© Zoological Institute, St.Petersburg, 2006 Anew synonym of Halicyclops sarsiAkatova, 1935 (Copepoda: Cyclopoida) V.I. Moncbenko Monchenko, V.I. 2006. A new synonym of Halicyclops sarsi Akatova, 1935 (Copepoda: Cyclopoida). Zoosystematica Rossica, 14(2), 2005: 197-201. The lectotype of H. sarsi Akatova, 193 5 is designated and described. H. pygmaeus Sars, 1927 (nomen nudum) and H setifer Lindberg, 1949 are placed in synonymy under H sarsi. V.l. Monchenko, Institute of Zoology, National Academy of Sciences of Ukraine, ul. B. Khmelnitskogo 15, Kiev 01601, Ukraine. E-mail: [email protected] Introduction Description. Female (lectotype). Body length 428 µm without furcal setae. Body slender, col The most common cyclop of the Caspian Sea, ourless. Length of abdomen (with genital double H. sarsi, was described incompletely (Akatova, somite) 51 % of prosoma length (Fig. l ). Genital 1935). Subsequently, this species was included double somite as long as wide (Fig. 2), laterally in three keys (Lindberg. 1957; Borutsky, 1960; broadly rounded in its anterior part, broadest in Kun, 1968) and recorded from plankton of dif anterior half, and tapering posteriorly. Distal bor ferent parts of the Caspian Sea. The more fully der of anal segment ventrally with fine denticles described H setifer was found in plankton near (Fig. 4). Caudal rami 1.4 times as long as wide Iranian coast (Lindberg, 1949, 1951) and was (Fig. 3). Outennost apical seta twice as long as included in keys, as well as in lists of Caspian caudal rami. Length ratio of distal setae, starting fauna (Lindberg, 1957; Borutsky, 1960; Mor with the outer seta, 1 : 2.4 : 6.5 : 0.3, i.e. inner dukhai-Boltovskoy, 1960; Kun, 1968). It was most seta is short. Lateral seta inserted at about subsequently redescribed in detail from the west distal 2/5 oframi. Very long dorsal seta 3 times as Caspian coast (near Derbent) (Monchenko, long as rami and 1.8 times as long as outermost 1978). The comparison of the type material of seta. Antennule (Fig. 5) 6-segmented, reaching to H. sarsi with the redescription of H. setifer half of cephalosoma length, with numerous setae (Monchenko, 1978) showed that they refer to the and other armaments from proximal to distal seg same species. As it will be shown below very ments. Antenna (Fig. 6) 3-segmented, with basis important diagnostic character was unnoticed, in bearing 2 setae at anterior comer, without ex the first description of H. sarsi (Akatova, 1935). opodite-seta and surface ornamentation; en dopodite segments 1 and 2 with 1 and 10 setae, Halicyclops sarsiAkatova, 1935 respectively. Mandible surface without ornamen (Figs 1-21) tation; tiny palp with 2 setae (very long and very short) (Fig. 7). Maxillule (Fig. 8) with palp (Fig. 9) Akatova, 1935: 320; Lindberg, 1949: 8; 1957: 144; Borut of common structure for the family, with 7 setae sky, 1960: 75; Kun, 1968: 171. - setifer Lindberg, and without spinules on surface. Maxilla (Fig. I 0) 1949: 7, syo. n.; 1951: 162; 1957: 141; Borutsky, 1960: 4-segmented, with one minute seta on coxopodite; 75;Kun, 1968: 171;Monchenko, !978:81.-pygmaeus basal endite with two straight spines of different Sars, 1927: 329 (nomen nudum), syn. n. lengths. Maxilliped (Fig. 11) 2-segmented; prae coxa fused with coxa bearing at whole 3 setae; all Material. Lectotype (present designation). ~,dissect­ other segments also fused, with 5 setae. Swim ed and mounted in glycerol-gelatin on a slide, Caspian Sea, gulf Mertvyi Kuitu!