Rowella simplicissima Lopes & Klautau 2023

• Main Authors: Lopes, Matheus Vieira, Klautau, Michelle
• Format: Other/Unknown Material
• Language: unknown
• Published: 2023
• Subjects: Biodiversity; Taxonomy; Animalia; Porifera; Calcarea; Clathrinida; Leucettidae; Rowella; Rowella simplicissima; Burton; Fontana; Lion Island
• Online Access: https://zenodo.org/record/8152332; https://doi.org/10.5281/zenodo.8152332

ROWELLA SIMPLICISSIMA (BURTON, 1932) COMB.NOV. (FIGS 13, 14; TABLE 7) Synonyms: Leucettusa simplicissima – Burton, 1932: 261; Burton, 1963: 51. Leucettusa simplissima – Borojević et al., 1990: 257 (misspelling). Leucaltis nuda – Azevedo et al., 2009: 9; Leucettusa nuda – Klautau et al., 2013: 449; Fontana et al., 2018: 336 Lopes et al., 2018a: 59; Riesgo et al., 2018: 830. Type specimen: Holotype (BMNH 1928.2.15.35). Type locality: Off Sea Lion Island, East Falkland Island, South Atlantic (52°33ʹ S, 59°04ʹ W). Malvinas / Falklands and Araucanian MEOW ecoregion. Description: Sponge tubular or ramified with cylindrical tubes (Fig. 13A). It grows parallel to the substrate and raises the tubes that bear oscula. Colour white in life and creamy-white to beige in ethanol (Fig. 13A, B). Consistency slightly compressible and friable to the touch. Outer surface smooth, while the atrial surface is hispid due to the apical actines of tetractines. Single, circular and naked oscula are present in each tube. Body wall overall thin. Atrial cavity wide and spacious, many excurrent canals are evident (Fig. 13B). Aquiferous system syconoid, with elongated choanocyte chambers (Fig. 13C). Reproductive elements (oocytes) are present in the MNRJ specimens. Skeleton: Oscular margin has a transitional skeleton comprised of sagittal triactines and rare tetractines, gradually becoming regular as the body wall thickens. Cortical skeleton well developed and comprised of several layers of tangential triactines and fewer tetractines (Fig. 13D, E). Choanosomal skeleton with sparse pygmy triactines and tetractines, mostly present around the exhalant canals. The atrial skeleton is not well developed, often with pygmy tangential triactines and tetractines (Fig. 13F). Overall, the pygmy triactines are less abundant than the pygmy tetractines. Spicules (Table 7): Cortical triactines (Fig. 14A). Regular. Variable sizes. Actines are mostly cylindrical, straight, with blunt to sharp tips. Sometimes there is a constriction near the tip. Size – 274.0 (± ...