Paramaja gibba ( Alcock, 1895 )

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 : 133-135

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/03A9654B-FF96-0741-54B4-F8FE7ABDFC76

treatment provided by

Valdenar

scientific name

Paramaja gibba ( Alcock, 1895 )
status

 

Paramaja gibba ( Alcock, 1895) View in CoL

( Figs. 10 View Fig , 11 View Fig , 13D View Fig , 14F, G View Fig , 15K–M View Fig , 36I View Fig , 39I, J View Fig , 41F View Fig , 43L, M View Fig , 48F, G View Fig , 52D View Fig , 53K View Fig , 55H View Fig , 68B, C View Fig )

Maia gibba Alcock, 1895: 239 View in CoL , pl. 4, fig. 5, 5a. – Alcock & Anderson, 1898: pl. 21 fig. 5. – Alcock, 1899: 56.

Maja gibba – Serène, 1968: 57. – Serène & Lohavanijaya, 1973: 50 (not specimen figured Pl. IX B = Maja compressipes View in CoL ). – T. Sakai, 1976: 239 (part). – Griffin & Tranter, 1986: 216 (part). – Poore et al., 2008: 62. – Ng et al., 2008: 117 (list).

Material examined. Lectotype (here designated): juvenile female (25.1 × 21.2 mm) ( NHM 1896.5.14.9), code zoo2012- 1157 T, Andaman Sea, 250 fms, coll. Investigator . Others: India – 1 male (79.5 × 77.9 mm) ( ZRC 2013.1232 View Materials ), Gulf of Bengal , V. Kakati , 2011. Thailand – 1 male (65.0 × 59.8 mm) (NSMT-Cr 16618), Andaman Sea , 400 m, coll. Y. Tamura, 5 June 1987. Australia – 1 juvenile female (33.9 × 29.4 mm) ( NMV J54316 View Materials ), off Point Cloates , 22°37.07’S 113°29.03’E – 22°37.2’S et 113°28.57’E, Western Australia, 355–382 m, coll. G. Poore, CSIRO RV Southern Surveyor , 9 December 2005. — 1 female (46.7 × 41.6 mm) ( NMV J61055 View Materials ), Kulurnburu L 29 Transect, 13°15.9’S 123°22.45’E – 13°16.35’S 123°21.4’E, northwestern Australia , 390–394 m, beam trawl, coll. D. Bray, CSIRO RV Southern Surveyor , 6 July 2007. Madagascar – 1 male (24.6 × 20.9 mm) (MNHN- IU-2010-61), station CP 3189, 12°30’S 48°18’E, 346–376 m, coll. MIRIKY, 27 June 2009. — 1 ovigerous female (47.6 × 44.1 mm) ( ZRC 2013.1405 View Materials , ex MNHN-IU-2010-508), station CP 3192, 578– 580 m, 12°26’S- 48°13’E, coll. MIRIKY, 27 June 2009. — 1 ovigerous female (47.1 × 42.6 mm) (MNHN-IU-2010-507), station DW 3198, 440– 447 m, 12°05’S- 48°59’E, coll. MIRIKY, 28 June 2009. — 1 male (58.6 × 52.2 mm) ( ZRC 2013.1406 View Materials , ex MNHN-IU-2010-63), station CP 3183, 420- 436 m, 12°38’S 48°14’E, coll. MIRIKY, 26 June 2009. — 1 male (61.3 × 54.8 mm), 3 ovigerous females (45.1 × 40.6 mm, 46.3 × 43.3 mm, 45.0 × 40.7 mm) (MNHN-IU-2010-467), station CP 3183, 420– 436 m, 12°38’S- 48°14’E, coll. MIRIKY, 26 June 2009. – 1 male (37.8 × 33.1 mm), 1 ovigerous female (47.1 × 44.3 mm), 1 female (24.4 × 20.3 mm) (MNHN-IU-2010-510), CP 3223, 430– 488 m, 12°46’S- 48°11’E, coll. MIRIKY, 2 July 2009. — 1 ovigerous female (48.7 × 44.5 mm) (MNHN-IU-2010-506), station DW 3212, 367– 369 m, coll. MIRIKY, 30 June 2009. — 2 males (60.4 × 53.4 mm, 62.8 × 57.8 mm), 1 ovigerous female (47.7× 42.2 mm) (MNHN-IU-2010-926), station DW 3217, 391– 438 m, 12°33’S- 47°56’E, coll. MIRIKY, 30 June 2009. — 1 ovigerous female (44.6 × 42.2 mm), 1 juvenile male (22.4 × 18.8 mm) (MNHN-IU-2010-927), station CP 3190, 415– 416 m, 12°31’S- 48°15’E, coll. MIRIKY, 27 June 2009. — 1 male (50.8 × 45.7 mm) (MNHN-IU-2010-509) MIRIKY, CP 3289, 332– 379 m, 14°29’S- 47°26’E, 14 July 2009. — 1 ovigerous female (43.5 × 40.1 mm) (MNHN- IU-2010-58) (specimen barcoded), station CP 3183, 420– 436 m, 12°38’S- 48°14’E, coll. MIRIKY, 26 June 2009. — 1 female (20.9 × 16.9 mm) (MNHN-IU-2010-931), station CP 3293, 268– 408 m, 14°30’S- 47°26’E, coll. MIRIKY, 14 July 2009. — 1 juvenile male (16.4 × 12.5 mm) (MNHN- IU-2010-55), station CP 3223, 430– 488 m, 12°46’S- 48°11’E, coll. MIRIKY, 2 July 2009. — 1 juvenile male (10.6 × 8.1 mm) (MNHN-IU-2010-54) (specimen barcoded), station CP 3223, 430– 488 m, 12°46’S 48°11’E, coll. MIRIKY, 2 July 2009. — 1 juvenile male (9.9 × 8.0 mm) (MNHN- IU-2010-56), station CP 3184, 492– 524 m, 12°40’S 48°12’E, coll. MIRIKY, 26 June 2009. Indian Ocean – 1 male (64.7 × 60.7 mm) ( SIO), cruise 17, station 2560, near Socotra Island , Indian Ocean, 12°17.7’N 53°08.9’E 12°21.8’N 53°05.6’E, depth 375–380 m, coll. RV Vitiaz, trawl, 27 October 1988. — 1 female (67.7 × 63.2 mm) ( SIO), cruise 17, station 2804, Saya de Malha , Indian Ocean, 11°06’S 62°14’E – 11°09’S 62°13’E, 235- 230 m, coll. RV Vitiaz, 7 January 1989. GoogleMaps

