Mothocya lineata (Miers, 1876) Miers, 1876

Martin, Melissa B., Bruce, Niel L. & Nowak, Barbara F., 2015, Review of the fish-parasitic genus Ceratothoa Dana, 1852 (Crustacea: Isopoda: Cymothoidae) from Australia, with description of two new species, Zootaxa 3963 (3), pp. 251-294 : 285

Mothocya lineata (Miers, 1876) comb. nov.

Ceratothoa lineata Miers, 1876a: 227 ; 1876b: 105, pl. III, fig. 1.— Filhol, 1885: 448.— Thomson & Chilton, 1886: 153.— Thomson, 1889: 263.— Stebbing, 1902: 58.— Collette, 1974: 19.— Avdeev, 1982a: 65; 1982b: 69.—Beumer, Ashburn, Burbury, Jetté & Latham, 1983: 31.— Trilles, 1994: 122.

Meinertia lineata .— Hutton, 1904: 262.

Codonophilus lineatus .— Nierstrasz, 1931: 132.— Hurley, 1961: 268, 284.— Hewitt & Hine, 1972: 83, 94, 108.— Hine, Jones & Diggles, 2000: 79.

Irona melanosticta .— Stephenson, 1969: 427, figs. 1–20; 1976: 167.— Hewitt & Hine, 1972: 94, 108.

Mothocya ihi Bruce, 1986: 1166 , figs. 47.

Excluded (identity not known)

Meinertia lineata .— Avdeev, 1978b: 281 –282.

Types and type locality. The holotype is deposited at the Natural History Museum, London ( Miers (1876a; BMNH 1845.61) collected in New Zealand ( Hadfield 2012). The holotype of Mothocya ihi Bruce, 1986 is held at the Auckland Institute and Museum (AIM 5370), from the host Hyporhamphus ihi Phillipps, 1932 in New Zealand. Hadfield (2012) described and figured the holotype of Ceratothoa lineata Miers, 1876 .

Remarks. Mothocya lineata ( Miers, 1876a) has a rounded cephalon anterior margin; narrow body with large coxae on pereonites 5–7; pleon as wide as pereon; rounded pleotelson; and uropods that are elongate and extend to the posterior margin of the pleotelson ( Hadfield 2012).

This species is known only from Hyporhamphus ihi and is the only known buccal-attaching species within the genus Mothocya . It comes to no surprise that the site attachment and the unique elongate body shape shows convergences to that of other buccal-attaching genera ( Bruce 1986), in this case, the species previously synonymised with Ceratothoa . The large rounded coxae (with coxae 5–7 dorsally visible), evenly rounded pleotelson, pleon to a greater degree immersed in pereonite 7 ( Bruce 1986) are typical characters of Mothocya , and agrees entirely with the description of Bruce (1986) for Mothocya ihi . The species, having previously been reported on Hyporhampus ihi confirms the identity of the species.

Avdeev (1978b) is the only Australian record of the species from four hosts. As no indication of the locality of the examined specimens, and knowledge that the species is known only from New Zealand from Hyporhamphus ihi , the species is excluded from Australian fauna.

Distribution. New Zealand ( Miers 1876a, 1876b; Thomson 1889). As the host is a species restricted to New Zealand waters, ( Collette 1974; Bruce 1986; Froese & Pauly 2013) previous Australian records by Avdeev (1978b) are here excluded.

Hosts. From the mouth of the garfish Hyporhamphus ihi (previously Reporhamphus ihi ) ( Hewitt & Hine 1972; Hine et al. 2000; Bruce 1986). As the species is host-specific to Hyporhamphus ihi , records from other host are probably misidentifications and here excluded from the synonymy: from the mouth of a “gaurd (gar?) fish” ( Thomson 1889); throat of butterfish Odax pullus (J. R. Forster, 1801) (previously Coridodax pullus ); from mouth cavity of blue warehou Seriolella brama (Günther, 1860) and Pagrosomus sp. (see Avdeev 1978b).