Planaja plana, 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 : 180-181

Planaja plana n. sp.

( Figs. 2G , 34A, B , 35A–E , 38A , 40N , 42G , 46M, N , 51F, G , 52K , 54N , 56K )

Material examined. Holotype: male (43.7 × 37.1 mm) ( NMCR), Balicasag Island , Panglao, Bohol, Philippines, coll. fishermen with tangle nets, July 2003 . Paratypes: Philippines – 3 males (42.9 × 35.0 mm, 38.3 × 30.1 mm, 33.3 × 26.9 mm), 2 ovigerous females (47.9 × 40.9 mm, 45.1 × 37.8 mm) ( ZRC 2013.1319 ), same data as holotype . — 1 male (40.2 × 33.2 mm) ( ZRC 2001.0435 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, December 2000 . — 8 males (38.2 × 31.7 mm, 44.4 × 36.8 mm, 38.5 × 31.7 mm, 38.7 × 31.0 mm, 38.2 × 31.0 mm, 30.4 × 24.3 mm, 26.3 × 21.2 mm, 34.4 × 27.3 mm), 4 ovigerous females (44.7 × 37.2 mm, 42.4 × 34.5 mm, 36.1 × 29.7 mm, 44.5 × 38.6 mm) ( ZRC 2001.0430 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, December 2000 . — 1 male (39.3 × 30.3 mm) ( ZRC 2001.0591 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, 28 November 2001 . — 2 males (40.2 × 31.8 mm, 35.8 × 27.9 mm), 1 female (44.4 × 34.8 mm) ( USNM), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, June 2002 . — 1 juvenile male ( ZRC 2013.1316 ), Balicasag Island , Panglao, Bohol, 200–300 m, coll. fishermen with tangle nets, June 2002 . — 2 males (42.5 × 34.9 mm, 38.1 × 29.8 mm), 1 ovigerous female (48.8 × 41.4 mm), 1 female (45.3 × 37.8 mm) ( ZRC 2013.1369 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, July 2003 . — 2 males, 1 female (NSMT-Cr 22331), Balicasag Island , Panglao, Bohol, 200–300 m, coll. fishermen with tangle nets, February 2004 . — 2 males (22.2 × 17.5 mm, 22.7 × 18.3 mm) ( ZRC 2013.1325 ), Balicasag Island , Panglao, Bohol, 200–300 m, coll. fishermen with tangle nets, May 2004 . — 1 male (42.1 × 35.1 mm), 2 ovigerous females (44.8 × 37.2 mm, 44.9 × 37.3 mm) ( ZRC 2013.1368 ), Balicasag Island , Panglao, Bohol, station PN1, coll. P.K.L. Ng from fishermen with tangle nets, 29 May 2004 . — 1 male (42.8 × 34.3 mm), 1 female ( AM), station PN1, Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, January 2004 . — 1 female ( ZRC 2013.1320 ), Stn PN 1, Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, 3 January 2004 . — 1 female (37.1 × 30.2 mm) ( ZRC 2013.1321 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, February 2004 . — 2 males (35.3 × 28.8 mm, 33.6 × 26.7 mm), 2 females (41.0 × 32.0 mm, 28.9 × 23.0 mm) ( ZRC 2013.1326 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, March 2004 . — 1 male (38.3 × 30.7 mm) ( ZRC 2013.1370 ), Balicasag Island , Panglao, Bohol, coll. fishermen with tangle nets, 28 May 2004 . — 2 males (41.0 × 34.0 mm, 45.4 × 36.5 mm) ( ZRC 2012.1206 ), Balicasag, Panglao, Bohol, 200–300 m, coll. local fishermen with tangle nets, 29 May 2004 . — 1 ovigerous female (45.2 × 36.9 mm) ( ZRC 2012.1205 ), station DW 2402, Dipolog Bay, off Balicasag Island , Bohol Sea, 9°30.8’N 123°41.5’E, coll. PANGLAO 2005, 31 May 2005 . Others: Taiwan – 1 female (46.6 × 40.9 mm) ( ZRC 2001.0057 ), Nangfangao port, Su-Ao, Ilan County, northeastern Taiwan , coll. P.K.L. Ng, 5 November 2000 .

