Revista Chilena de Historia Natural 83 (2): 249-257, 2010
RESEARCH ARTICLE
Description of two new species of Malacoceros and Rhynchospio
spionids (Polychaeta: Spionidae) from the Grand Caribbean region
Two new species of spionids are described from the Caribbean Sea, Malacoceros
cariacoensis n. sp. from Venezuela and Rhynchospio harrisae n. sp. from Guana in the Virgin Islands, British Virgin
Island. Malacoceros cariacoensis n. sp. can be differentiated by the shape of the prostomium, which has two short frontal
horns and the posterior portion laterally prolonged into a faintly demarcated, double looped nuchal organ, extending to the base of
setiger 2, a reduction in the size of setiger 1, the absence of body pigmentation, and the number of apical teeth on the hooded hooks.
Rhynchospio harrisae n. sp. differs from other species of the genus in that the peristomium is moderately developed with
low lateral wings, and the anterior notopodial setae are arranged in two rows with a superior tuft of capillaries. A key to
Malacoceros species worldwide is provided.
Key words:
Caribbean,
Malacoceros, Rhynchospio, Spionidae, taxonomy
