title: Vansoestia caribensis gen. nov., sp. nov.: first report of the family Ianthellidae (Verongida, Demospongiae) in the Caribbean.
abstract: A thin fiber-less sponge from Caribbean reefs (Bocas del Toro, Panama) with close genetic affinities (based on 18S and 28S nuclear ribosomal RNA gene sequences) to large fan-shaped fiber-bearing sponges (Ianthella and Anomoianthella) from the Indo-Pacific Ocean is here presented. We describe its overall external morphology, histological features, and ultrastructure. Its genetic distance from the only previously known fiber-less verongid genus, Hexadella, prompted the need to erect a new genus to classify this species. This novel species constitutes the first record for a member of the family Ianthellidae in the Caribbean. The characterization of the family Ianthellidae (sensu Cook and Bergquist, 2000) is here modified by: i) highlighting the cavernous nature of the choanosome, with many lacunae and channels reported for all genera included in the family; ii) extending the family distribution to the Caribbean; and iii) adding a fourth genus to the group of verongids with eurypylous chambers. The possession of a cellularized cortex (10-300 µm in thickness) is here proposed as a potential synapomorphic character of the Ianthella-Anomoianthella-Vansoestia clade. The main issues regarding the suprageneric classification of verongids are discussed.
authors.affiliation: Museo Marino, Boulevard de Boca del Rio, Nueva Esparta, Venezuela Oceanographic center, NOVA SEU, 8000 N. Ocean Dr, Dania Beach, Fl 33004; Email: taxochica@gmail.com.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Díaz
authors.affiliation: Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294-1170, USA; Email: unknown.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Thacker
authors.affiliation: NMNH, Smithsonian Institution, Washington, DC, USA; Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA; Email: unknown.
authors.forename: Niamh E
authors.initials: NE
authors.lastname: Redmond
authors.affiliation: CNRS UMR 7263 Institut Méditerranéen de Biodiversité et d'Ecologie Marine et continentale (IMBE), 13007, Marseille, France; Email: unknown.
authors.forename: Thierry
authors.initials: T
authors.lastname: Perez
authors.affiliation: National Systematics Laboratory of NOAA's Fisheries Service, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.; Email: unknown.
authors.forename: Allen G
authors.initials: AG
authors.lastname: Collins
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D004275:DNA, Ribosomal / Q000235:genetics; D009929:Organ Size; D010140:Pacific Ocean; D010176:Panama; D010802:Phylogeny; D011161:Porifera / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000254:growth & development
chemical_list: D004275:DNA, Ribosomal