glandcells attached externally to retractor in bulb; bulbs project into pars proliferans scolecis; pars postbulbosa absent. Tentacles up to 1,150 long; basal swelling present; tentacle 130–160 (140, n = 5) in diameter at base, 70–90 (80, n = 5) in diameter in metabasal region. Hooks hollow, arranged in ascending rows beginning on internal surface, terminate on external surface. Hooks of basal armature consisting of c.10 rows; initial row of hooks small, uncinate; subsequent rows falcate increasing in size along bothrial and antibothrial surfaces of tentacle, terminate in spiniform hooks on external surface of tentacle; hooks at commencement of rows 38–55 (47, n = 5) long, base 15–23 (19, n = 5); hooks at ends of rows 35–40 (38, n = 5) long, base 8–13 (10, n = 5). On internal surface of base, hook rows part to form small space free of hooks; space occupied by 3 enlarged hooks or macrohooks arranged in longitudinal file resembling chainette, diminish in size anteriorly; hooks uncinate with broad bases; chainette hook 1 90–

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125 (108, n = 4) long, base 48–90 (78, n = 4); hook 2 smaller, 88–90 (89, n = 2) long, base 48–63 (55, n = 2); hook 3 53–65 (60, n = 3) long, base 35–45 (40, n = 2). Metabasal armature commences immediately anterior to chainette. Hook files 1(1¢) separated on internal surface of tentacle by space; 10 hooks per principal row, terminating on external surface with slight space between ends of rows. Hooks 1(1¢) robust, uncinate with sharply recurved blade, guard with prominent, medially directed protuberance, 30–45 (38, n = 5) long, base 20–25 (22, n = 5); hooks change in shape along tentacle becoming smaller and with reduced base, lacking medial projection; hooks 2(2¢) uncinate with elongate base but lacking medial projection, 28–35 (33, n = 5) long, base 23–33 (29, n = 5); hooks 3(3¢) uncinate with slightly shorter base, 28–43 (34, n = 5) long, base 20–25 (23, n = 5); hooks 4(4¢) falcate, with longer blade but shorter base, 33–43 (38, n = 5) long, base 13–20 (18, n = 5); hooks 5(5¢) falcate with shorter base 35–40 (39, n = 5) long, base 10–15 (13, n = 5); in subsequent files, hooks of similar shape, diminish in size gradually; hooks 10(10¢) 25–30 (27, n = 5) long, base 6–10 (8, n = 5). Mature segments acraspedote, wider than long, 750–1,300 (1,060, n = 5) long, 1,330–1,730 (1,520, n = 5) wide; genitalia single, with genital pores alternating irregularly; genital pore in anterior half of lateral segment margin, 140–270 (200, n = 5) or 16–21 (19, n = 5)% from anterior extremity of segment. Genital atrium shallow, surrounded anteriorly and posteriorly by muscular pads; cirrus-sac ovoid, 330–350 (310, n = 5) long, 240–280 (260, n = 5) wide, with poorly defined walls; cirrus with distinct, corrugated walls, surrounded by radial muscle fibres; internal seminal vesicle small, semi-lunar, at proximal pole of cirrus-sac; accessory seminal vesicle large, 220– 300 (270, n = 5) long, 190–270 (230, n = 5) wide, extending medially from cirrus-sac; outer wall of accessory seminal vesicle with thick muscle layer, inner epithelium thick, basophilic, with nuclei projecting into lumen; external seminal vesicle dorsal to accessory seminal vesicle, fusiform, 130 long, 47 wide, leads to coiled vas deferens, which descends towards ovarian isthmus. Testes numerous, c.260, arranged in 2–3 layers in medulla, occupying almost all of medulla, not con-

