Two new species of Tantulocarida from the Atlantic deep sea with first CLSM pictures of tantulus larva

Abstract

During the deep-sea expedition ANTARKTIS XIII/5 of RV Polarstern in 1996, abundant material on Tantulocarida was collected. Here, we present a description of the two new species Tantulacus coroniporus sp. nov. and Polynyapodella thieli sp. nov. The genus Tantulacus is characterized by a prominent spine on endopods of thoracopods 2–5 in tantulus larva. The new species is placed in this genus on the account of this character and represents the first Tantulacus from the Atlantic deep sea. Thus, the genus now comprises five species, showing wide distribution in the World ocean. The monotypic species Polynyapodella ambrosei Huys, Mobjerg, & Kristensen, 1997 is known to have only one seta on the exopod of thoracopods 1–5, which is unique among tantulocaridans except monophyletic family Microdajidae having reduced rami on thoracic limbs. The new species is assigned to Polynyapodella based on this character; however, it could be distinguished from P. ambrosei in the pore formula and morphology of furcal setae. Confocal laser scanning microscopy (CLSM) is, for the first time, used to study the external morphology of tantulus larva and is proved to be helpful to detect even smaller elements of cuticle ornamentation and setation of appendages. Some details of tantulocarid anatomy could also be studied using CLSM.