Yucatalana robustispina

Phylum Arthropoda
Subphylum Crustacea
Class Eumalacostraca
Order Isopoda
Family Cirolanidae

Yucatalana robustispina Botosaneanu & Iliffe, 1999

Taxonomic Characterization: A very small stygobitic cirolanid isopod without eyes and pigment, not able to roll into a ball. Cephalon with round lateral bulges (possibly indicating where the lost eyes were located) and with a rather large triangular rostrum. Five well developed pleonites. Telson subtrapezoidal, with sinuous lateral margins and distal margin only with a few very short setae. Short and subequal antennulae and antennae with pauci-articulate flagelli. Mandibles: acies with strong "teeth" "plump lobe" armed with quite a few short points distant from the margin. Only pereiopod I raptorial, with very large spines with particular structure (articulate-like in their distal half); on propodus (2), carpus (1) and merus (1), and with long unguis finishing in a hook; pereiopods II-VII ambulatory, all similar (very slender), although progressively longer. Appendix masculina subbasally inserted, with capitate apex preceded by short row of minute "teeth" (Botosaneanu & Iliffe, 1999).

Ecological Classification: Stygobitic

Size: Body length - males 3 mm, females 3.5-4 mm.

Number of Species in Genus: One

Genus Range:

Yucatan Peninsula:

Species Range: Originally described from Cenote Pabakal and Cenote Kankirixche in the state of Yucatan (Botosaneanu & Iliffe, 1999). Later reported from Cenote Kakuel and Cenote Chuih-Hol (Botosaneanu & Iliffe, in prep.)

Closest Related Species: No close relationship with any other Cirolanidae.

Habitat: Freshwater limestone caves

Ecology: Specimens were collected by divers with a plankton net from the water column at 20-33 m depth in Cenote Papakal and individually in vials from the water column at 20-50 m depth in Cenote Kankirixche (Botosaneanu & Iliffe, 1999).

Life History: Collected specimens include 5 males, 4 females 1 manca and 1 exuvium.

Evolutionary Origins: Due to the enigmatic affinities of this genus, its origins are unclear, but like most other stygobitic fauna from Yucatan, it is probably derived from a marine ancestor.

Conservation Status: Restricted to four caves in the state of Yucatan.

References:

Botosaneanu, L. and T.M. Iliffe (1999). On four new stygobitic cirolanids (Isopoda: Cirolanidae) and several already described species from Mexico and the Bahamas. Bulletin de L'Institute Royal des Sciences Naturelles de Belgique, Biologie, 69:93-123, 91 figures.