Diagnosis. Carapace pyriform; dorsal surface gently convex, covered by numerous rounded granules ( Fig. 34A, B ). Pseudorostral spines long, diverging ( Fig. 38A ). Supraorbital eave expanded, with long sharp antorbital tooth; intercalated spine triangular, sharp, shorter than others; postorbital tooth triangular, very long, touching base of long, curved hepatic spine; median row with 5, usually 6 short spines ( Fig. 34A, B , 38A ). Lateral margin with 6 or 7 short spines, regularly arranged; 1 short branchial spine and 1 submedian tubercle; 3 small spines on posterior carapace margin ( Fig. 34A, B ). Ambulatory legs short, setose ( Figs. 34A, B , 56K ). Basal antennal article distinctly granulated with 2 strong spines distally ( Fig. 40N ). Subhepatic area strongly granulated ( Fig. 40N ). Ischium of third maxilliped almost smooth, gently rugose or with scattered low granules ( Fig. 46M, N ). G1 long, slender, distal part bent approximately 90°, distal part chitinised with rows of short stiff setae, tapering to sharp tip ( Fig. 35A–E ).

Etymology. From the Latin “ planum ” for flattened, alluding to the relatively flatter carapace of the species.

Remarks. Planaja plana is superficially similar to Sakaija japonica in general form, especially with regard the relatively short ambulatory legs. Planaja plana , however, has six or seven lateral carapace spines behind the hepatic one and its dorsal surface is conspicuously less convex. Smaller specimens of P. plana about 20 mm in carapace width (e.g., 22.2 × 17.5 mm, 22.7 × 18.3 mm; ZRC 2013.1325) have a slightly more inflated carapace, and the G1 is less strongly bent outwards with the distal part relatively shorter ( Fig. 35D ).

Surprisingly , this new genus and new species was obtained in large numbers in Balicasag , all collected by tangle nets. None were collected from trawls or dredges from the Philippines. The one specimen from Taiwan, a female (46.6 × 40.9 mm, ZRC 2001.0057 ), was obtained by a commercial trawl .

Figures

Fig. 2. Basal antennal article and position of flagellum.A, Maja brachydactyla, male (98.4 × 89.0 mm) (ZRC 2009.1130), U.K.; B, Paramaja kominatoensis, dried male (62.6 × 56.1 mm) (KPM NH0104298), Japan; C, Alcomaja irrorata n. sp., holotype male (52.6 × 45.7 mm) (NMCR), Philippines; D, Paramaya ouch n. sp., paratype ovigerous female (68.3 × 54.2 mm, with rhizocephala) (ZRC 2013.1317); E, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; F, Sakaija africana, male (32.2 × 25.4 mm) (MNHN-IU-2010-928), Madagascar; G, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; H, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 34. General habitus. A, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; B, Planaja plana n. gen. n. sp., paratype male (38.3 × 30.7 mm) (ZRC 2013.1370), Philippines; C–E, Ovimaja compressipes, holotype female (51.2 × 40.5 mm) (NHM 1860.15), China; F, Ovimaja compressipes (type of Maja linapacanensis Rathbun, 1916, 27.0 × 20.0 mm, USNM 48225), Philippines; G, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan. A–C, F, G, overall dorsal views; D, antennae, antennules, orbit and epistome; E, thoracic sternum.

Fig. 35. Left G1s. A–C, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; D, Planaja plana n. gen. n. sp., paratype male (38.3 × 30.7 mm) (ZRC 2013.1370), Philippines; E, Planaja plana n. gen. n. sp., paratype male (42.8 × 34.3 mm) (AM), Philippines; F–H, Ovimaja compressipes (as Maja brevispinosa, after Dai, 1981: pl. 1 figs. 8, 9); I–L, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan. Scale bars = 1.0 mm [A, I]; 2.0 mm [F]; 0.5 mm [B–E, J, K]; 0.2 mm [G, H].

