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245 results on '"van Herwerden, Lynne"'

21. Variation in stable isotope (δ 18O and δ 13C) signatures in the sagittal otolith carbonate of king threadfin, Polydactylus macrochir across northern Australia reveals multifaceted stock structure

Author

Newman, Stephen J., Allsop, Quentin, Ballagh, Aaron C., Garrett, Rod N., Gribble, Neil, Meeuwig, Jessica J., Mitsopoulos, Gabby E.A., Moore, Bradley R., Pember, Matthew B., Rome, Ben M., Saunders, Thor, Skepper, Craig L., Stapley, Jason M., van Herwerden, Lynne, and Welch, David J.

Published
2010
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35. Population-specific locomotor phenotypes are displayed by barramundi, Lates calcarifer, in response to thermal stress

Author

Edmunds, Richard C., van Herwerden, Lynne, and Fulton, Christopher J.

Subjects
Animal swimming -- Research, Barramundi -- Research, Heat tolerance (Biology) -- Research, Phenotypic plasticity -- Research
Abstract

We investigated how thermal stress may alter the locomotor phenotype of barramundi, Lates calcarifer, from genetically distinct northern (low latitude) and southern (high latitude) populations in tropical Australia. Following early growth and development under native (25 °C and 30 °C) and non-native (20 °C and 35 °C) temperatures, we observed distinct differences in the swimming performance of northern and southern individuals that were consistent with expectations based on local thermal adaptation. Southern population fish exhibited significantly faster swimming speeds (32.10 ± 0.33 [cm*s.sup.-1], mass-adjusted mean ± 95% confidence limit) than their northern counterparts (28.58 ± 0.64 [cm*s.sup.-1] under cold-stress (20 °C) conditions. Conversely, northern population fish performed significantly better (51.63 ± 2.1 [cm*s.sup.-1]) than their southern counterparts (44.18 ± 3.11 [cm*s.sup.-1]) under heat-stress (35 °C) conditions. We conclude that L. calcarifer display locomotor phenotypes thermally adapted to their local environment, with early growth under non-native temperatures leading to significantly reduced phenotypic fitness. Resume: Nous etudions de quelle maniere le stress thermique peut modifier le phenotype locomoteur du barramundi, Lates calcarifer, dans des populations genetiquement distinctes du nord (de basse latitude) et du sud (de haute latitude) d'Australie tropicale. Apres le debut de la croissance et du developpement a des temperatures de leur milieu d'origine (25 °C et 30 °C) ou non (20 °C et 35 °C), nous observons de nettes differences dans la performance de nage entre les individus du nord et du sud qui correspondent aux attentes basees sur l'adaptation thermique locale. Les populations du sud nt des vitesses de nage significativement plus elevees (32,10 ± 0,33 [cm*s.sup.-1], moyenne ajustee a la masse ± intervalles de confiance de 95 %) que les populations du nord (28,58 ± 0,64 [cm*s.sup.-1]) dans des conditions de stress au froid (20 °C). A l'inverse, les populations de poissons du nord performent significativement mieux (51,63 [+ or -] 2,1 [cm*s.sup.-1]) que celles du sud (44,18 ± 3,11 [cm*s.sup.-1]) dans des conditions de stress a la chaleur (35 °C). Nous concluons que L. calcarifer possede des phenotypes locomoteurs adaptes thermiquement a leur environnement local et qu'une croissance au debut de la vie a des temperatures autres que celles de son milieu d'origine mene a une reduction significative de la fitness phenotypique. [Traduit par la Redaction], Introduction Organisms can respond via changes in their morphology, physiology, or survivorship to the temperature regime of their native habitat. Ectothermic, or cold-blooded, organisms are particularly responsive to their home-range [...]

