Sakaija serenei, Ng & Forges, 2015

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 : 171-173

publication ID	https://doi.org/ 10.5281/zenodo.5384590
publication LSID	lsid:zoobank.org:pub:40BCDD62-D35E-46D1-95A3-2CC0DF219DEE
persistent identifier	https://treatment.plazi.org/id/742365E7-CA03-408B-8581-A056F3106B59
taxon LSID	lsid:zoobank.org:act:742365E7-CA03-408B-8581-A056F3106B59
treatment provided by	Valdenar
scientific name	Sakaija serenei
status	sp. nov.

Treatment

Sakaija serenei View in CoL n. sp.

( Figs. 30 View Fig , 31D–F View Fig , 33K–M View Fig , 37M View Fig , 40L View Fig , 46J View Fig , 51D View Fig , 54K View Fig , 56I View Fig , 70D View Fig )

Maja japonica View in CoL – Serène & Lohavanijaya, 1973: 50, figs. 93–97, pl. 9 fig. A.

Maja sakaii View in CoL – Serène & Vadon, 1981: 124.

Material examined. Holotype: male (17.4 × 14.7 mm) ( NMCR), Balicasag Island , Panglao, Bohol, Philippines, coll. fishermen with tangle nets, July 2003 . Paratypes: Philippines – 5 males (18.3 × 14.4 mm, 16.0 × 13.5 mm, 15.3 × 11.8 mm, 16.9 × 13.2 mm, 16.5 × 13.1 mm), 3 ovigerous females (15.2 × 11.6 mm, 14.9 × 11.5 mm, 14.4 × 11.3 mm) ( ZRC 2013.1263 View Materials ), same data as holotype . — 3 males, 1 female ( ZRC 2001.0413 View Materials ) Balicasag Island, Panglao, Bohol, 200–300 m, coll. fishermen with tangle nets, Balicasag Island , Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, December 2000 . — 2 males, 2 females ( ZRC 2001.0601 View Materials ) Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, 28 November 2001 . — 1 female (NSMT-Cr 15389), Balicasag Island, Panglao , Bohol, coll. local fisherman via M. Takeda & H. Komatsu, February 2003 . — 8 males, 5 females (1 ovigerous) ( ZRC 2013.1265 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, November 2003 . — 1 male, 1 female ( ZRC 2013.1260 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, December 2003 . — 1 male ( ZRC 2013.1257 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, January 2004 . — 6 males (smallest 13.9 × 11.3 mm, 14.6 × 11.1 mm; largest 17.1 × 13.8 mm), 1 female ( ZRC 2013.1256 View Materials ) , 2 males (larger 18.8 × 15.1 mm), 1 female (NSMT-Cr 22330), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, March 2004 . — 1 ovigerous female ( ZRC 2013.1244 View Materials ), Balicasag Island, Panglao, Bohol, 200–300 m, coll. fishermen with tangle nets, Balicasag Island , Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, May 2004 . — 11 males, 14 females ( ZRC 2013.1255 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, May 2004 . — 2 males ( ZRC 2013.1258 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, 29 May 2004 . — 2 males ( ZRC 2013.1259 View Materials ), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, 29 May 2004 . — 3 males, 2 females ( ZRC 2013.1243 View Materials ), station P4, 9°31.1’N 123°41.5’E, Panglao, Bohol, coll. tangle nets from local fishermen, 31 May 2004 GoogleMaps . — 1 male, 1 female ( AM), Balicasag Island, Panglao , Bohol, 200–300 m, coll. fishermen with tangle nets, 4 June 2004 . — 1 male (19.3 × 15.4 mm), 1 female (15.3 × 12.4 mm) ( ZRC 2013.1261 View Materials ), Balicasag Island, Panglao , Bohol, coll. fishermen with tangle nets, June 2004 . — 1 male (17.7 × 14.6 mm) ( ZRC 2013.1262 View Materials ), station 1, Maribojoc Bay , Bohol, 9°36.1’N 123°45.0’E, 90–200 m, coll. tangle nets from local fishermen, 30 May 2004 GoogleMaps . — 1 ovigerous female (14.4 × 10.7 mm) ( ZRC 2013.1242 View Materials ), northwest Panglao , Bohol, coll. J. Arbasto with tangle nets, 2006 . Papua New Guinea – 1 ovigerous female (18.2 × 14.8 mm) (MNHN-IU-2011-3898), Jacquinot Bay , New Britain, station DW 3770, 05°34’S 151°32’E, 220–294 m, coll. RV Alis, BIOPAPUA, 16 October 2010 GoogleMaps .

