Phylum Arthropoda
Subphylum Crustacea
Subclass Ostracoda
Order Podocopida
Family Paracyprididae
Subfamily Thalassocypridinae
Dolerocypria bifurca Maddocks, 1986
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Dolerocypria bifurca: right and left valve exteriors of male
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Taxonomic Characterization: Dolerocypria bifurca has a very
thin-walled carapace which is compressed, fragile, and translucent white showing
reddish-brown epidermis and a conspicuous eye underneath. This species has broad
open vestibules with no radial pore canals visible. The ovaries and testes are
housed between valve lamellae in the posterior, with the testes extending
forward to another coil in the anterior vestibule as well. The antennae have
five swimming setae and the palp of the male fifth limb has two grotesquely
elongated, flattened, stiff, ribbon-like setae that arise ventrally and
proximally near its base. They are probably homologous with the "pegs" and
"small setae" that occur on the ventrodistal edge of the basal in other marine
Cypridacea. The distal hook is plump, lobate, terminated by large, possibly
sensory seta that are moderately asymmetrical. The furca has two stout pectinate
claws and a tiny anterodistal seta. The hemipenis is roughly oblong, sinuous and
lobate in outline. Zenker's organ is small with five chitinous rosettes
(Maddocks & Iliffe, 1986).
Disposition of Specimens: All specimens were deposited in the United
States Museum of Natural History: male holotype (USNM 216452) and paratypes
(USNM 216453-216455).
Ecological Classification: Either stygophilic or accidental
Size: Length of right valve 0.32 mm.
Number of Species in Genus: At least 6
Species Range: Known from Green Bay, Deep Blue, and Walsingham Caves,
Bermuda (Maddocks & Iliffe, 1986).
Closest Related Species: Dolerocypria bifurca
is similar to D. taalensis from the Philippines. However, the later
species has a slightly more acute posterior end, a larger comb on the pectinate
seta of the seventh limb with longer, more sharply tapering barbs, and a fourth,
very tiny, dorsal seta on the furca. Another similar species, D. fastigata
found in the Florida Everglades differs in that it is much more elongate
posteriorly with a more stretched-out adductor muscle-scar pattern. D.
bifurca differs from D. inopinata as this species is nearly ovate,
less elongate, with two small ventral setae on the palp of the male fifth limb
(Maddocks & Iliffe, 1986).
Habitat: Anchialine limestone caves
Ecology: D. bifurca was separated from algae at 1-2 m water depths
of the cave entrance pools, collected with a long-handled fine-mesh dip net from
open water and from algal covered rocks in 0-2 m water depths, and collected in
16 m open water depths using a fine-mesh hand net. The occurrence of D.
bifurca in a plankton tow in Green Bay Cave suggests good swimming ability,
even though the so-called "swimming setae" are reduced. It has not yet been
found in sediment samples outside of caves, perhaps because it is rather small
and fragile (Maddocks & Iliffe, 1986).
Life History: Collected specimens included 2 males, 1 female and 3
juveniles.
Evolutionary Origins: D. bifurca may be related to species
described from mangrove swamps and coastal lagoons of Florida and the
Netherlands West Indies (Maddocks & Iliffe, 1986).
References:
- Maddocks, R.F. and T.M. Iliffe. 1986. Podocopid
Ostracoda of Bermudian caves. Stygologia, 2: 26-76, 18 figures.
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Links:
Contributor: Dr. Rosalie F. Maddocks, University of Houston, Houston,
Texas USA
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