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Syst Parasitol (2006) 65:235–249 Figs. 1–6 Vittirhynchus squali n. g., n. sp. from Squalus melanurus off New Caledonia. 1. Scolex. 2. Mature segment. 3. Bulb and origin of retractor muscle. 4. Terminal genitalia. 5. Composite diagram of transverse sections through terminal genitalia (longitudinal muscles not shown). 6. Transverse section at level of uterine pore. Abbreviations: asv, accessory seminal vesicle; do, dorsal osmoregulatory pore; esv, external seminal vesicle; f, vitelline follicle; isv, internal seminal vesicle; lm, longitudinal muscle; t, testis; u, uterus; up, uterine pore; v, vagina, vd, vas deferens; vo, ventral osmoregulatory canal. Scalebars: 100 lm

fluent posterior to ovaries; testes 30–48 (39, n = 10) long, 13–23 (19, n = 10) wide. Vagina tubiform, entering genital atrium ventral to cirrus-sac, runs medially, passes uterine pore medially and descends towards ovarian isthmus, terminates in diminutive seminal receptacle. Ovary at posterior extremity of segment, 4-lobed; each lobe 240–300 (270, n = 5) long, 220–280 (250, n = 5) wide. Mehlis’ gland posterior to ovarian isthmus, c.80 in diameter. Vitelline follicles internal to muscle bundles, circum-medullary, 20–30 (24, n = 10) long, 8–13 (9, n = 10) wide. Uterus sinuous, extending anteriorly to uterine pore in middle of ventral surface of segment. Outer longitudinal musculature poorly organised, arranged as individual fibres or linear clusters of 3–5 fibres; inner longitudinal muscles arranged in c.50 fusiform bundles, with maximum diameter on medial aspect; transverse muscles form prominent band internal to longitudinal muscles. Ventral osmoregulatory canal 30–45 (40, n = 2) in diameter, external to testis fields; dorsal canal tiny, 10 in diameter, internal to ventral canal, lies dorsal to testis field; genital ducts pass ventral to canals. Gravid segments absent. Remarks The new genus clearly belongs to the Gilquiniidae as it possesses four bothria, a typical, heteroacanthous metabasal armature and internal, external and accessory seminal vesicles (Beveridge, 1990). However, it differs from Aporhynchus in possessing a rhyncheal system, from Plesiorhynchus and Deanicola in having an acraspedote scolex, and from Plesiorhynchus in lacking a prominent pars postbulbosa. It differs from Gilquinia and all of the abovementioned

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genera in possessing a short file of three macrohooks arranged in the form of a chainette on the internal surface of the base of the tentacle. A comparable chainette of about five elements is known from the eutetrarhynchid genus Paroncomegas Campbell, Marques & Ivanov, 1999, except that the chainette in the latter genus occurs on the external surface of the tentacle, not the internal surface. A longer chainette occurs on the external surface of the tentacle of Mixodigma Dailey & Vogelbein, 1982, belonging to the family Mixodigmatidae but placed, along with Paroncomegas, in the superfamily Eutetrarhynchoidea by Palm (2004). The presence of a chainette-like array of hooks on the basal armature of the tentacle does not exclude the genus from the Heteracanthoidea Dollfus, 1942, as defined by Campbell & Beveridge (1994), since their definitions of armature types referred to the metabasal rather than to the basal armature. Paroncomegas, with a basal chainette, likewise has a heteroacanthous metabasal armature and is a member of the heteroacanthoid family Eutetrarhynchidae Guiart, 1927. In all other gilquiniids, the uterus curves porally to terminate at the uterine pore adjacent to the cirrus-sac. Vittirhynchus squali n. g., n. sp. is the only species in which the uterine pore is in the centre of the segment.

Sagittirhynchus n. g. Diagnosis Small cestodes with numerous segments. Scolex acraspedote; four bothria; pars bothrialis shorter than pars vaginalis. Metabasal armature heteroacanthous, typical; hook rows begin on internal surface of tentacle, terminate on external surface of tentacle and do not overlap; hooks hollow; terminal hooks of principal rows enlarged. Basal swelling absent; slight modification of basal armature. Bulbs short; retractor originates at base of bulb. Prebulbar organ absent. Segments acraspedote; genitalia single; genital pores alternate irregularly. Testes numerous, scattered, not confluent posterior to ovary.

