Taxonomy and distribution of Macrothricidae (Crustacea: Anomopoda) in southeastern México, northern Guatemala and Belize

Abstract

A SURVEY CONDUCTED IN NUMEROUS TEMPORAL AND PERMANENT FRESHWATER SYSTEMS (LAGOONS, LAKES, SINKHOLES, WETLANDS, PUDDLES) SINCE 1995 TO 2001 IN SOUTHEASTERN MEXICO, NORTHERN GUATEMALA AND BELIZE, ESTABLISHED THE OCCURRENCE OF EIGHT MACROTHRICID SPECIES. HALF OF THE TAXA ARE SUBTROPICAL-PANTROPICAL (50%), OTHERS ARE CIRCUMTROPICAL (37.5%) AND 12.5% ARE POSSIBLE ENDEMICS. MACROTHRIX ELEGANS IS THE MOST COMMON SPECIES IN THE STUDIED REGION. GRIMALDINA CF. BRAZZAI AND GUERNELLA CF. RAPHAELIS CONSTITUTE TAXA WITH LOCAL CHARACTERISTICS AND DIFFERENT FROM AFRICAN POPULATIONS. MACROTHRIX SPINOSA IS IN A SITUATION SIMILAR TO THE FORMER SPECIES. ONCHOBUNOPS TUBERCULATUS AND MACROTHRIX MARTHAE ARE SPECIES WITH RESTRICTED DISTRIBUTION, THE LATTER IS PROBABLABLY AND ENDEMIC OF SOUTHER MEXICO. MACROTHRIX PAULESIS AND STREBLOCERUS PYGMAEUS ARE RECORDED BY THE FIRST TIME, AND DDESCRIBED IN DETAIL. WE ESTIMATE THAT THE MACROTHRICID FAUNA REPRESENTS 66.67% OF THE THEORETICAL MAXIMUM FOR THIS REGION, ACCORDING TO CLENCH S EQUATION. FINALLY, A KEY FOR MACROTHICIDS OF THIS REGION IS PROPOSED.