FIRST RECORD OF BRACHYURUS MÜLLER, 1776 (, LAEVICAUDATA, LYNCEIDAE) IN FRANCE

BY

NICOLAS RABET1,3), JEAN-FRANÇOIS CART2), DAVID MONTERO1) and HABIB BOULEKBACHE1) 1) Laboratoire de Biologie du Développement, Université Paris 7- Denis Diderot, case 7077, 2 Place Jussieu, F-75251 Paris cedex 5, France 2) 15, avenue du Général de Gaulle, F-10400 Nogent-sur-Seine, France

ABSTRACT Lynceus brachyurus (Branchiopoda, Laevicaudata, Lynceidae) has been found in France for the first time. This species lives in various types of temporary ponds that depend on the ground water level. We provide some ecological, biogeographical, and morphological information about Lynceus brachyurus and indicate the occurrence of remarkable sympatric organisms, such as the endemic fairy shrimp Chirocephalus spinicaudatus (Branchiopoda, ). Those species confined to a restricted area are considered as seriously threatened because of the severe degradation of their biotope.

RÉSUMÉ Lynceus brachyurus (Branchiopoda, Laevicaudata, Lynceidae) a été signalé pour la première fois en France. Cette espèce est présente dans différentes mares temporaires dépendant du niveau d’eau souterrain. Nous présentons des informations écologiques, biogéographiques et morphologiques sur cette espèce et signalons la présence de remarquables espèces sympatriques comme l’endémique Chirocephalus spinicaudatus (Branchiopoda, Anostraca). Ces espèces restreintes à une zone limitée sont sérieusement menacées en raison d’une rapide dégradation du biotope.

INTRODUCTION In Europe, the order Laevicaudata is represented by only two species of Lynceus: L. andronachensis Botnariuc, 1947, an endemic of the Bucarest region (Romania) and L. brachyurus Müller, 1776, a Holarctic species. Members of this order are

3) Current address: Université Pierre et Marie Curie, Département “Systematique Adaptation ◦ Evolution” UMR 7138, Equipe “Evolution & Développement”, 9 quai Saint Bernard, Bât. B, 7 étage, F-75005 Paris, France; e-mail: [email protected] © Koninklijke Brill NV, Leiden, 2005 Crustaceana 78 (8): 931-940 Also available online: www.brill.nl 932 NICOLAS RABET ET AL. only rarely collected (Martin & Belk, 1988) and some aspects of their ecology and distribution are still unknown. The majority of these organisms develops in temporary streams or pools, and their presence is often unpredictable. In order to actually find these species, a regular sampling protocol is necessary. Moreover, due to specific meteorological conditions, some species can be effectively absent, i.e., be present only as dormant cysts, for several years. The last inventory of French branchiopods shows the geographical distribution of 18 species: 12 Anostraca, 2 , and 4 Spinicaudata, but no Laevicaudata (cf. Defaye et al., 1998), even though large branchiopods are considered relatively well known in France (Thiéry, 1987). However, since 1997 we have detected nu- merous new localities for Chirocephalus diaphanus Prévost, 1803 and Lepidurus apus (L., 1758) along the Seine valley, upstream of Paris (Rabet & Cart, 1998). This fact encouraged us to undertake a systematic investigation of the temporary pools in the eastern portion of the Paris Basin. In 1999, the use of a fibreglass canoe and a long-handle net enabled us to explore the deepest stations of large temporary ponds. Thus, we detected Lynceus brachyurus for the first time in France, in two pond networks along the Seine river: between Montereau-Fault-Yonne (Ile-de-France region) and Troyes (Champagne-Ardenne region). Other similar biotopes of the area have been damaged by human activities and present a rather poor biodiversity, probably as a result of the massive use of insecticides and intensive drainage. Temporary ponds, which represent a fundamental aspect of biodiversity (Collinson et al., 1995), have not been considered interesting until now, but in our opinion should definitely be reconsidered. In this regard, we think that “rare” species should be legally protected, and their biotopes properly preserved, or at least managed to enhance the possibilities of actual preservation.

MATERIAL AND METHODS

This study is based on a survey of temporary pools located in the department Aube (Champagne-Ardenne region, France; see figs. 1, 2). We prospected those ponds from April to July 1999, from January to July 2000, and from November to July 2001. Most specimens of Lynceus brachyurus were found from April to July 1999. In contrast, the low population density in 2000 and 2001 did not allow us to collect more than a dozen . The specific situation of the ponds and in particular their somewhat difficult accessibility, necessitated us to use a canoe and a long-handle net, especially in the deepest areas (more than 2 m deep). The organisms collected were fixed in 10% neutralized formalin. Specimens used for scanning electron microscopy (SEM) were prepared following techniques