Michaelcallianassa indica Sakai, 2002

Poore, Gary C. B., 2023, New records and one new species of Callichiridae (Crustacea, Axiidea) from the Indo-West Pacific, with keys to species of Corallianassa, Lepidophthalmus and Neocallichirus, Memoirs of Museum Victoria (Mem. Mus. Vic.) 82, pp. 71-95 : 76-77

Michaelcallianassa indica Sakai, 2002

Figure 4

Michaelcallianassa indica Sakai, 2002: 481–488 , figs 11–14.— Sakai, 2005: 157–160, fig. 33.— Sakai, 2011: 450–451.— Robles et al., 2020: figs 1, 4, 7, tables S1, S2.— Padate et al., 2022: 198 (list).— Al-Kandari et al., 2020: 271 , fig. 13.

Material examined. Australia, Arafura Sea , 10° 29.2' S, 134° 20.3' E, 57–59 m ( R. Williams stn RW92–49), NTMAG Cr009817 (male, 5.6 mm) .

Supplementary description of male. Carapace c. 0.3 times total length; with distinct linea thalassinica, with defined dorsal oval marked posteriorly by shallow transverse cervical groove extending anteroventrally to each side above linea thalassinica as shallow groove demarcating posterior half of dorsal oval; frontal margin continued ventrolaterally beyond anterolateral lobe as ridge towards linea thalassinica. Branchiostegite with oblique groove terminating at anterior end of rounded hepatic boss; anterior branchiostegal lobe articulating at junction of oblique ridge and linea thalassinica. Rostrum strongly convex in lateral view, narrowly triangular, reaching almost to cornea; anterolateral lobe flat, rounded in dorsal view, square in lateral view.

Antennular peduncle 0.55 times carapace length, article 3 1.8 times as long as article 2, with ventrolateral rows of long setae. Antennal peduncle just exceeding antennular peduncle; article 4 with 3 long dorsal setae; article 5 little longer than article 4; scaphocerite semicircular. Maxilliped 3 ischium 1.4 times as long as wide, proximally lobed, widest at midpoint, extensor margin slightly concave, flexor margin straight; merus subtriangular, 1.2 times as wide as long, flexor margin broadly rounded, distal margin oblique; carpus suboval, 1.6 times as long as wide, with lobe on flexor margin; propodus 1.1 times as wide as long, free distal margin slightly oblique, flexor margin almost semicircular; dactylus slightly arcuate, 0.7 times as long as propodus; crista dentata curved, of 3 small spines on basis, 11 uneven short sharp spines on proximal two-thirds of ischium.

Pereopods 1 (chelipeds) unequal, dissimilar. Major cheliped carpus–dactylus 1.5 times carapace length; ischium slender, lower (flexor) margin with 1 denticle just beyond midpoint; merus twice as long as wide, upper margin arcuate, lower margin with c. 12 denticles over proximal two-thirds, first 2 slightly more prominent; carpus 1.6 times as wide as long, lower proximal margin regularly curved; propodus upper margin twice as long as carpus, 1.1 times as long as greatest width, widest proximally, upper and lower margins of palm carinate, rolled mesially; palm distomesial margin with blunt tubercle at base of fixed finger; fixed finger one-third length of lower margin, twice as long as width at base, cutting edge lateral, with finely serrate concave blade over proximal half, smooth, concave beyond; dactylus 0.6 as long as upper margin of palm, cutting edge with blunt tooth in proximal half, irregularly toothed beyond, with acute hooked tip. Minor cheliped 1.2 times carapace length; palm 0.6 width of major; ischium narrow, with small tooth on flexor margin, as long as merus; merus 1.8 times as long as wide, margins curved, unarmed; carpus longer than merus, 1.2 times as long as wide, parallel-sided over distal half; palm upper margin 0.7 times as long as carpus, 0.8 times as long as wide, lower margin 1.6 times as long as carpus; fixed finger evenly tapering, more than half length of lower margin, cutting edge with 10 well-spaced denticles over distal half; dactylus 1.7 times as long as upper margin of palm, curved, cutting edge unarmed.

Pereopod 3 propodus with proximally directed rounded lobe of lower margin extending beyond lower margin of carpus, with spiniform seta on lower distal angle; dactylus broadly teardrop-shaped, 1.5 times as long as wide. Pereopod 4 propodus with distal thumb, its margin with c. 10 marginal sharp short setae.

Male pleopod 1 of 2 articles; article 2 longer than article 1, with distolateral triangular projection, with rounded distomesial lobe bearing long setae. Male pleopod 2 of 2 articles; article 2 longer than article 1, lateral margin convex, apex oblique; without appendix masculina. Pleopod 3 endopod with appendix interna embedded in mesial margin, with minute hooks.

Uropodal endopod 1.65 times as long as wide, anterior and posterior margins converging on rounded corner, posterior margin with subdistal cluster of dorsal setae, submarginal row of setae; exopod 1.8 times as wide as anterior margin, anterior margin almost straight, distal margin evenly curved, delimited each end by rounded angles, dorsal plate extending almost half width of exopod, bearing c. 30 spiniform setae on overlapping margin.

Telson 1.33 times wide as long, broadest at lateral lobes near midpoint, with strong lateral excision near anterior margin, tapering to rounded posterolateral corners, posterior margin weakly concave, posterolateral corners each bearing tuft of long setae; dorsal surface with prominent transverse ridge, 2 pairs of spiniform setae and 5 pairs of fine setae posterior to ridge.

Size. Cl. 9.5 mm.

Distribution. Somali/Arabian, Bay of Bengal, Andaman, Sahul Shelf (Persian Gulf [type locality]; Kuwait; Iran; India; Australia, NT); 0– 65 m.

Remarks. Sakai (2002) selected a large male, the only specimen from the Persian Gulf, as holotype of M. indica and listed many specimens from the Andaman Sea as paratypes. Sakai (2005) added more records from the south-eastern coast of India. Robles et al. (2020) recorded a second specimen from the Persian Gulf that contributed molecular data to their analysis. The small male figured here differs from those illustrated by Sakai (2002, 2005), which themselves vary. The rostrum is strongly convex (fig. 4a; similar to that of the holotype of M. indica , but a female from the Andaman Sea appears much flatter), the fixed finger of the major cheliped of the new male has a concave tooth occupying the proximal half (fig. 4f; resembling that of the Indian female; the tooth is much shorter in a paratype male and little shorter in a paratype female), the propodus of pereopod 3 (fig. 4d) is not as strongly lobed as figured by Sakai, and the maxilliped 3 is much wider and with a squarer propodus than previously figured (fig. 4b, c). The strong thumb on the propodus of pereopod 4 (fig. 4e) has not been noted previously. Male pleopods 1 and 2 are similar to those of M. indica (fig. 4i, j; labels E and F are reversed on Sakai’s (2002) fig. 14). The armature of the cheliped merus, the shapes of the uropod and the telson of the newly found specimen (fig. 4h) are essentially identical to that previously figured.