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Syst Parasitol (2006) 65:235–249 Figs. 7–11 Vittirhynchus squali n. g., n. sp. from Squalus melanurus off New Caledonia. Tentacular armature. 7. Metabasal region, internal surface, bothrial surface on right hand side. 8. Metabasal region, bothrial surface, internal surface on right hand side. 9. Metabasal region, external surface, bothrial surface on left hand side. 10. Basal region, internal surface, bothrial surface on left hand side; larger numerals (1–3) indicate hooks of chainette. 11. Basal region, bothrial surface; larger numerals (1–3) indicate hooks of chainette. Scale-bars: 100 lm; figures 7,8,10,11 to same scale

Internal, external and accessory seminal vesicles present. Vagina tubiform; ovary tetra-lobed, at posterior extremity of segment; uterus tubular, median, with anterior end deviated porally, terminates at uterine pore on poral side of mid-line. Vitelline follicles circum-medullary. Parasitic in spiral valves of squalid sharks. Type-species: S. aculeatus n. sp. Etymology: The generic name is derived from the Latin sagitta, meaning an arrow and referring to the arrow-like hooks 7(7¢).

Sagittirhynchus aculeatus n. sp. Type-host: Centrophorus sp. (undescribed) (Centrophoridae). Cestodes collected from one of two specimens in ichthylogical collections, MNHN 2002–1178 and 2002–1207. Type-locality: CHONDRICAL cruise, Stn PAL7, off Iˆle des Pins, New Caledonia (2259¢E, 16736¢E), depth 662–753 m, 31 January, 2002. Site: Spiral valve. Type-material: Two complete individuals (holotype and 1 paratype) and fragments (paratype), MNHN. Holotype, 1 slide JN70A1; paratype, 3 slides JN70A2–A5; paratype fragments, 2 slides JN70A6–A7; paratype serial sections, 8 slides JN70A8–A15. Cestodes fixed alive in 70% ethanol. Etymology: The specific name is from the Latin aculeatus, meaning prickly and alluding to the manner in which hooks 7(7¢) project from the external surface of the tentacle. Description (Figs. 12–20) Total length 35–46 (41, n = 2) mm; maximum width 1,560–1,852 (1,705, n = 2); number of seg-

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ments 80–85 (83, n = 2). Scolex acraspedote, 4,160–4,320 (4,240, n = 2) long, maximum width in pars bulbosa 960–1,100 (1,030, n = 2); four bothria with distinct margins; pars bothrialis much shorter than pars vaginalis, 590–640 (615, n = 2) long; width of bothria 300–350 (325, n = 2); sheaths sinuous; pars vaginalis 2,560–3,040 (3,000, n = 2). Bulbs elongate; prebulbar organ absent; bulbs 1,250–1,330 (1290, n = 2) long, 370 (370, n = 2) wide, length:width ratio 1:3.4–3.6 (1:3.5, n = 2); retractor muscle originates at base of bulb; no gland-cells attached externally to retractor in bulb; bulbs project into pars proliferans scolecis; pars postbulbosa absent. Tentacles up to 1100 long, with basal swelling absent; tentacle 90–104 (100, n = 5) in diameter at base, 90–104 (95, n = 5) in diameter in metabasal region. Hooks hollow, arranged in ascending rows begin on internal surface, terminate on external surface. Basal armature consists of c.5 rows of closely packed hooks; initial row of hooks small, uncinate; subsequent hooks subtriangular, increase in size along bothrial and antibothrial surface of tentacle, 20–31 (25, n = 5) long, base 7–17 (13, n = 5), terminate in spiniform hooks on external surface of tentacle. On internal surface of base, metabasal armature commences immediately anterior to 5 basal hook rows. Hook files 1(1¢) separated on internal surface of tentacle; 7 hooks per principal row, terminate on external surface with slight space between ends of rows. Hooks 1(1¢) robust, uncinate with sharply recurved blade, guard with prominent, medially directed protuberance, 59–69 (63, n = 5) long, base 32–38 (35, n = 5); hooks change in shape along tentacle becoming smaller and with reduced base, lacking medial projection; hooks 2(2¢) uncinate with elongate base but lacking medial projection, 43–50 (47, n = 5) long, base 26–33 (30, n = 5); hooks 3(3¢) falcate, longer with slightly shorter base, 37–46 (43, n = 5) long, base 26–30 (27, n = 5); hooks 4(4¢) falcate, with shorter blade and shorter base, 35–44 (37, n = 5) long, base 13–20 (18, n = 5); hooks 5(5¢) slender, falcate with shorter base 41–56 (49, n = 5) long, base 13– 19 (15, n = 5); hooks 6(6¢) spiniform, 48–59 (54, n = 5) long, base 9–15 (12, n = 5); hooks 7 (7¢) robust, deltate, with broad base, 48–56 (53, n = 5) long, base 20–26 (23, n = 5); in metabasal region