<, Spit Zhilaya, no. 488a, st. 2, ming legs (Figs 12-14) all with 3-segmented rami. 4.Vl.1931 (Suvorov), deposited at Zoological Institute, Exopodite segments 1 and 2 and endopodite seg St.Petersburg. ment l each with 1 medial seta; endopodite seg Paralectotypes. 3 ~,the same data as in the lectotype, ment 2 ofleg 1 with 1 seta, endopodite segments deposited at Institute of Zoology, National Academy of 2 of legs 2-4 each with 2 medial setae; each ex Sciences, Kiev (no. 602), 240 undissected females and males preserved in alcohol, deposited at fustitute of Zo opodite terminal segment with 5, 5, 5, 5 setae and ology, Kiev (no. 602) and Zoological Institute, St.Peters 3, 4, 4, 3 spines, respectively. On leg 4, medial burg (no. 488b). spine replaced by thin plumose seta. Legs 2 and 198 V.J. Monchenko: A new synonym ofH alicyclops sarsi • ZOOSYST. ROSSICA Vol. 14 Figs 1-10. Halicyclops sarsi Akatova, female: I, habitus, dorsal; 2, genital double-segment, dorsal; 3, caudal rami, dorsal side; 4, caudal rarni, lateral; 5, antennule; 6, antenna; 7, mandible; 8, rnaxillule; 9, taster ofmaxillule; 10, maxilla. Long scale bar: 1 - 100 µm, 2 - 45 µrn; 3, 7-9 - 20 µrn; 6-30 µm. Short scale bar: 4, 5, 10-30 µrn. ZOOSYST. ROSSICA Vol. 14 • V.J. Monchenko: A new synonym of Halicyclops sarsi 199 Figs 11-15. Ha/icyclops sarsi Akatova, female: 11, maxilliped; 12, leg l; 13, leg 2; 14, leg 4; 15, leg 5. Scale bar: 11, 12, 14, 15-20 µm; 13 -30 µm. 200 V.J. Monchenko: A new synonym ofH alicyclops sarsi • ZOOSYST. ROSSICA Vol. 14 Figs 16-21. Ha/icyclops sarsi Akatova, male: 16, caudal rami, dorsal; 17, caudal rami, lateral; 18, antennule; 19, leg 4; 20, legs 5 and 6; 21, leg 6. Scale bar: 16, 19, 20, 21 - 20 µm; 17, 18 - 30 µm. ZOOSYST. ROSSICA Vol. 14 • V.J. Monchenko: A new synonym ofH alicyclops sarsi 201 3 of equal length, have the same armament. Dis Acknowledgements tal segment ofleg 4 endopodite elongate, 1.6 times as long as wide, with two straight apical spines; This work is based on the scientific collection of Zoo inner spine 1. 7 times as long as outer spine and logical Institute, Russian Academy of Sciences, and In stitute of Zoology, National Academy of Sciences, Ukra 1.6 times as long as the segment; inner setae of ine. I thank curator of the hydrobiological department of this distal segment modified into straight spines the first Institute, Prof. L.A. Kutikova for the opportunity reaching top ofnearest apical spine. Couplers of to examine the material. all legs without prominent paired rounded pro trusions of free margins, but with small hairs on References leg I. Medial projections of basipodites of legs 1-4 with short stout hairs. Identical hairs present Akatova, N.A. 1935. Drei neue Copepoden-Arten aus on outer side of exopodite segments oflegs 1-4. dern Kaspi-See. Zoo/. Anz., 111(1 l /12): 319-326. Borutsky, E.V. 1960. Determination keys off ree-living Thin hairs present on outer margins of all en freshwater Copepada of USSR and neighbouring dopodite segments oflegs 1-4. On leg 5 (Fig. 15), countries by fragments in fish guts. Moscow: Acad. segment 1 fused with 5th thoracal segment, with Sci. USSR. 218 p. (In Russian). long lateral seta; form and armament of single free Kun, M.S. 1968. Order Copepoda. In: Atlas of inverte segment characteristic of genus Halicyclops, with brates ofC aspian Sea: 160-183. Moscow: Pishchep very long apical plumose seta, which is twice as rom. (In Russian). Lindberg, K. 1949. Contribution a l'etude des Cyclopi long as the segment. des (Crustaces, Copepodes). K. Fysiogr. Sii/lsk. Lund Male. Body length of dissected specimen Forhand/., 19(7): 1-24. 