Phylum Arthropoda
Subphylum Crustacea
Class Copepoda
Order Cyclopoida
Family Cyclopidae

Halicyclops cenoticola Rocha, 1998

Halicyclops cenoticola: dorsal view, after Rocha et al., 1998

Taxonomic Characterization: Halicyclops cenoticola is characterized by the presence of 2 inner setae on the leg 5 exopod in the males, having the dorsal caudal seta as long as the outer middle caudal setae; legs 2 and 3 are dimorphic concerning the structure of the 3 inner setae on the terminal endopodal segment; and leg 6 of both the male and female consists of only 2 elements (Rocha et al., 1998).

Taxonomic Key: see Rocha et al., 1998

Disposition of Specimens: National Museum of Natural History, Smithsonian Institution, catalog numbers USNM 261781-9; and Museu de Zoologia of the University of Sao Paula, catalog number MZUSP 12796, and El Colegio de la Frontera Sur, catalog number ECO-CHZ 00313.

Ecological Classification: Stygophilic

Size: Female body length, excluding caudal setae, measures between 0.38-0.425 mm. Adult male length, excluding caudal setae, measures 0.345-0.365 mm.

Number of Species in Genus: Numerous; 19 are stygophilic and 10 of which are found in anchialine environments

Species Range: Known only from Grutas de Santa Maria, Homun; Grutas de Tzab-Nah, Tecoh; Cenote Kambul, Noc Ac; Cenote Yuncu, in the State of Yucatan, Mexico. In the State of Quintana Roo, H. cenoticola is known from Cenote Mayan Blue, Cenote Carwash, and Cenote Najarone, all of which are commercial swimming holes near Tulum.

Closest Related Species: H. cardophilus from Borneo and H. tetracanthus from Belize in that they exclusively share the presence of 2 inner setae on the leg 5 exopod in males. According to Rocha et al. (1998), G. Pesce is describing a species of Halicyclops from north-western Australia that is also morphologically similar to these three species.

Habitat: Anchialine limestone caves

Ecology: Found free-swimming and on sandy bottom of cave pools and passages at depths between 0-30 m. Other species in the caves included numerous cave-dwelling crustaceans like shrimp, mysids, amphipods, and ostracods; the blind eel Ophisternon infernale; and the fish Ogilbia pearsei.

Life History: Collected specimens included 19 females, 15 males and 11 copepodids.

Evolutionary Origins: Considering the similar morphology and current distribution of H. cenoticola from Mexico; H. cardophilus from Borneo; H. tetracanthus from Belize; and the undescribed species from Australia, the distribution of this group is probably linked to the ancient Tethys Sea (Rocha et al., 1998).

Conservation Status: Restricted to caves in the Yucatan Peninsula.

References:

Links:

Contributor: Carlos Eduardo F. da Rocha, Universidade de São Paulo, Brazil