Hircella Mayer, 1882

Takeuchi, Ichiro & Lowry, James K., 2015, A taxonomic study on the Phtisicidae (Crustacea: Amphipoda) of New South Wales, Australia, Journal of Natural History 50, pp. 603-648 : 616

Genus Hircella Mayer, 1882

Diagnosis

Head fused with pereonite 1. Antenna 1 well developed, flagellum with more than two articles; accessory flagellum absent. Antenna 2 well developed; flagellum with two or three articles. Mandible well developed; molar absent; palp 3-articulate; palp setal formula 0 – x – 1. Maxilliped well developed; inner plate (basal endite) larger than outer plate (ischial endite); palp article 3 without distal projection; palp article 4 well developed. Pereonite 4 clavate appendage absent. Pereonites 6 and 7 not fused. Pereopod 3 absent. Pereopod 4 absent. Pereopod 5 present with one article. Pereopods 6 and 7 well developed, with seven articles. Gills on pereonites 2 to 4. Pleopods absent. Uropods 2 pairs; uropod 1, uniramous; uropod 2, uniramous. Telson (dorsal lobe) present.

Type species

Caprella cornigera Haswell, 1879b , monotypy.

Included species

Hircella includes three species: Hircella berentsae Guerra-García, 2006 ; Hircella cornigera ( Haswell, 1879b) ; Hircella inermis Guerra-García and Takeuchi, 2004 .

Remarks

The genus Hircella was established specifically for H. cornigera ( Haswell, 1879b) by Mayer (1903). Recently, Guerra-García and Takeuchi (2004) described the second species of Hircella , H. inermis Guerra-García and Takeuchi, 2004 from the Tasmanian coast. Mayer (1903) mentioned that pereopod 5 of Hircella was completely degenerate, and the diagnosis of Takeuchi (1993) followed his conclusion. Since the type specimen deposited in the Australian Museum is lost ( Springthorpe and Lowry 1994), this new diagnosis is based on recently collected specimens from the Solitary Islands, New South Wales. Observation revealed that pereopod 5 is composed of one tiny article and the number of articles in the flagellum of antenna 2 increases from two to three during growth (see Figure 10 ). Hence, the generic diagnosis of the present genus is revised as above.

Figures

Figure 10. Hircella cornigera (Haswell, 1879b) from Solitary Islands, Coffs Harbour, and out of Jervis Bay, New South Wales. Number of articles in the flagellum of antenna 2 against the body length.