Lernanthropus pomadasysis Rangnekar & Murti, 1961

Boxshall, Geoff A., Bernot, James P., Barton, Diane P., Diggles, Ben K., Q-Y, Russell, Atkinson-Coyle, Toby & Hutson, Kate S., 2020, Parasitic copepods of the family Lernanthropidae Kabata, 1979 (Copepoda: Siphonostomatoida) from Australian fishes, with descriptions of seven new species, Zootaxa 4736 (1), pp. 1-103 : 72-73

Lernanthropus pomadasysis Rangnekar & Murti, 1961

( Fig. 10 C–D)

Material examined: 4♀♀, 1♂ from Pomadasys kaakan (Cuvier, 1830) , Bynoe Harbour , Northern Territory, 16 October 2014, collected by B.K. Diggles. 1♀, 1♂ MAGNT Reg. No. Cr-019247 . 1♀ QM Reg. No. W29498 , 2♀♀ (1 dissected) NHMUK Reg. No. 2018.228–229 .

Differential diagnosis: Cephalothorax wider than long, widest posteriorly and narrowing to medially pointed frontal margin, giving triangular outline in dorsal view ( Fig. 7C ); lateral margins of cephalothorax produced anteroventrally. Anterior part of trunk (second and third pedigerous somites) narrower than cephalothorax, becoming gradually wider towards posterior part (fourth pedigerous somite) covered by dorsal trunk plate. Dorsal trunk plate short and wide, with entire but irregularly-convex free posterior margin. Urosome comprising fifth pedigerous somite, genital complex and abdomen, all fused ( Fig. 7D ); genital complex ornamented with 2 pairs of sensillae on dorsal surface, abdomen with 1 pair. Paired caudal rami elongate; ramus about 2.2 times longer than wide; tapering towards blunt apex. Parabasal flagellum simple, cylindrical. Leg 3 forming fleshy outer lamella, splayed outwards at right angle to longitudinal axis of body, plus smaller inner lobe partly fused along midline to other member of leg pair. Leg 4 bilobate; inner and outer lobes subequal, distal 60% of both lobes protruding beyond free posterior margin of dorsal trunk plate. Leg 5 absent. Body length of ♀ ranging from 1.82 to 1.94 mm, with a mean of 1.87 mm (based on 4 specimens); body length of single ♂ 1.00 mm.

Distribution: This species was originally described from Pomadasys maculatus (Bloch, 1793) caught off Bombay in Indian waters ( Rangnekar & Murti, 1961). Subsequently Ho et al. (2008) reported it from P. kaakan landed in Taiwan. This is the first record of L. pomadasysis from Australian waters.

Remarks: Pillai (1985) relegated this species to synonymy with L. abitocephalus , which occurs on the same host ( P. maculatus ), but Ho et al. (2008) resurrected L. pomadasysis as a valid species after examining and redescribing material of both sexes collected from P. kaakan landed in Taiwan. They highlighted the differences between L. abitocephalus and L. pomadasysis in the shape of the cephalothorax and the shape and size of legs 3 and 4 (see Fig. 7 ). In L. pomadasysis the inner and outer lobes of leg 4 are about equal in length whereas in L. abitocephalus the inner (endopodal) lobe is markedly shorter than the outer (exopodal). These differences are consistent with the character states exhibited by these two species in Australian waters.

Figures

FIGURE 7. Lernanthropus abitocephalus Tripathi, 1962, adult ♀. A, habitus, dorsal; B, urosome plus caudal rami, dorsal. Lernanthropus pomadasysis Rangnekar & Murti, 1961, adult ♀. C, habitus, dorsal; D, urosome plus caudal rami, dorsal. Scale bars A, C, 0.5 mm; B,D, 200 μm.

FIGURE 10. Lernanthropus belones Krøyer, 1863, adult ♀. A, habitus, dorsal. Lernanthropus brevicornutus Kabata, 1979 adult ♀. B, habitus, dorsal. Lernanthropus tylosuri Richiardi, in Goggio, 1906, adult ♀. C, habitus, dorsal. [Figures modified from Cressey & Collette, 1970, Kabata, 1979a, and Ho & Do, 1985, respectively]. Lernanthropus brevicornutus Kabata, 1979, adult ♀, D. urosome and caudal rami, dorsal; E, leg 4; F, tip of exopod of leg 4; G, tip of endopod of leg 4. Adult ♂. H, habitus, dorsal. All scale bars 0.5 mm.