Hatschekia jonesi, 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 : 7-10

Hatschekia jonesi n. sp.

( Figs 16–29 )

Type material. Holotype, female ( NSMT –Cr 20901), ex Sufflamen bursa (Bloch & Schneider) ( Tetraodontiformes : Balistidae ), off Cape Maeda (26°26’N, 127°46’E), Okinawa-jima Island, the Ryukyu Islands, East China Sea, Japan, 2 September 2005. Paratypes: 6 females ( NSMT –Cr 20902), ex S. bursa , off Cape Maeda (26°26’N, 127°46’E), Okinawa-jima Island, the Ryukyu Islands, East China Sea, Japan, 2 September 2005.

Other material examined. 5 females ( RUMF –ZC–00922), ex S. fraenatum (Latreille) , off Chatan (26°19’N, 127°44’E), Okinawa-jima Island, the Ryukyu Islands, East China Sea, Japan, 9 December 2005.

Description of female. Body ( Fig. 16 ) 837–1034 (902 ± 61) long, excluding caudal rami (n = 12). Cephalothorax round, slightly shorter than wide [175–220 (195 ± 16) × 212–276 (236 ± 20)], with dorsal, Mshaped chitinous frame. Trunk rod-like, longer than wide [666–818 (711 ± 47) × 166–198 (182 ± 12)], widest in anterior ¼. Urosome ( Fig. 17 ) excluding caudal ramus shorter than wide [34–49 (42 ± 5) × 58–80 (69 ± 7)]. Genital complex fused to abdomen without border. Caudal ramus ( Fig. 17 ) slightly longer than wide [15–28 (20 ± 4) × 10–17 (13 ± 2)], bearing 5 naked setae.

Rostrum expanded anteriorly with 1 round process on each posterolateral corner ( Fig. 18 ). Antennule ( Fig. 18 ) indistinctly 5-segmented, 138–166 (146 ± 9) long; armature formula: 9, 5, 4, 1, 13 + 1 aesthetasc. Antenna ( Fig. 19 ) 3-segmented; proximal segment (coxa) unarmed; middle segment (basis) ornamented with surface pits; terminal claw bearing 1 basal seta; proximal segment length 41–50 (39 ± 16); middle segment length 101–135 (99 ± 42); terminal claw length 25–32 (24 ± 10); total length 169–210 (162 ± 67). Parabasal papilla ( Fig. 20 ) well developed, wrinkled, extending to mid-lateral level of cephalothorax and visible from dorsal side. Oral cone robust. Mandible ( Fig. 21 ) slender, with 4 sharp apical teeth. Maxillule ( Fig. 22 ) bilobate; both lobes armed with 2 tapering elements; 2 elements on inner lobe swollen. Maxilla ( Fig. 23 ) 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 24–25 ) biramous, with exopods composed of 2 indistinct segments and 2–segmented endopods; leg armature formula as follows:

Leg 1 ( Fig. 24 ) 87–105 (93 ± 6) long; protopod length 44–59 (50 ± 4); exopod length [39–46 (42 ± 2)] exceeding endopod length [24–36 (29 ± 3)]. Leg 2 ( Fig. 25 ) length 94–114 (102 ± 7); protopod length 57–69 (64 ± 4); exopod length 35–45 (38 ± 3); endopod length 45–56 (51 ± 3). Both exopods and protopod of leg 2 ornamented with rows of blunt spinules on anterior surface. Endopod of leg 2 broad.

Intercoxal sclerites of legs 1 and 2 ( Figs 26–27 ) bearing 4 processes.

Leg 3 ( Fig. 28 ) represented by 2 simple setae on small conical process at anterior mid-lateral surface of trunk. Leg 4 ( Fig. 29 ) represented by 1 simple lateral seta on posterior ¾ of trunk.

