Aqaballianassa Poore, Dworschak, Robles, Mantelatto and Felder, 2019

Poore, Gary C. B., 2023, New records, one new genus and 21 new species of Callianassidae (Crustacea, Axiidea) from the Indo-West Pacific, Memoirs of Museum Victoria 82, pp. 167-255 : 168-170

Aqaballianassa Poore, Dworschak, Robles, Mantelatto and Felder, 2019

Aqaballianassa Poore et al., 2019: 90–91 .— Robles et al., 2020).—

Poore and Ahyong, 2023: 211.

Remarks. Aqaballianassa is recognised primarily by the presence of a branchiostegal sclerite isolating the anterodorsal corner of the branchiostegite (Dworschak, 2003; Poore et al., 2019). The mandibular molar seems characteristic of this genus only (fig. 3l, m); it is calcified with a swollen molar process lacking a sharp edge and an incisor with few teeth ( Poore et al., 2019). Poore et al. (2019) recognised eight named species ( Table 1), some rather poorly described and not easily differentiated. Robles et al.’s (2020) molecular phylogram included three named species and another as Aqaballianassa PNG-116. The identity of the last was supported by sequences from four individuals and is described here as A. papua sp. nov. Another new species, not part of the molecular study, A. seychellensis sp. nov., is also described.

Species of Aqaballianassa are differentiated largely on the shapes of the eyestalk, rostrum and anterior carapace margin, telson and uropod, and extent of the cervical groove. Descriptions of some nominal species are incomplete.

Aqaballianassa contains both gonochoristic and hermaphroditic species. Both sexes of A. lewtonae are known, males and females having different pleopods 1 and 2. All specimens of A. papua have female gonopores on the coxae of pereopod 3; all including the ovigerous individual have male gonopores on the coxae of pereopods 5. Dworschak (2003) labelled the largest specimen of A. aqabaensis a male but noted the presence of gonopores on pereopods 3 and 5, leading him to call it “intersex”. This specimen has a uniarticulate pleopod 1 and a bud-like pleopod 2. His illustration of the chelipeds are similar to those of ovigerous “females” of A. lewtonae (fig. 3n) and A. papua . The male chelipeds of A. lewtonae (fig. 3g, h) show the dimorphism typical of many callianassids, a short carpus and gaping fingers. Pleopod 1 of A. lewtonae is uniarticulate, as in A. aqabaensis ; pleopod 2 is biramous, whereas it is bud-like in A. aqabaensis . All other species are known from one or few individuals identified as female.

A. aqabaensis (Dworschak, 2003) Red Sea and Gulf of Aden, Western Coral Triangle ( Jordan, Egypt, Philippines, Indonesia) A. brevirostris ( Sakai, 2002) Andaman ( Thailand, Singapore)

A. ehsani ( Sepahvand, Tudge and Momtazi, 2018) Somali /Arabian (Gulf of Oman)

A. lewtonae ( Ngoc-Ho, 1994) Northeast Australian Shelf, Eastern Coral Triangle (Qld, Australia; Papua New Guinea) A. nieli ( Sakai, 2002) Andaman ( Thailand)

A. papua sp. nov. Eastern Coral Triangle ( Papua New Guinea)

A. seychellensis sp. nov. Western Indian Ocean ( Seychelles)

A. spinoculata ( Sakai, 2005) Sunda Shelf ( Malaysia)

A. thorsoni ( Sakai, 2005) Somali /Arabian (Persian Gulf)