Presentation Abstracts Sorted according to surname of presenting author (underlined) Jason I. Airst and Susan Lingle Department of Biology, University of Winnipeg, Winnipeg, Manitoba, R3B 2E9 Do differences between courtship of white-tailed and mule deer males reflect species differences in antipredator and social behaviour? / Est-ce que les différences de courtisage des mâles cerfs de Virginie et les cerfs mulets réflectent les différences d'espèces dans les comportements antiprédateurs et sociaux? White-tailed and mule deer are closely related species that coexist on many sites in western North America. Although a few studies have described aspects of courtship behaviour for each species alone, there have been no quantified comparisons where the species are sympatric. To test whether differences described reflect species differences in courtship behaviour or are simply facultative responses to varying habitat conditions, we conducted focal observations of 229 males, which ranged in body size, on an open grassland study site during the 2014 and 2015 breeding season. As reported elsewhere, males of both species mostly used tending bonds (serial pair-breeding) during late-stage courtship, even though this habitat was extremely open and might be expected to lead to harem breeding. Consistent with our predictions, mule deer males were more likely to court in multiple male/multiple female groups than white-tailed males, and to tolerate concurrent courtship by other males in the same group. In contrast, white-tailed males almost exclusively tended females in isolated pairs, due in part to increased aggression between white-tailed males during late-stage courtship. Species differences in male courtship behaviour appeared consistent with species differences in antipredator and social behaviour and were not due to varying habitat conditions. Angelika A. Aleksieva1, Jason R. Treberg2, 3 and Kyle H. Elliott1 1Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec, H9X 3V9 2Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 3Centre on Aging, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Skin pentosidine does not covary with age in four species of wild seabirds / La pentosidine de peau ne covarie pas avec l’âge dans quatre espèces d’oiseaux marins sauvages The process of aging is progressive, unavoidable and universal to all living beings. Unlike in many other organisms (fish otoliths, clam growth rings, mammal tooth wear), there is no known technique for accurately ageing birds in the wild. Recent studies identified pentosidine as a potential biomarker of chronological aging in several bird species. The objective of this study is to verify whether pentosidine accumulation is applicable as an aging biomarker in four species of long-lived seabirds. Skin biopsies were collected from foot webbings of known-age seabirds from four species: black-legged kittiwakes (Rissa tridactyla), Atlantic puffins (Fratercula arctica), razorbills (Alca torda), and thick-billed murres (Uria lomvia). Samples were analysed with High performance liquid chromatography (HPLC) to quantify pentosidine levels. Collagen levels were estimated through hydroxyproline assays to normalize pentosidine content across individuals. Kittiwakes displayed a weak correlation (r2=0.39, P=0.009) between age and pentosidine concentration (pmol pentosidine/mg collagen). Puffins (r2=0.02, P=0.65), razorbills (r2=0.08, P=0.49), and murres (r2=0.04, P=0.20) did not show any associations with age. We concluded that although determination of an individual’s exact age would have invaluable applications, pentosidine does not appear to be a reliable method in these species. Garett J.P. Allen and Dirk Weihrauch Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Filling in the gaps of ‘leaky’ epithelia: Branchial acid-base regulatory capacity and mechanisms of the Dungeness crab, Metacarcinus magister / Remplir les trous de l'épithélium poreux: La capacité régulatrice acido-basique des branchies et les mécanismes du crabe de Dunganess, Metacarcinus magister Osmoconforming invertebrates, whilst important ecologically and economically, have been poorly investigated for acid-base regulatory mechanisms – likely due to the attractive nature of euryhaline regulating species. Stenohaline osmoconforming crustaceans, such as the Dungeness crab, Metacarcinus magister, are expected to perform minimum iono-transport across their gill epithelium and possess a characteristically ‘leaky’ epithelium compared to ionoregulating species. Studies have shown, however, + that M. magister is well-suited for active NH4 -excretion against a 16-fold inwardly-directed gradient suggesting their simplistic ionotransport capacity may be inapt regarding acid-base regulatory molecules and is thus worthy of investigation. Perfused posterior gills (7-9) of M. magister bathed in control seawater + -1 -1 - (pH 8.10) demonstrate active NH4 -excretion rates of 3.0 ± 0.5 µmolg h , net HCO3 -loss of 3.2 ± 0.5 µmolg-1h-1, and slight alkalinization of perfusate (ΔpH +0.10 ± 0.02 units). HCl-induced environmental + -1 -1 acidification (pH 7.10; HEPES-buffered) increased NH4 -excretion rates (5.3 ± 0.4 µmolg h ) and - -1 -1 induced net-gain of HCO3 (-2.6 ± 0.5 µmolg h ) in slightly acidified perfusate (ΔpH -0.10 ± 0.02 units). + Basolaterally applied ouabain and KM91104 abolish active NH4 -excretion across epithelia of control gills whereas in acidified seawater ouabain reduces excretion by 50% suggesting an alternative pH- induced mechanism exists. Basolateral application of colchicine, acetazolamide, amiloride, and EIPA will be discussed. Hend Alnafea and Sara V. Good University of Winnipeg, Department of Biology, Winnipeg, Canada Expression of insulin superfamily genes and functional characterization of insulin-like peptide 5 (INSL5) in Japanese medaka (Oryzias latips) / L'expression d'une superfamille de gènes reliés à l'insuline et la charactérisation fonctionnelle du peptide 5 (INSL5) chez le medaka japonais (Oryzias latips) The relaxin peptides are a relatively recently discovered group of peptides hormones that belong to the insulin superfamily and appear to play diverse roles in vertebrate neuroendocrine regulation and reproduction. There are four relaxin family peptide hormones present in most vertebrates: namely relaxin (Rln) and relaxin 3 (Rln3) and insulin-like peptides 3 (INSL3) and INSL5. Fish additionally have two paralogous copies of RLN3 (rln3a and rln3b) and INSL5 (insl5a and ins5b). The relaxin family peptides signal via G-protein coupled receptors (GPCR) known collectively as the relaxin family peptide receptors (RXFP). In mammals, the cognate receptor for RLN and INSL3 are RXFP1 and RXPF2 respectively. On the other hand, the cognate receptors for RLN3 and INSL5 in mammals are RXFP3 and RXFP4 respectively. In correspondence with the presence of paralogous copies of rln3a/rln3b and insl5a/insl5b in teleosts, teleosts also have a greatly expanded repertoire of rxfp3 and rxfp4 receptors through which they are hypothesized to exert their physiological action, although the primary binding relationship and function of rln3 and insl5 genes and the diversity of fxfp3/4 receptors in teleosts is not well understood. Of all of the relaxin peptides, the functional role of INSL5 is the least well understood. There is evidence in mammals that INSL5 hormone expressed in the colon acts in a paracrine manner on RXFP4 receptors expressed on nerves innervating the colon, but there is also evidence that serum levels of INSL5 respond to multiple physiological cues including nutritional status (serum INSL5 levels increase during calorie restriction), stress (especially cortisol production), and gender. Despite these recent intriguing and highly debated hypotheses, no functional studies have been performed on this emerging peptide hormone in teleosts, despite there being several advantages to using a fish model. Studying the role of insl5 in a model fish species such as Japanese medaka or zebrafish should provide insights into the ancestral role of this peptide hormone in vertebrates. Moreover, since there are paralogous copies of both the peptides insl5a/insl5b and the receptors (rxfp3-2, rxpf3-3 and rxfp4) in teleosts, studying the functional role of insl5 in a model teleost opens opportunities for studying the processes of sub- and neo-functionalization during gene evolution. Elaine Anjos1,2 and Jane Waterman1 1Department of Biological Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 2 Science Without Borders -CAPES/Brazil – Proc. Number 1218-13-1 Sperm competition in a highly promiscuous African ground squirrel / Compétition de sperme chez l'écureuil terrestre Africaine à promiscuité sexuelle When females copulate with two or more males, competition for fertilization can occur internally among sperm of different males. Cape ground squirrels (Xerus inauris) are African species that has a promiscuous mating system. Pre-copulatory sexual selection appears to be weak, as males are non-territorial, and fighting and aggression are rare. However, males have large testes and high operational sex ratios (F1: M11), suggesting very high levels of sperm competition. As litter sizes are small (1-2), most copulating males will not have fertilization success. Our genetic data found males had very low reproductive success, with only 28% siring offspring. The goal of this research is to understand how males maximize their