Symethis

Symethis is a genus of crabs. It differs from other genera in the family Raninidae by the lack of ornamentation of the male first pleopods and by the reduced number of gills (7 pairs rather than 8 pairs), and is therefore placed in a separate subfamily, Symethinae.^[1]

Symethis Temporal range: Paleogene–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Preserved specimen of S. variolosa
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Infraorder:	Brachyura
Family:	Raninidae
Subfamily:	Symethinae Goeke, 1981
Genus:	Symethis Weber, 1795
Species
Symethis corallica Davie, 1989 Symethis garthi Goeke, 1981 Symethis variolosa (Fabricius, 1793) † Symethis johnsoni Rathbun, 1935

There are three extant species:^[2]

• Symethis corallica Davie, 1989 – Chesterfield Reefs, Coral Sea ^[3]
• Symethis garthi Goeke, 1981 – Pacific coast of Panama ^[1]
• Symethis variolosa (Fabricius, 1793) – western Atlantic Ocean, from North Carolina, to Bahia, Brazil ^[1]

One further species,^[4] Symethis johnsoni is known from fossils of Paleogene age,^[5] but may belong in the subfamily Lyreidinae rather than in Symethis.^[5]

References

1. Gary D. Goeke (1981). "Symethinae, new subfamily, and Symethis garthi new species, and the transfer of Raninoides ecuadorensis to Notosceles (Raninidae: Brachyura: Gymnopleura)". Proceedings of the Biological Society of Washington. 93 (4): 971–981.
2. Peter Davie (2010). "Symethis Weber, 1795". WoRMS. World Register of Marine Species. Retrieved January 1, 2012.
3. P. J. F. Davie (1989). "Smethis corallica sp. nov. (Crustacea, Brachyura, Raninidae), the first member of the Smethinae to be recorded" (PDF). Bulletin du Muséum National d'Histoire Naturelle. 4th. 11 (A2): 425–430.
4. Sammy De Grave; N. Dean Pentcheff; Shane T. Ahyong; et al. (2009). "A classification of living and fossil genera of decapod crustaceans" (PDF). Raffles Bulletin of Zoology. Suppl. 21: 1–109.
5. David A. Waugh, Rodney M. Feldmann & Carrie E. Schweitzer (2009). "Systematic evaluation of raninid cuticle microstructure" (PDF). Bulletin of the Mizunami Fossil Museum. 35: 15–41.