Pereionotus hirayamai, Coleman, Oliver & Lowry, James K., 2012

Coleman, Oliver & Lowry, James K., 2012, The genus Pereionotus (Crustacea, Amphipoda, Phliantidae) from Australia, Zootaxa 3486, pp. 63-88 : 86

Pereionotus hirayamai sp. nov.

Palinnotus thomsoni japonicus Hirayama, 1987: 35 , figs 244–246.

Material examined. Holotype, male, 7.0 mm, paratypes, 6 specimens, May, 1978, AMBL-Amph. 98.

Type locality. Tomioka Bay, Japan.

Etymology. This species is named after the Japanese taxonomist, Akira Hirayama.

Diagnosis. Dorsal keel on pereonites 1–7 very shallow. Antenna 1 peduncular article 2 longer than wide. Coxae 1–4 with very few short setae on the distal margins of. Pereopods 1–7 propodi without additional robust setae half-way on posterior and anterior margins.

Remarks. Hirayama (1987) originally called this species Palinnotus thomsoni japonicus , not knowing that Tzvetkova (1967) had already used the name and thus creating a junior homonym. We raise the subspecies to species status, and at the same time, give it the new name, Pereionotus hirayamai .

Coleman (2009b) pointed out that P. t. japonicus was probably an undescribed species due to many differences to the Australian material.

Hirayama (1987) considered that compared with P. t h o m s o n i: the propodus of gnathopod 1 is less setose; coxa 4 is prominently extended posteromedially; the peduncle of uropod 2 is lacking the inner triangular expansion; the inner plate of maxilla 1 is prominently smaller; the distal protrusion of peduncular article 1 of antenna 1 is more pronounced; and the protrusions on the head, pereon and pleon are more developed.

Unlike Hirayama (1987) we consider these to be species level differences. Because P. japonicus ( Tzvetkova, 1967) is already in use, we are giving this species the name P. h ir a y a m a i.