Echiniscidae in the Mascarenes: the wonders of Mauritius

Yevgen Kiosya,Katarzyna Vončina,Piotr Gąsiorek

doi:10.3897/evolsyst.5.59997

Yevgen Kiosya, Katarzyna Vončina + Show 1 more

Open Access

https://doi.org/10.3897/evolsyst.5.59997

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Journal: Evolutionary Systematics	Publication Date: Apr 9, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: Jagiellonian University

Abstract

Many regions of the world remain unexplored in terms of the tardigrade diversity, and the islands of the Indian Ocean are no exception. In this work, we report four species of the family Echiniscidae representing three genera from Mauritius, the second largest island in the Mascarene Archipelago. Two species belong in the genus Echiniscus: Echiniscus perarmatus Murray, 1907, a pantropical species, and one new species: Echiniscus insularissp. nov., one of the smallest members of the spinulosus group and the entire genus, being particularly interesting due to the presence of males and supernumerary teeth-like spicules along the margins of the dorsal plates. The new species most closely resembles Echiniscus tropicalis Binda &amp; Pilato, 1995, for which we present extensive multipopulation data and greatly extend its distribution eastwards towards islands of Southeast Asia. Pseudechiniscus (Meridioniscus) mascarenensissp. nov. is a typical member of the subgenus with elongated (dactyloid) cephalic papillae and the pseudosegmental plate IV’ with reduced posterior projections in males. Finally, a Bryodelphax specimen is also recorded. The assemblage of both presumably endemic and widely distributed tardigrade species in Mauritius fits the recent emerging biogeographic patterns for this group of micrometazoans.

Highlights

Tardigrades, as many micrometazoan taxa, remain mostly ignored in biodiversity surveys, molecular techniques indicate the presence of multiple lineages and high potential for cryptic speciation (Blaxter et al 2003, Cesari et al 2020)
Two species belong in the genus Echiniscus: Echiniscus perarmatus Murray, 1907, a pantropical species, and one new species: Echiniscus insularis sp. nov., one of the smallest members of the spinulosus group and the entire genus, being interesting due to the presence of males and supernumerary teeth-like spicules along the margins of the dorsal plates
The new species most closely resembles Echiniscus tropicalis Binda & Pilato, 1995, for which we present extensive multipopulation data and greatly extend its distribution eastwards towards islands of Southeast Asia

Summary

Introduction

Tardigrades, as many micrometazoan taxa, remain mostly ignored in biodiversity surveys, molecular techniques indicate the presence of multiple lineages and high potential for cryptic speciation (Blaxter et al 2003, Cesari et al 2020). Yevgen Kiosya et al.: Mauritian Echiniscidae greatest attention and appeals for conservation effort of the best-studied insects, especially beetles (Motala et al 2007) The purpose of this contribution is to provide the first integrative data for the Mauritian members of the armoured tardigrades from the family Echiniscidae (Heterotardigrada). The records of species with wide tropical or even pantropical distribution support the supposition that very broad geographic ranges may be typical for tropical tardigrade taxa (Gąsiorek et al 2019). This is in accordance with data for oribatid mites inhabiting the Madagascan region, a significant fraction of which comprises pantropical species (Niedbała 2017)

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