Seven new deep-water Tetractinellida (Porifera: Demospongiae) from the Galápagos Islands – morphological descriptions and DNA barcodes

Abstract

The Galapagos Islands, positioned in the confluence of warm and coldwater currents in the Eastern Pacific, is well known for the high degree of endemism of its marine invertebrate fauna. This fauna has been studied extensively in recent years: the echinoderms, corals and other benthic cnidarians, but little is known about the deep- and shallow-water sponge faunas. To date, only 70 sponge species have been described from the Galapagos Islands, 37 of which are endemic. Of these 70 species, only one shallow-water species of desma-bearing Tetractinellida (Demospongiae), Corallistes isabela, has been reported. In 1995, Harbor Branch Oceanographic Institution, Florida, led an expedition around the Galapagos archipelago, focussed on the collection of deep-water Porifera. Here, we describe seven new species and provide DNA barcodes for the tetractinellids from these collections. Phylogenetic relationships of these new species are discussed and compared with other material from the Caribbean, the Central and West Pacific Oceans. The new species represent five genera (Craniella, and desma-bearing Tetractinellida Neophrissospongia, Corallistes, Raeodiscula and Scleritoclerma). Phylogenetic reconstructions combining independent markers (mtDNA and rDNA) support the generic affiliation of these new species and confirm the separation of Eastern Pacific species from Caribbean and Central to West Pacific species.