Variability of measurement. Specimens used as “other materials” did not show remarkable differences in meristic characters. Measurements of body parts and appendages as follows: body length 598–874 (779 ± 105), cephalothorax length 126–199 (180 ± 31), cephalothorax width 187–224 (210 ± 41), trunk length 472– 690 (603 ± 80), trunk width 125–227 (199 ± 42), abdomen length 28–46 (38 ± 7), abdomen width 49–74 (65 ± 10), caudal ramus length 17–23 (20 ± 3), caudal ramus width 9–13 (12 ± 2), antennule length 110–160 (141 ± 20), antenna proximal segment length 28–44 (39± 7), antenna middle segment length 57–92 (80 ± 16), antenna terminal segment length 18–35 (26 ± 6), antenna total length 103–163 (145 ± 25), leg 1 length 58–84 (76 ± 11), leg 1 protopod length 34–52 (44 ± 8), leg 1 exopod length 24–38 (33 ± 5), leg 1 endopod length 18– 29 (26 ± 4), leg 2 length 58–92 (80 ± 14), leg 2 protopod length 37–60 (53 ± 9), leg 2 exopod length 21–32 (27 ± 5), leg 2 endopod length 23–38 (31 ± 6).

Attachment site. Gill filaments.

Remarks. Hatschekia jonesi n. sp. also has 4 processes on the intercoxal sclerites of legs 1 and 2. These processes are shared with 10 species (see remarks for H. hemicyclium ) and one new species, namely H.

hemicyclium n. sp. Hatschekia jonesi n. sp. is distinguishable from 7 species ( H. balistae , H. bibullae , H. cylindrus , H. khahajya , H. kuroshioensis , H. monacanthi and H. pseudostracii ) by having leg 3 located on a small conical process. Even though the base of leg 3 was not described for H. balistae it can be separated from the new species by the presence of an apex on the cephalothorax. Hatschekia hemicyclium n. sp. differs from the new species as follows: leg 2 with the exopod longer than the endopod, a considerably higher leg 2 exopod length/endopod length ratio [1.39 ± 0.16 vs. 0.80 ± 0.08 (U-test; p <0.001), Table 1], a smaller parabasal papilla, leg 3 represented by setae on a small papilla, and leg 2 with a broad endopod. Hatschekia lima is distinguishable from the new species by having 4 setae on the distal tip of the endopod of leg 1 and the maxillule with a highly sclerotized inner lobe while H. sunaoi is differentiated from the new species by having a distinctly higher antenna length/body length ratio [0.40 ± 0.03, vs. 0.18 ± 0.06 (U-test; p <0.001), Table 1, see also table 1 in Uyeno & Nagasawa 2009b] and by not having a well-developed parabasal papilla ( Uyeno & Nagasawa 2009b).

Etymology. The specific name of the new species, jonesi , honors Dr. J. B. Jones who has greatly contributed to the taxonomy of the genus Hatschekia .

Figures

FIGURES 16 – 23. Hatschekia jonesi n. sp., female, holotype NSMT – Cr 20901. 16, habitus dorsal; 17, posterior part of trunk, dorsal; 18, antennule, ventral, rp = rostrum process (drawn from a paratype, NSMT – Cr 20902); 19, antenna, ventral. (drawn from a paratype, NSMT – Cr 20902); 20, antenna with parabasal papilla (drawn from a paratype, NSMT – Cr 20902); 21, mandible (drawn from a paratype, NSMT – Cr 20902); 22, maxillule; 23, maxilla. Scale bars: 16, 200 μm; 17 – 19, 23, 40 μm; 20, 22, 20 μm; 21, 10 μm.

FIGURES 24 – 29. Hatschekia jonesi n. sp., female, holotype NSMT – Cr 20901. 24, leg 1, anterior view; 25, leg 2, anterior view; 26, intercoxal sclerite of leg 1, anterior view; 27, intercoxal sclerite of leg 2, anterior view; 28, leg 3, ventral; 29, leg 4, ventral. Scale bars: 24 – 27, 30 μm; 28 – 29, 10 μm.