Littoral tanaidaceans (Crustacea: Peracarida) from Guerrero and Oaxaca, Mexico

Abstract

The tanaidaceans are essential components in food chains of marine benthos, since they are the main food source for commercially important species and other marine organisms. Despite their importance, problems related to their biology and taxonomy have delayed the understanding of the group, as observed on the coasts of Guerrero and Oaxaca, where only 1 genus was previously known. The aim was to determine the species richness and distribution patterns of littoral tanaids from Guerrero and Oaxaca. A total of 4 275 specimens were collected and 6 families and 9 morphotypes have been identified: Hexapleomera robusta, Sinelobus stanfordi, Leptochelia cf. dubia, Paratanais cf. denticulatus, Paradoxapseudes cf. garthi, Apseudormorpha sp., Cyclopoapseudes cf. indecorus, Synapseudes sp. and Parapseudes pedispinis. All species are new records for the littorals of Guerrero and Oaxaca. Hexapleomera robusta increased the range distribution to the north, from the Galapagos to Guerrero; and S. stanfordi and P. pedispinis are the first intermediate records for a previously disjunct distribution in the East Pacific. With respect to the distribution patterns, 6 species have restricted distribution, represented by possible new species; 2 species have a wider distribution, and 1 species has restricted distribution to the tropical eastern Pacific.