New insights into the diversity of Scopalinida (Porifera: Demospongiae) in the Eastern Tropical Pacific

Abstract The genus Svenzea Alvarez, van Soest & Rützler, 2002 is a widely distributed marine sponge group in the Caribbean and South Atlantic coralline areas, and even in the Indo-Pacific regions, with no previous records in the Eastern Tropical Pacific (ETP). Using a comprehensive taxonomic and molecular approach, a new species and the first record of a marine sponge from the genus Svenzea distributed in the ETP is described herein. Svenzea marialmae sp. nov. is an abundant species widely distributed over semi-shaded substrates in the coral communities of the Mexican Pacific area. Morphologically, it is a thickly encrusting sponge characterized by its bright orange color, a microscopically hispid surface, and a cavernous structure supported by spongin fibers cored with slightly curved styles. Molecular analyses of independent mitochondrial (COI) and ribosomal (18S) loci demonstrate that the new species is clustered with other members of the genus Svenzea and is recovered as a sister group with Scopalina Schmidt, 1862, and Stylissa Hallmann, 1914, all of which are included in the family Scopalinidae. Notably, this species constitutes a new Scopalinida, and the first documented record of the genus Svenzea within the extended geographical area of the ETP.