Holthuija suluensis ( Rathbun, 1916 )

Ng, Peter K. L. & Forges, Bertrand Richer De, 2015, Revision of the spider crab genus Maja Lamarck, 1801 (Crustacea: Brachyura: Majoidea: Majidae), with descriptions of seven new genera and 17 new species from the Atlantic and Indo-West Pacific, Raffles Bulletin of Zoology 63, pp. 110-225 : 162

Holthuija suluensis ( Rathbun, 1916)

( Figs. 1A, 24E, 26A, 27D, E, 37F, 40F, 42D, 46B, 50F, 54E, 56D)

Maja suluensis Rathbun, 1916: 552 . – Serène, 1968: 57. – Griffin, 1976: 200, Fig. 7a. – Griffin & Tranter, 1986: 210, 218 (part), fig. 71f. – Ng et al., 2008: 117 (list).

Material examined. Holotype: female (32.4 × 41.2 mm) ( USNM 48224 a), station 5165, Observation Island, Tawi Tawi Group, Sulu Islands , 4°58.33’N 119°50.5’E, Philippines, coll. RV Albatross , 24 February 1908 . Paratypes: 2 females (22.5 × 30.6 mm, 22.4 × 30.9 mm) ( USNM 48224 a), same data as lectotype. Others : Philippines – 1 male (11.5 × 8.2 mm), 1 young female (26.8 × 20.8 mm) ( USNM 48507 ), station 5557, Jolo Island and vicinity, 19 fathoms, coll. RV Albatross , 18 September 1909 . — 1 female (36.3 × 27.4 mm) ( USNM 49697 ), station 5163, Tawi Tawi Group, Sulu Archipelago, 28 fathoms, coll. RV Albatross , 24 February 1908 .

Diagnosis. Carapace covered with small granules ( Fig. 24E). Pseudorostral spines straight, strongly diverging ( Fig. 37F). Antorbital spine long, curved, directed anteriorly; intercalated spine short, leaving narrow gaps on each side; postorbital spine very long, slightly curved outwards; hepatic spine directed anteriorly, half length of postorbital spine ( Figs. 24E, 37F). Lateral margin with 3 long spines; 1 branchial spine; median row with 3 long spines: 2 gastric, 1 cardiac; 2 small spines on posterior carapace margin ( Fig. 24E). Basal antennal article broad with median row of granules, 2 sharp distal spines ( Fig. 40F). Epistome with 2 granulated lobes on anterior margin ( Fig. 40F). G1 almost straight, distal part not dilated or curved [juvenile] ( Fig. 27D, E).

Remarks. Rathbun (1916: 553) provided measurements for only one female specimen (the holotype) but did not mention how many more specimens she had. In the bottle are two other female specimens with the same data and they should be treated as paratypes. Rathbun (1916: 552) stated that the specimen was collected from 9 fathoms depth but the label says 46 fathoms. Griffin (1976: 200) said 9 to 28 fathoms.

The record by Griffin & Tranter (1986: 218) from Sulu Islands and Kei Islands ( Moluccas) almost certainly contains two species. They comment that the specimen they had from Moluccas has only one gastric spine in contrast to the material from Sulu Islands which has two spines (including the types). They suggested that this character may be variable and used other characters to differentiate H. suluensis from H. miersi . While the characters they use are valid, we are more inclined to believe that his Moluccas specimen is actually another species, possibly allied to H. pauli n. sp. (see below). Holthuija suluensis and H. pauli are superficially very close, but the large series of H. pauli on hand tells us that the position and number of gastric spines (two versus one) is very reliable and not variable, even between sexes or specimens very different in size. Otherwise, they are similar in general carapace form.

Serène & Vadon (1981: 119, 124, 128) records “ Maja miersi ” from the Philippines but their material will need to be checked to see if they are really this species or perhaps the allied H. pauli or H. suluensis . Maramura & Kosaka’s (2003: 35) record of “ Maja aff. suluensis ” from Japan will also need to be examined before its identity can be confirmed.