First report of non-marine ostracods (Crustacea, Ostracoda) from the Dahlak Archipelago (Eritrea), with the description of two new species
Accepted: 16 January 2025
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Authors
The information on Recent non-marine ostracod faunas of the north-eastern part of the Afrotropical region is still limited. Here we report the first record of ostracods from the Dahlak Archipelago, a group of small islands located in the southern part of the Red Sea off the Eritrean coast. Specimens were obtained by hatching in the laboratory of diapausing eggs occurring in dried mud collected in temporary freshwater ponds, following the so-called “Sars’ method”. A total of five species were found, including two species new to science, of which four belong to the family Cyprididae (Cypris galefensis, Plesiocypridopsis newtoni, Heterocypris sp., and Chrissia martensi n.sp.) and one to the family Ilyocyprididae (Ilyocypris dahlakensis n.sp.). A detailed description of the morphology of valves and soft parts is given, and COX1 sequences were obtained for four species. Cypris galefensis was so far only known for its type locality in Somalia with a population containing both males and females, whereas our samples consisted exclusively of females. Plesiocypridopsis newtoni, a species characterised by a wide geographic distribution and previously known to occur also in the Afrotropical region, shows marked variability in the prehensile palps of males, as evidenced by comparing the specimens from this study with descriptions available in the literature. The genus Heterocypris (with 15 species) and the genera of the two new species described here, Chrissia (with 17 species) and Ilyocypris (with four species), have been previously reported from this biogeographic region as well. The specimens analysed of Chrissia martensi n.sp. were all females, none of which had sperm inside the carapace, indicating the possibility of parthenogenetic reproduction in this species. A peculiar sexual dimorphism in the valve morphology characterises Ilyocypris dahlakensis n.sp., with females having a straight posterior margin, forming a right angle at the ventral anterior edge. Rehydration of dry sediments collected from arid areas where wet periods are short and often unpredictable has proven to be a successful method for describing aquatic invertebrate biodiversity.
Edited by
Diego Fontaneto, CNR-IRSA Water Research Institute, Verbania-Pallanza, ItalySupporting Agencies
“NextGenerationEU” of the European Union (D.M. 737/2021-CUP B79J21038330001), Società Zoologica La TorbieraHow to Cite

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Similar Articles
- Alberto BARBIERI, Rosario MOSELLO, Recent trends in chemistry and mass budget of a high altitude lake in the southern Alps (Laghetto Inferiore, Canton Ticino, Switzerland) , Journal of Limnology: Vol. 59 No. 2 (2000)
- Jan SYCHRA, Zdeněk ADÁMEK, The impact of sediment removal on the aquatic macroinvertebrate assemblage in a fishpond littoral zone , Journal of Limnology: Vol. 70 No. 1 (2011)
- Murat KAYA, Diego FONTANETO, Hendrik SEGERS, Ahmet ALTINDAĞ, Temperature and salinity as interacting drivers of species richness of planktonic rotifers in Turkish continental waters , Journal of Limnology: Vol. 69 No. 2 (2010)
- Roman Baran, Michal Tušer, Helge Balk, Petr Blabolil, Martin Čech, Vladislav Draštík, Jaroslava Frouzova, Tomáš Jůza, Jan Kubecka, Quantification of Chaoborus and small fish by mobile upward-looking echosounding , Journal of Limnology: Vol. 78 No. 1 (2019)
- Sebastian Lenz, Uta Raeder, Juergen Geist, Representative monitoring of the calcifying alga Phacotus lenticularis (Chlamydophyceae) in lentic ecosystems , Journal of Limnology: Vol. 79 No. 2 (2020)
- Oscar RAVERA, An index for estimating the potential impact on the environment of the pollutant content in aquatic populations , Journal of Limnology: Vol. 67 No. 1 (2008)
You may also start an advanced similarity search for this article.