Reference 16918

From 1979 to 1986, large series of specimens of decapod crustaceans were obtained from intertidal and shallow- water habitats of the Gulf of California (Mexico) to a depth of about 125 m.Approximately 65,000 specimens, representing 383 species and subspecies, were gathered.This collection plus an extensive review of the literature enabled a compilation of all 530 species known from the entire Gulf: 22 Penaeoidea, 112 Caridea 13 Thalassinidea, 6 Palinura, 108 Anomura, and 269 Brachyura.For each species, the following information was obtained and analyzed: (1) a list of all reported collecting localities, (2) for non-endemics, the range outside the Gulf (throughout the eastern Pacific), and (3) the principal habitats, including depth ranges for offshore species.Gulf of California species were found in the following habitats: coastal lagoons/estuaries, 43 species (8.1%); sandy beaches, 12 species (2.3%); rocky shores, including coral reefs, 142 species (26.8%); continental shelf, 318 species (60.1%).The last are stratified bathymetrically: shore to 40 m, 162 species; 40 to 90 m, 131 species; gt 90 m, 25 species.Among the intertidal fauna, there is a sharp decrease of the number of tropical species in the northern Gulf.Similarly, only 35% of the Gulf's coastal lagoon/estuary species are found in the northern Gulf.The epibenthic water temperature on the shelf does not change dramatically from summer to winter, and the tropical fauna associated with this habitat extends much farther north than that associated with other habitats.Some 75.7% of the Gulf of California's decapod species show a clear tropical affinity.The endemic component varies from 11% (southern Gulf only) and 17% (central Gulf only) to 22% (northern Gulf only) and is 15.3% for the entire Gulf.About half of these endemic species are broadly distributed within the Gulf.If endemic is defined as restricted to an extended Cortez Province, including the Cabo San Lucas-Magdalena Bay portion of Baja California, the percentage of endemism increases to 17.5%.A larger Mexican Province should be considered, from Magdalena Bay and the whole Gulf of California south to a southern limit yet to be defined.