Microscopic priapulid larvae from Antarctica

We report 24 larvae of macroscopic priapulids from north of the Antarctic Peninsula and from Potter Bay, King George Island. We assign the larvae to four groups according to their lorica pattern, which consists of platelets created by ridges. In larvae of the first group the platelets in the middle region of the lorica interdigitate in a zig-zag way, this has been described only for Priapulopsis australis. Larvae of groups 2 and 3 have more rectangular platelets and differ in the presence and abundance of paired versus unpaired platelets. The position of the larval tubuli corresponds to reported larvae of Priapulus tuberculatospinosus, but the lorica pattern has not been described in detail for this species. It is assumed to resemble the one in P. caudatus, from which our larvae differ. Therefore the assignment to P. tuberculatospinosus is a bit vague. Larvae of group 4 are small and have little lorica structure. They may represent very young larval stages, probably of the co-occurring P. australis.

Source: A Journal of Comparative Zoology - June 10, 2019 Category: Zoology Source Type: research