« New stygobitic ostracod species of the genus Candonopsis (Candonidae) from interstitial waters of Nouvelle-Aquitaine, France »

Naturalista sicil., S. IV, XLVIII, 2024, pp. 57-58
MICHALINA KIJOWSKA, AGATA SZWARC, FRANÇOIS LEFEBVRE, THIERRY
ALEZINE, XAVIER CHEVILLOT, FLORIAN MALARD, CHRISTOPHE DOUADY,
ANNA WYSOCKA & TADEUSZ NAMIOTKO
NEW STYGOBITIC OSTRACOD SPECIES OF THE GENUS
CANDONOPSIS (CANDONIDAE) FROM INTERSTITIAL WATERS
OF NOUVELLE-AQUITAINE, FRANCE
The subfamily Candoninae, one of the most species-rich lineages of
non-marine Ostracoda, includes now about 550 extant species across more
than 50 genera classified in seven tribes (MEISCH et al., 2019). The tribe
Candonopsini is usually distinguished on the basis of the absence of posterior seta on the caudal ramus, but due to the frequent reductions of setae and
claws in a number of various candonid species, to correctly diagnose Candonopsini this feature must be considered carefully and in concert with
other morphological traits (carapace shape, elongation of terminal segments
of mandibular palp, chaetotaxy of the cleaning leg or the male clasping
organs and hemipenis morphology) (HIGUTI & MARTENS, 2012), and if only
possible supplemented with molecular data in integrative taxonomy. In general, the proper assignment of a new candonid species to the tribe and genus
remains often challenging due to considerable homoplasy frequently occurring in this group.
The genus Candonopsis Vávra, 1891 is the type genus of the tribe Candonopsini and comprises 33 recent species classified in two subgenera
(MEISCH et al., 2019): Abcandonopsis Karanovic, 2004 with seven species
restricted to Australia (KARANOVIC, 2004) and Candonopsis with 25 species.
Although the nominotypical sugenus has a worldwide distribution, most
species occur in the Southern Hemisphere (KARANOVIC & MARMONIER, 2002;
KARANOVIC, 2012). Of the six species known from Europe, two are epigean
and four hypogean (SCHÄFER, 1945; DANIELOPOL, 1980; KARANOVIC &
PETKOVSKI, 1999; MEISCH, 2000).
In this study, we describe a new species of the subgenus Candonopsis
from male and female individuals collected from hyporheal of three rivers
within the catchment of the Dordogne-Garonne Rivers in the Corrèze
Department of Nouvelle-Aquitaine in central France. The samples were
taken following the protocol of the PASCALIS project (MALARD et al., 2002).
The newly identified species based on morphological evidence differs from
other members of the genus by its unique carapace shape and also the structure of the male copulatory organs (mainly shape of the inner lope of the
hemipenis). Additionally, phylogenetic analysis based on cytochrome oxidase
subunit I mitochondrial gene (COI mtDNA) and a nuclear region (28S
rDNA nDNA) provided further support for the differentiation of the new
species, which formed a distinctly separate clade, yet with the closest relationship with Candonopsis kingsleii (Brady & Robertson, 1870), the other
species of the genus used in our genetic analysis.
The present study underscores the significance of employing an integrative approach, which combines the analysis of carapace, morphology of limbs
(soft-body) as well as molecular data, to accurately characterize the biodiversity of groundwater ostracods.
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Authors’ Addresses – M. KIJOWSKA, A. SZWARC, A. WYSOCKA, T. NAMIOTKO, Department of Evolutionary Genetics and Biosystematics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308
Gdańsk, Poland, michalina.kijowska@ug.edu.pl; agata.szwarc@ug.edu.pl; anna.wysocka@ug.edu.pl;
tadeusz.namiotko@ug.edu.pl; F. LEFEBVRE, Sepanso Aquitaine, 4 Rue de Polverel, 19100 Brive-la-Gaillarde, France, France, francois.lefebvre@sepanso.org; T. ALEZINE, X. CHEVILLOT, Sepanso Aquitaine, 1
Rue de Tauzia, 33800 Bordeaux, France, thierry.alezine@sepanso.org; xavier.chevillot@sepanso.org; F.
MALARD, C. DOUADY, Lehna, University of Lyon 1, Rue Raphaël Dubois, 69622 Villeurbanne Cedex,
France, florian.malard@univ-lyon1.fr; christophe.douady@univ- lyon1.fr
58 M. KIJOWSKA, A. SZWARC, F. LEFEBVRE, T. ALEZINE, X. CHEVILLOT, ET AL.