Diagnosis. Adult carapace with branchial and gastric regions rounded; dorsal surface convex, covered by numerous rounded and sharp granules, those on median row larger, tuberculate, forming low raised crest ( Figs. 10 View Fig , 11 View Fig , 13D View Fig , 14F, G View Fig ). Adult pseudorostral spines usually almost straight, gently diverging, appears dorso-ventrally flattened ( Figs. 10 View Fig , 11 View Fig , 13D View Fig , 36I, J View Fig ). Supraorbital eave large, curved with very long, sharp antorbital spine; 1 strong postorbital tooth; 1 intercalated spine large nearly as long as supraorbital spine; short hepatic spine; 3 spines on lateral margin ( Figs. 10 View Fig , 11 View Fig , 36I, J View Fig ). Adult male anterior thoracic sternum relatively broad ( Fig. 48F, G View Fig ); lateral margins of anterior edge of male sterno-abdominal cavity gently curved ( Fig. 48F, G View Fig ). Distal part of G1 relatively shorter, tip gently bent laterally ( Fig. 15 View Fig K-M).

Remarks. Maja gibba was described by Alcock (1895: 239, pl. 4 fig. 5) from the Andaman Sea (463 m) on the basis of two specimens, supposedly one male 32.0 mm (carapace length, with spines) and one female 41.0 mm, both with relatively short ambulatory legs with all the articles prominently setose. The small figure of Alcock (see also Alcock & Anderson, 1898: pl. 21 fig. 5; present Fig. 10B View Fig ) shows a posterior carapace margin lined with short spines, a relatively long ocular peduncle; four spines on the lateral carapace margin and the branchial regions separated by deep grooves. The NHM specimen ( Fig. 10A View Fig ) was labelled as a syntype and agrees with the measurements of Alcock (1895) of the male (without the pseudorostrum). Tune Sakai (1976: 240) also noted that he examined this “cotype” male specimen in NHM. However, this NHM specimen is actually a juvenile female, but since the abdomen is subrectangular and resembles that of a male, he (and T. Sakai) probably accidentally misidentified the sex of the specimen. It is here designated as the lectotype of Maja gibba Alcock, 1895 ( Fig. 10A View Fig ).

Interestingly, the species has not been reported from the Bay of Bengal area since its original description. Specimens that have been referred to “ Maja gibba ” from the Pacific by various authors after Alcock (1895) should be referred to other taxa. Serène & Lohavanijaya (1973: 50) provided a key to the genus and noted that their Maja gibba has spines on the median row of the carapace. The specimen they figured from the South China Sea, however, has a longitudinally ovoid carapace that is covered with flattened tubercles and short, densely setose ambulatory legs which have a large flattened carpus; features diagnostic of Maja compressipes ( Miers, 1879) (here referred to Ovimaja n. gen.).

Tune Sakai (1976: 239) reported the species from Japan and his colour plate depicted a male 54 mm in carapace length with short setose ambulatory legs(T. Sakai, 1976: pl. 84, fig. 1) with his text figure showing a specimen with three lateral spines and two posterior carapace margin spines (T. Sakai, 1976: 240, text-fig. 127). Tune Sakai (1976) commented that he had examined a type specimen in the NHM of Maja gibba as well. Griffin (1976: 200) recorded a male as “ Maja gibba ” from between Negros and Siquijor Islands in Philippines; while small specimens were recorded from off Bali and the South China Sea by Griffin & Tranter (1986: 216). In their keys to the genus, T. Sakai (1976: 236) stated that for his “ M. gibba ” and M. kominatoensis , the “carapace without median spine”. This was also cited by Griffin & Tranter (1986: 210) in their key to Maja . Their specimens are here provisionally referred to P. turgida .

