Neoanchisquilla tuberculata, Ahyong, 1998

Ahyong, Shane T., 1998, Review of Neoanchisquilla Moosa, 1991 and Neclorida Manning, 1995 (Crustacea: Stomatopoda: Squilloidea), with descriptions of two new species of Neoanchisquilla from the Indian Ocean, Records of the Australian Museum 50 (2), pp. 217-229 : 224-225

Neoanchisquilla tuberculata n.sp.

Fig. 4

Material. HOLOTYPE: USNM 260879 , male (TL 74 mm), Comores, 12°11'09"S 44°19'03"E, 9-20 m, RW88-26, colI. R. Winterbottom, 21 November 1988.

Diagnosis. Rostral plate triangular; longer than broad; apex narrow, blunt. Carapace anterolateral spines small, not extending to base of rostral plate. Raptorial claw dactylus with 7 teeth. TS6-7 lateral processes flattened, margin slightly sinuous. Abdominal carinae spined as follows: SM 6, IM 6, LT 2-6, MG I-S; sternum posterior margin unarmed. Telson dorsal surface withMD carina, tuberculate accessory MD carina and numerous curved rows of tubercles; ventral surface with 2 rows of irregularly spaced tubercles lateral to postanal carina.

Description of holotype. TL 74 mm. Eye with cornea strongly bilobed, not extending beyond Al peduncle segment 1; Cl 480. Al peduncle 0.86CL. Al dorsal processes with spiniform apices, directed anterolaterally. A2 scale length 0.62CL. Rostral plate triangular; slightly longer than broad; apex blunt. Carapace anterior width O.5SCL; anterolateral spines small, not extending to base of rostral plate. Raptorial claw dactylus with 7 teeth. TS6- 7 lateral processes flattened, margin slightly sinuous. TS8 sternal keel subtruncate. AS 6 with minute ventrolateral spine anterior to uropodal articulation. Abdominal carinae spined as follows: SM 6, IM 6, LT 2-6, MG I-S; sternum posterior margin unarmed. PLPl endopod in male with slender, curved hook process and broad, flattened tube process; apex of hook process acute, exceeding apex of tube process. Telson prelaterallobe longer than margin of LT tooth; denticles 7-8, 17-18, 1. Dorsolateral surface with proximal cluster of tubercles, tuberculate accessory MD, and 7-8 curved rows of closely set tubercles. Carinae of primary teeth tuberculate. Telson ventral surface with tuberculate postanal carina and 2 rows of irregularly spaced tubercles laterally. Uropodal protopod inner margin armed with IS-18 slender spines. Terminal spines of uropodal protopod with lobe on outer margin of inner spine rounded to angular, narrower than adjacent spine, proximal margin concave. Uropodal exopod proximal segment with 7 graded movable spines on outer margin, distal 2 flattened with acute apices, distalmost not exceeding midlength of distal segment. Exopod distal segment with length subequal to proximal segment. Uropodal endopod with row of 3 tubercles ventrally, adjacent to articulation with protopod.

Colour in alcohol. Rostral plate, antennal protopods and anterior cephalon dark brown. Al and A2 peduncles pale. A2 scale with dark posterior margin and apex. Carapace with dark anterior margin and three, broad, diffuse, irregular transverse bands; reflected marginal carinae enclosing black patch with diffuse margins. Thoracic and abdominal somites each with posterior margin dark; broad, diffuse submedian patches, with darker distal patch between intermediate and lateral carinae extending onto following somite. Telson with darkly pigmented carinae; with broad, diffuse, dark patch covering intermediate and lateral teeth; with broad, diffuse longitudinal median band extending from anterior margin to apices of SM teeth, excepting a short, unpigmented rectangle distally. Raptorial claw propodus with dark opposable margin and dark articulation with carpus; carpus dark; merus dark distally, ventrally and dorsally, unpigmented midlaterally; meral depression unpigmented excepting black trapezoid spot proximally. Pereiopods with dark protopod. Uropodal protopod and endopod dark; exopod proximal segment dark on distal half and articulation with distal segment; exopod distal segment dark along midline and outer margin.

Measurements. Holotype male: TL 74 mm, CL 16.8 mm, CW 3.S mm, Al peduncle 14.S mm.

Etymology. Named for the tuberculate dorsal ornamentation of the telson.

Remarks. Neoanchisquilla tuberculata is unique in the genus in bearing tuberculate dorsal and ventral telson ornamentation (10[1], 13[1]). Neoanchisquilla tuberculata n.sp. also differs from N. semblatae in bearing fewer teeth on the raptorial claw (seven instead of eight); in having shorter anterolateral spines of the carapace; in having a narrower, more pointed apex of the rostral plate; the hook process of the male PLPl endopod is shorter and apically acute; more lateral carinae on the abdominal somites are armed; the cornea is distinctly bilobed; the inner margin of the uropodal protopod bears IS-18 instead of 10-12 spines; and there are more movable spines on the outer margin of the uropodal exopod. Although an adult ( Moosa, 1991), the holotype of N. semblatae is small (TL 26 mm). The first four distinguishing characters are unlikely to change with age but the latter four may be size related and should be used with caution.

Neoanchisquilla tuberculata is most closely related to N. australiensis in sharing a similar rostral plate, short anterolateral spines of the carapace, and seven teeth on the dactylus of the raptorial claw (2[1], 3[1], 7[1]). As well as the tuberculate dorsal and ventral telson ornamentation, N. tuberculata differs fromN. australiensis in the shape of the cornea, in bearing truncate lateral processes of TS6-7, in having more abdominal somites with armed lateral carinae and in having a tuberculate accessory median carinae. Whereas the dorsolateral carinae of the telson are sharp and well formed in N. australiensis , the accessory median carina is completely suppressed.

Other than N. semblatae and N. australiensis , the only other species likely to be confused with N. tuberculata is Anchisquilla Jasciata (De Haan). Ghosh (1973) reported material of A. Jasciata from the Gulf of Oman which differed from the account of Kemp (1913) in bearing interrupted, instead of entire, dorsal carinae and

lacking supplementary ventral carinae on the telson. Although A. fasciata may lack supplementary ventral carinae on the telson, the dorsal carinae are entire or only interrupted proximally. Ghosh (1973) may have been dealing with N. tuberculata , but his account is

unfortunately too brief to confirm the identity of his material.

Distribution. Known from the type locality, the Comoro Islands, and possibly the Gulf of Oman.