Hatschekia mongarah, 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 : 24-28

Hatschekia mongarah n. sp.

( Figs 106–118 )

Type material. Holotype, female ( NSMT –Cr 20912), ex Balistoides conspicillum (Bloch & Schneider) ( Tetraodontiformes : Balistidae ), off Zamami-jima Island (26°13’N, 127°17’E), the Ryukyu Islands, East China Sea, Japan, 27 May 2006. Paratypes: 4 females ( NSMT –Cr 20913), ex B. conspicillum , off Yonagunijima Island (24°26’N, 123°1’E), the Ryukyu Islands, East China Sea, Japan, 8 July 2007; 3 females ( RUMF – ZC–00928) ex B. conspicillum , off Yonaguni-jima Island (24°26’N, 123°1’E), the Ryukyu Islands, East China Sea, Japan, 8 July 2007.

Description of female. Body ( Fig. 106 ) 723–853 (800 ± 43) long, excluding caudal rami (n = 8). Cephalothorax oval with flat anterior and posterior margins, shorter than wide [140–190 (165 ± 16) × 265– 307 (289 ± 16)], widest in anterior ½, with dorsal, M-shaped chitinous frame. Trunk fusiform, tapering posterior, longer than wide [575–672 (631 ± 33) × 202–248 (221 ± 14)] with protrusion near base of leg 2. Urosome ( Fig. 107 ) excluding caudal ramus shorter than wide [35–55 (41 ± 6) × 61–75 (70 ± 4)]. Genital complex fused to abdomen without border. Caudal ramus ( Fig. 107 ) slightly longer than wide [15–26 (21 ± 3) ×12–13 (12 ± 1)], bearing 5 naked setae.

Rostrum with 1 lobe-like process at each posterolateral corner ( Fig. 108 ). Antennule ( Fig. 108 ) indistinctly 5-segmented, 161–190 (179 ± 10) long; armature formula: 9, 5, 4, 1, 13 + 1 aesthetasc; some setae blunt, papilliform. Antenna ( Fig. 109 ) 3-segmented; proximal segment (coxa) unarmed; middle segment (basis) ornamented with surface pits; terminal claw with basal seta; proximal segment length 33–57 (43 ± 8); middle segment length 74–108 (95 ± 11); terminal claw length 23–44 (31 ± 6); total length 146–187 (169 ± 16). Parabasal papilla not observed. Oral cone robust. Mandible ( Fig. 110 ) slender, with 4 sharp apical teeth. Maxillule ( Fig. 111 ) bilobate; both lobes armed with 2 tapering elements. Maxilla ( Fig. 112 ) 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 113–114 ) biramous; both legs with exopod composed of 2 indistinct segments and 2- segmented endopod; leg armature formula as follows:

Leg 1 ( Fig. 113 ) 92–107 (97 ± 5) long; protopod length 51–57 (53 ± 2); exopod length 38–50 (43 ± 3); endopod length 21–34 (27 ± 4). Leg 2 ( Fig. 114 ) length 73–103 (91 ± 9); protopod length 44–63 (55 ± 6); exopod length 29–40 (35 ± 4); endopod length 31–43 (36 ± 5). Protopods of legs 1 and 2 ornamented with rows of blunt spinules on anterior surface. Both rami of legs 1 and 2 ornamented with semicircular membranes.

Intercoxal sclerites of legs 1 and 2 ( Figs 115–116 ) bearing 2 long and 2 short processes.

Leg 3 ( Fig. 117 ) represented by 2 simple setae on conical process at mid-lateral surface of trunk. Leg 4 ( Fig. 118 ) represented by 1 simple lateral seta on posterior ¾ of trunk.

Attachment site. Gill filaments.

Abbreviations: body length (BL), cephalothorax length (CeL), cephalothorax width (CeW), trunk length (TL), trunk width (TW), Urosome length excluding caudal ramus(UL), Urosome width (UW), caudal ramus length (CaL), and caudal ramus width (CaW), antennule length (A1L), antenna length (A2L), middle segment length of antenna (A2ML), terminal claw length of antenna* (A2TL), Leg 1 length (L1L), exopod length of leg 1 (L1ExL), endopod length of leg 1 (L1EnL), Leg 2 length (L2L), exopod length of leg 2 (L2ExL), and endopod length of leg 2 (L2EnL).

* This length was expressed as the “terminal segment length” in Uyeno & Nagasawa (2009a, 2009b).