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Figs. 12–17 Sagittirhynchus aculeatus n. g., n. sp. from Centrophorus sp. off New Caledonia. 12. Scolex. 13. Mature segment. 14, 15. Terminal genitalia showing variation in shape of internal and accessory seminal vesicles. 16. Transverse section of segment at level of terminal genital ducts. 17. Bulb showing origin of retractor muscle. Abbreviations: asv, accessory seminal vesicle; do, dorsal osmoregulatory pore; esv, external seminal vesicle; f, vitelline follicle; isv, internal seminal vesicle; lm, longitudinal muscle; t, testis; u, uterus; up, uterine pore; v, vagina, vd, vas deferens; vo, ventral osmoregulatory

hooks 7(7¢) project at almost 90 to longitudinal axis of tentacle. Mature segments acraspedote, wider than long, 780–1,330 (1,030, n = 5) long, 1,560–1,850 (1710, n = 5) wide; genitalia single, with genital pores alternating irregularly; genital pore in anterior half of lateral segment margin, 195–310 (270, n = 5) or 12–20 (16, n = 5)% from anterior extremity of segment. Genital atrium shallow, surrounded anteriorly and posteriorly by muscular pads; cirrus-sac ovoid, frequently (but not invariably) partly sub-divided into 2 parts, distal part 195–310 (240, n = 5) long, 280–130 (260, n = 5) wide, proximal part 78–150 (112, n = 5) long, 65–98 (79, n = 5) wide; cirrus-sac with poorly defined walls; cirrus short, sinuous, unarmed, enters voluminous internal seminal vesicle which occupies most of cirrus-sac; accessory seminal vesicle large, 228–380 (320, n = 5) long, 90–260 (178, n = 5) wide, extends medially from cirrus-sac, often partly subdivided into smaller distal region and larger proximal section; outer wall of accessory seminal vesicle with thick muscle layer, inner epithelium thick, basophilic, with nuclei projecting into lumen; external seminal vesicle dorsal to accessory seminal vesicle, small, 65–110 (85, n = 5) long, 46–65 (56, n = 5) wide, leads to voluminous, coiled vas deferens, which descends towards ovarian isthmus. Testes numerous, arranged in 1–2 layers in medulla, occupy almost all of medulla, not confluent posterior to ovary; c.160 testes in aporal half of segment; in poral half, c.18 prevaginal, c.140 post vaginal; total number of testes c.380; testes 46–72 (55, n = 10) long, 26–46 (34, n = 10) wide. Vagina tubiform, enters genital atrium ventral to cirrus-

