How is the anchialine fauna distributed within a cave? A study of the Ox Bel Ha System, Yucatan Peninsula, Mexico

Abstract

A study describing the diversity and distribution pattern of the stygobitic fauna in the Ox Bel Ha anchialine cave system adjacent to the Caribbean coast of the Yucatan Peninsula, Mexico is presented. A total of 15 species of crustaceans were collected in three surveys at four points situated along a 10.2 km transect perpendicular to the coast line. A freshwater mass dominated throughout the transect with a halocline that appeared progressively deeper, from 10 to 18 m, with increasing distance from the coast. All the recorded species, except for one, occurred throughout the transect with no defined pattern. Abundance and species richness did not vary significantly with distance from the coast, whereas diversity (H') peaked in the second sampling site at 3.17 km from the coast. As expected, most of the organisms occurred only in the freshwater layer, except for the remipede Xibalbanus tulumensis (Yager, 1987) that was found always at or below the halocline, and five other species that were found above and below the halocline. In the horizontal scale, species composition and occurrence mixed without a defined pattern, both, for sampling dates and sites. The results show that the analyzed fauna is distributed throughout the 10.2 km transect without showing any defined horizontal zonation pointing to a high connectivity among all sections. Due to the high connectivity within the caves in the area, it is expected that significant variation in species composition and distribution will be found at a larger regional scale.

New distribution records of subterranean crustaceans from cenotes in Yucatan (Mexico)

“…It is most likely that this species has a coastal distribution along the anchialine systems of the Yucatan Peninsula. Previous records were reported from cenotes located 2-10 km from the coastline near Tulum, where they occurred mostly above and at the halocline (Álvarez & Iliffe 2008;Álvarez et al 2015;Benítez et al 2019). In Cenote Cervera, 3.6 km inland from the northern coast of the Yucatan Peninsula, we observed individuals both above and below the halocline, as well as in the hydrogen sulfide layer.…”

“…Previous distribution. Gordon 1958;Botosaneanu 1980;Bowman et al 1984;Pesce and Iliffe 2002;Álvarez and Iliffe 2008, Álvarez et al 2015, Benítez et al 2019 Type locality is Devil's Hole, St. Martin, Lesser Antilles (France). The species is known from the Bahamas, Anguilla, Puerto Rico, and the Yucatan Peninsula.…”

“…Previous distribution. Creaser 1936Creaser , 1938Nicholas 1962;Bowman 1977;Reddell 1977Reddell , 1981Holsinger 1990;Iliffe 1992Iliffe , 1993Fiers et al 1996;Rocha et al 1998Rocha et al , 2000Suárez-Morales and Rivera Arriaga 1998;Pohlman et al 2000;Pesce and Iliffe 2002;Schmitter-Soto et al 2002;Álvarez and Iliffe 2008;Álvarez et al 2015;Benítez et al 2019. Type locality is Grutas de Balankanche (Yucatan). Widely distributed in the central and northern parts of the Yucatan Peninsula, known from several wells, cenotes and caves of Quintana Roo and Yucatan.…”

“…As M. troglomorpha was found in approximately 30% of the visited sites, it does not appear to be a rare freshwater stygobiotic element in the Yucatan cenotes. Holsinger 1977Holsinger , 1990Reddell 1981;Álvarez and Iliffe 2008, Álvarez et al 2015, Angyal et al 2018, Benítez et al 2019 Type locality is Cenote Xtacabiha (Yucatan). From Yucatan the species was also known from Cueva de Orizaba, Cenote Nohchen, Grutas de Tzab-Nah and Grutas de Santa Maria.…”

“…Holsinger (1990) found that the species is associated mainly with freshwater habitats, with few populations occurring in weak brackish water. Individuals found in the Ox Bel Ha System (Quintana Roo) by Álvarez et al (2015) and Benítez et al (2019) also occurred in freshwater. Type locality is Cenote Calavera (Temple of Doom) in Quintana Roo.…”