Zootaxa 2855: 1–79 (2011) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Monograph ZOOTAXA Copyright © 2011 · Magnolia Press ISSN 1175-5334 (online edition) ZOOTAXA 2855 A subjective checklist of the Recent, free-living, non-marine Ostracoda (Crustacea) KOEN MARTENS1 & SUKONTHIP SAVATENALINTON2 Royal Belgian Institute of Natural Sciences, Freshwater Biology, Vautierstraat 29, Brussels 1000, Belgium and University of Ghent, Department of Biology, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium Department of Biology, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand. E-mail: [email protected] (corresponding author) Magnolia Press Auckland, New Zealand Accepted by R. Matzke-Karasz: 21 Feb. 2011; published: 29 Apr. 2011 KOEN MARTENS & SUKONTHIP SAVATENALINTON A subjective checklist of the Recent, free-living, non-marine Ostracoda (Crustacea) (Zootaxa 2855) 79 pp.; 30 cm. 29 Apr. 2011 ISBN 978-1-86977-671-8 (paperback) ISBN 978-1-86977-672-5 (Online edition) FIRST PUBLISHED IN 2011 BY Magnolia Press P.O. Box 41-383 Auckland 1346 New Zealand e-mail: [email protected] http://www.mapress.com/zootaxa/ © 2011 Magnolia Press All rights reserved. No part of this publication may be reproduced, stored, transmitted or disseminated, in any form, or by any means, without prior written permission from the publisher, to whom all requests to reproduce copyright material should be directed in writing. This authorization does not extend to any other kind of copying, by any means, in any form, and for any purpose other than private research use. ISSN 1175-5326 (Print edition) ISSN 1175-5334 (Online edition) 2 · Zootaxa 2855 © 2011 Magnolia Press MARTENS & SAVATENALINTON Table of contents Abstract . 3 Introduction . 3 Procedure and Literature used . 4 Taxonomic notes . 5 Format . 6 Main Results . 6 Acknowledgements . 6 References . 7 TABLE 1. The hierarchical taxonomic position of the extant genera of non-marine Ostracoda . 9 TABLE 2. Checklist of the Recent, free-living, non-marine ostracods . 14 Abstract We present a subjective list of the Recent, free-living, non-marine ostracods species and genera of the world, with their distribution in the large zoogeographical regions, as well as a list of genera in their present hierarchical taxonomic position. Based on the recognised synonymies, there are at present about 2090 species in c. 209 genera. About half of all species occur in one family, the Cyprididae, which is especially common in the southern Hemisphere. We give three new names for extant homonyms (Cypretta bradyi nom. nov., Cypria kliei nom. nov. and Physocypria dadayi nom. nov.), propose one new combination and one new synonymy and elevate the rank of the tribe Mytilocypridini to that of subfamily (with the same diagnosis). Keywords: Ostracoda, distribution, biodiversity, taxonomy, nomenclature Introduction Non-marine, aquatic biodiversity is declining rapidly, faster than terrestrial or marine diversity (Dudgeon et al. 2006). In addition, non-marine aquatic habitats hold a much higher diversity than terrestrial and marine ones of comparable sizes: freshwater comprises only 0.01% of all water on the planet and occupies only 0.8% of the Earth’s surface, yet it holds about 12% of all known animal species, including 40% of all fish species and 1/4 of all vertebrates. This incongruence between diversity and occupied surface is known as the paradox of freshwater (Lévèque et al. 2005). In order to establish more precise species numbers of the various freshwater groups, the Royal Belgian Institute of natural Sciences and the Belgian Biodiversity Platform (Brussels) conducted the “Freshwater Animal Diversity Assessment”, an initiative that involved c. 150 taxonomic experts, covering all freshwater animal groups (Balian et al. 2008; http://FADA.biodiversity.be). The Ostracoda (small, bivalved crustaceans, which abound in all aquatic, marine and freshwater, and even in (semi-) terrestrial environments) were analysed by Martens et al. (2008). They found that there are at present c. 2000 species in c. 200 genera; the family Cyprididae in the superfamily Cypridoidea is the most diverse group and comprises more than 50% of all extant non-marine ostracod species. The present checklist is an updated and expanded version of the one used by Martens et al. (2008). It enumerates names of classic species and genera described up to 2008 (with some selected species described later also being included), providing synonyms as well as broad distribution of species over the main zoogeographical regions. The present list includes only the free-living non-marine ostracod species, the parasitic/symbiotic Entocytheridae are not listed here. Readers are referred to the monograph by Hart & Hart (1974), to which little has been