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sac, runs medially, passes uterine pore medially and descends towards ovarian isthmus, terminates in diminutive seminal receptacle c.85 in diameter. Ovary at posterior extremity of segment, 4-lobed; each lobe 220–260 (250, n = 5) long, 228–400 (317, n = 5) wide. Mehlis’ gland posterior to ovarian isthmus, 90–195 (150, n = 5) in diameter. Vitelline follicles internal to muscle bundles, circum-medullary, 23–42 (34, n = 10) in diameter. Uterus central, with lateral diverticula, extends anteriorly and porally to uterine pore on ventral surface of segment posterior to vagina and accessory seminal vesicle. Outer longitudinal musculature poorly organised, arranged as individual fibres or linear clusters of 3–5 fibres; inner longitudinal muscles arranged in c.50 fusiform bundles, with maximum diameter on medial aspect; transverse muscles form prominent band internal to longitudinal muscles. Ventral osmoregulatory canal 23–42 (34, n = 5) in diameter, external to testis fields; dorsal canal tiny, 10 (10, n = 5) in diameter, internal to ventral canal, lies dorsal to testis field; genital ducts pass ventral to canals. Gravid segments absent. Remarks Sagittirhynchus, the new genus described here, has the characteristics of the Gilquiniidae: four bothria, a typical, heteroacanthous armature, external and accessory seminal vesicles, a porallydeviated uterus and a uterine pore. In lacking a prominent pars postbulbosa and having an acraspedote scolex, the genus most closely resembles Gilquinia. It differs significantly however, from all species of Gilquinia, as well as from Vittirhynchus n. g., in lacking a basal swelling of the tentacle, in having a very much reduced basal armature and in having the hooks of the final files enlarged with a broad base. Because of the striking difference in the final files of hooks, a new genus has been created to contain the species. Hooks 1(1¢) have a very prominent medial protuberance on the handle, as do the hooks in the metabasal region of Vittirhynchus. This feature is shared with members of Plesiorhynchus and, whilst a prominent characteristic, does not distinguish these genera from all other gilquiniids.

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Figs. 18–20 Sagittirhynchus aculeatus n. g., n. sp. from Centrophorus sp. off New Caledonia. Tentacular armature. 18. Basal and metabasal regions, antibothrial surface, internal surface on right hand side. 19. Basal and metabasal regions, external surface, bothrial surface on right hand side. 20. Basal and metabasal regions, internal

Gilquinia minor n. sp. Type-host: Centrophorus sp. (undescribed) (Centrophoridae). Specimen in ichthylogical collections, MNHN 2002–1181. Type-locality: CHONDRICAL cruise, Stn PAL4, between Lifou and Re´cif Jouan, New Caledonia (2034¢S, 16657¢E), depth 711–793 m, 27 January, 2002. Site: Spiral valve. Type-material: Holotype and 23 paratypes, MNHN. Holotype, 1 slide JN10D1 (with other paratype specimens); paratypes, 2 slides JN10B1, JN10C1. JN10B–C, cestodes fixed alive in 70% ethanol, JN10D, spiral valve fixed in formalin. Etymology: The specific name is from the Latin minor, meaning smaller and referring to the reduced number of hooks in the principal rows. Description (Figs. 21–29) Small cestodes, with total length 3.22–5.92 (4.70, n = 5) mm; maximum width 240–350 (288, n = 5); number of segments 7–10 (8, n = 5). Scolex acraspedote, 780–1494 (1205, n = 5) long, maximum width in pars bulbosa 163–326 (234, n = 5); 4 bothria with distinct margins; pars bothrialis shorter than pars vaginalis, 280–306 (293, n = 5) long; width of scolex in dorso-ventral view 306– 390 (338, n = 5); width of bothrium 130–163 (143, n = 5); sheaths sinuous; pars vaginalis 455–1138 (852, n = 5). Bulbs short, with prebulbar organ absent; bulbs 215–377 (280, n = 5) long, 65–104 (85, n = 5) wide, length: width ratio 1: 7.0–1: 13.3 (1: 10.1, n = 5); retractor muscle originates at base of bulb; no gland-cells attached externally to retractor in bulb; bulbs project into pars proliferans scolecis; pars postbulbosa absent. Tentacles up to 550 long, with slight basal swelling present; tentacle 26–33 (31, n = 5) in diameter at base, 20–26 (22, n = 5) in diameter

