Priapulus abyssorum, New Species, the first Abyssal Priapulid

Abstract

A SINGLE example of Priapulus was collected on November 27, 1958 by the R.V. Vema from a depth of 5680–5690 m. (corrected) at the southern end of the Mid-America Trench. Besides being a new species and the first abyssal record for the genus, this specimen represents the first priapulid collected from off the west coast of Central America. The specimen is a ‘missing link’ in what was considered a classic case of bipolar distribution for a benthic genus. The bipolarity of Priapulus is discussed in detail by Ekman¹. He states ‘Here the present day discontinuity may be regarded as proved’. The species Priapulus horridus Theéle (1911) from Argentina customarily has been dismissed from the problem on account of its distinctive and unusual morphology. Possibly horridus belongs in another genus. The same can not be said for the species reported here. The animal is allied so closely to Priapulus tuberculatospinosus Baird, the species characterizing the Antarctic, that some may doubt whether the two are distinct species. A positive decision can not be reached without additional specimens of various sizes. Nevertheless, with this record the tropical submergence of Priapulus may be considered a fact and its ‘bipolarity’ only a matter of historical interest.