added in later years. Recently, there is a pronounced interest in so-called cryptic species in several (mostly aquatic) groups (see review in Bickford et al. 2007). Such species can only be identified with molecular methods, and are generally not morphologically recognisable. Bode et al. (2010) analysed almost 450 specimens from c. 135 European populations of the temporary pool ostracod species, Eucypris virens (Jurine, 1820), and found close to 40 cryptic CHECKLIST OF RECENT, FREE-LIVING, NON-MARINE OSTRACODA Zootaxa 2855 © 2011 Magnolia Press · 3 species, some sexual, some asexual, within this one classic species. Preliminary experiments also showed that amongst the sexual clusters, males preferred females belonging to the same cluster (Schmit et al. in prep.), supporting the specific status according to the biological species concept for at least some of these clusters. It is at present unclear if such cryptic species should be formally described, but it is now certain that at least E. virens should be considered a species complex. It belongs to the family Cyprididae, and several more taxa belonging to this family have similar morphological and molecular diversities as E. virens (e.g. Cypridopsis vidua (O.F. Müller, 1776), Heterocypris incongruens (Ramdohr, 1808)). It is thus important to take into account that the actual (cryptic) diversity in non-marine ostracods might be much higher than the classic specific diversity, as indicated in the present checklist. Whereas previously the presence of E. virens was simply noted as one species, it is now clear that a ‘classic’ population of E. virens can comprise anything between one and a dozen cryptic species (Bode et al. loc.cit.). We should urgently assess the extent of cryptic diversity in this group (and others), because what we do not know, we cannot protect. Procedure and Literature used The basis for the present subjective checklist was the series of objective species lists in the “Kempf Database Ostracoda” (KDO) (Kempf 1980a–d, 1997a–d, 2006 and subsequent unpublished updates). We also follow, as much as possible, Kempf’s decisions on what constitutes a freshwater species. This way, some brackish water species are included, others are not. Higher taxonomy follows Horne et al. (2002), unless mentioned differently. The present list was drafted in different stages. 1. The above indexes (KDO) contain both fossil and Recent species, so an objective list of Recent species was first drafted. We only consider living species, so species described on (sub-) fossil valves only are not included, unless when they constitute the type species of a genus with also living representatives, such as Tonnacypris. 2. Subsequently, for each species the different combinations were checked in the KDO. The most recent combinations were retained, the older ones were cited below this most recent combination. 3. These combinations were then checked against recent revisions (e.g. Martens 1986 for Megalocypridinae; Martens 1990, 1992 for Cypridini; Gonzalez et al. 1996 for Herpetocypris; Rossetti & Martens 1998 for Darwinulidae and others), extant checklists (De Deckker & Jones 1978 for Australia; Martens 1984 for Africa; Martens & Behen 1994 for South America) as well as websites (NODE for Europe http:// biobel.biodiversity.be/project/show/2337; and NANODE for North America (http:// www.personal.kent.edu/~alisonjs/nanode/); and if necessary, updated and/or changed. 4. Finally, most older and all recent (until 2008) literature has been screened to check for (1) new species and genera not included in checklists and revisions, (2) new combinations of species and genera, (3) new synonymies and (4) presence/absence in different zoogeographical regions. Various papers not used by Martens et al. (2008) were here included, most noteworthy the monograph on NW Australian interstitial Candoninae by Karanovic (2007) and the monographic treatises on Cypricercinae by Savatenalinton & Martens (2009, 2010) and on Japanese Candoninae by Smith & Janz (2008), but also dozens of shorter contributions (not listed here). It is thus important to note that the present list is fully subjective, and represents the taxonomic views of the authors. In addition, as perfection is not of this world, omissions and erroneous interpretations will doubtlessly occur. The authors invite readers to send comments to the corresponding author; updated versions of the present database will be posted on http://fada.biodiversity.be/group/list?current_page=groups. 4 · Zootaxa 2855 © 2011 Magnolia Press MARTENS & SAVATENALINTON Taxonomic notes 1. Synonymies a. Synonymies should preferably be based on investigation of type (or at least topotypical) materials, and on descriptions only if they are exhaustive and detailed.