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in metabasal region. Hooks hollow, arranged in ascending rows beginning on internal surface, terminating on external surface. Initial row of hooks on base small, uncinate, well-spaced, 8–11 (9, n = 5) long, base 5–7 (6, n = 5); subsequent 5 rows elongate, subtriangular, 9–14 (11, n = 5) long, base 3–5 (4, n = 5); subsequent 10 rows of hooks small, uncinate, with elongate base, 5–8 (6, n = 5) long, base 7–8 (7, n = 5). Metabasal armature commences immediately anterior to distinctive basal armature. Hook files 1(1¢) separated on internal surface of tentacle; 5 hooks per principal row, terminating on external surface with prominent space between ends of rows. Hooks 1(1¢) uncinate with sharply recurved blade, elongate base, 15–22 (20, n = 5) long, base 8–14 (12, n = 5); hooks change in shape along tentacle becoming smaller; hooks 2(2¢) uncinate with elongate base, 10–19 (15, n = 5) long, base 8–14 (11, n = 5); hooks 3(3¢) slender, falcate with shorter base, 11–15 (13, n = 5) long, base 5–11 (8, n = 5); hooks 4(4¢) falcate, with longer blade but shorter base, 15– 18 (16, n = 5) long, base 5–8 (6, n = 5); hooks 5(5¢) falcate, 13–18 (16, n = 5) long, base 4–7 (6, n = 5). Mature segments acraspedote, longer than wide, 1,040–1,900 (1,420, n = 5) long, 215–293 (247, n = 5) wide; genitalia single; genital pores alternating irregularly, in anterior half of lateral segment margin, 228–280 (254, n = 5) or 14–22 (18, n = 5)% from anterior extremity of segment. Genital atrium shallow, surrounded anteriorly and posteriorly by muscular pads; cirrus-sac ovoid, 98– 163 (130, n = 2) long, 65–80 (73, n = 5) wide, with poorly defined walls; cirrus short, sinuous, unarmed leading to voluminous internal seminal vesicle filling most of cirrus-sac; accessory seminal vesicle large, 140–228 (176, n = 3) long, 81–120 (104, n = 3) wide, extending anteriorly from cirrus-sac; external seminal vesicle dorsal to accessory seminal vesicle, fusiform, 42–49 (46, n = 2) long, 23–65 (28, n = 2) wide, leads to coiled vas deferens, which descends towards ovarian isthmus. Testes numerous, arranged in 2 layers in medulla, occupy almost all of medulla, present posterior to ovaries; testes 48–70 (58, n = 10) long, 30–52 (42, n = 10) wide; 62–92 (72, n = 5) testes anterior to ovary, 6–10 (8, n = 5) posterior to ovary; total

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Figs. 21–24 Gilquinia minor n. sp. from Centrophorus sp. off New Caledonia. 21. Entire mature cestode. 22. Scolex.

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23. Mature segment. 24. Terminal genitalia. Abbreviations: asv, accessory seminal vesicle; esv, external seminal vesicle; isv, internal seminal vesicle; u, uterus; up, uterine

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Figs. 25–29 Gilquinia minor n. sp. from Centrophorus sp. off New Caledonia. Tentacular armature. 25. Basal and metabasal region, beginning slightly anterior to base, external surface. 26. Metabasal region, antibothrial surface, internal surface on left hand side. 27. Basal and metabasal region,

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internal surface on right hand side. 28. Metabasal region, internal surface, bothrial surface on left hand side. 29. Metabasal region, external surface, bothrial surface on right hand side. Scale-bar: 10 lm

