Morphological diversity in Selenoribates (Acari, Oribatida): new species from coasts of the Red Sea and the Indo-Pacific

Abstract

Four new species of the oribatid mite genus Selenoribates from coasts of the Indo-Pacific and the Red Sea are described, Selenoribates asmodaeus sp. nov. from Singapore, Selenoribates arotroventer sp. nov. and Selenoribates niccus sp. nov. from the Maldives and Selenoribates divergens sp. nov. from Egypt. Selenoribates asmodaeus sp. nov. shows two horn-like notogastral projections like Selenoribates satanicus Pfingstl, 2013 but differs in the shape of sensillus, number of anal setae and the notogastral cerotegumental pattern. The other three new species are well distinguishable but share a unique character among Selenoribates species, namely branched lamellar and notogastral setae. Based on these new species, Selenoribates shows the highest morphological diversity known among intertidal selenoribatid genera, and this may be related to the small body size of this taxon. A detailed comparison of all described Selenoribates species further revealed three distinct morphological groups; first, a “foveiventris group” including Selenoribates foveiventris Strenzke, 1961, Selenoribates mediterraneus Grandjean, 1966, Selenoribates ghardaqensis Abd-El-Hamid, 1973 and Selenoribates elegans Pfingstl, 2013; second, a “satanicus group” with morphological modifications on the anterior part of the notogaster with Selenoribates quasimodo Pfingstl 2013, S. satanicus and S. asmodaeus sp. nov.; and third, a “divergens group” with branched notogastral setae including S. arotroventer sp. nov., S. divergens sp. nov. and S. niccus sp. nov. An identification key for all species of this genus and a map showing their global distribution are provided.

http://zoobank.org/urn:lsid:zoobank.org:pub:A1126D56-D645-438C-9190-B805F3DE6E3D

Keywords:

• thalassobiontic
• Selenoribatidae
• systematics
• new species
• biogeography

Acknowledgements

Thanks to Walter Fiala and his wife for collecting samples from the Maldives and thanks to Reinhart Schuster for providing me with the specimens extracted from these samples and for giving important advice concerning systematics. I am also grateful to Ernst Ebermann for the samples from Egypt. Thanks also to Ilse Bartsch providing specimens from Singapore; the samples were collected during the Comprehensive Marine Biodiversity Survey of Singapore: International Workshops 2012/2013: Johor Strait Workshop organised by Tan Koh Siang, Peter Ng, Tan Heok Hui and Joelle Lai, National Parks Board and sponsored by Shell Eastern Petroleum (Pte Ltd), Asia Pacific Breweries (Singapore), Care-for-Nature Trust Fund and Hong Kong & Shanghai Bank. Thanks also to two anonymous reviewers for providing very helpful comments.

Additional information

Funding

The present research was supported by a research incentive funded by the University of Graz.