Paracalliacidae Sakai, 2005

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 128-129

Paracalliacidae Sakai, 2005

Figure 20

Paracalliacinae Sakai, 2005b: 215.

Paracalliacidae .— Dworschak and Poore, 2018: 70.

Diagnosis. Rostrum flat, short, triangular, shorter than eyestalks; median carina on rostrum only; submedian gastric carinae absent; cervical groove well defined; suture between ocular lobe and end of linea thalassinica horizontal in lateral view; anterior branchiostegal margin sinusoidal or semicircular; anterior branchiostegal lobe simple, scarcely calcified, merging smoothly with anterodorsal branchiostegal angle and anterolateral margin of carapace; posterior margin of carapace with lateral lobes interacting with anterolateral lobes on pleomere 1. Eyestalks flattened, contiguous, with subdistal dorsal cornea. Antennal scaphocerite simple, triangular. Maxilla scaphognathite without long seta on posterior lobe extending into branchial chamber. Maxilliped 1 epipod with acute anterior lobe lying alongside exopod. Maxilliped 3 propodus longer than wide, not prominently lobed on lower margin; dactylus slender, digitiform, with setae irregularly spaced along all margins. Cheliped merus lower margin spinose; major cheliped palm oval in cross-section, barely crested above or below. Pereopod 3 propodus elongate-oval, tapering, without proximal lobe on lower margin, without distal spiniform setae on lateral face (often with 1 distal spiniform seta on lower margin). Pereopod 5 minutely chelate or subchelate. Female pleopod 2 rami similar to following pleopods, with regularly setose margins. Pleopods 3–5 with oblique peduncles meeting mesially, endopods triangular, with straight mesial margin, exopods attached laterally, proximally lobed, longer than and enclosing endopods; appendices internae elongate, much longer than wide. Uropodal exopod without elevated dorsal plate.

Remarks. The only species differs from all other callianassoids in having pleomere 1 with dorsolateral lobes interacting and overlapping the posterolateral margin of the carapace (fig. 20a; Dworschak and Poore, 2018; Robles et al., in press). Pleopod 2 is similar to pleopods 3–5 (figs 20d, e). The uropodal exopod lacks a dorsal plate (fig. 20b) and maxilliped 3 is exceptionally narrow (fig. 20c). The male is not known.

Manning and Felder (1991) included the only genus Paracalliax in Ctenochelidae . The subfamily was erected as member of Callianassidae by Sakai (2005b) who was uncertain about its affinities (not in Gourretiidae as he asserted later [ Sakai, 2011]). The family was ignored by Sakai (2011) and Sakai et al. (2015) who treated the genus as part of Gourretiidae despite treating most other basal groups as distinct families. Sakai (2017a) also included the genus in Gourretiidae but considered it a possible synonym of one of three new gourretiid genera erected at the time.

Figures

Figure 20. Diagnostic characters for Paracalliacidae, Paracalliax bollorei: a, posterior carapace, pleomeres 1, 2; b, telson, uropod; c, maxilliped 3; d, e, female pleopods 1, 2.