Saccocirridae (Annelida) from the southern and southeastern Brazilian coasts

Abstract

Pharyngocirrus gabriellae (Du Bois-Reymond Marcus 1946) and Saccocirrus pussicus Du Bois-Reymond Marcus 1948 are redescribed based on newly collected material from the south and southeastern Brazilian coasts. Neotypes are designated, since no type material was formally indicated in the original descriptions. New morphological information on the muscular ventral pharynx, ciliation, chaetae and pygidium is provided. Pharyngocirrus gabriellae is additionally characterised by the presence of mouth ciliary patches, capillary lyrate chaetae with a single median tooth and equally bifid medium chaetae with denticulate prongs. The novel diagnostic characters of Saccocirrus pussicus include the absence of a pharynx and the presence of 1–3 pygidial, adhesive ridges and 20 fertile segments. The two species live in very distinct interstitial habitats, with varying hydrodynamics. Pharyngocirrus gabriellae is found at sheltered intertidal and shallow areas in sediments with a redox layer, whereas Saccocirrus pussicus prefers the swash zone of exposed, oxygenated, reflective beaches. Morphology and habitat preferences of P. gabriellae and S. pussicus are consistent with other Saccocirridae species from the ‘Pharyngocirrus’ and ‘Saccocirrus’ genera, respectively.