Baccadromia bullifera ( Alcock, 1900 ) Alcock, 1900

Mclay, Colin L. & Hosie, Andrew M., 2022, The sponge crabs of Western Australia and the Northwest Shelf with descriptions of new genera and species (Crustacea: Brachyura: Dromiidae), Zootaxa 5129 (3), pp. 301-355 : 316-318

Baccadromia bullifera ( Alcock, 1900) comb. nov.

( Figs. 8 , 9 )

Dromia (Cryptodromia) bullifera Alcock, 1900: 143 .

Cryptodromia bullifera . — Alcock, 1901: 51, pl. 2 fig. 9.— Borradaile, 1903: 577.— Laurie, 1906: 352.— Lenz, 1910: 562.— Ihle, 1913: 40.— Sakai, 1936: 23, pl. 7, fig. 3: 1976: 36, text fig. 8.— Ward, 1941: 1.— Gordon, 1950: 206.—Kensley, 1970: 107, text figs. 4a–c; 1981: 36.— Lewinsohn, 1977: 15, fig. 3; 1984: 111.— Guinot & Tavares, 2003: 57.

Cryptodromiopsis bullifera . — McLay, 1993: 189, fig. 17e.

Material examined. Western Australia: WAM C42521, Ningaloo Marine Park, off Osprey Reef , 40.5– 40 m, 22°10’04”S, 113°50’39”E to 22°10.01”S, 113°50’40”E, 11-05-2006: male 7.7 × 8.2 mm (damaged).

Description. Carapace as wide as long, evenly convex, covered in short tomentum, margins fringed with longer spatulate setae; branchial groove distinct but shallow; rostrum with 3 similar strong acute teeth, lateral teeth slightly divergent, median tooth on lower level; frontal groove extending posteriorly separating 2 low mounds; small, acute supraorbital tooth and strong postorbital and suborbital teeth visible dorsally; anterolateral margin distant from postorbital corner, shoulder-like, marking widest point, with strong tooth followed by smaller tooth close by; 2 tiny tubercles between postorbital corner and widest point, a little above the anterolateral margin; small posterolateral tooth behind branchial groove; subhepatic area with 2 prominent rounded smooth pearl-like tubercles, with similar tubercle on second antennal article; smaller tubercle on merus of third maxilliped. Edges of epistome shelf-like.

Chelipeds well developed, covered in coarse setae (as with other pereopods), 3 prominent erect tubercles on carpus and similar distal tubercle on superior margin of propodus. Fingers white, gaping, occlusal margin with 6–7 small teeth.

P2–3 shorter than chelipeds, distal border of carpus produced, dactylus long curved, bearing 5 small spines along inner margin. P4–5 legs slender, shorter than P2–3, P4 shortest, P5 subdorsal, dactylus short curved and opposed by single propodal spine. Female sternal grooves ending close together on elevated platform between bases of chelipeds.

Male abdomen held in place by uropods between bases of first pair of walking legs, third to fifth segments with 3 median tubercles and flattened lateral tubercle on each side. Telson wider than long, apex rounded.

Remarks. The small female specimen reported by McLay (1993) had sternal grooves ending close together on an elevated platform between the bases of the chelipeds. In species of Cryptodromia Stimpson, 1858 , the sternal grooves are shorter, ending apart between the bases of P2. The main features used for establishing Baccadromia gen. nov. are the longer sternal grooves ending close together as well as the unusual facial ornamentation. Our male specimen has a damaged left rostral tooth and the right postorbital tooth is broken off, but otherwise intact. The distinctive features of this crab include the rather long and acute nature of the rostral teeth as well as the tubercles on the chelipeds and the pearl-like tubercles that adorn its “face”. These characteristic rounded tubercles are to be found on the sub-hepatic area, on the basal article of the antenna and on the merus of the third maxilliped. Together each group of four is reminiscent of a constellation of stars mirrored about the median plane. Their pearl-like shape is a reminder of the large pearl-like tubercles found on the fourth abdominal segment of the dynomenid, Acanthodromia spp.

Distribution. Red Sea, East Africa, Madagascar, South Nilanda Atoll, Maldives Archipelago, Cinque Island (Andaman Sea) (type locality), Philippines, Japan, Chesterfield Ids. The specimen from Ningaloo Marine Park, off Osprey Reef, Western Australia, represents a new record for Australia. Baccadromia bullifera is a widespread IndoWest Pacific shallow water species recorded mostly from depths of 30– 60 m.

Figures

FIGURE 8. Baccadromia bullifera (Alcock, 1900), male 7.7 × 8.2 mm (WAM C42521): A, dorsal view; B, frontal view; C, ventral view. Note that the left rostral tooth is damaged and the right postorbital tooth is missing.

FIGURE 9. Baccadromia bullifera (Alcock, 1900), male 7.7 × 8.2 mm (WAM C42521): A, facial details showing arrangement of pearl-like tubercles; B, cheliped ventral view showing details of prominent tubercles; C, dorsal view of cheliped, rostrum and anterolateral margin showing details.