Elthusa propinqua ( Richardson, 1904 )

Ravichandran, S., Vigneshwaran, P. & Rameshkumar, G., 2019, A taxonomic review of the fish parasitic isopod family Cymothoidae Leach, 1818 (Crustacea: Isopoda: Cymothooidea) of India, Zootaxa 4622 (1), pp. 1-99 : 25

Elthusa propinqua ( Richardson, 1904)

Lironeca propinqua Richardson, 1904: 37 , figs 6 , 7.—Richardson, 1909: 87; 1910: 23.— Thielemann, 1910: 42.— Nierstrasz, 1931: 43.— Barnard, 1936: 170.

Elthusa propinqua . — Bruce, 1990: 262–263, figs 8, 9 .— Saito & Yamauchi, 2016: 64.— Kazmi, Schotte & Yousuf, 2002: 102, fig. 85.

Type and type locality. The three female syntypes are held at the Smithsonian Institution, Washington, USA ( USNM 29086). Richardson (1904) states Port Heda, Japan as the locality from which his specimens originated.

Remarks. Elthusa propinqua has been taken only from moderately deep water, and can be identified by the short cephalon (with moderately large eyes) with an acute rostral point, wide pleon, short uropods, close set antennulas and the distinctive basis on pereopods 4–7.

Two species show some similarity to E. propinqua : Elthusa caudata ( Schiöedte & Meinert, 1884) and Elthusa myripristae Bruce, 1990 . Elthusa propinqua can be separated from both these species by having having pleonite 1 partially concealed in dorsal view by pereonite 7 and all coxae shorter than respective segment. Elthusa caudata lacks the acute rostral point, but little else is known of this species. Elthusa myripristae has pleonite 1 totally concealed in dorsal view by pereonite 7, and by the much smaller coxae on pereonites 4–7.

Distribution. Elthusa propinqua reported from several localities in Japan and the Philippines ( Richardson 1904, 1909), eastern Australia ( Bruce 1990) and Lakshadweep Island in India ( Barnard, 1936).

Hosts. This species recorded from “chalinura” (Richardson 1909) in Japan, “a macrurid” ( Richardson 1910) in the Philippines, and from the gills of Macrurus sp. in India ( Barnard 1936). Latter, Bruce (1990) recorded this species from Ventrifossa cf. nigrodorsalis family Macrouridae .

Figures

FIGURE 6. Nerocila depressa Milne Edwards, 1840, female (30 mm), (ZSI/MBRC D1-541). a, dorsal view; b, lateral view; c, forns; d, antennula; e, antenna; f, mandible; g, maxillula; h, maxilla; i, maxilliped.

FIGURE 9. Nerocila loveni Bovallius, 1887, female (20 mm), (ZSI/MBRC D1-544). a, dorsal view; b, lateral view; c, forns; d, uropod.