Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Isopoda
Family Cirolanidae

Bahalana exumina Botosaneanu & Iliffe, 2002

	Bahalana exumina: after Botosaneanu & Iliffe, 2003

Taxonomic Characterization: Completely depigmented, eyeless.  A fragile animal, some appendages easily coming off. Cephalon very well individualized, large first pereional segment is only very feebly built-in; lateral and posterior margins gently rounded; anterior margins, converging towards a short but distinct rostrum, may appear slightly sinuate. Lamina frontalis narrow, elongate, ending in sharp point; clypeus with strongly obtuse lateral ends laterally outrunning the labrum but not descending along its sides. Pereionite I devoid of coxal plates; those of pereionites II-VII all very small, in contrast with those well developed of pleonites I-V. Pleotelson roughly square, lateral margins feebly rounded, posterior margin maybe very feebly emarginate. Antennula reaching at least the limit between pleonites II and III; 2^nd peduncular article shorter than 1^st, 3^rd slightly longer than 1^st and 2^nd together, and with well individualized apical zone; remarkably long flagellum has at least 50 articles. Antenna II reaching at least the end of pleon. Strong asymmetry of the two acies of the mandibles. The pereiopods I-III show numerous structural or allometric peculiarities distinguishing them from those of already described species. The propodus of PIII is distinctly shorter and narrower than that of PI or PII. The unguis of all three is rudimentary, reduced to a minute, hyaline, indistinctly limited cone. Internal margins of carpus, propodus, dactylus, as well as of several long projections, are finely but distinctly crenelate. Uropods of about the same length as the pleotelson (Botosaneanu & Iliffe, 2002).

Disposition of Specimens: Zoological Museum Amsterdam crustacean collection (Is. 205829).

Ecological Classification: Stygobitic

Size: Length of male holotype from tip of rostrum to middle of pleotelson is 7 mm.

Number of Species in Genus: Six, all stygobitic

Genus Range:

Species Range: Known only from Oven Rock Cave in the Exuma Cays, Bahamas (Botosaneanu & Iliffe, 2002).

Closest Related Species: Bahalana geracei and Bahalana cardiopus

Habitat: Anchialine limestone caves

Ecology: Collections from Oven Rock Cave were in the main passage just below the old bat roost at depth of 15 m in fully marine salinity waters (35 ppt). Other inhabitants of this cave include remipedes, copepods, hadziid amphipods, thermosbaenaceans, and the shrimp Barbouria cubensis (Botosaneanu & Iliffe, 2002).

Life History: Only a single, male specimen has been collected.

Evolutionary Origins: The family Cirolanidae is considered the most primitive of the families of the suborder Flabellifera. It is thought that stygobitic cirolanids were stranded when high sea levels receded, either during the Cenozoic Era (55 million years ago) or during the Late Cretaceous Period (135 million years ago) (Carpenter, 1981). All five species in the genus Bahalana are found in the Bahamas archipelago.  Speciation in Bahalana was very probably a rather recent event.

Conservation Status: Restricted to a single anchialine cave in the Exuma Cays, Bahamas.

References:

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Contributor: Lazare Botosaneanu, University of Amsterdam, The Netherlands