Rotifera from the Mediterranean Sea, with Description of Ten New Species

Zootaxa 4028 (2): 151–196 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2015 Magnolia Press ISSN 1175-5334 (online edition) http://dx.doi.org/10.11646/zootaxa.4028.2.1 http://zoobank.org/urn:lsid:zoobank.org:pub:D47167E0-5C14-47F9-B4AA-9E906D13DF89 Rotifera from the Mediterranean Sea, with description of ten new species

WILLEM H. DE SMET University of Antwerp, Department of Biology, Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk (Antwerpen), Belgium. E-mail: [email protected]

Table of contents

Abstract ...... 152 Introduction ...... 152 Material and methods ...... 152 Results ...... 155 Description of new species ...... 156 Subclass MONOGONONTA Plate, 1889 ...... 156 Order PLOIMA Hudson & Gosse, 1886 ...... 156 Family BRACHIONIDAE Ehrenberg, 1838 ...... 156 Genus Notholca Gosse, 1886...... 156 Notholca bythonoma sp. nov...... 156 Family DICRANOPHORIDAE Harring, 1913 ...... 158 Genus encentrum Ehrenberg, 1838 ...... 158 Encentrum aluligerum sp. nov...... 158 Encentrum foroiuliense sp. nov...... 161 Encentrum loefgreni sp. nov...... 164 Encentrum pugiodigitatum sp. nov...... 166 Subgenus Tricellatum subgen. nov...... 168 Encentrum (Tricellatum) uncinatoides sp. nov. et subgen. nov...... 168 Paradicranophorus halophilus sp. nov...... 170 Family LINDIIDAE Harring & Myers, 1924 ...... 172 Genus Lindia Dujardin, 1841 ...... 172 Lindia aequorea sp. nov...... 172 Family NOTOMMATIDAE Hudson & Gosse, 1886 ...... 173 Genus Pleurotrocha Ehrenberg, 1830 ...... 173 Pleurotrocha fontanetoi sp. nov...... 173 Family PROALIDAE Harring & Myers, 1924 ...... 176 Genus Proales Gosse, 1886 ...... 176 Proales francescae sp. nov...... 177 Notes on selected taxa ...... 179 Genus Allodicranophorus gen. nov...... 179 Genus Halolepadella gen. nov...... 181 Rotaria laticeps Wulfert, 1942 ...... 184 Cephalodella sp...... 184 Encentrum astridae Sørensen, 2001 ...... 184 Encentrum kutikovae De Smet & Chernyshev, 2006 ...... 185 Encentrum longirostrum Tzschaschel, 1978 ...... 186 Encentrum psammophilum Althaus, 1957...... 187 Encentrum spp...... 188 Encentrum striatum Althaus, 1957 ...... 188 Encentrum valkanovi Althaus, 1957 ...... 188 Lindia elsae De Smet, 2006 ...... 189 Lindia gravitata (Lie-Pettersen, 1905) ...... 189 Paradicranophorus spp...... 190 Proales litoralis De Smet, 1996 ...... 191 Proales syltensis Tzschaschel, 1978 ...... 191 Trichocerca pediculus Remane, 1949 ...... 191

Accepted by H. Segers: 14 Sept. 2015; published: 8 Oct. 2015 151 Notes on ecology and distribution ...... 192 Discussion ...... 193 Acknowledgements ...... 194 References ...... 194

Abstract

A total of 43 rotifer taxa, belonging to 14 genera, was identified in 47 psammon and periphyton samples collected in the northern part of the western basin of the Mediterranean Sea. Of these, 10 previously described species are new to the Med- iterranean, 10 species are new to science and could be described, and 5 others are potential new ones of which insufficient material was available to warrant a full description. Rotifers formed a constant component of meiofauna, from the eulittoral to at least 8 km off shore and a depth of 66 m. A clear zonation was apparent with one to two species only found in the eulittoral zone and sublittoral fringe, and 42 taxa occurring in the sublittoral zone. The trophi of seven previously known species are redescribed based on scanning electron microscopy. Dicranophorus bulgaricus Althaus, 1957 is redirected to Allodicranophorus gen. nov. and Lepadella pontica Althaus, 1957 to Halole- padella gen. nov.

Key words: Allodicranophorus, Halolepadella, marine, Mediterranean, biodiversity, psammon, Rotifera

Introduction

Rotifera are among the least known taxonomic groups in marine and brackish water habitats, to date accounting for a total number of about 115 strictly thalassic species reported world-wide (Fontaneto et al. 2006; Appeltans et al. 2012). Besides a general lack of knowledge on marine rotifer species diversity, our information on their biogeographical distribution is also very patchy since huge areas of the world remain unexplored, and even for the European seas, which belong to the most intensively studied areas, geographical coverage is incomplete (Costello et al. 2006). Information on the thalassic rotifer fauna of the Mediterranean is scarce, and mostly restricted to brackish habitats. Reviews of the rotifer fauna of the Mediterranean Sea were compiled by Ahlrichs (2003), Ricci & Fontaneto (2003), and Fontaneto et al. (2006, 2008a), reporting about 90 species with only 21 of them being strictly marine, and seven of them occurring in both marine and inland saline waters. Since then several new species have been described: Myersinella longiforceps and M. uncodonta from the Tyrrhenian Sea (De Smet 2007), Lecane insulaconae from the Northern Adriatic Sea (Fontaneto et al. 2008b), and Testudinella bicorniculata and T. elongata from the Hyères Archipelago (De Smet 2009). Ten new species are described in the present contribution. Morphological and distributional data, as well as the descriptions of the trophi based on scanning electron microscopy, are provided for several other species.

Material and methods

Samples of algal vegetation and psammon were hand-collected in the eulittoral zone, the sublittoral fringe, and the sublittoral zone; psammon was obtained by scraping ~200 ml of the uppermost centimetre of sand; the sublittoral samples were taken during scuba-diving. Fixation was done on the spot, by adding 35% formalin up to a final concentration of ~4%. The rotifers were extracted in the laboratory by washing the algae or by multiple swirling and decantation of the psammon using filtered seawater, and consequent filtering on a 40 µm mesh width net (Fontaneto et al. 2008). Specimens were examined and drawn using a Leitz Orthoplan microscope equipped with camera lucida. Rotifer trophi were prepared with dilute NaOCl according to De Smet (1998). Scanning electron microscopy (SEM) of the trophi was done with a Philips SEM 515, operated at 20 kV. The areas sampled (Fig. 1) are restricted to the northern part of the western subregion of the Mediterranean Sea, and located in the Balearic Sea at the Costa Blanca and Costa Brava (Spain), the Golfe du Lion, the Hyères Archipelago and the Côte d’Azur (France), and the Tyrrhenian Sea, Elba Island (Italy). The naming of the larger Mediterranean subregions is according to the database MarineRegions.org. by Claus et al. (2015). The annotated list of samples is shown in Table 1.