FN Archimer Export Format PT J TI Plasticity matches phenotype to local conditions despite genetic homogeneity across 13 snake populations BT AF Bonnet, Xavier Brischoux, François Briand, Marine Shine, Richard AS 1:1;2:1;3:2;4:3; FF 1:;2:;3:PDG-ODE-LITTORAL-LERPAC;4:; C1 CEBC, UMR 7372 CNRS and University of La Rochelle, 79360 Villiers en Bois, France ODE, Ifremer, Issy-les-Moulineaux, France Department of Biological Sciences, Macquarie University, New South Wales 2109, Australia C2 UNIV LA ROCHELLE, FRANCE IFREMER, FRANCE UNIV MACQUARIE, AUSTRALIA SI TOULON SE PDG-ODE-LITTORAL-LERPAC IN WOS Ifremer UPR copubli-france copubli-univ-france copubli-int-hors-europe IF 5.531 TC 7 UR https://archimer.ifremer.fr/doc/00677/78892/81189.pdf https://archimer.ifremer.fr/doc/00677/78892/81190.docx https://archimer.ifremer.fr/doc/00677/78892/81191.docx https://archimer.ifremer.fr/doc/00677/78892/81192.docx https://archimer.ifremer.fr/doc/00677/78892/81193.docx https://archimer.ifremer.fr/doc/00677/78892/81194.docx LA English DT Article DE ;gape limited;jaw size;Laticauda;local adaptation;New Caledonia;sea krait AB In a widespread species, a matching of phenotypic traits to local environmental optima is generally attributed to site-specific adaptation. However, the same matching can occur via adaptive plasticity, without requiring genetic differences among populations. Adult sea kraits (Laticauda saintgironsi) are highly philopatric to small islands, but the entire population within the Neo-Caledonian Lagoon is genetically homogeneous because females migrate to the mainland to lay their eggs at communal sites; recruits disperse before settling, mixing up alleles. Consequently, any matching between local environments (e.g. prey sizes) and snake phenotypes (e.g. body sizes and relative jaw sizes (RJSs)) must be achieved via phenotypic plasticity rather than spatial heterogeneity in gene frequencies. We sampled 13 snake colonies spread along an approximately 200 km northwest–southeast gradient (n > 4500 individuals) to measure two morphological features that affect maximum ingestible prey size in gape-limited predators: body size and RJS. As proxies of habitat quality (HQ), we used protection status, fishing pressure and lagoon characteristics (lagoon width and distance of islands to the barrier reef). In both sexes, spatial variation in body sizes and RJSs was linked to HQ; albeit in different ways, consistent with sex-based divergences in foraging ecology. Strong spatial divergence in morphology among snake colonies, despite genetic homogeneity, supports the idea that phenotypic plasticity can facilitate speciation by creating multiple phenotypically distinct subpopulations shaped by their environment. PY 2021 PD JAN SO Proceedings Of The Royal Society B-biological Sciences SN 0962-8452 PU The Royal Society VL 288 IS 1943 UT 000613752100006 DI 10.1098/rspb.2020.2916 ID 78892 ER EF