Abstract

Porifera has been relatively well studied from underwater caves worldwide. However, sponges in Mexico are only known from two anchialine caves: La Quebrada and El Aerolito, both in Cozumel Island. An ecological study found that sponges have the second highest species richness and density in La Quebrada. The aim of the present work is to describe the sponge biodiversity inhabiting the dark zone of La Quebrada anchialine cave. A total of ten species were found and are described herein, six are new species to science vis. Calyx maya n. sp. a thinly branched sponge; Haliclona (Reniera) stygobia n. sp. globe-shaped with the thinnest diameter of oxeas in its group; Haliclona (Halichoclona) chankanaabiis n. sp. tubular habit with the smallest oxeas in its group; Neosiphonia microtriaeneae n. sp. characterized by very small dichotriaenes; Svenzea germanyanezi n. sp. a lone conical shape; and Diplastrella cozumella n. sp. for its tri to multilobed tylostyles. The other four species are previously known from open reefs or deep-sea: Discodermia adhaerens, Siphonidium ramosum, Cinachyrella kuekenthali, and Plakinastrella onkodes. This is the only inventory of Porifera in Mexican caves up to now, thus the species here described are the first stygobiont sponges from Mexico with an endemism rate of Porifera in this anchialine cave of 60%. Conservation programs are needed to preserve this unique and special ecosystem.