Alcomaja, 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 : 145

publication ID	https://doi.org/ 10.5281/zenodo.5384590
publication LSID	lsid:zoobank.org:pub:40BCDD62-D35E-46D1-95A3-2CC0DF219DEE
DOI	https://doi.org/10.5281/zenodo.5466795
persistent identifier	https://treatment.plazi.org/id/C3EE8C3E-4F10-433C-B1FA-974B8F3E563E
taxon LSID	lsid:zoobank.org:act:C3EE8C3E-4F10-433C-B1FA-974B8F3E563E
treatment provided by	Valdenar
scientific name	Alcomaja
status	gen. nov.

Treatment

Key to species of Alcomaja View in CoL n. gen.

1. Dorsal surface of carapace and ambulatory legs densely covered with long, stiff setae ( Fig. 17F View Fig ); G1 almost straight with distinct ventral fold ( Fig. 20R–T View Fig ); Philippines..................................... ......................................................... Alcomaja desmondi View in CoL n. sp.

– Dorsal surface of carapace and ambulatory legs covered with scattered short, hooked setae, sometimes dense; G1 curved... .................................................................................................2

2. Dorsal surface of carapace covered with small rounded granules, lateral and branchial spines strong even as adults, with 2 hepatic spines; adult ambulatory legs relatively short, with first leg of adult males not substantially elongated ( Figs. 17A–E View Fig ) .........3

– Dorsal surface of carapace covered with small and large granules, sometimes sharp, lateral and branchial spines distinct but low to absent in adults, with 2 hepatic spines; adult ambulatory legs long, with first leg of adult males prominently elongated ( Figs. 16A–E View Fig )..........................................................................5

3. Carapace relatively more elongate; pseudorostral spines long ( Figs. 17E View Fig , 36O View Fig ); G1 gently curved with distal part gently curved downwards ( Fig. 20O–Q View Fig ); Madagascar........................ .............................................................. Alcomaja miriky View in CoL n. sp.

– Carapace relatively broad; pseudorostral spines relatively shorter ( Figs. 17A–D View Fig , 36M, N View Fig ); G1 similar to above or otherwise ..4

4. Intercalated spine acutely triangular ( Fig. 36M View Fig ); G1 strongly curved, with distal part gently curved downwards ( Fig. 20A–J View Fig ); Japan and Taiwan...................................................................... ............................. Alcomaja nagashimaensis (T. Sakai, 1969) View in CoL

– Intercalated spine basally subquadrate ( Fig. 36N View Fig ); G1 gently curved, with distal part gently curved upwards ( Fig. 20K–M View Fig ); Solomon Islands................................... Alcomaja latens View in CoL n. sp.

5. Dorsal surface of carapace with distinct small and large sharp and rounded granules; intercalated tooth triangular ( Figs. 16D, E View Fig , 18A, B View Fig ); G1 gently curved, distal part relatively short ( Fig. 19G View Fig ); Moluccas and Western Australia ................................... ...................... Alcomaja confragosa ( Griffin & Tranter, 1986) View in CoL

– Dorsal surface of carapace as above or otherwise ( Figs. 16A–C View Fig , 18C–F View Fig ); intercalated tooth subtruncate basally ( Fig. 18C–F View Fig ): G1 gently or strongly curved..................................................6

6. Dorsal surface of carapace with distinct small and large sharp, rounded granules ( Figs. 16B, C View Fig , 18C, D View Fig ); pseudorostral spines with rounded cross-section ( Fig. 18C, D View Fig ); ischium of third maxilliped distinctly granular ( Fig. 45B, C View Fig ); G1 gently curved, distal part straight ( Fig. 19D–F View Fig ); South China Sea and Philippines............... Alcomaja gracilipes ( Chen & Ng, 1999) View in CoL

– Dorsal surface of carapace with small and large rounded granules, some of which merge basally ( Figs. 16A View Fig , 18E, F View Fig ); pseudorostral spines dorsoventrally flattened ( Fig. 18E, F View Fig ); ischium of third maxilliped smooth ( Fig. 45A View Fig ); G1 strongly curved, distal part curved upwards ( Fig. 19A–C View Fig ); Philippines........................................................... Alcomaja irrorata View in CoL n. sp.