Spelaeoecia styx

Phylum Arthropoda
Subphylum Crustacea
Class Ostracoda
Order Halocyprida
Family Halocyprididae

Spelaeoecia styx Kornicker, 1990

Taxonomic Characterization: Carapace uncalcified, flexible and elongate. Dorsal margin straight. Ventral margin convex but fairly straight at midlength. Sexual dimorphism is present. Posterodorsal gland of right valve on protuberance. Adult furca with 7 claws on each lamella. First antenna without ventral bristle on 3rd joint (Kornicker, Yager & Williams, 1990).

Disposition of Specimens: National Museum of Natural History, Smithsonian Institution, catalog numbers USNM 193440, 194260-1, 194266, 194270, 194270-8, 194285, 194295-9, 194300, 194325-7, 194414-5, 194434, 194450, 194530-1.

Ecological Classification: Stygobitic

Size: Adult male carapace length ranges from 0.91-1.11 mm; adult female from 0.95-1.16 mm.

Number of Species in Genus: Ten, all from anchialine caves.

Genus Range:

Bahamas:
- Exuma Cays: S. capax Kornicker, 1990 and S. styx Kornicker, 1990 as reported by Kornicker & Iliffe, 1998, 2000
- Grand Bahama Island: S. sagax Kornicker, 1990; S. parkeri Kornicker & Iliffe, 2002
- Long Island: S. capax Kornicker, 1990
- South Andros Island: S. styx Kornicker, 1990
- San Salvador: S. barri Kornicker & Barr, 1997
Bermuda: S. bermudensis Angel & Iliffe, 1987
Cuba:
- S. cubensis Kornicker & Yager, 1996
- S. saturno Kornicker & Yager, 2002
Jamaica: S. jamaicensis Kornicker & Iliffe, 1992
Yucatan, Mexico: S. mayan Kornicker & Iliffe, 1998

Spelaeoecia: genus range

Species Range: Found only in El Dorado Cave, South Andros Island (type locality), Oven Rock Cave, Great Guana Cay, Exuma Cays, and Norman's Pond Cay, Exuma Cays, all on the Great Bahama Bank, Bahamas.

Closest Related Species: Resembles S. sagax from Grand Bahama Island on the Little Bahama Bank.

Habitat: Anchialine limestone caves

Ecology: Collected at depths of 0-35 m in fully marine salinity waters (35 ppt). In addition to being found in the water column, specimens were collected from fine, dark brown silt on ledges. Gut contents of some female specimens composed of crustacean-like claws, suggesting a carnivorous or scavenger-like lifestyle.

Life History: Species is composed of adults and instars A-1 to A-5. 80 specimens have been collected. Of the 80 specimens, 15 were adult females, 16 were adult males, 2 were A-1 males, 15 were A-1 females, 12 were A-2 (sex unknown), 9 were A-3 (sex unknown), 6 were A-4 (sex unknown) and 5 were A-5 (sex unknown). At least one adult male had sperm clusters near the copulatory limbs, with each cluster containing abundant thread-like filaments (Kornicker, Yager & Williams, 1990).

Evolutionary Origins: The evolutionary origins of stygobitic ostracodes remain undetermined. They may have originated from the deep sea (Iliffe 1990:95; 1991:227-228) or from shallow water crevices (Danielopol, 1990:141; Danielopol et al., 1996:82). These ostracodes may have been in shallow anchialine pools and then migrated to the more stable cave environment (Iliffe in Kornicker & Iliffe, 1998:2). The genera Deeveya Kornicker & Iliffe, 1985 and Spelaeoecia Angel & Iliffe, 1987 comprise the subfamily Deeveyinae Kornicker & Iliffe, 1985. The distribution of this subfamily is restricted to the Caribbean, West Indies, Bermuda, and Yucatan Peninsula.

Conservation Status: Restricted to two anchialine limestone caves on the Great Bahama Bank.

References:

Angel, M.V. and T.M. Iliffe. 1987. Spelaeoecia bermudensis new genus, new species, a halocyprid ostracod form marine caves in Bermuda. Journal of Crustacean Biology, 7:541-553, 7 figures, 3 tables.
Danielopol, D.L. 1990. The origin of the anchialine cave fauna - the "deep sea" versus the "shallow water" hypothesis tested against the empirical evidence of the Thaumatocyprididae (Ostracoda). Bijdragen tot de Dierkunde, 60(3/4):137-143, figure 1.
Danielopol, D.L., A. Baltanas, and G. Bonaduce. 1996. The darkness syndrome in subsurface-shallow and deep-sea dwelling Ostracoda (Crustacea). In: F. Uiblein, J. Ott and M. Stachowitsch, editors, Deep-Sea and Extreme Shallow-Water Habitats: Affinities and Adaptations. Biosystematics and Ecology Series, 11:123-144. Vienna: Austrian Academy of Sciences.
Iliffe, T.M. 1990. Crevicular dispersal of marine cave faunas. Memoires de Biospeologie, 17:93-96.
Iliffe, T.M. 1991. Anchialine fauna of the Galapagos Islands. In M.J. James, editor, Galapagos Marine Invertebrates. Pages 209-231. New York: Plenum Press.
Kornicker, L.S. and D.J. Barr. 1997. Anchialine Ostracoda (Halocypridinae) from San Salvador, Bahamas. Smithsonian Contributions to Zoology, 588:1-20, 11 figures, 2 tables.
Kornicker, L.S. and T.M. Iliffe. 1992. Ostracoda (Halocypridina, Cladocopina) from anchialine caves in Jamaica, West Indies. Smithsonian Contributions to Zoology, 530:1-22, 11 figures, 9 tables.
Kornicker, L.S. and T.M. Iliffe. 1998. Myodocopid Ostracoda (Halocypridina, Cladocopina) from anchialine caves in the Bahamas, Canary Islands, and Mexico. Smithsonian Contributions to Zoology, 599:1-93, 62 figures, 2 maps, 9 tables.
Kornicker, L.S. and T.M. Iliffe. 2000. Myodocopid Ostracoda from Exuma Sound, Bahamas, and from marine caves and blue holes in the Bahamas, Bermuda and Mexico. Smithsonian Contributions to Zoology, 606:1-98, 56 figures, 2 maps, 9 tables.
Kornicker, L.S. and J. Yager. 1996. The troglobitic halocyprid Ostracoda of anchialine caves in Cuba. Smithsonian Contributions to Zoology, 580:1-16, 9 figures, 1 table.
Kornicker, L.S. and J. Yager. 2002. Description of Spelaeoecia saturno, a new species from an anchialine cave in Cuba, (Crustacea: Ostracoda: Myodocopa: Halocyprididae). Proceedings of the Biological Society of Washington, 115(1):153-170, 11 figures, 2 tables.
Kornicker, L. S., J. Yager, and D. Williams. 1990. Ostracoda (Halocyprididae) from anchialine caves in the Bahamas. Smithsonian Contributions to Zoology, 495:1-51, 30 figures, 4 tables.

Contributor: Louis S. Kornicker, National Museum of Natural History, Washington, DC