Comprehensive sponge inventory of the submerged reef Los Picos, Southwestern Gulf of Mexico, with six new species described

Abstract This study presents the first sponge biodiversity inventory of Los Picos reef in Veracruz, Mexico. Although the Veracruz Reef System is known for its high sponge diversity, several recently discovered submerged reefs – including Los Picos – had remained biologically uncharacterised until this investigation. Our comprehensive inventory documents 37 species, identified at the species level, all belonging to Demospongiae; 15 of which are new records for the Mexican coast, and 13 for the Gulf of Mexico (GoM). Six species are described as new: Psammocinia alcoladoi sp. nov., distinguished by a dermal surface armoured with sand and spongin filaments, lightly fasciculated primary fibres, and non fasciculated secondary with long conules and slender fiber diameters; Hyatella hyattus sp. nov., distinguished by its soft and lobular habitus, and slender fiber diameters; Zyzzya marinagreenae sp. nov., is an open fistula with acanthostrongyles irregularly spined and both, acanthostrongyles and isochelae, smaller in size; Desmapsamma paulumharenae sp. nov., has an encrusting shape with larger spicules than D. anchorata; Phorbas veracruzanus sp. nov., consists of conule-shaped processes on an embedded layer and morphometric differences on spicules; and Timea citlallitzina sp. nov., stands out by the lumpy tips of the oxyaster type. The whole, highlighted by two genera, Psammocinia and Zyzzya , both reported for the first time in the GoM. Samples were obtained by SCUBA surveys at 10–16 m depth, between August and October 2017.