First record of Bathynellacea (Crustacea: Malacostraca) in Benin (West Africa): two new species and their phylogenetic position within the Parabathynellidae family

ABSTRACT

One new species of Racovitzaibathynella Serban and Coineau, 1994 and one of Cteniobathynella Schminke, 1973 of the order Bathynellacea Chappuis, 1915 (family Parabathynellidae Noodt, 1065) are described from Benin in West Africa. These represent the first records of Bathynellacea species in Benin following a broad sampling throughout the country. Two species of the genus Racovitzaibathynella are known from South Africa and one is known from Chad and Israel. Specimens of Racovitzaibathynella beninensis Camacho and Lagnika sp. n. and Cteniobathynella boutini Camacho and Lagnika sp. n. have a unique combination of morphological characters and several shared generic features. Racovitzaibathynella beninensis sp. n. has a six-segmented antennule with three aesthetascs on segment five; a five-segmented antenna; concave labrum; mandible with only three teeth on the distal endite; no epipod on thoracopods I to III; plumose setae on the exopod of thoracopods I to VII; female thoracopod VIII distal-end bilobed, and two plumose setae on the endopod of the uropod. Cteniobathynella boutini sp. n. has a six-segmented antennula; five-segmented antenna; no epipod on thoracopods I to III; endopod on ThVIII of males as exopod, and five setae on the endopod of the uropod. To complement the morphological description of the two new species, a phylogenetic analysis based on the 18S ribosomal RNA (rRNA) gene was performed to infer their phylogenetic position within the family Parabathynellidae. The phylogenetic reconstruction shows an Afrotropical clade, which includes the new African species, and is clearly distinct from the European, Australian and Asiatic clades.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:7F97EBD0087C4324A601-EE8194E8E577

KEYWORDS:

• Africa
• groundwater fauna
• morphological taxonomy
• new species
• 18S rRNA

Acknowledgements

We gratefully acknowledge C. Puch for the help with sampling, among other things. We thank the colleagues who sent us specimens collected in different parts of the world so that these papers are possible and we can learn about the real diversity of this group of stygobiont crustaceans: K. Abrams, C. Bou, A. Brancelj, D. Jaume, P Hancock, B. Hutchins, P. Leclerc, J. Little, B. Newell, V. Ortuño, Y. Ranga Reddy, J. Rodriguez, A. Tinaut and S. Watiroyram. We thank Melinda Modrell who helped us with the English translations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the MICINN/FEDER Project PID2019-110243GB-I00. PMP was supported by the Postdoctoral Fellowship Margarita Salas [CA4/RSUE/2022-00171]. LM and PM are deeply indebted to CEBioS (Capacities for Biodiversity and Sustainable Development, Royal Belgian Institute of Natural Sciences) and the Belgian Directorate-General for Development Cooperation and Humanitarian Aid (DGD) for funding this research in Benin through several ‘GTI Capacity Development Grants’ awarded between 2015 and 2023.