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number of testes 69–98 (78, n = 5). Vagina tubiform, enters genital atrium ventral to cirrus-sac, runs medially, passes uterine pore medially and descends towards ovarian isthmus. Ovary 4-lobed, situated anterior to posterior extremity of segment; each lobe 114–200 (145, n = 5) long, 46–114 (72, n = 5) wide. Mehlis’ gland posterior to ovarian isthmus, 55–80 (68, n = 5) in diameter. Vitelline follicles circum-medullary, 16–33 (21, n = 10) in diameter. Uterus extends anteriorly and porally to uterine pore on ventral surface of segment, posterior to vagina, medial to seminal vesicles. Ventral osmoregulatory canal 10–20 (14, n = 5) in diameter, external to testis fields; dorsal canal not seen; genital ducts pass ventral to canal. Gravid segments absent.

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Material examined: CHONDRICAL cruise, Stn PAL2, Baie du Santal, Lifou, New Caledonia (2050¢S, 16707¢E), depth 665–720 m, 26 January, 2002, 6 specimens on 3 slides, JN4B1–B3, cestodes fixed alive in 70% ethanol; CHONDRICAL cruise, Stn PAL6, male fish specimen in ichthylogical collections, MNHN 2002–1179, off New Caledonia (2038¢S, 16704¢E), depth 600– 680 m, 28 January, 2002, 6 specimens on 6 slides, JN21B1–B6, cestodes from spiral valve fixed in formalin; CHONDRICAL cruise, Stn PAL7, off Iˆle des Pins, New Caledonia (2259¢E, 16736¢E), depth 662–753 m, 31 January, 2002, 1 specimen on 1 slide, JN60F1, cestode observed in sea-water then fixed alive in 70% ethanol. Remarks

Remarks This species most closely resembles G. stevensi Beveridge, 1990 described from Squalus mitsukurii Jordan & Snyder off Townsville, Australia. Both species have 108 testes per segment or fewer, differentiating them from G. robertsoni Beveridge, 1990 with 140–220 testes and G. squali (Fabricius, 1794) with 280–350 testes per segment. The number of testes in G. minor n. sp. (62–92, mean 72) is slightly lower than that for G. stevensi (87–108, mean 99), but the ranges overlap. However, in G. stevensi, the testes are distributed in a single layer, while in G. minor they are in two dorso-ventral layers. G. minor differs from all three known species of Gilquinia in the form of the basal armature with the c.10 rows of triangular hooks which are not present in its congeners. In the remaining species, there is a direct transition from the basal to the metabasal armature without the 10 rows of triangular hooks interpolated between them as occurs in G. minor. It also differs from all its congeners in having five hooks per principal row compared with six in G. stevensi and G. robertsoni and six to eight in G. squali.

Gilquinia robertsoni Beveridge, 1990 Host: Squalus megalops (Macleay) (Squalidae) Site: Spiral valve.

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These specimens conform with the description of Gilquinia robertsoni given by Beveridge (1990) in having approximately 150 testes per segment. Beveridge (1990) described G. robertsoni from Squalus megalops, an unidentified species of Squalus and several other genera collected off the southern coast of Australia. Palm (2004) has recently reported the same species from S. megalops from off Pelabuhan Ratu, Indonesia. According to Last and Stevens (1994), S. megalops appears to be a species complex in this region. The identification of the host may therefore require future clarification. Gravid segments of G. robertsoni placed in seawater immediately released filamentous extrusions containing numerous eggs. Gilquinia sp. Host: Squalus melanurus Fourmanoir & Rivaton (Squalidae), fish specimen in MNHN ichthylogical collections 2002–1197. Locality: CHONDRICAL cruise, Stn CH3, off Banc du Co¨etlogon, New Caledonia (2217¢S, 16712¢E), depth 385–401 m, 30 January, 2002. Site: Spiral valve. Material examined: deposited in MNHN, 17 specimens on 1 slide, JN37B1, fixed in formalin. In this series of specimens, there is only one everted tentacle. The features of the scolex and armature indicate that the species belongs to