367 µm. Caudal rami (Fig. 16) 1.4 times as long Lindberg, K. 1951. Notes sur quelques Halicyclops de as wide. Outermost seta 2.5 times as long as in lamer Caspienne. Description du H. oblongus n. sp. nermost seta; dorsal seta slightly longer than out et du H. robustus n. sp. Medd. Zoo/. Mus. Oslo, 58: 157-164. ermost one (Fig. 17). Antennule (Fig. 18) 13-seg Lindberg, K. 1952. Cyclopides (Crustaces, Copepodes) mented. Middle spine on exopodite segment 3 du Royaurne du Cambodge. Bull. Inst. roy. Sci. natur. ofleg 4 modified (Fig. 19) into thin plumose seta. Relg., 28(15): 1-16. Distal endopodite segment of leg 4 elongate, 1. 7 Lindberg, K. 1957. Cyclopoides (Crust. Cop.)de la Cote times as long as wide; inner apical spine 1. 7 times d'Ivoire. Bull. Inst. frani;. Afrique Noire, Ser. A, 19(1): 134-179. as long as outer spine and 1.3 times as long as Monchenko, V.I. 1978. Second record of Halicyclops the segment. Leg 5 (Figs 20-21) with additional setifer (Crustacea, Copepoda), redescription of spe very long seta; leg 6 with strong outer spine and cies and first description of males. Dokl. Akad. Nauk two setae; their length ratio, starting with outer Ukr. SSR, 1978(1): 81-84. (In Russian with English spine, as 1 : 0.4 : 0.8 (Fig. 20). summary). Discussion. In the description of H. sarsi, Aka Mordukhai-Boltovskoy, F.D. 1960. Caspian fauna in Azov-Blacksea basin. Moscow & Leningrad: Izd. tova (1935: 321) wrote that distal exopodite seg Akad. Nauk SSSR. 288 p. (In Russian). ment ofleg 4 was armed "as in H. aequoreus and Reid, J.W. 1990. Continental and coastal free-living all other species of the genus"; a drawing of this Copepoda (Crustacea) of Mexico, Central America exopodite was not given. However, in actuality and the Carribean region. In: Diversidad Biologica H. sarsi has a rare modification of the middle en la Reserva de la Biosfera de Sian Ka·an Quin tana Roo, Me:icico: 175-213. spine on the last segment ofleg 4 into a thin plu Sars, GO. 1927. Notes on the Crustacean-fauna of the mose seta. The same modification is known also Caspian Sea. In: Sbornik v chest 'professora Nilrolaya in two other (of approximately 95 described) spe Mikhailovicha Knipovicha.1885-1925 [The book in cies of the genus; in H b/achei Lindberg from honour of Professor N.M. Knipovich. 1885-1925]. Cambodia (Lindberg, 1952) and H. fosteri Wil Moscow: 315-329. Wilson, M.S. 1958. The copepod genus Halicyclops in son from North America (Wilson, 1958; Reid, North America with description of a new species from 1990, etc.). Lake Pontchartrain, Louisiana, and the Texas Coast. In the list of Caspian cyclops, Sars (1927) not Tulane Stud. Zool.,6(4): 176-189. ed H. pygmaeus without description. This nomen nudum obviously must be referred to the small est Caspian Halicyclops, H. sarsi. Received 30 April 2005