World Congress of Malacology Antwerp ... - Unitas Malacologica

Evidence for sexual selection in Ariolimax species (Stylommatophora: Arionidae)
Leonard, Janet L. 1 ; Pearse, John S. 1 ; Turner, M.Q. 1 ; Diep, P.J. 1 ; Breugelmans, Karin 2 ,
Backeljau, Thierry 2
1. Joseph M. Long Marine Laboratory, 100 Shaffer Rd, University of California, Santa Cruz, Santa
Cruz, CA 95060 USA,
Email: jlleonar@ucsc.edu; pearse@biology.ucsc.edu
2. Department of Invertebrates, Royal Belgian Institute of Natural Sciences, Rue Vautier 29,
Brussels, B-1000, Belgium,
Email: Thierry.Backeljau@naturalsciences.be; Karin.Breugelmans@naturalsciences.be
Systematics in banana slugs (Ariolimax spp) has been based on genital morphology, with subgenera
distinguished by the presence (Meadarion) or absence (Ariolimax) of an “epiphallus” and species
distinguished by the size and shape of the penis and vaginal musculature. This rapid evolutionary
divergence of genitalia has been accompanied by an even more striking radiation in sexual behavior.
Each of the species studied has a unique pattern of courtship and copulation. Copulation may be
either brief (mean = 25 min) and unilateral in bouts (A. californicus, A. brachyphallus) or
simultaneously reciprocal [A. dolichophallus (mean =198 min), A. stramineus (mean = 62 min)]. In
A. buttoni copulation can last more than 24 h. Courtship ranges from 2 h of conspicuous biting and
head-swinging in Meadarion species to a brief (20 min) mutual exploration (A. stramineus). Both A.
californicus and A. brachyphallus show bouts of copulations but in A. brachyphallus there is mutual
penial stroking between copulations in the bout. Apophallation can occur in A. californicus and A.
dolichophallus. Individuals that have suffered apophallation may mate as females and (in one case)
even as a male, subsequently. Phally polymorphism is present in at least some populations in A.
buttoni. In a population with aphally, individuals reared in isolation produced more hatchlings than
grouped individuals whereas in a population without aphally, hatchling production correlated with
the number of sexual partners available. The long duration of sexual interactions, apparent high
energetic costs and evidence for reciprocity suggest that sexual selection has been involved in the
evolution of these species. Each species also has a unique suite of life history characteristics,
including egg size, hatchling color and growth rate, suggesting that natural selection has also created
differences between species. Mean egg size varies from 0.20 g to 0.45 g with sister taxa representing
the extremes.
Combined effects of tidal conditions and environmental contamination on the activities of
antioxidant enzymes in Mytilus edulis
Letendre, Julie 1 ; Vince, Erwann 1 ; Budzinski, Hélène 2 ; Leboulenger, François 1 ; Durand,
Fabrice 1
1. Laboratoire d’Ecotoxicologie – Milieux aquatiques, EA 3222, Université du Havre, France,
Email: julie.letendre@univ-lehavre.fr
2. Laboratoire de Physico et Toxico Chimie des Systèmes Naturels, UMR 5472, Université de
Bordeaux I, France,
Email: h.budzinski@lptc.u-bordeaux.fr
The coastal zone is characterized by a high variability of abiotic parameters linked to the tidal cycle
and by the presence of diverse chemical compounds in the water. These particular conditions
represent a multiple stress that resident organisms have to deal with. Interactive effects of
physiological and toxicological stresses were investigated in the blue mussel (M. edulis) by studying
the activities of 5 antioxidant enzymes (Cu/Zn superoxide dismutase, Cu/Zn SOD; catalase, CAT;
glutathione peroxydase, GPx, glutathione reductase, GRd, glutathione-S-transferase, GST) in gills
and digestive gland of mussels sampled at high shore (HS) and low shore (LS) in a reference site
(Yport, France) and a contaminated site (Le Havre harbour, France) during the tidal cycle.
Antioxidant activities in gills presented higher levels in HS mussels than in LS mussels in the clean
site, whereas at the polluted site an inverse trend was observed for Cu/Zn SOD and both HS and LS
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