Axius Leach, 1815

Poore, Gary C. B. & Collins, David J., 2009, Australian Axiidae (Crustacea: Decapoda: Axiidea), Memoirs of Museum Victoria 66 (2), pp. 221-287 : 242-244

Axius Leach, 1815

Axius Leach, 1815: 343 .— Sakai and de Saint Laurent, 1989:

26.— Ngoc-Ho, 2003: 447.

Remarks. Axius was diagnosed most recently by Ngoc-Ho (2003). Three species are known, the type species, A. stirhynchus Leach, 1815 , from the eastern North Atlantic ( Ngoc-Ho, 2003) and two from the western North Atlantic, A. serratus Stimpson, 1852 , and A. armatus Smith, 1881 ( Kensley, 2001). Species of Axius are recognised by having a triangular, laterally armed rostrum, undifferentiated supraocular spine, unarmed submedian gastric carina anteriorly flexed towards the midline, uropodal exopod with a transverse suture, pleurobranchs present above pereopods 2–4 and sometimes 5, male pleopod 1 present, and pleopods 2–5 with an appendix interna. We confirmed Ngoc-Ho’s (2003) observation that the male pleopod 1 of A. stirhynchus is simple but with an obsolete suture between two articles and a ridge that hints at an obsolete appendix interna (fig. 14a). Kensley reported for A. serratus the “pleopod 1 in both sexes consisting of single slender setose ramus.” We include Axiopsis (Axiopsis) werribee Poore and Griffin, 1979 (and possibly another species, see below) in this genus, the only ones outside the North Atlantic.

Sakai and de Saint Laurent (1989) listed Axiopsis australiensis as a member of Axius but this species lacks a male pleopod 1 and appendix masculina and possesses more complex gastric armature. It is here redescribed in a new genus, Michelaxiopsis gen. nov.