Thetispelecaris remex

Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Subclass Eumalacostraca
Superorder Peracarida
Order Bochusacea (Mictacea partim)
Family Hirsutiidae

Thetispelecaris remex Gutu & Iliffe, 1998

Taxonomic Characterization: Cylindrical body. Cephalon fused with one thoracic somite. Pereon formed of seven free pereonites. Pleon with six pleonites. Telson free. Eye lobes absent. Antennule with three-segmented peduncle and two flagella. Antenna with squama. Mouthparts, completely uncovered, large sized, with numerous long setae. Distinguished from other members of family Hirsutiidae by pereopod I with exopodite. Also, labium (paragnaths) with palpiform rostral prolongation distally covered with long hairs. (View Scanning Electron Micrographs of T. remex)

Ecological Classification: Stygobitic

Size: Females' length range from 1.2 to 1.6 mm.

Number of Species in Genus: Two

Genus Range:

Bahamas: Exuma Cays: Great Exuma Island: Thetispelecaris remex Gutu & Iliffe, 1998 Norman's Pond Cay: Thetispelecaris remex Gutu & Iliffe, 1998 Stocking Island: Thetispelecaris remex Gutu & Iliffe, 1998 Cayman Islands: Grand Cayman Island: Thetispelecaris yurikago Ohtsuka, Hanamura & Kase, 2002
		*Thetispelecaris*: genus range

Species Range: Norman's Pond Cave, Norman's Pond Cay; Mystery Cave, Stocking Island; and Master Harbour Cave, Great Exuma Island, all within the Exuma Cays, Great Bahama Bank, Bahamas

Closest Related Species: T. remex is most closely related to the only other species in the genus, T. yurikago from Grand Cayman Island. Thetispelecaris is a sister genus of Hirsutia, which consists of deep-sea species from the Tasmanian Sea and Atlantic Ocean.

Habitat: Anchialine and marine limestone caves

Ecology: Found in fully marine salinity water, at depths ranging from 6 to 50 m. They were collected from the ceiling, walls, silt ledges, and sandy floor of both inland anchialine caves and ocean blue holes.

Life History: The order Bochusacea is unique among the Peracarida. Most peracaridan females have a marsupium formed of oostegites (temporary structures) which are developed on adults only in the reproductive period. In Bochusacea, the epipodites (permanent structures) probably have the temporary role of sustaining the eggs without forming a marsupium. However, pereopod I is functional, morphologically similar to a maxilliped, and can be considered maxilliped II. 16 females and 5 manca were collected. The males of this species are unknown. The manca stage is characterized by absence of the last pair of pereopods and epipodites, while the pleopods are present. Manca range in size from 0.80 to 0.95 mm.

Evolutionary Origins: The presence of the epipodites in females, which may play the role of oostegites, indicate that this may be the most primitive order of Peracarida, bordering the superorder Syncarida. It is questionable that Bochusacea are actually Peracarida (Sanders, Hessler & Garner, 1985:55; Gutu & Iliffe, 1998:98; Gutu, 1998:121; Hessler, 1999:90).

Conservation Status: Restricted to three caves within the Exuma Cays.

Gutu, M. 1998. Spelaeogriphacea and Mictacea (partim) suborders of a new order, Cosinzeneacea (Crustacea, Peracarida). Travaux du Museum National d'Histoire Naturelle "Grigore Antipa", 40:121-129.
Gutu, M. 2001. Emendations on the description of Thetispelecaris remex Gutu and Iliffe, 1998 and the diagnosis of the Order Bochusacea (Crustacea: Peracarida). Travaux du Museum National d'Histoire Naturelle "Grigore Antipa", 43:47-57.
Gutu, M. and T.M. Iliffe. 1998. Description of a new Hirsutiid (n.g., n.sp.) and reassignment of this family from order Mictacea to the new order, Bochusacea (Crustacea, Peracarida). Travaux du Museum National d'Histoire Naturelle "Grigore Antipa", 40:93-120, 12 figures.
Hessler, R.R., 1999. Ordre des Mictaces. In: Traite de Zoologie (P. Grasse, Ed.), Crustaces, Peracarides (sans la direction de J. Forest), 7(3A), Memories de l'Institut Oceanographique Monaco, 19:87-91.
Ohtsuka, S., Y. Hanamura and T. Kase. 2002. A new species of Thetispelecaris (Crustacea: Peracarida) from submarine cave on Grand Cayman Island. Zooloigcal Science, 19(5):611-624.
Sanders, H.L., R.R. Hessler and S.P. Garner. 1985. Hirsutia bathyalis, a new unusual deep-sea benthic peracaridan crustacean from the tropical Atlantic. Journal of Crustacean Biology, 5(1):30-57.

Contributor: Modest Gutu, Grigore Antipa National Museum of Natural History, Bucharest, Romania