Callianidea H. Milne Edwards, 1837

Poore, Gary C. B., 2015, Rediagnosis of Callianideidae and its genera (Crustacea: Decapoda: Axiidea), and description of a new species of Heardaxius Sakai, 2011, Zootaxa 3995 (1), pp. 229-240 : 232

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 .