Cumella (Cumella) radui Petrescu & Iliffe, 1992
Taxonomic Characterization: Small cumacean, with hairy integument. The
carapace represents less than 1/3 of the total length. The pleon has short,
widened, scaled segments and with a dorsal ridge. Long pseudorostrum. The notch
less marked. Optic lobe with 5 lenses, the lateral ones pigmented (Petrescu &
Disposition of Specimens: Grigore Antipa, Natural History Museum, collection number 751, inventory number 49,482.
Ecological Classification: Probably stygophilic
Size: Adult female measured 1.49 mm in length.
Number of Species in Genus: More than 60 species are included in the genus Cumella, the subgenus Cumella is the most numerous (about 40). None are known to be stygobitic.
Subgenus Cumella Range:
Species Range: Rat Cay Blue Hole, Rat Cay, or Bluehole Cay Blue Hole (Forfar
Blue Hole), Stafford Creek, both on North Andros Island, Great Bahama Bank,
Bahamas. Samples collected from these two caves were combined so the specific
collection location is not known.
Closest Related Species: By the body shape C. radui resembles C. clavicauda Calman, 1911.
Habitat: Marine limestone caves (ocean Blue Holes)
Ecology: Specimens were collected using a 0.3 mm mesh plankton net with a mouth diameter of 0.45 m set in the approximately 0.25 m/sec suck or blow currents at the mouth of Rat Cay and Bluehole Cay caves on Andros Island. Tidal inequalities across the broad, shallow water Bahama banks generate strong reversing currents through the caves with a period 2 to 3 hours out of phase with tides in the surrounding sea (Warner and Moore, 1984). While the inward or 'suck' currents draw slightly turbid seawater with normal temperature, salinity and dissolved oxygen levels into the caves, the outward flowing or 'blow' water is clearer, slightly cooler and may contain hydrogen sulfide.
Cumaceans were most abundant in the blow waters emanating from the Blue Holes. A total of 65 specimens were obtained in three blow plankton samples, while only 3 specimens were found in two suck samples. This indicates that these cumaceans are originating from the cave itself and are at least stygophiles if not stygobites. Blow samples in general were characterized by comparatively greater amounts of sand, crustacean exuvia, ostracod valves, fecal pellets, hydroid pieces, foraminiferans, small gastropods, ostracods, harpacticoid copepods, amphipods and isopods. Conversely, suck samples contained relatively more algal fragments and filaments, planktonic copepods and crustacean larvae (Warner & Moore, 1984).
Life History: One female has been collected.
Evolutionary Origins: Probably originated from an open water ancestor.
Conservation Status: Restricted to Rat Cay or Bluehole Cay Blue Holes, North Andros Island, Bahamas
Contributor: Iorgu Petrescu, Grigore Antipa Museum of Natural History,
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