Diagnosis. Carapace branchial area gently inflated, ovate; with relatively short lateral and branchial spines ( Figs. 30 View Fig , 31D, E View Fig ). Pseudorostral spines short, diverging ( Fig. 37M View Fig ). Supraorbital eave distinctly curved with triangular antorbital spine; intercalated spine shorter, triangular; postorbital spine longest, slightly curved outwards and upwards; hepatic spine short ( Fig. 37M View Fig ). Lateral margin with 2 large tubercles or short spines and several smaller granules; 1 low but strong branchial spine; median row with 3 tubercles: 2 gastric, 1 cardiac, intestinal not easily discernible; posterior carapace margin with 2 low tubercles, sometimes not visible ( Figs. 30 View Fig , 31D, E View Fig ). Basal antennal article covered with granules, with 2 distal blunt spines ( Fig. 40L View Fig ). Ischium of third maxilliped covered with low granules ( Fig. 46J View Fig ). Adult ambulatory legs relatively long ( Figs. 30 View Fig , 56I View Fig ). G1 gently curved, distal part long, tapering with very long setae ( Fig. 33K–M View Fig ).

Etymology. The species is named after the renowned French carcinologist Raoul Serène, who first recorded this species as Maja japonica from the Philippines.

Remarks. The good series of S. serenei on hand shows the variation in carapace shape as the specimens increase in size. The carapace is relatively more pyriform ( Fig. 30A, B View Fig ) in smaller specimens of S. serenei (ca. carapace length 12 mm) but as they get larger (ca. carapace length 16 mm), the carapace becomes somewhat more rounded in appearance ( Fig. 30C View Fig ). Even so, it never gets as rounded or as broad as similarly sized specimens of S. japonica ( Fig. 28A–C View Fig ). The carapaces are also different in the degree of their inflation and the depth of grooves separating the regions. Sakaija japonica differs in having the branchial region more evenly swollen, with the grooves separating it from the gastric, cardiac and intestinal regions visible but shallow and narrow, so much so that the surfaces of all these regions look evenly convex ( Figs. 28A–C View Fig , 31A, B View Fig ). In S. serenei on the other hand, the grooves separating the branchial region from the gastric, cardiac and intestinal regions are distinct, relatively broader, and the regions are clearly separated ( Figs. 30 View Fig , 31D, E View Fig ). Since the branchial region is more inflated, the dorsal branchial spine in S. japonica is directed obliquely vertically ( Figs. 28A–C View Fig , 31A, B View Fig ) while that of S. serenei is directly obliquely laterally ( Figs. 30 View Fig , 31D, E View Fig ). Significantly, the ambulatory legs, notably the meri, are proportionately shorter and stouter in S. japonica ( Figs. 28A–C View Fig , 31C View Fig ) compared to S. serenei where they are relatively more slender and longer ( Figs. 30 View Fig , 31F View Fig ).

The G1 structures of S. japonica and S. serenei are superficially similar, both are curved and have the distal part lined with long setae. The G1 of S. japonica figured by T. Sakai (1934: text fig. 11b) (as M. nipponensis ) is that of a small male measuring 14.5 by 13.0 mm, but in larger adult males, the distal part of the G1 is slightly more elongate and more setose ( Fig. 33G View Fig ). However, the G1 structure of adult S. japonica clearly differs from that of S. serenei by being distinctly more strongly curved outwards ( Fig. 33A–F View Fig versus Fig. 33K–M View Fig ).

Serène & Lohavanijaya (1973: 50, figs. 93–97, pl. 9 fig. A) recorded “ Maja japonica ” from off Nhatrang, Vietnam, on the basis of a 16.0 by 11.5 mm male. Their excellent figures leave no doubt that their specimen is S. serenei . Serène & Vadon (1981) reported “ Maja sakaii ” from the Philippines, but in view of the present study, their records are almost certainly referrable to S. serenei n. sp. instead.

An ovigerous female from Papua New Guinea (MNHN- IU-2011-3898) is tentatively referred to S. serenei . Although it was collected some distance from the Philippines, it agrees best with S. serenei with regards to the carapace shape and ambulatory leg proportions.