Elthusa parva (Richardson, 1910) Richardson, 1910

Hadfield, Kerry A., Bruce, Niel L. & Smit, Nico J., 2016, Redescription of poorly known species of Ceratothoa Dana, 1852 (Crustacea, Isopoda, Cymothoidae), based on original type material, ZooKeys 592, pp. 39-91 : 67-69

Taxon classification Animalia Isopoda Cymothoidae

Elthusa parva (Richardson, 1910) comb. n. Figure 12

Meinertia parva Richardson, 1910: 21, fig. 20.

Codonophilus parvus .- Nierstrasz 1931: 132.

Ceratothoa parva .- Trilles 1994: 127.

Material examined.

Holotype. United States National Museum, USA (USNM 40938) - female (19 mm TL; 8.5 mm W), collected from Opol, Mindanao, Philippines, 4 August 1909, host unknown ( Richardson 1910).

Remarks.

Ceratothoa parva was originally described as having distinct eyes; rounded anterolateral processes on pereonite 1 which extend half the length of the cephalon; and short uropods which do not reach the end of the pleotelson.

Examination of the holotype revealed many characters not usually present in Ceratothoa . Pleonite 1 is as wide as the other pleonites (usually narrower), pleonite 4 is slightly wider than pleonite 5, slender and short antennae, and, most significantly, the bases of the antennae do not touch (a defining characteristic of Ceratothoa ). These characters, together with the shape of the head and pereopod morphology all agree well with the generic characters for Elthusa Schioedte & Meinert, 1884 (see Bruce 1990), and the species is here placed in that genus.