Published
2010
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48. Phylogeography of the reef fish Cephalopholis argus (Epinephelidae) indicates Pleistocene isolation across the indo-pacific barrier with contemporary overlap in the coral triangle

Author

Gomez Juan A, Newman Stephen J, Rocha Luiz A, Bordenave Tiana-Rae, Bowen Brian W, Gaither Michelle R, van Herwerden Lynne, and Craig Matthew T

Subjects
Evolution, QH359-425
Abstract

Abstract Background The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein). Results Population structure was significant (ΦST = 0.297, P < 0.001; FST = 0.078, P < 0.001; FST = 0.099, P < 0.001 for the three loci, respectively) among five regions: French Polynesia, the central-west Pacific (Line Islands to northeastern Australia), Indo-Pacific boundary (Bali and Rowley Shoals), eastern Indian Ocean (Cocos/Keeling and Christmas Island), and western Indian Ocean (Diego Garcia, Oman, and Seychelles). A strong signal of isolation by distance was detected in both mtDNA (r = 0.749, P = 0.001) and the combined nuclear loci (r = 0.715, P < 0.001). We detected evidence of population expansion with migration toward the CT. Two clusters of haplotypes were detected in the mtDNA data (d = 0.008), corresponding to the Pacific and Indian Oceans, with a low level of introgression observed outside a mixing zone at the Pacific-Indian boundary. Conclusions We conclude that the Indo-Pacific Barrier, operating during low sea level associated with glaciation, defines the primary phylogeographic pattern in this species. These data support a scenario of isolation on the scale of 105 year glacial cycles, followed by population expansion toward the CT, and overlap of divergent lineages at the Pacific-Indian boundary. This pattern of isolation, divergence, and subsequent overlap likely contributes to species richness at the adjacent CT and is consistent with the region of overlap hypothesis.

Published
2011
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50. Strong trans-Pacific break and local conservation units in the Galapagos shark (Carcharhinus galapagensis) revealed by genome-wide cytonuclear markers

Author

Pazmiño, Diana A, Maes, Gregory E, Green, Madeline E, Simpfendorfer, Colin A, Hoyos-Padilla, E Mauricio, Duffy, Clinton J A, Meyer, Carl G, Kerwath, Sven E, Salinas-de-León, Pelayo, and van Herwerden, Lynne

Subjects
Male, Conservation of Natural Resources, Pacific Ocean, Genetics, Population, Genotype, Sharks, Animals, Genetic Variation, Female, Ecuador, DNA, Mitochondrial, Polymorphism, Single Nucleotide, Phylogeny
Abstract

The application of genome-wide cytonuclear molecular data to identify management and adaptive units at various spatio-temporal levels is particularly important for overharvested large predatory organisms, often characterized by smaller, localized populations. Despite being "near threatened", current understanding of habitat use and population structure of Carcharhinus galapagensis is limited to specific areas within its distribution. We evaluated population structure and connectivity across the Pacific Ocean using genome-wide single-nucleotide polymorphisms (~7200 SNPs) and mitochondrial control region sequences (945 bp) for 229 individuals. Neutral SNPs defined at least two genetically discrete geographic groups: an East Tropical Pacific (Mexico, east and west Galapagos Islands), and another central-west Pacific (Lord Howe Island, Middleton Reef, Norfolk Island, Elizabeth Reef, Kermadec, Hawaii and Southern Africa). More fine-grade population structure was suggested using outlier SNPs: west Pacific, Hawaii, Mexico, and Galapagos. Consistently, mtDNA pairwise ΦST defined three regional stocks: east, central and west Pacific. Compared to neutral SNPs (FST = 0.023-0.035), mtDNA exhibited more divergence (ΦST = 0.258-0.539) and high overall genetic diversity (h = 0.794 ± 0.014; π = 0.004 ± 0.000), consistent with the longstanding eastern Pacific barrier between the east and central-west Pacific. Hawaiian and Southern African populations group within the west Pacific cluster. Effective population sizes were moderate/high for east/west populations (738 and 3421, respectively). Insights into the biology, connectivity, genetic diversity, and population demographics informs for improved conservation of this species, by delineating three to four conservation units across their Pacific distribution. Implementing such conservation management may be challenging, but is necessary to achieve long-term population resilience at basin and regional scales.

Published
2018

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