62
Views
1
CrossRef citations to date
0
Altmetric
Original Article

Ontogenetic variation of the ossicles in Pseudothyone belli (Ludwig, 1887) with a description of a new Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from Southwestern Atlantic

ORCID Icon
Pages 434-443 | Received 23 Jan 2019, Accepted 03 Jun 2019, Published online: 10 Sep 2019
 

ABSTRACT

In this paper, data about ontogenetic variation of dermal ossicles in Pseudothyone belli, a species widely distributed in the western Atlantic are provided. These data are important since juveniles often lack many of the characters used to identify adult specimens and in some cases, they have been described as separate species. The main differences between juveniles and adults are related to the form of knobbed buttons in the body wall (adults). The juveniles have four-holed and multilocular buttons, whereas the adults have only (or predominantly) four-holed buttons. Additional differences are related to the plates, which are knobbed in juveniles and smooth in adults. Although these ossicles are subject to wide variation, the ossicles from the introvert and tentacles are quite consistent in both juveniles and adults. In addition, a new species of Sclerodactylinae, collected along of the Brazilian coast is here described. Havelockia smirnovi sp. nov. is characterized by having two pillared body wall tables; discs four-holed, with oval and undulating margins; spire often undeveloped or ending in few teeth (2–4). Introvert with rosettes and two-pillared tables; table pillars united at the top and forming a cluster of teeth. Tentacles with rosettes and tube feet with two-pillared supporting tables, arched plates and end plates.

Acknowledgements

I am thankful to Marcos Tavares (MZUSP), Jon Norenburg (USNM) and Marc Eleaume (MNHN) for granting access to the museum collections under their responsibility and Carla Menegola (Laboratório de Porifera, UFBA) for logistical support. Instituto Gonçalo Moniz (FIOCRUZ/BA) for SEM analysis. Also, Wagner Magalhães (University of Hawaii at Manoa) for his helpful comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.