The dataset contains information on specimens examined in the paper “An update on marine sponge diversity in the Southern Gulf of Mexico coral reefs” submitted in Zootaxa. This dataset contains information on 231 specimens of 80 species of the Demospongiae class, including their distribution in coral reefs in the Southern Gulf of Mexico, and their depth. All specimens are hosted in the National Collection of the Phylum Porifera Gerardo Green” (CNPGG), at the Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mexico City.