Range extension of brachyuran crabs of the family Camptandriidae Stimpson , 1858 ( Crustacea : Decapoda : Brachyura ) in Indian waters

We report the presence of 3 species of brachyuran crabs, Opusia indica (Alcock, 1900), Nasima dotilliformis (Alcock, 1900) and Leptochryseus kuwaitensis (Jones & Clayton, 1983) (family Camptandriidae), for the first time from Indian waters. The species are so far reported from Iran, Iraq, Kuwait, UAE, Saudi Arabia and Pakistan. Records of these species in Indian waters extend their distribution range in the northern Indian Ocean.

This study was carried out as part of an ongoing study on the brachyuran crab fauna of Gujarat state, India.The specimens were collected from coastal areas of Lakhpat (23°50′01″ N, 068°46′26″ E) and Jakhau (23°13′26″ N, 068°37′37″ E) (Fig. 1) located on the coast of northern Arabian Sea in the Gulf of Kachchh, Gujarat, and consisting of mangrove mudflat habitats.Specimens were collected by hand during low tide.Specimens were washed properly to remove sediment and photographed in the field using a Canon 1000D with 18-55 mm lens.Specimens were preserved in 70% alcohol and deposited in the Zoology Museum of the Department of Zoology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India.Specimen catalogue numbers are provided in the species accounts below.Maximum carapace width (CW) and length (CL) were measured for each speci-men.The abbreviation G1 is used for male first left gonopod and coll.for specimen collector.

Family Camptandriidae Stimpson, 1858
Genus Opusia Ng, Rahayu & Naser, 2009 Opusia indica (Alcock, 1900) (Figs. 2, 3, 8-13)   Description.Carapace wider than long (Figs. 2, 8), dorsal surface with pits and folds with long plumose setae, 2 short transverse parallel grooves on either side of gastric region, anterolateral margin with row of granules extending halfway to posterior, ptergostomial region swollen beyond anterolateral margin; posterolateral margin strongly convex, rounded.Anterior straight with thick margin.Cornea small, eyestalk long, slender with plumose setae.Third maxilliped (Fig. 9)  with ischium widening gradually distally, inner margin setose, merus about ½ of ischium length, outer distal angle expanded to form round lobe.Cheliped slender with long plumose setae on outer margin, chela (Fig. 10) palm with ridge parallel to lower margin on outer surface, row of short setae running parallel to lower margin on outer surface extending to immovable finger, fingers slender, about twice palm length, cutting edges sharp with row of setae running parallel to cutting edges.Ambulatory legs thick, flattened laterally, third ambulatory leg highly setose with granular merus; fifth ambulatory leg shortest.Male abdomen (Figs. 3,11) with all the sutures between somites complete and clear, somite 1 slightly wider than somite 2, somites 3-5 immovable, somite 5 constricted near proximal end, telson about as long as broad with rounded apex.G1 (Fig. 12) recurved with distal part sharply bent, tip (Fig. 13) with row of small, thick spines, backward curving spines distal to apex, large mushroom-shaped spines subapi-cally on inner side (Ng et al. 2009).
Habitat.The specimens were collected from small burrows in soft muddy substratum of the outer margin of a small channel located in the open mudflat habitat of Lakhpat.
Coloration in life.Carapace, cheliped and ambulatory legs cream with brown plumose setae; ventral body pale cream to white.
Habitat.The specimens were collected from small burrows located in the upper intertidal zone of mangrove mudflat habitat located near Jakhau fishing harbor.
Coloration in life.Carapace light grey with cream patches.Cheliped outer margin cream with tinge of grey.Ambulatory legs cream with pale brown setae.Abdomen and thoracic sternite grey to pale cream.
Description.Carapace (Figs. 4,14) wider than long; dorsal surface with well demarcated regions, 2 shallow depressions present behind external orbital tooth, slightly large granules forming a lobe posterior to external orbital tooth along anterolateral margin; posterolateral margin beaded; beaded ridge present parallel to posterior margin of carapace.Suborbital ridge with row of granules.Front deflexed.Third maxilliped (Figure 15) with Y-shaped groove on surface.Ptergostomial region with shallow Y-shaped groove.Chelipeds slender, not swollen or enlarged in both sexes as well as in large specimens; fingers (Fig. 16) of chela with dorsal and ventral row of long setae ending in spoon-shaped tips.Fingers without denticles on cutting edges.Ambulatory legs robust and broad, anterior duced anterior distal angle; ischium roughly circular with prominent Y-shaped groove present on distal margin.Chelipeds globular, equal, longer and stouter; carpus inner margin with projecting rounded lobe covered with pointed granules; fingers (Fig. 22) with row of setae on inner margin terminating in rounded, slightly spatulate tips, movable finger with large, triangular tooth on cutting edge near proximal end; female chela similar to male but slightly elongated and more setose.Ambulatory legs elongated and robust; carpi and propodi with thick tomentum; second ambulatory leg longest, fifth ambulatory leg shortest; posterodorsal margin of meri of third and fourth walking legs with prominent sharp granules.Ventral margin with sharp spines; dactylus of third ambulatory leg with comb of hair in large males.Male abdomen broad (Figs. 7,23), somite 1 subequal in width to somite 2, not reaching coxae of fourth ambulatory leg exposing part of sternite eight; somites 2-5 immobile, sutures incomplete to shallow, sutures between third and fourth visible as short, transverse, median groove; telson sub-semicircular.G1 (Figure 24) gradually recurved, tip (Fig. 25) broad, truncate, robust with numerous low subterminal spines on 1 side (Ng et al. 2009).
Habitat.The specimens were collected from large inclined burrows made in the soft muddy substratum of the outer margin of a small channel located in the open mudflat habitat of Lakhpat.
Coloration in life.Carapace bottle-green to olive with brown setae on lateral margins; chelipeds and ambulatory legs yellow with dark brown setae; ventral body yellow.
Distribution: The species is so far reported from Iran (Naderloo et al. 2015), Kuwait (Ng et. al. 2009), and now, from Gujarat, India.
The specimens of Opusia indica examined in this study agreed with the description and illustrations given by Alcock (1900) and Ng et al. (2009).Ng et al. (2009) revised the taxonomy of Tylodiplax indica (Alcock, 1900) and established the new genus Opusia Ng, Rahayu & Naser, 2009 for the species.Opusia indica (Alcock, 1900) differs from species of Tylodiplax in carapace shape and morphology of male G1 (Ng et al. 2009).The specimens of Nasima dotilliformis examined in this study agreed with the description and illustrations given by Alcock (1900), Jones & Clayton (1983), Manning (1991) and Ng et al. (2009).Alcock (1900) described Cleistostoma dotilliforme on the basis of single ovigerous female specimen collected from Karachi, Pakistan.Manning & Holthuis (1981) transferred C. dotilliforme to the genus Paracleistostoma De Man, 1895 on the basis of specimens collected from southern China.Later Manning (1991) revised the taxonomy of C. dotilliforme and placed the species in the new genus Nasima Manning, 1991.Nasima dotilliformis Manning, 1991 differs from other closely related genera in having similar chelipeds in both sexes and male abdomen having all 6 somites and telson free (Ng et al. 2009).The specimen of Leptochryseus kuwaitensis examined in this study agreed with the description and illustrations given by Jones & Clayton (1983), Al-Khayat & Jones (1996) and Ng et al. (2009).The specimen from Gujarat varies slightly in having complete and prominent sutures between male abdominal somites 2-5; these were incomplete to shallow in the male specimen examined by Ng et al. (2009).