Phylum Arthropoda
Subphylum Crustacea
Class Eumalacostraca
Order Isopoda
Family Cirolanidae

Haptolana yunca Botosaneanu & Iliffe, 2000

	Haptolana yunca after Botosaneanu & Iliffe, 2000

Taxonomic Characterization: Haptolana yunca is completely unpigmented, lacking eyes. Habitus slender, body margins slightly convex. The cephalon is twice as wide as long, lateral margins oblique, posterior margin strongly concave. Rostrum produced as blunt knob, in lateral view curved ventrally, ending in sharp point. Antenna 1 short, first two articles coalescent, flagellum with 11 articles; antenna 2 relatively short, peduncle with five articles, flagellum with 25 articles. On the pereiopods, especially IV to VII, the characteristic spines arranged in V-shapes are well developed, but the dactily, although swinging, are rather thick and short. Pleopods with scarce coupling hooks on the coxopodites, all exopodites setose and broad. Pleotelson as long as basal width, anterolateral angles produced, distal margin rounded, with six spines and plumose setae (Botosaneanu & Iliffe, 2000).

Ecological Classification: Stygobitic

Size: Length of adult female holotype: ca 10 mm.

Number of Species in Genus: Six

Genus Range:

Species Range: Known only from Cenote Sabakha, located near Yuncu, Yucatán, Mexico.

Closest Related Species: H. yunca is most similar to H. bowmani from Yucatan and H. belizana from Belize.

Habitat: Anchialine limestone caves

Ecology: H. yunca was collected in one of the deepest cenotes of the Yucatán Peninsula. Cenote Sabakhá, meaning “turbid water”, was explored down to 147 m at which depth, and with 30 m visibility, no walls, bottom or ceiling were seen. The halocline was recorded at depths of 55 to 60 m, and just above it two horizontal passages extending 123 and 129 m in opposite directions were found. In one of the tunnels, abundant cave fish, Typhliasina pearsei, were observed. In this passage, at 60 m depth, one specimen of H. yunca was collected. The conditions were: salinity 1.4‰, temperature 27.5ºC, pH 6.4, and dissolved oxygen concentration 3.8 mg/l (Botosaneanu & Iliffe, 2000).

Life History: Only one adult female has been collected.

Evolutionary Origins: The genus Haptolana has a widely disjunct distribution with species known from Australia, Somalia and the Caribbean. It is considered to be a Tethyan relict having its origins in the Tethys Sea - the shallow tropical sea that formed between the supercontinents of Gondwana (in the South) and Laurasia (in the North), in what is now southern Europe during the Triassic period about 200 million years ago. It is believed that cave colonization took place relatively early on and that dispersal occurred through plate tectonic rafting (Humphreys, 1993).

Conservation Status: Restricted to a single cenote in the state of Yucatán.

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Contributor: Lazare Botosaneanu, University of Amsterdam, The Netherlands