Hatschekia churaumi, Uyeno, Daisuke & Nagasawa, Kazuya, 2010

Uyeno, Daisuke & Nagasawa, Kazuya, 2010, 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, Zootaxa 2478, pp. 1-40 : 16-18

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:

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.

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.

Figures

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, 100 μm; 63 – 64, 68 – 69, 20 μm; 67, 10 μm.

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, 20 μm; 74 – 75, 10 μm.