Phylum Arthropoda
Subphylum Crustacea
Subclass Copepoda
Order Misophrioida
Family Misophriidae

Speleophria bivexilla Boxshall & Iliffe, 1986

	Speleophria bivexilla: dorsal view, after Boxshall & Iliffe, 1986

Taxonomic Characterization: S. bivexilla has a large, 5-segmented prosome. Carapace is better developed laterally than dorsally. Nauplius eye is absent. Labrum is small, bilobed and not fused to the rostrum. Rostrum is free and not anteroventrally directed. Antenules are 19-segmented, while antenna is biramous. Mandible consists of a well-developed gnathobase bearing several teeth along the distal margin. Maxilla is 6-segmented and maxilliped is 8-segmented. S. bivexilla is unique in possessing an asymmetrical female reproductive system which includes fused genital and first abdominal somites. Also notable is the 2-segmented endopod of the first swimming leg, the 2-segmented antennary endopod and the articulation between the maxillulary praecoxa and coxa. Two pairs of long aesthetascs on the antennules are very noticeable (Boxshall & Iliffe, 1986).

Disposition of Specimens: All specimens were deposited in the British Museum (Natural History): female holotype (registration number 1985.116) and 14 female paratypes (registration number 1985.117-126).

Ecological Classification: Stygobitic

Size: Total body length of adult female ranges from 375-408 microns, average 391 microns.

Number of Species in Genus: Two, both anchialine. Two former species of Speleophria - Speleophria campaneri Boxshall & Iliffe, 1990 and Speleophria scottodicarloi Boxshall & Iliffe, 1990 - have been transferred to Speleophriopsis by Jaume & Boxshall (1996).

Genus Range:

Species Range: Known only from Roadside Cave, Hamilton Parish, Bermuda (Boxshall & Iliffe, 1986).

Closest Related Species: Speleophria gymnesica from anchialine caves in Mallorca. Speleophria appears to be closely related to Speleophriopsis with species in Palau, Bermuda and the Balearic Islands, although much of the resemblance is due to shared primitive character states (Jaume & Boxshall, 1996).

Habitat: Anchialine limestone caves

Ecology: S. bivexilla inhabits Roadside Cave, a small single room cave located in the Walsingham Tract of Bermuda. Tides in this cave are 57% of those of the open ocean with an 80 minute lag time. Specimens were collected from a saltwater-filled fissure 8 m long by 1 m wide and 6 m deep. The water was very clear, surface salinity being 32.53 ppt and temperature being 19.9°C. At 1 m depth, salinity was 32.93 ppt and temperature was 20.5°C. Specimens were collected at depths of 1-5 m using a hand-held plankton net with a mesh size of 93 microns.

Life History: Of the 15 specimens collected, all were females. Males of this genus are unknown.

Evolutionary Origins: Speleophria and Speleophriopsis display a circumtropical distribution which fits within the ancient limits of the Early Tethys Sea (Jaume & Boxshall, 1996). They are limited to anchialine habitats with salinities close to seawater and thus, their potential for dispersal is extremely limited. They appear to have survived in place during the Upper Tertiary when the entire Mediterranean Sea dried up with the corresponding extinction of its marine biota. The discovery of stygobiont misophrioids on continental, non-volcanic islands casts doubt on the previous proposed hypothesis for a deep sea origin of anchialine lineages (Jaume & Boxshall, 1996).

Conservation Status: This species is considered to be critically endangered (IUCN, 1996). Restricted to single anchialine cave in Bermuda.

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