The copepod genus Hatschekia Poche, 1902 (Siphonostomatoida: Hatschekiidae) from triggerfishes (Pisces: Tetraodontiformes: Balistidae) from off the Ryukyu Islands, Japan, with descriptions of eleven new species Author Uyeno, Daisuke Author Nagasawa, Kazuya text Zootaxa 2010 2478 1 40 journal article 10.5281/zenodo.195334 5c776f2d-8efa-408e-855d-5688a5ca2c0e 1175-5326 195334 Hatschekia churaumi n. sp. ( Figs 62–75 ) Type material. Holotype , female ( NSMT –Cr 20907), ex Pseudobalistes flavimarginatus (Rüppell) ( Tetraodontiformes : Balistidae ), off Ishikawa Beach ( 26°25’N , 127°49’E ), Okinawa-jima Island, the Ryukyu Islands, North Pacific Ocean, Japan , 1 September 2005 . Paratypes : 2 females ( NSMT –Cr 20908), ex P . flavimarginatus , off Ishikawa Beach ( 26°25’N , 127°49’E ), Okinawa-jima Island, the Ryukyu Islands, North Pacific Ocean, Japan , 1 September 2005 ; 2 females ( RUMF –ZC–00925), ex P . flavimarginatus , off Ishikawa Beach ( 26°25’N , 127°49’E ), Okinawa-jima Island, the Ryukyu Islands, North Pacific Ocean, Japan , 1 September 2005 . Description of female. Body ( Fig. 62 ) 644–738 (700 ± 39) long, excluding caudal rami (n = 5). Cephalothorax blunt sub-triangular, slightly shorter than wide [242–273 (261 ± 12) × 270–299 (292 ± 13)], widest in anterior ½, with dorsal, Y-shaped chitinous frame with mid-line ending as short horizontal bar immediately before triangular depression connecting posteriormost slit, bearing two small setae in small dorsal pits. Trunk tapering posteriorly, longer than wide [433–523 (470 ± 41) × 190–223 (208 ± 14)], widest near anterior end. Urosome ( Fig. 63 ) excluding caudal ramus shorter than wide [27–43 (35 ± 6) × 41–62 (56 ± 9)]. Genital complex fused to abdomen without border. Caudal ramus ( Fig. 63 ) slightly longer than wide [18– 23 (20 ± 2) × 11–15 (13 ± 1)], bearing 5 naked setae. Rostrum with 1 digitiform process at each posterolateral corner ( Fig. 64 ). Antennule ( Fig. 64 ) indistinctly 5-segmented, 144–184 (162 ± 15) long; armature formula: 10, 5, 4, 1, 13 + 1 aesthetasc. Antenna ( Fig. 65 ) 3- segmented; proximal segment (coxa) unarmed; middle segment (basis) ornamented with surface pits; terminal claw without armature; proximal segment length 77–88 (82 ± 5); middle segment length 143–172 (162 ± 11); terminal claw length 34–57 (48 ± 9); total length 273–312 (293 ± 15). Parabasal papilla ( Fig. 66 ) developed, digitiform. Oral cone robust. Mandible ( Fig. 67 ) slender, with 3 sharp apical teeth. Maxillule ( Fig. 68 ) bilobate; both lobes armed with 2 tapering elements. Maxilla ( Fig. 69 ) 4-segmented; proximal segment unarmed; second segment rod-like, with 1 basal seta; third segment elongate, with 1 distal seta; terminal segment small, with 1 small seta and bifid claw. Maxilliped absent. Legs 1 and 2 ( Figs 70–71 ) biramous, with both exopods composed of 2 indistinct segments and 2– segmented endopods; leg armature formula as follows:
Protopod Exopod Endopod
Leg 1 1–1 1–0; 3 0–0; 2
Leg 2 1–0 1–0; 2 (1–2) 0–1; 2
Protopods of legs 1 and 2 ornamented with rows of blunt spinules on anterior surface. Both rami of legs 1 and 2 carrying semicircular wrinkles (it is uncertain whether these wrinkles are spinulate or membranous). Leg 1 ( Fig. 70 ) 81–105 (88 ± 10) long; protopod length 42–59 (49 ± 7); exopod length 35–46 (40 ± 4); endopod length 23–35 (28 ± 4). Leg 2 ( Fig. 71 ) length 79–89 (82 ± 4); protopod length 44–53 (50 ± 3); exopod length 29–36 (33 ± 3); endopod length 23–29 (26 ± 3). Intercoxal sclerites of legs 1 and 2 ( Figs 72–73 ) bearing 4 spatulate, wrinkled processes. Leg 3 ( Fig. 74 ) represented by 2 simple setae originating on mid-lateral surface of trunk. Leg 4 ( Fig. 75 ) represented by 1 simple lateral seta on posterior ¾ of trunk. FIGURES 62–69. Hatschekia churaumi n. sp. , female, holotype NSMT–Cr 20907. 62, habitus dorsal; 63, posterior part of trunk, dorsal; 64, antennule, ventral, rp = rostrum process; 65, antenna, ventral; 66, antenna with parabasal papilla; 67, mandible; 68, maxillule; 69, maxilla. Scale bars: 62, 65–66, 100μm; 63–64, 68–69, 20μm; 67, 10μm. FIGURES 70–75. Hatschekia churaumi n. sp. , female, holotype NSMT–Cr 20907. 70, leg 1, anterior view; 71, leg 2, anterior view; 72, intercoxal sclerite of leg 1, anterior view; 73, intercoxal sclerite of leg 2, anterior view; 74, leg 3; 75, leg 4. Scale bars: 70–73, 20μm; 74–75, 10μm. Attachment site. Gill filaments. Remarks. Hatschekia churaumi n. sp. shares the presence of 4 processes on the intercoxal sclerites of legs 1 and 2 with 10 species (see remarks of H . hemicyclium ) and 4 new species (i.e. H . hemicyclium n. sp. , H . izenaensis n. sp. , H . jonesi n. sp. and H . kabatai n. sp. ). The new species lacks the distinct apex on the cephalothorax present in H . balistae and differs from H . bibullae , H . cylindrus , H . hemicyclium n. sp. , H . izenaensis n. sp. , H . jonesi n. sp. , H . kabatai n. sp. , H. khahajya , H . kuroshioensis , H . monacanthi and H . ostracii in having 10 setae on the proximal segment of the antennule and in the spatulate shape of the 4 processes on the intercoxal sclerites of legs 1 and 2. Hatschekia lima and H . sunaoi both have 10 setae on the proximal segment of the antennule but differ from the new species in having 4 pointed, non-spatulate processes on the intercoxal sclerites of legs 1 and 2. In addition, the new species can also be separated from these two species by having 2 setae on the endopods of legs 1 and 2, instead of 4–5. Etymology. The specific name of the new species, churaumi , is a dialect of Okinawa, referring to the beautiful ocean around the Ryukyu Islands.