Callianidea H. Milne Edwards, 1837

Callianidea H. Milne Edwards, 1837: 319 (see Poore 1997: 349, Sakai 2011: 198 and Sakai et al. 2014: 495 for extensive synonymy)

Type species. Callianidea typa H. Milne Edwards, 1837 (monotypy, confirmed by ICZN 1989: 61, 62).

Diagnosis. Gonochoristic. Rostrum obsolete. Linea thalassinica absent. Thoracic sternite 7 with narrow anterior part, slightly separating cushion-like coxae of pereopods 4. Pleomere 1 tergite with strongly domed and narrow anterior part. Eyestalks flattened, contiguous, each with truncate apex; weakly pigmented cornea dorsal. Antennal scaphocerite minute and articulating. Maxilliped 3 exopod reaching at least as far as end of ischium, with toothed crista dentata, ischium and merus with rows of simple tapering setae. Pereopods 1 dissimilar, minor cheliped cylindriform. Pereopod 3 propodus about as long as broad, with distal spiniform seta. Pereopod 4 propodus with distal spiniform seta. Pereopod 5 subchelate, fixed finger with distal row of spiniform setae. Setal-rows on anterolateral carapace, pleomeres 1 and 6. Male pleopod 1 present, appendix interna thumb-like, slightly projecting. Pleopod 2 of male without appendix masculina, with small digitiform appendix interna. Pleopods 2–5 rami with tubular segmented marginal filaments, branching or not. Uropodal endopod without transverse row of short spiniform setae; exopod ovate, without dorsal plate.

Included species. Callianidea madagascariensis Sakai, 2011; C. typa H. Milne Edwards, 1837 .

Remarks. The type species was described in detail by Poore (1997). Dworschak (2014) illustrated variation in the development of the male pleopod 1, where the appendix interna ranges from absent through a small lobe to a digitiform thumb. Poore (1997) and others (e.g., Dworschak 2014) described the male pleopod 2 as having a reduced appendix interna and no appendix masculina. The appendix interna of pleopod 2 of the male and female are reillustrated here (Figs 4 a, b). Sakai (1992) agreed with this but described both structures as free and well developed on another specimen (SMF 7936) (Sakai 2011: fig. 40D). Re-examination of the SMF specimen by Peter Dworschak (pers. comm., 28 Jan 2015) and of another by me (NMV J34096, male cl. 12.7 mm, Djibouti) failed to find free appendices and confirm the earlier observations. The spiniform setae on the fingers of pereopod 5 are figured here (Fig. 4 c).

Sakai’s (2011) generic diagnosis is wrong on three counts: the linea thalassinica is absent (not short), a spine may be present on the merus of maxilliped 3, and the male pleopod 2 appendices are not as he described.

The specimen diagnosed and illustrated by Poore (1997: 354, figs 4D–I) as ‘ Callianidea sp.’ was named C. madagascariensis by Sakai (2011). Dworschak (2014) synonymised C. ryukyu Sakai, 2011 with C. typa .