Fig. 38. Frontal regions of carapaces. A, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; B, Ovimaja compressipes, holotype female (51.2 × 40.5 mm) (NHM 1860.15), China; C, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 40. Antennae, antennules and epistomes. A, Paramaya spinigera, male (85.0 × 66.4 mm) (ZRC 1999.738), Taiwan; B, Paramaya ouch n. sp., holotype male (76.8 × 60.0 mm) (NMCR), Philippines; C, Paramaya coccinea n. sp., holotype male (69.0 × 55.6 mm) (MNHN), Vanuatu; D, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; E, Holthuija miersii, male (22.3 × 16.5 mm) (CBM ZC4001), Singapore; F, Holthuija suluensis, holotype female (32.4 × 41.2 mm) (USNM 48224a), Philippines; G, Holthuija pauli n. sp., holotype male (37.3 × 28.0 mm) (NMCR), Philippines; H, Holthuija aussie n. sp., holotype ovigerous female (42.1 × 34.4 mm) (NMV J63752), Arafura Sea; I, Holthuija poorei n. sp., holotype male (24.3 × 18.7 mm) (NMV J63749), Timor Sea; J, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; K, Sakaija africana, male (32.2 × 25.4 mm) (MNHN-IU-2010-928), Madagascar; L, Sakaija serenei n. sp., holotype male (17.4 × 14.7 mm) (NMCR), Philippines; M, Sakaija santo n. sp., holotype male (9.4 × 6.6 mm) (MNHN), Vanuatu; N, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; O, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 42. Epistomes. A, Paramaya spinigera, male (85.0 × 66.4 mm) (ZRC 1999.738), Taiwan; B, Paramaya coccinea n. sp., holotype male (69.0 × 55.6 mm) (MNHN), Vanuatu; C, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; D, Holthuija suluensis, holotype female (32.4 × 41.2 mm) (USNM 48224a), Philippines; E, Holthuija aussie n. sp., holotype ovigerous female (42.1 × 34.4 mm) (NMV J63752), Arafura Sea; F, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; G, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; H, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 46. Third maxillipeds. A, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; B, Holthuija suluensis, holotype female (32.4 × 41.2 mm) (USNM 48224a), Philippines; C, Holthuija pauli n. sp., holotype male (37.3 × 28.0 mm) (NMCR), Philippines; D, Holthuija cognata n. sp., holotype male (29.5 × 23.7 mm) (CBM-ZC3662), Japan; E, Holthuija aussie n. sp., holotype ovigerous female (42.1 × 34.4 mm) (NMV J63752), Arafura Sea; F, Holthuija poorei n. sp., holotype male (24.3 × 18.7 mm) (NMV J63749), Timor Sea; G, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; H, Sakaija sakaii, male (9.0 × 6.6 mm) (NSMT-Cr 8094), Japan; I, Sakaija africana, male (32.2 × 25.4 mm) (MNHN-IU-2010-928), Madagascar; J, Sakaija serenei n. sp., holotype male (17.4 × 14.7 mm) (NMCR), Philippines; K, Sakaija santo n. sp., holotype male (9.4 × 6.6 mm) (MNHN), Vanuatu; L, Sakaija longispinosa n. sp., paratype ovigerous female (14.2 × 10.7 mm) (NMV J63197), Australia; M, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; N, Planaja plana n. gen. n. sp., paratype male (38.3 × 30.7 mm) (ZRC 2013.1370), Philippines; O, Ovimaja compressipes, holotype female (51.2 × 40.5 mm) (NHM 1860.15), China; P, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 51. Anterior thoracic sternums and abdomens. A, Sakaija japonica, holotype male (16.2 × 13.0 mm) (USNM 48252), Japan; B, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; C, Sakaija africana, male (32.2 × 25.4 mm) (MNHN-IU-2010-928), Madagascar; D, Sakaija serenei n. sp., holotype male (17.4 × 14.7 mm) (NMCR), Philippines; E, Sakaija santo n. sp., holotype male (9.4 × 6.6 mm) (MNHN), Vanuatu; F, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; G, Planaja plana n. gen. n. sp., paratype male (38.3 × 30.7 mm) (ZRC 2013.1370), Philippines; H, Ovimaja compressipes, holotype female (51.2 × 40.5 mm) (NHM 1860.15), China; I, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 52. Male sterno-abdominal cavities. A, Maja brachydactyla, male (98.4 × 89.0 mm) (ZRC 2009.1130), U.K.; B, Maja crispata, male (63.1 × 51.9 mm) (MNHN-IU-2013-4042), Italy; C, Neomaja goltziana, male (73.4 × 65.0 mm) (MNHN-IU-2013-4046), Congo; D, Paramaja gibba n. sp., male (79.5 × 77.9 mm) (ZRC 2013.1232), Bay of Bengal; E, Alcomaja irrorata n. sp., holotype male (52.6 × 45.7 mm) (NMCR), Philippines; F, Alcomaja desmondi n. sp., holotype male (35.4 × 28.3 mm) (NMCR), Philippines; G, Alcomaja nagashimaensis, male (30.5 × 26.0 mm) (ZRC 2001.430), Philippines; H, Paramaya spinigera, male (85.0 × 66.4 mm) (ZRC 1999.738), Taiwan; I, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; J, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; K, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; L, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 54. Chelae. A, Paramaya spinigera, male (85.0 × 66.4 mm) (ZRC 1999.738), Taiwan; B, Paramaya ouch n. sp., paratype male (76.5 × 61.3 mm) (ZRC 2001.0577), Philippines; C, Paramaya coccinea n. sp., holotype male (69.0 × 55.6 mm) (MNHN), Vanuatu; D, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; E, Holthuija suluensis, holotype female (32.4 × 41.2 mm) (USNM 48224a), Philippines; F, Holthuija pauli n. sp., holotype male (37.3 × 28.0 mm) (NMCR), Philippines; G, Holthuija cognata n. sp., holotype male (29.5 × 23.7 mm) (CBM-ZC3662), Japan; H, Holthuija aussie n. sp., holotype ovigerous female (42.1 × 34.4 mm) (NMV J63752), Arafura Sea; I, Holthuija poorei n. sp., holotype male (24.3 × 18.7 mm) (NMV J63749), Timor Sea; J, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; K, Sakaija serenei n. sp., holotype male (17.4 × 14.7 mm) (NMCR), Philippines; L, Sakaija santo n. sp., holotype male (9.4 × 6.6 mm) (MNHN), Vanuatu; M, Sakaija africana, male (32.2 × 25.4 mm) (MNHN-IU-2010-928), Madagascar; N, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; O, Ovimaja compressipes, holotype female (51.2 × 40.5 mm) (NHM 1860.15), China; P, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.

