New species of Thyasira, Mendicula, and Axinulus (Bivalvia, Thyasiroidea) from Sub-Antarctic and Antarctic waters

• Published in: Polar Biology
• Main Author: Zelaya, Diego Gabriel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer
• Subjects: SOUTHERN OCEAN; SYSTEMATICS; MOLLUSCA; BIVALVIA; https://purl.org/becyt/ford/1.6; https://purl.org/becyt/ford/1; Antarctic; Argentina; Southern Ocean; Antarc*; antarcticus
• Online Access: http://hdl.handle.net/11336/242384

Three new thyasirid species from the Sub-Antarctic and Antarctic waters are described: Thyasira patagonica, Mendicula sudamericana, and Axinulus antarcticus. T. patagonica is characterized by its strong commarginal sculpture, shell as height as length or higher than long, posterior auricle delimited by a deep submarginal sulcus, and a long and sloping straight anterior half of dorsal margin. M. sudamericana distinguished by its longer than high shell outline, elongated tooth-like enlargement anterior to beak, gills with only one demibranch at each side, and foot with a marked heel. A. antarcticus has aminute, subquadrate shell, hinge with a small swelling anterior to beak, gills with a single demibranch, and the lateral body pouch elongated and almost smooth. The present study provides the first reliable record of thyasirids, with a single demibranch from the Southern Ocean. Moreover, characters for a better definition of Mendicula are provided. Fil: Zelaya, Diego Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina