Effects of diet and salinity on the survival, egg laying and metabolic fingerprints of the ground-dwelling spider Arctosa fulvolineata (Araneae, Lycosidae) Natacha Foucreau a, b, 1 , David Renault a, ⁎ , 1 , Kévin Hidalgo a , Raphaël Lugan c, d , Julien Pétillon e, f a Université de Rennes 1, UMR CNRS 6553 Ecobio, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France b Université de Lyon, UMR CNRS 5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, Université de Lyon 1, ENTPE, 6 rue Raphaël Dubois, 69622 Villeurbanne Cedex, France c Université de Rennes 1, UMR INRA IGEPP, Campus Beaulieu, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France d Institut de Biologie Moléculaire des Plantes, UPR2357, 12 rue du général Zimmer, 67084 Strasbourg Cedex, France e Terrestrial Ecology Unit, Biology Department, Ghent University, K. L. Ledeganckstraat 35, B-9000 Gent, Belgium f Université de Rennes 1, URU 420, UMR CNRS UPMC 7204, Muséum National d'Histoire National, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France abstract article info Article history: Received 19 March 2012 Received in revised form 4 July 2012 Accepted 5 July 2012 Available online 14 July 2012 Keywords: Wolf spider Amphipods Survival GC–MS Compatible solute Amino acid Alanine Soil salinity and the salinity of trophic resources may alter the osmoregulatory processes of arthropod, chal- lenging the smooth regulation of body water, and, ultimately, survival. The intra and extracellular build-up of osmolytes represent a common strategy to attenuate acute hyperosmotic stress in several arthropod species. In the present study, we aimed to determine the impact of substrate and trophic resource salinities on salt tolerance in the female wolf spider, Arctosa fulvolineata, which is considered a specialist salt marsh species. We evaluated adult female survival and egg laying, and quantified the osmo-induced accumulation of com- patible solutes (GC–MS). Three concentrations of substrate salinity were tested (0‰, 35‰ and 70‰) under three trophic conditions (starved spiders, spiders fed with salt prey [intertidal amphipods] and spiders fed with unsalted prey [freshwater amphipods]). We found no support for diet preferences in female A. fulvolineata, which exhibited similar predation rates on freshwater and marine amphipods. Survival and egg-laying were significantly impaired when female A. fulvolineata were exposed to hypersaline conditions for 12 days. Our results showed an increase in the level of several compatible solutes when spiders were ex- posed for 12 days to saline conditions. For instance, α-alanine, β-alanine, arginine, asparagine, aspartate, homoserine, glutamine, glycine, proline and serine levels were 4–10 times higher under hypersaline condi- tions. The osmo-induced accumulation of amino acids may increase the osmolality of body fluids, thus enhancing the smooth regulation of body fluids and survival ability of wolf spider under extreme saline conditions. © 2012 Elsevier Inc. All rights reserved. 1. Introduction All living organisms must contend with fluctuating environmental parameters in their natural habitats (Clarke, 1991), including food and water availability, temperature, radiation and salinity (Hochachka and Somero, 2002). Soil salinity and the salinity of tro- phic resources may alter the osmoregulatory processes of organisms, challenging the smooth regulation of body water content (Verhoef and Witteveen, 1980; Elnitsky et al., 2009). Arthropods exhibit two main strategies to maintain adequate osmotic pressure and cellular volume when exposed to saline conditions (Witteveen and Joosse, 1987; Charmantier and Charmantier-Daures, 1994). First, there are osmoconformers, which adjust body fluid osmolality to conform to the surrounding environment. Second, there are osmoregulators, which maintain a constant haemolymph and intracellular osmolality, regardless of habitat salinity. In arthropods, salt is actively excreted via the Malpighian tubules, anal papillae and rectum or gills. Additional osmoregulation process- es involve the osmo-induced accumulation of inorganic (Donini et al., 2007) and organic compounds (Yancey, 2005). Organic compounds include polyols, sugars and free amino acids (Frolov et al., 1991; McNamara et al., 2004; Sowers et al., 2006), which are synthesised by organisms from nutrients (Greenstone, 1979) or body stores. These osmolytes bind water molecules and increase haemolymph os- molality, thus limiting the amount of body water loss. In addition, these osmolytes balance the negative effects of NaCl on enzyme activ- ities (Pollard and Wyn Jones, 1979). Thus, the intra and extracellular build-up of osmolytes represent a common strategy to attenuate acute hyperosmotic stress (Edwards, 1982). For example, in several species, proline, alanine and glycine are three amino acids that are as- sociated with osmotic adjustments at the cellular level when environ- mental salinity increases (Larher et al., 2003; Misra and Gupta, 2005). In addition, some organic compounds have protective effects on Comparative Biochemistry and Physiology, Part A 163 (2012) 388–395 ⁎ Corresponding author. Tel.: +33 223 236627; fax: +33 223 235026. E-mail address: david.renault@univ-rennes1.fr (D. Renault). 1 These authors contributed equally to the work. 1095-6433/$ – see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.cbpa.2012.07.001 Contents lists available at SciVerse ScienceDirect Comparative Biochemistry and Physiology, Part A journal homepage: www.elsevier.com/locate/cbpa