A new meiobenthic priapulid (Priapulida, Tubiluchidae) from a Mediterranean submarine cave

Abstract

A new priapulid species belonging to genus Tubiluchus is described on the basis of specimens collected in November, 2000 and June, 2001 in a submarine cave along the Ionian coast of Apulia, Southern Italy. The new species closely resembles T. corallicola that inhabits the tropical‐subtropical areas of the Western Atlantic Ocean but can be distinguished by the smaller size of the adults, and the smaller size and the shape of the pharyngeal teeth of the larval stages. A careful microscopical survey of the sensorial elements led to the discovery of a central bristle in the flosculi and a small hole at the tip of the associated setae, allowing speculation about a tactile sensorial function for the former and a chemoreceptive function for the latter. While T. troglodytes n. sp. represents the first fully described species of this genus from the Mediterranean Sea, the population densities recorded, particularly those found in June, 2001 (83.8 ± 40.1 SD ind./10 cm²) rank among the highest value reported for priapulids from any location in the world. On both sampling dates the sex ratio (female/total adults) in the T. troglodytes n. sp. population averaged about 0.6. Presence of larval stages of different ages during both sampling periods could imply that Tubiluchus spp reproduce the year around.

Key words:

• Priapulid
• Mediterranean meiofauna
• Submarine caves
• Benthos
• Taxonomy