Micro-crustacean communities (Crustacea: Ostracoda, Cladocera) from karst aquatic ecosystems of the Yucatan Peninsula

NORMA FERNANDA CHARQUEÑO CELIS; ALEXANDER CORREA-METRIO; LISETH PÉREZ

Torino

Congreso; SIL 2016; 2016

The Neotropical Yucatan Peninsula is a karst environment that possesses a large number of aquatic ecosystems. The most famous water bodies on the peninsula are the open cenotes, or solution sinkholes. In the southern part of the region there are several lakes of different origin. Numerous aquatic invertebrates are found on the peninsula, and among the most abundant and diverse are the Ostracoda and Cladocera. We collected and identified ostracodes and cladocerans from surface sediments obtained with an Eckman dredge of 11 aquatic ecosystems in the southern Yucatan Peninsula (Muyil, Señor, Chichancanab, Sijil Noh Ha, Emiliano Zapata, Chacchoben, Miguel Hidalgo, Bacalar, Encantada, Chacanbacab, and San Jose de la Montaña). This study provides basic information about the species richness, relative abundances and spatial distribution of cladocerans and ostracodes that inhabit karst aquatic ecosystems in southeastern Mexico. A total of 1420 individuals were identified, of which ostracodes represented 69.7% and cladocerans 30.3%. Cladocerans, however, displayed higher species richness, with 16 species from 13 genera and five families. Chydoridae was the family with the greatest number of species (8). Macrothrix elegans was the most common cladoceran, represented by 164 individuals from nine localities. Ostracoda were represented by 14 species from 13 genera and five families. The family Cyprididae was the most diverse, with five species. Cypridopsis vidua was the most abundant taxon, with 447 individuals. Lakes Chacanbacab and Chichancanab showed the highest diversity, with a combined total of 10 microcrustacean species, but Chacanbacab had more species of cladocerans (7) than ostracodes (3). In Lakes Chichancanab and Bacalar, we found a higher number of ostracodes, with 10 species in each. Emiliano Zapata had the greatest overall crustacean abundance, and of 424 individuals, 414 were ostracodes. Chacanbacab was second in terms of total crustacean abundance (244 individuals), but the cladocerans dominated (195). This represents the first time that Chacanbacab, Sijil Noh Ha, Señor and San Jose de la Montaña were studied. All of the crustacean species found have a Neotropical distribution and were reported previously from other aquatic ecosystems in the lowlands of the Yucatan Peninsula. We encountered the ostracode Darwinula stevensoni and the cladoceran Ilyocryptus spinifer, which are widely distributed in water bodies on the peninsula. Both ostracodes and cladocerans are common invertebrates in the karst aquatic ecosystems of the southern Yucatan Peninsula. In general, they display similar species richness, but ostracodes often outnumber cladocerans, except in Lake Chacanbacab, where the most numerous and diverse microcrustaceans are Cladocera.