Cloridina malaccensis

Cloridina malaccensis (Manning, 1968)

(Figs. 1B, 4A–H, 5A–H)

Clorida malaccensis Manning, 1968: 244, fig. 2a–e.— Manning 1978: 26.— Naiyanetr 1980a: 43 (list).— Naiyanetr 1980b: 54.— Moosa 1986: 399.— Moosa 1991: 202.

Cloridina malaccensis.— Manning 1995: 24 (list), 180 (remarks), 192 (key).— Moosa 2000: 410 (list), 439.— Ahyong 2001: 230 (list), 231 (key).— Ahyong & Naiyanetr 2002: 306 (list).— Ahyong 2007: 335.— Naiyanetr 2007: 142 (list).— Poupin 2010: 39 (list).

Material examined. IO /SS/STO/00016, 2♂ (TL 62.0–68.0 mm), Bay of Bengal, India, off Nagapattinam, Tamil Nadu, 10.79°N, 80.11°E, 56 m, FORVSS 39214, chain dredge, coll. Vinay P. Padate, 30 November 2019.

Description of Indian specimens. Body depressed. Eye small, reaching distal end antennular article 1. Eyestalk bulging, widest in proximal half. Cornea bilobed, dark, as wide as eyestalk. Ocular scales fused into single plate, rounded distally; anterior margin of ophthalmic somite rounded. Antennular somite dorsal processes trianguloid, with sharp apices directed anterolaterally. Antennular peduncle 0.69–0.71 CL. Antennal protopod unarmed; antennal scale margins fully setose, length 0.46 CL.

Rostral plate subtriangular, longer than wide. Carapace with anterolateral spine, posterolateral margin rounded. Dorsal surface with only marginal carina on posterolateral margin; gastric and cervical groove present.

Mandibular palp present, with 3 articles. Maxillipeds 1–4 each with epipod, epipod 1 largest; maxillipeds 1, 3–5 ischium elongate, merus moderately long, carpus short, propodus ovate, dactylus elongated, apposed to propodus.

Raptorial claw ischiomeral articulation terminal. Carpus bearing sharp dorsal ridge. Propodus occlusal margin closely pectinate in sinuous row, bearing 3 movable spines proximally. Dactylus outer margin with proximal notch and large triangular lobe; occlusal margin bearing 5 teeth, basal tooth minute.

Thoracic somites 5–8 smooth, without carinae; somite 5 lateral process short slender spine, directed anterolaterally, with short ventral spine. Somites 6–7 lateral process rounded, undivided.

Abdominal somites 1–5 with intermediate, lateral and marginal carinae; somite 6 with submedian, intermediate and lateral carinae. Abdominal carinae spined as follows: submedian 6, intermediate 5–6, lateral 5–6, marginal 5.

Telson trianguloid-subquadrate, inflated, dorsal surface with rows of tubercles, median carina sharp, elevated, with small posterior spine; submedian, intermediate and lateral carinae slender; apices of submedian carinae movable; prelateral lobe slightly shorter than margin of lateral tooth; denticles: submedian 3, intermediate 8–9, lateral 1. Ventral surface with tuberculate postanal-carina.

Uropodal protopod bearing 2 curved primary spines, inner spine longer; lobe on outer margin of inner spine wider than adjacent spine; protopod inner margin with row of 7 spines; endopod shorter than exopod; exopod distal article longer than proximal; proximal article with 6 blunt movable spines on outer margin, distalmost not reaching midlength of distal exopod article.

Colour (in life). Body (including carapace, thoracic sternites, abdomen, telson, and raptorial claw merus) light brown with brownish mottling; cornea with dark pigmentation; raptorial claw carpus and propodus, as well as pereiopods pale grey; raptorial claw dactylus greyish with basal half reddish; uropodal endopod with distal twothirds black, exopod proximal article with distal half of inner side black, distal segment with inner half black.

Remarks. Cloridina malaccensis was originally described (as Clorida malaccensis) from a single female (TL 55.8 mm) from Malacca Strait, Indonesia (Manning 1968: fig. 2a–e) and subsequently from Madagascar (Manning 1978), Thailand (Naiyanetr 1980a, 1980b), the Philippines (Moosa 1986), and New Caledonia (Moosa 1991; Ahyong 2007). Manning (1978) synonymised Clorida malaccensis var. moluccensis Moosa, 1973 with C. malaccensis but Ahyong (2001) showed the two species to be distinct and provided a key to the species of the genus. The present specimens agree well with the original description of C. malaccensis except that the postanal carina is tuberculate rather than smooth. We regard this variation as part of normal intraspecific variation that is often present in members of the Clorida -group of genera (Ahyong 2005; Van Der Wal et al. 2019) including species of Clorida Eydoux & Souleyet, 1842, Cloridina Manning, 1995, Fallosquilla Manning, 1995 and Levisquilla Manning, 1995 (see Ahyong 2001).

Geographical distribution and habitat. Malacca Straits (Manning 1968), Madagascar (Manning 1978), Andaman Sea (Naiyanetr 1980a, 1980b), Philippines (Moosa 1986), New Caledonia (Moosa 1991; Ahyong 2007), Gulf of Thailand (Naiyanetr 2007); 42 m in muddy sand (Manning 1978), 36–37 m (Moosa 1986), 29–80 m in mud, fine sandy mud with bryozoans to coarse sand and blocks (Moosa 1991). The present specimens were collected from sandy silt substratum at 56 m depth. The present observation is the first record from the Indian waters.