Bellorchestia Serejo & Lowry, 2008

Lowry, J. K., 2012, Talitrid amphipods from ocean beaches along the New South Wales coast of Australia (Amphipoda, Talitridae), Zootaxa 3575, pp. 1-26 : 2

Bellorchestia Serejo & Lowry, 2008

Type species. Bellorchestia richardsoni Serejo & Lowry, 2008 , original designation.

Included species. Bellorchestia includes 9 species:? B. chathamensis ( Hurley, 1956) ; B. kirki ( Hurley, 1956) ; B. mariae sp. nov.; B. marmorata ( Haswell, 1880) ; B. pravidactyla ( Haswell, 1880) ; B. quoyana (Milne-Edwards, 1840) ; B. richardsoni Serejo & Lowry, 2008 ; B. spadix ( Hurley, 1956) ; B. tumida ( Thomson, 1885) .

Diagnostic description (based on male). Eyes medium (1/5 to 1/3 head length). Antenna 1 short, not longer than article 4 of antenna 2 peduncle. Antenna 2 peduncular articles well developed, incrassate; peduncular article 3 without ventral process. Labrum with robust setae. Mandible left lacinia mobilis 5-dentate. Maxilliped palp article 2 distomedial lobe well developed; article 4 reduced, button-shaped. Gnathopod 1 sub or parachelate; posterior margin of propodus with lobe covered in palmate setae. Gnathopod 2 subchelate; merus and carpus free; dactylus not modified distally. Pereopods 3–7 cuspidactylate. Pereopods 5–7 without setae along posterior margin of the dactylus. Pereopods 6–7 sexually dimorphic, without row of short setae along posterior margin of dactyli. Pleonites 1–3 without dorsal spines. Pleopods all well developed. Epimera without vertical slits. Uropod 1 rami without apical spear-shaped setae; outer ramus slender; with marginal robust setae. Uropod 3 well developed; ramus subequal to or longer than peduncle. Telson apically incised, with 7–10+ robust setae per lobe.

Remarks. A number of taxa in the genus Bellorchestia are still poorly known. Bellorchestia chathamensis ( Hurley, 1956) should be placed in a new genus mainly because it has a well developed palmate lobe on the carpus of male gnathopod 2. Bellorchestia kirki ( Hurley, 1956) is poorly described. It remains in Bellorchestia based on Hurley’s indications that it is very similar to B. tumida . Other taxa, such as B. marmorata ( Haswell, 1880) and B. pravidactyla ( Haswell, 1880) are badly in need of redescription.

Bellorchestia belongs in the Orchestia group of talitrids ( Lowry & Coleman 2012) that contains genera with robust setae on the outer ramus of uropod 1, a 5-dentate lacinia mobilis and more that 7 robust setae on each lobe of the telson. However, robust setae on the labrum of the upper lip, a palmate lobe only on the propodus of male gnathopod 1 and sexually dimorphic pereopods 6–7, makes it is difficult to align Bellorchestia with other genera in the Orchestia group.