Tune Sakai (1976: 239–240) had small and large specimens of “ Maja gibba ” from Japan, East China Sea and Philippines and commented that the spines on the carapace median row and lateral margins are relatively sharper and longer in smaller specimens and become very short in large adults, with the granules on the surface also becoming more rounded. Griffin & Tranter (1986) discussed the possible conspecificity of what they regarded as Maja gibba Alcock, 1895 , with Paramaja kominatoensis Kubo, 1936 , noting that the large wart-like granules on the carapace supposedly diagnostic of the latter species may be variable once a good series of specimens become available. As discussed under P. kominatoensis , this is indeed the case, but the species can still be separated by other characters.

The present study has an excellent series of specimens of various sizes and sexes of P. turgida n. sp. from the Philippines and confirms T. Sakai’s (1976) observations of changes in the strength and sharpness of the carapace spines and granules – large male and female specimens have almost indiscernible median and lateral spines, and the granules are relatively lower and eroded. The specimens of P. turgida from the Philippines are consistent in how they vary in carapace and ambulatory leg form and armature; and specimens of similar sizes do not vary much. Comparing the good series of specimens of P. turgida from the Philippines of similar sex and sizes, several other variation patterns are apparent. The eyes are proportionately less elongated in large specimens (also true for P. gibba ). The proportions of the ambulatory legs, especially the first two, become very long and elongated in large adult males, with the propodus becoming very elongate, almost devoid of setae; and the chelipeds also become enlarged with the palm inflated ( Figs. 12 View Fig , 53L View Fig ). This is also true for P. gibba ( Figs. 10 View Fig , 11 View Fig , 53K View Fig ). The rostrums in smaller specimens of P. gibba and P. turgida form a more distinct V, with the pseudorostral spines gently curved outwards ( Figs. 10A View Fig , 11A–C, E View Fig , 12A–C View Fig , 36K View Fig ). In large specimens, the rostrums become straighter and less curved ( Figs. 9C, D View Fig , 11D View Fig , 12E View Fig , 36 View Fig , I, J). While the lateral margins of male abdominal somites 4–6 are parallel in adult males of P. gibba and P. turgida , with the abdomen rectangular ( Fig. 48G, I View Fig ), the lateral margins become gently convex in very large males and the abdomen becomes slightly oval ( Fig. 48F, H View Fig ).

The series of specimens of P. turgida show that while there is variation in the sharpness and length of the carapace spines and granules, they never reach the degree seen in P. kominatoensis , in which the granules can become large and swollen, with those along the median row fused basally ( Fig. 8B, C View Fig ). Nor does the degree of inflation of the carapace vary to the degree seen in P. kominatoensis . As discussed earlier, the carapace of P. kominatoensis is almost always more swollen and inflated ( Figs. 13A–C View Fig , 14A–D View Fig ) than P. gibba or P. turgida ( Fig. 13D–F View Fig , 14F–H View Fig ), and this is obvious from lateral and frontal views. The material of P. turgida also demonstrates that the form of the pseudorostrum, male abdomen and G1 structure are relatively constant characters.

Understanding the degree of variation in P. turgida also means that we are confident that the material from the Indian Ocean, Japan, Taiwan and Philippines belong to three species. Paramaja kominatoensis is clearly a distinct species. The Indian Ocean appears to have only one species, P. gibba s. str. The Philippine material is referred to a new species, Paramaja turgida . However, most of the characters discussed and regarded as of species-identification value are useful only for adults. Juvenile specimens of these species about 30–40 mm in carapace length cannot be easily separated.

See also remarks for P. turgida for discussion of differences with P. gibba .

NHM

University of Nottingham

T

Tavera, Department of Geology and Geophysics

V

Royal British Columbia Museum - Herbarium

NMV

Museum Victoria

CSIRO

Australian National Fish Collection

RV

Collection of Leptospira Strains

SIO

Scripps Institution of Oceanography

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Majidae

Genus

Paramaja

Loc

Paramaja gibba ( Alcock, 1895 )

Ng, Peter K. L. & Forges, Bertrand Richer De 2015
2015
Loc

Maja gibba

Poore GCB & McCallum AW & Taylor J 2008: 62
Ng PKL & Guinot D & Davie PJF 2008: 117
Griffin DJG & Tranter HA 1986: 216
Sakai T 1976: 239
Serene R & Lohavanijaya P 1973: 50
Serene R 1968: 57
1968
Loc

Maia gibba

Alcock A 1899: 56
Alcock A 1895: 239
1895
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