Abstract
Neopetrosia proxima (Porifera: Demospongiae: Haplosclerida) is described as a morphologically variable sponge common on shallow reefs of the Caribbean. However, the range of morphological and reproductive variation within putative N. proxima led us to hypothesize that such variability may be indicative of cryptic species rather than plasticity. Using DNA sequences and morphological characters we confirmed the presence of three previously undescribed species of Neopetrosia. Morphological differences of each new congener were best resolved by partial gene sequences of the mitochondrial cytochrome oxidase subunit 1 over nuclear ones (18S rRNA and 28S rRNA). Several new characters for Neopetrosia were revealed by each new species. For example, N. dendrocrevacea sp. nov. and N. cristata sp. nov. showed the presence of grooves on the surface of the sponge body that converge at the oscula, and a more disorganized skeleton than previously defined for the genus. N. sigmafera sp. nov. adds the (1) presence of sigma microscleres, (2) significantly wider/longer oxeas (>200 μm), and (3) the presence of parenchymella larvae. Sampling of conspecifics throughout several locations in the Caribbean revealed larger spicules in habitats closer to the continental shelf than those in remote island locations. Our study highlights the importance of integrating molecular and morphological systematics for the discrimination of new Neopetrosia spp. despite belonging to one of several polyphyletic groups (families, genera) within the current definition of the order Haplosclerida.
Keywords:
Caribbean; Demosponges; Haplosclerida; Molecular systematics; Neopetrosia.
Grants and funding
Taxonomical studies of sponges from the Colombian Caribbean have been carried out as part of several ecological, chemical, and systematic studies funded by the Colombian Administrative Department of Science and Technology—COLCIENCIAS (grants CO–30003–33–81, 30003–154–83, 2105–09–030–86, 2105–09–023–93), the US National Science Foundation—NSF (grant INT–86117–17), INVEMAR (grants 220–50, 220–54, 220–95, and others), and Universidad Nacional de Colombia—Bogotá Campus (grants CINDEC 006–1982 and others) and Caribbean Campus (grant HERMES 26594). The work of Jaime Andrés Ríos at Santa Marta was funded by Universidad Nacional de Colombia Caribbean Campus Program for Undergraduate Special Academic Practice (code 40000008163), with Laboratory and bench work carried out at INVEMAR facilities in Santa Marta, under agreement with Universidad Nacional de Colombia. Project funding for collection of type material in Bocas del Toro was provided to Jan Vicente through a Smithsonian Tropical Research Institute short-term fellowship. Stipend money to work on histology and sequencing of type specimens was provided to Jan Vicente by NSF Postdoctoral Research Fellowship in Biology (award no. 2023254002). Analyses of sponges from Panama by Sven Zea were carried out as part of the “PorToL Integrative Taxonomy Workshop 2012” at Bocas del Toro, funded by the Smithsonian Tropical Research Institute. Those from Martinique were studied by Sven Zea during the “2013 Training Course on the sponge biodiversity of the Caribbean Sea, workshop of La Martinique” and the “Kick-off meeting of the Associated International Laboratory MARRIO,” both funded by CNRS France. Support for sequencing of sponge samples and publication was provided by the NSF-OA#1416889 grant to Robert J. Toonen. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.