Fig. 56. First ambulatory dactyli and propodi. A, Paramaya spinigera, dried female (70.1 × 58.8 mm) (KPM NH4195), Japan; B, Paramaya coccinea n. sp., holotype male (69.0 × 55.6 mm) (MNHN), Vanuatu; C, Holthuija miersi, male (32.6 × 25.6 mm) (ZRC 2000.1497), Singapore; D, Holthuija suluensis, holotype female (32.4 × 41.2 mm) (USNM 48224a), Philippines; E, Holthuija cognata n. sp., holotype male (29.5 × 23.7 mm) (CBM-ZC3662), Japan [figure laterally inverted]; F, Holthuija aussie n. sp., holotype ovigerous female (42.1 × 34.4 mm) (NMV J63752), Arafura Sea; G, Holthuija poorei, n. sp. paratype female (27.0 × 22.5 mm) (NMV J63751), Arafura Sea; H, Sakaija japonica, male (22.3 × 17.8 mm) (ZRC 2013.1267), Taiwan; I, Sakaija serenei n. sp., holotype male (17.4 × 14.7 mm) (NMCR), Philippines [figure laterally inverted]; J, Sakaija santo n. sp., holotype male (9.4 × 6.6 mm) (MNHN), Vanuatu; K, Planaja plana n. gen. n. sp., holotype male (43.7 × 37.1 mm) (NMCR), Philippines; L, Ovimaja compressipes, male (49.6 × 39.6 mm) (ZRC 2008.1318), Taiwan.