Taxonomic revision of Cirratulus (Polychaeta: Cirratulidae) from the coasts of Argentina, with description of a new species

SARACHO BOTTERO, M. ANDREA, ELIAS, RODOLFO AND MAGALHAES, WAGNER

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2017

0025-3154

Among the polychaetes, the family Cirratulidae is one of the mostchallenging taxonomically because most of the currently used diagnosticcharacters change during ontogeny. It is therefore necessary to use acombination of characters to make an accurate identification. The presentwork is the first of a planned revision of the genus Cirratulus from coastalzones of Argentina. The examined material came from the two largestnatural history museums of the country, and showed several morphotypes.Some specimens corresponded to described species, but others wereundoubtedly undescribed. Among the previously known Cirratulidae,Cirratulus jucundus (Kinberg, 1866) and Cirratulus patagonicus (Kinberg,1866), formerly distributed for Antarctica are now also present in coastalcontinental areas of Argentina. The new species Cirratulus mianzanii sp.nov. is described from subtidal areas off Peninsula Valdés, Patagonia. Thisspecies is distinguished from its congeners by the segmental origin of bothtentacular filaments and first pair of branchiae in the junction between theperistomium and first chaetiger. Branchiae arise some distance from thenotopodium but not at the dorsal midline of the body. Ventral groovepresent along the body, with a fine dark midline. Capillary chaetae areserrate seen under an optical microscope, and the segmental origin ofneuro- and notopodial spines is different from other species of the genus.