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Gilquinia, but the basal armature differs from all known species. However, there is insufficient material upon which to base a full description and name the species. Discussion The description of these new species of cestodes expands considerably the number of genera in the family Gilquiniidae. Both new genera share the distinctive features of the mature segments of other gilquiniids in possessing an internal seminal vesicle, an external seminal vesicle and an enlarged accessory seminal vesicle, as well as a uterine pore and, in the case of Sagittirhynchus n. g., a porally deviated uterus. Vittirhynchus n. g. differs from all remaining members of the family in having the uterine pore in the centre of the segment rather than adjacent to the genital atrium, but the details of the ducts otherwise resemble the pattern found in the remaining gilquiniid genera. Plesiorhynchus and Deanicola have been distinguished based on features of the scolex, whether or not it is craspedote and whether or not there is an extensive pars post-bulbosa. The genera described here, however, are distinguished primarily on the basis of armature. Vittirhynchus possesses a short file of three enlarged hooks arranged in the form of a chainette on the internal surface of the basal swelling, resembling in some respects that found in the eutetrarhynchid genus Paroncomegas. In Sagittirhynchus, the terminal hooks of each principal row are modified and enlarged such that they form two parallel files of enlarged hooks on the external surface of the tentacle. As with other trypanorhynch families, such as the Eutetrarhynchidae Guiart, 1927 and the Otobothriidae Dollfus, 1942, the description of new genera has resulted in a wider range of armature types being found within a single family (Palm, 2004). The same appears to be true in the case of the Gilquiniidae. All of the parasites here were collected from squalid sharks obtained at between 380 and 790

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metres of depth. Trypanorhynch cestodes have been reported from only 23 of the more than 70 known species of squaliform sharks (Palm, 2004), suggesting that more gilquiniid cestodes remain to be discovered. The moderate depths at which these sharks are found and their relative inaccessibility for parasitological examination may be the principal reason that the Gilquiniidae is so poorly represented in collections. Isopods collected from sharks from the same cruise have been described in Trilles and Justine (2004); tetraphyllidean cestodes have been deposited in the MNHN; copepods have been determined by G. Boxshall (Natural History Museum, London, BMNH) and are deposited in both the MNHN and BMNH. Acknowledgement The CHONDRICAL cruise was organised by Bernard Se´ret (IRD), who is thanked for his help and for the identification of the fish specimens.

References Beveridge, I. (1990). Revision of the family Gilquiniidae Dollfus (Cestoda: Trypanorhyncha) from elasmobranch fishes. Australian Journal of Zoology, 37, 481– 520. Campbell, R. A., & Beveridge, I. (1994). Order Trypanorhyncha Diesing, 1863. In L. F. Khalil, A. Jones, & R.A. Bray (Eds.), Keys to the cestode parasites of vertebrates (pp. 51–148). Wallingford: Commonwealth Agricultural Bureaux International. ´ tudes critiques sur les Te´traDollfus, R.-P. (1942). E rhynques du Muse´um de Paris. Archives du Muse´um National d’Histoire Naturelle, 6e`me se´r, 19, 1–466. Eschmeyer, W. N. (1998). Catalog of fishes. San Francisco: California Academy of Sciences, 2905 pp. Jones, M. K., Beveridge, I., Campbell, R. A., & Palm, H. W. (2004). Terminology of the sucker-like organs of the scolex of trypanorynch cestodes. Systematic Parasitology, 59, 121–126. Last, P. R., & Stevens, J. D. (1994). Sharks and rays of Australia. Australia: CSIRO, 513 pp. Palm, H. W. (2004). The Trypanorhyncha Diesing, 1863. Bogor: PKSPL-IPB Press, 710 pp. Trilles J.-P., & Justine J.-L. (2004). Une nouvelle espe`ce de Cymothoidae et trois Aegidae (Crustacea, Isopoda) re´colte´s sur des poissons de mer profonde au large de la Nouvelle Cale´donie. Zoosystema, 26, 211–233.

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