Bahadzia setodactylus

Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Amphipoda
Family Hadziidae

Bahadzia setodactylus Holsinger, 1992

Taxonomic Characterization: Relatively large amphipod lacking eyes and pigment. Clearly distinguishable from all other species in the genus by reduced lacinia mobilis of right mandible (reduced to a single tooth), more palmar margin spines on male gnathopod 2, elongate and heavily setose dactyl of pereopod 6, reduced number of spines on peduncle of uropod 3, and fewer spines on telson (Holsinger, 1992). A key to the genus is presented in Jaume & Wagner, 1998.

Disposition of Specimens: National Museum of Natural History, Smithsonian Institution catalog number USNM 239476; Zoölogisch Museum, Amsterdam; and in the private collection of John Holsinger.

Ecological Classification: Anchialine stygobitic

Size: Males to 9.0 mm; females to 10.0 mm

Number of Species in Genus: Nine (8 anchialine and 1 freshwater), all stygobitic

Genus Range:

Bahamas: Cat Island: B. obliqua Stock, 1986 Grand Bahama: B. williamsi Holsinger, 1985 Abaco: B. williamsi Holsinger, 1985 South Andros: B. setimana Stock, 1986 Caicos Islands: Providenciales: B. stocki Holsinger, 1985 Cuba: B. yagerae Ortiz & Perez, 1995 Dominican Republic: B. jaraguensis Jaume & Wagner, 1998 Haiti: B. latipalpus Stock, 1985 Mexico: Isla Cozumel: B. bozanici Holsinger, 1992 and B. setodactylus Holsinger, 1992 Yucatan Peninsula: B. bozanici Holsinger, 1992
		Genus range for Bahadzia

Species Range: B. setodactylus is known only from Xcan-ha Cenote on Cozumel (Holsinger, 1992)

Closest Related Species: B. bozanici and B. setodactylus appear to be sister taxa that evolved from a common ancestor (Holsinger, 1992).

Habitat: Anchialine limestone caves

Ecology: B. setodactylus was collected below a halocline (34 ppt salinity) at 12 m depth. Associated fauna includes the shrimp Agostocaris bozanici (Holsinger, 1992).

Life History: The type series consisted of 2 males and 8 females.

Evolutionary Origins: The genus Bahadzia is most closely allied phylogenetically with Mayaweckelia and Tuluweckelia from the Yucatan Peninsula (Holsinger, 1992). Of these three genera, Bahadzia represents the most recent cave colonization event, thought to have occurred during the middle to late Pleistocene. B. bozanici is believed to be close to the putative ancestral species that independently and simultaneously colonized caves on both Cozumel and the mainland (Holsinger, 1992). B. setodactylus, inhabiting an adjacent but apparently separate aquifer system on Cozumel, has diverged to a greater degree.

Conservation Status: Known only from a single cave on the the island of Cozumel.

References:

Holsinger, J.R. 1992. Two new species of the subterranean amphipod genus Bahadzia (Hadziidae) from the Yucatan Peninsula region of southern Mexico, with an analysis of phylogeny and biogeography. Stygologia, 7:85-105.
Holsinger, J.R. and J. Yager. 1985. A new genus and two new species of subterranean amphipod crustaceans (Hadziidae) from the Bahamas and Turks and Caicos Islands. Bijdragen tot de Dierkunde, 55(2):283-294.
Jaume, D. and H.P. Wagner. 1998. New cave-dwelling amphipods (Lysianassidae, Hadziidae) from the Dominican Republic (Hispaniola). Contributions to Zoology, 68(1):37-66, 19 figures.
Ortíz, M.R. and A. Pérez. 1995. Una nueva especie de anfipodo cavernícola hadzioideo (Amphipoda, Gammaridea) de Cuba. Graellsia, 51:165-168.
Stock, J.H. 1985. Stygobiont amphipod crustaceans of the Hadzioid group form Haiti. Bijdragen tot de Dierkunde, 55:331-426.
Stock, J.H. 1986. Two new amphipod crustaceans of the genus Bahadzia from 'blue holes' in the Bahamas and some remarks on the origin of the insular stygofaunas of the Atlantic. Journal of Natural History, 20:921-933, 5 figures.