Bahalana caicosana Botosaneanu & Iliffe, 2003
Bahalana caicosana: after Botosaneanu & Iliffe, 2003
Taxonomic Characterization: Cephalon dorsally distinctly wider than long, apically rounded, lateral margins sinuous with proximal bulges; it is well built in the first pereional segment, this being especially well seen o the ventral side; no rostrum. Antennula reaching at least the end of pereionite IV, but sometimes that of pereionite V; structure of peduncle without original details, but flagellum (with 31 articles in the holotype) remarkable by its length. Antenna reaching at least the end of pleonite III, but more often the end of pleon; structure of pleon without original details, but flagellum (38 articles, mostly elongate, in the holotype) distinctly exceeding – with more than 1/3 - the length of peduncle. Pleopods with completely bipartite exopodite, III-V, distal part sometimes crumpled, deeply emarginate, or even split. Endopodite, also sometimes with distal emargination; in the two larger females, as well as in the male, all endopodites with distal setae, abundant on Pl I-II, and gradually less so on Pl III-V; in the two smaller females no setation has been found on the last endopodite. Appendix masculina rooted only slightly basal from the middle of the endopodite margin (and not basally), it is straight, not longer than the endopodite, and does not end sharply pointed. Penes are short and flat (ribbon-like), tips truncate. Pleotelson slightly more than 1.5 times wider than long, lateral margins gently convex, distal margin only very slightly convex, proximal and distal margins of about the same length. Distal margin with short plumose setae between the denticles.
Disposition of Specimens: All specimens were deposited in the collections of the
Natural History Museum “Grigore Antipa”, Bucharest, Romania (MGAB ISP 884 to
Ecological Classification: Stygobitic
Size: Length of females up to 12 mm, males to 5.5 mm.
Number of Species in Genus: Five, all stygobitic
Species Range: Known from Cottage Pond on North Caicos Island and Conch
Bar Cave on Middle Caicos Island, Turks and Caicos Islands.
Closest Related Species: B. caicosana is closely related to Bahalana geracei from San Salvador and to Bahalana cardiopus from Mayaguana and Acklins, and more distant from the two remaining described species.
Habitat: Anchialine limestone caves
Ecology: Specimens were collected from fully marine waters at 25-46 m depths in Cottage Pond and from 0-5 to 15 m depths in Conch Bar Cave. Cottage pond is a deep, completely submerged sinkhole, while Conch Bar is an extensive dry cave with anchialine lakes in the interior. Specimens were collected from the water column.
Life History: Four females, one male and one manca have 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 two caves in the Caicos Islands.
Contributor: Lazare Botosaneanu, University of Amsterdam, The Netherlands
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