Remarks. Hatschekia mongarah n. sp. shares the possession of 4 processes on the intercoxal sclerites of legs 1 and 2 with 10 species (see remarks of H. hemicyclium ) and 6 new species (i.e H. churaumi n. sp., H. hemicyclium n. sp., H. izenaensis n. sp., H. jonesi n. sp., H. kabatai n. sp. and H. zanpa n. sp.). In the new species, the location of leg 3 on a conical process is a character state which is shared with H. jonesi n. sp., H. lima , H. sunaoi and H. zanpa n. sp. Due to the inadequate original description ( Nuñes-Ruivo, 1954), it is unclear whether leg 3 of H. balistae is located on a conical process. Nevertheless, H. balistae can be distinguished from the new species by having a distinct apex on the cephalothorax. H. jonesi n. sp. is characterized by a well-developed parabasal papilla and the variable protrusions extending the mid-lateral line of the cephalothorax, whereas the new species lacks both these characters. H. lima differs from the new species by having the maxillule with a highly chitinized, inner lobe and an apex on the cephalothorax. H. sunaoi is distinguished from the new species in having a higher antenna length/body length ratio [0.40 ± 0.03 vs. 0.21 ± 0.02 (U-test; p <0.001), Table 2 , see also table 1 in Uyeno & Nagasawa 2009b] and a lower antenna length/antennule length ratio [0.66 ± 0.03 vs. 1.07 ± 0.12 (U-test; p <0.001), Table 2 , see also table 1 in Uyeno & Nagasawa 2009b]. H. zanpa n. sp. is characterized by the presence of lateral protrusions on the cephalothorax, a well-developed parabasal papilla and having the proximal segment of the antenna ornamented with small knobs. None of these characters are exhibited by the new species.

Etymology. The specific name of the new species, mongarah , is a Japanese vernacular name of the type host, Balistoides conspicillum .

Figures

FIGURES 106 – 112. Hatschekia mongarah n. sp., female, holotype NSMT – Cr 20912. 106; habitus dorsal; 107, posterior part of trunk, dorsal; 108, antennule, ventral, rp = rostrum process; 109, antenna, ventral; 110, mandible; 111, maxillule; 112, maxilla. Scale bars: 106, 100 μm; 107 – 109, 112, 20 μm; 110 – 111, 10 μm.

FIGURES 113 – 118. Hatschekia mongarah n. sp., female, holotype NSMT – Cr 20912. 113, leg 1, anterior view; 114, leg 2, anterior view; 115, intercoxal sclerite of leg 1, anterior view; 116, intercoxal sclerite of leg 2, anterior view; 117, leg 3; 118, leg 4. Scale bars: 113 – 116, 20 μm; 117 – 118, 10 μm.

Tables

TABLE 2. Ratios of body parts of females of Hatschekia fukurubi n. sp., H. mongarah n. sp., H. nakamurai n. sp., H. mihkagan n. sp. and H. pseudobalistesi n. sp. The data are shown as the mean ± standard deviation.

	H. fukurubi (n = 2)	H. mongarah (n = 8)	H. nakamurai (n = 6)	H. mihkagan (n = 12)	H. pseudobalistesi (n = 11)
CeL/BL CeW/BL	0.17 ± 0 0.21 ± 0	0.21 ± 0.01 0.36 ± 0.01	0.21 ± 0.02 0.24 ± 0.02	0.18 ± 0.01 0.23 ± 0.02	0.24 ± 0.01 0.29 ± 0.01
TL/BL	0.86 ± 0.03	0.79 ± 0.03	0.80 ± 0.02	0.83 ± 0.01	0.77 ± 0.01
TW/BL UL/BL	0.21 ± 0 0.02 ± 0	0.28 ± 0.01 0.05 ± 0.01	0.23 ± 0.02 0.06 ± 0.01	0.26 ± 0.03 0.03 ± 0.01	0.22 ± 0.01 0.06 ± 0.01
UW/BL	0.06 ± 0	0.09 ± 0	0.07 ± 0.01	0.05 ± 0.01	0.06 ± 0.01
CaL/BL CaW/BL	0.01 ± 0 0.01 ± 0	0.03 ± 0 0.02 ± 0	0.03 ± 0 0.02 ± 0	0.02 ± 0 0.01 ± 0	0.02 ± 0 0.01 ± 0
CeW/CeL	1.22±0.01	1.76 ± 0.09	1.16 ± 0.08	1.29 ± 0.08	1.21 ± 0.08
UL/UW A1L/BL	2.76 ± 0.31 0.08 ± 0.01	1.72 ± 0.15 0.22 ± 0.01	1.40 ± 0.24 0.18 ± 0.01	1.84 ± 0.36 0.08 ± 0.01	1.06 ± 0.08 0.21± 0.02
A2L/BL	0.08 ± 0	0.21 ± 0.02	0.21 ± 0.02	0.10 ± 0.01	0.32 ± 0.03
A2TL/A2ML L1L/BL	0.34 ± 0.10 0.04 ± 0.01	0.34 ± 0.10 0.12 ± 0.01	0.37 ± 0.07 0.09 ± 0.01	0.35 ± 0.04 0.06 ± 0.01	0.35 ± 0.04 0.11 ± 0.01