Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Amphipoda
Family Ingolfiellidae

Ingolfiella (Tethydiella) longipes Stock, Sket & Iliffe, 1987

	Ingolfiella longipes: entire animal

Taxonomic Characterization: The body of I. longipes is very slender with each somite having 2 dorsal setules. Ocular lobes are present. The maxilliped endite is small and narrow. The first gnathopod has a very elongate and narrow carpus and the second gnathopod has a triangular carpus. The coxal gills are small and slightly pedunculate. The oostegites are short, narrow and armed with 2 spinules and 1 seta. Pleopods 1 and 2 are roughly triangular, while pleopod 3 is ovate; all are unarmed. The telson is rounded, fleshy and has 2 dorsal setules.

Disposition of Specimens: Female holotype from Walsingham Sink Cave deposited in the Zoological Museum of Amsterdam, Amph. 107.880.

Ecological Classification: Stygobitic

Size: Female, without antennae, 1.6 mm.

Number of Species in Genus: 32

Species Range: Known only from Walsingham Sink Cave, Hamilton Parish, Bermuda (Stock et al., 1987).

Closest Related Species: I. longipes is similar to I. britannica, I. ruffoi, I. kapuri, I. quadridentata in having 4 teeth on the inner margin of the dactylus of the gnathopods and being marine.

Habitat: Anchialine limestone caves

Ecology: One female was collected from Walsingham Sink Cave with a surface salinity of 17 ppt and a 1 m salinity of 32 ppt. It was obtained by stirring up coarse sediments in 1 m water depth and collected with a fine mesh dip net.

Life History: Only one specimen, a female, has been collected.

Evolutionary Origins: Ingolfielids are an old group with three distributional patterns: 1) bathyal or abyssal, 2) inland groundwaters of old continental landmasses, and 3) coastal interstitial and groundwaters (Stock, 1977). Based on the female morphology, I. longipes appears to belong to this latter group. Stock et al. (1987) believed that I. longipes was most closely related to the marine subgenus Hansenliella which contains species from the English Channel, Peru, Indian Ocean and Curaçao. Ruffo & Taglianti (1989) assigned it to the subgenus Tethydiella with sister species from the south Atlantic coast of the US into the Gulf of Mexico, Curaçao, and the Indian Ocean. I. longipes lacks any distinguishing autapomorphic features, except those that it shares with its sister clade. Either this species is truly primitive with regard to the members of the sister clade, or it is simply too poorly known to adequately characterize it (Schram & Vonk).

Conservation Status: I. longipes is considered to be critically endangered (IUCN, 1996). It is restricted to a single anchialine cave and known only from one specimen.

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