Elthusa samariscii ( Shiino, 1951 )

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 samariscii ( Shiino, 1951)

Livoneca samariscii Shiino, 1951: 81 , 86, fig. 5.

Elthusa samariscii .— Bruce, 1990: 254, 287.—Biju Kumar & Bruce, 1999: 780–787, figs 1–4.

Lironeca samariscii .— Trilles, 1994: 190.

Type and type locality. Whereabouts the type material for these species remains unknown. Shiino (1951) stated that the type locality is Kochi , Japan .

Remarks. Elthusa samariscii can be distinguished by the cephalon with anterior margin rounded, not produced; pleonite 1 obviously shorter and narrower than pleonite 2; pleotelson rounded; pereopod dactyli all short, subequal in length to propodi; posterior pereopods without carina on basis and uropodal rami subequal in length, not reaching posterior margin of pleotelson, apices bluntly rounded.

There is no species obviously closely allied to E. samariscii , but the narrowed pleonite 1 is a character that does separate it from most other species of the genus where this character has been clearly recorded. Of the Australian species ( Bruce 1990) only Elthusa turgidula ( Hale, 1926) has this character state, but that species has the anterior margin of the head produced and truncate, and the posterior pereopods with a carinate basis.

Distribution. Recorded from the Japan ( Shiino 1951) and India (Biju Kumar & Bruce 1999).

Hosts. Known only from the family Samaridae : Samariscus japonicus Kamohara, 1936 ( Shiino 1951) and Samaris cristatus Gray, 1831 (Biju Kumar & Bruce 1999).