Rediscovering Fibulia myxillioides (Burton, 1932) (Porifera, Poecilosclerida) in the SW Atlantic Ocean

Abstract

Fibulia Carter, 1886 is a rare genus within the Order Poecilosclerida, at present it includes ten species: six have been reported from the Pacific Ocean (Australia and New Zealand), two from Antarctica and two from the southern Atlantic Ocean. Species of this genus have a plumose or confused skeleton composed of multispicular tracts and arcuate or reduced isochelae as microscleres. Ten specimens of Fibulia myxillioides (Burton, 1932) were collected during three expeditions on board RV “Puerto Deseado” to the first Argentinian off-shore Marine Protected Area Namuncurá/ Burdwood Bank. Herein we provide new records and update the bathymetric and latitudinal ranges of this rare and endemic species. Photographs of fresh specimens together with scanning electron micrographs and photomicrographs of the spicules and skeletal architecture of F. myxillioides are provided for the first time for this species and genus.