Phylum Arthropoda
Subphylum Crustacea
Class Remipedia
Order Nectiopoda
Family Speleonectidae

Cryptocorynetes haptodiscus Yager, 1987


Taxonomic Characterization: Maxilla 2 and maxilliped with inflated distal segments bearing many stalked discoid organs. Body elongate, slender, without pigment or eyes. Cephalic shield small, tapered slightly at anterior end. Sternites of trunk segments developed as plates, with small triangular posterolateral projections. The discord organs appear to be unique (Yager, 1987).

Ecological Classification: Stygobitic

Size: Maximum length of measured specimens is 16.3 mm.

Number of Species in Genus: One

Genus Range:

Bahamas: Abaco Island: C. haptodiscus Yager, 1987 Grand Bahama Island: C. haptodiscus Yager, 1987
	Cryptocorynetes: genus range

Species Range: Known from Dan's Cave, Abaco Island and Mermaid's Lair, Old Freetown Cave System, Grand Bahama Island, Bahamas.

Closest Related Species: This is the only species within the genus. It does share some characteristics with the remipede Speleonectes benjamini.

Habitat: Anchialine limestone caves

Ecology: Free-swimming. Collected in the water column in the aphotic zone below the density interface in polyhaline to euhaline water. Associated fauna include remipedes, amphipods, ostracods, cirolanid isopods, thermosbaenaceans, blind cave fish and the epigean spiny cheek sleeper fish.

Life History: Three adults and four subadults have been collected. According to Yager, 1994: "Remipedes are simultaneous hermaphrodites. The ovary originates in the posterior portion of the head and lies dorsal to the midgut. The oviducts extend ventrally to the 7th swimming or trunk appendages where the female gonopores are located. The female gonopore is a semicircular structure on the posterior base of the protopod.
The testes are paired organs which originate in the 7th trunk segment and extend posteriorly until about the 10th trunk segment. At this position, there is a transition from testes to vas deferens. The vas deferens extends to the male gonopores located at the base of the 14th swimming or trunk appendages. Spermatids are flagellate with a 9+2 microtubular arrangement. As they mature and move posteriorly, they are packages into spermatophores.
To date, nothing is known about remipede development. Small juveniles have been collected which resemble adults. They are about one-third or less the length of adults."

Evolutionary Origins: The large number of trunk segments, each with similar, laterally directed, biramous, swimming appendages, plus a combination of the other characteristics necessitated the erection of a new crustacean class, the Remipedia (Yager, 1981). Remipedes are believed to be the most primitive of living crustaceans. The fossil species Tesnusocaris goldichi Brooks from Late Mississippian deposits in Texas has been placed in this class. The recent discovery of remipedes from anchialine caves in Western Australia is further evidence for a Tethyan distribution (Yager & Humphreys, 1996).

Conservation Status: Restricted to two anchialine caves in Abaco and Grand Bahama.

References:

Links:

Contributor: Jill Yager, Antioch College, Yellow Springs, OH