Cycloachelous granulatus granulatus (H. Milne Edwards, 1834)

(Fig. 3F–G)

Lupea granulata H. Milne Edwards, 1834: 454 (type locality: Mauritius).

Achelous granulatus.—De Man 1888: 331.— Alcock & Anderson 1894: 201 (list).

Neptunus (Achelous) granulatus.—Alcock 1899: 45.— Klunzinger 1913: 341, pl. 11, fig. 18.— Bouvier 1915: 257.— Rathbun 1924: 23.— Balss 1938: 31.— Miyake 1939: 203.— Sakai 1939: 397 (part), fig. 8b.

Portunus (Achelous) granulatus.— Rathbun 1911: 205, pl. 15, fig. 10.— Michel 1964: 17.— Serène 1968: 68.

Cycloachelous granulatus.— Ward 1942: 53 (list), 80, pl. 5, fig. 5.— Barnard 1954: 124, fig. 3a–b.

Portunus granulatus.— Stephenson & Campbell 1959: 108, figs. 2I, 3I, pl. 3, fig. 1, pls. 4I, 5I.— Sankarankutty 1961a: 102 (list), 104.— Stephenson 1961: 108.— Crosnier 1962: 57, figs. 89, 92, 94a, b.— Sakai 1965: 118, pl. 58, fig. 1.— Stephenson & Rees 1967: 25 (part), fig. 5c–e.— Stephenson & Rees 1968: 293.— Stephenson 1972a: 136.— Stephenson 1972b: 15 (key), 39.— Stephenson 1975: 178, 183, figs. 1B, E, H, I, 2B, D, pl. 1, fig. 2.— Stephenson 1976: 16.— Kensley 1981: 42 (list).—Ţrkay 1981: 51.— Tirmizi & Ghani 1982: 105, fig. 1A–F.— Poupin 1996: 31.—Tirmizi & Kazmi 1996: 23, fig. 10A–F.— Apel & Spiridonov 1998: 286, figs. 97, 109.

Portunus (Cycloachelous) granulatus.— Sakai 1976: 348, figs. 187a–b, pl. 120, fig. 2.

Non Portunus (Achelous) granulatus.— Rathbun 1906: 871, pl. 12, fig. 2.— Edmondson 1954: 239, fig. 16a–b. [= Portunus suborbicularis Stephenson, 1975]

Non Neptunus (Achelous) granulatus.— Sakai 1939: 397 (part), pl. 81, fig. 2. [= Portunus suborbicularis Stephenson, 1975]

Non Portunus granulatus.— Stephenson & Rees 1967: 25 (part), fig. 5a–b. [= Portunus suborbicularis Stephenson, 1975]

Material examined. 1 male (damaged specimen, not measured), (NIO /BOD/AB/BRY/00008), RVSS 8, west of Vijaydurg, Arabian Sea, 16.42°N, 72.20°E, 23 m depth, Van Veen grab, coll. R. Periasamy, 7 January 2014.

Diagnosis. Carapace slightly broader than long, anterolateral margins divided into 9 acuminate teeth, first tooth broad, teeth 2–8 curved, ninth tooth longest and laterally directed; posterolateral junction rounded (Fig. 3F). Maxilliped 3 merus with prominent antero-external extension (Fig. 3G). Cheliped merus with 4 spines on anterior margin, 2 spines on posterior margin (Fig. 3F). P2–4 slender; P5 dactylus and propodus flattened (Fig. 3F, G).

Colouration. Fresh specimen: dorsal surface of carapace with orange specks along margins, mesogastric regions with 2 rounded brown blotches that interconnect medially in the cardiac region (Fig. 3F).

Biology. Known from coral reefs (Stephenson 1972), intertidal seagrass beds, and sand or sandy-mud substratum down to 60 m (Crosnier 1962). The present specimen was collected from sandy substratum, at 23 m depth, in the vicinity of Favites corals.

Remarks. Cycloachelous granulatus was originally described from Mauritius (H. Milne Edwards 1834). Stephenson & Campbell (1959) provided a detailed illustrated description of P. granulatus from Australia with emphasis on G1 morphology. Crosnier (1962) commented on the variations in pleonal morphology of this species. Stephenson’s (1972b) key to the Indo-West Pacific portunids grouped it with P. orbicularis, P. dubius and P. orbitosinus owing to a narrow carapace and short ninth anterolateral tooth. The present specimen conforms to the brief description of the holotype (H. Milne Edwards 1834) in the presence of spines on the anterior and posterior margins of the cheliped merus. The specimen also agrees with the description provided by Stephenson & Campbell (1959) and keys out as P. granulatus following the identification key provided by Stephenson (1972b). In the present specimen, the cheliped merus possesses 4 spines on the anterior margin, compared with 5 spines and 2 tubercles reported by Stephenson & Campbell (1959).

Geographical distribution. Red Sea and East coast of Africa to Japan, Australia and Hawaii (Stephenson 1972). In India, reported from Andaman and Nicobar archipelagos, Malabar coast (Alcock 1899) and Lakshadweep Islands (Sankarankutty 1961), eastern Arabian Sea off India (present study).