Genotype by environment interactions, heritabilities and genetic correlations for productive traits of Haliotis rufescens
Farías, W., Winkler, F., & Brokordt, K.
A critical aspect of a selective breeding program is whether responses of traits of interest are similar in different environments. The magnitude of the genotype by environment interaction (GEI) together with heritability (h2) accounts for this aspect. Despite the economic significance of abalones and the interest in genetic improvement programs for their cultivation, only one previous study has reported GEI estimations for this group of mollusks. The objective of the present study was to estimate h2 and the existence of GEI for growth traits of Haliotis rufescens cultivated in Chilean farms with different environmental and management conditions. A total of 2 cohorts (2007 and 2009) of 50 and 42 families of full sibs (FS), respectively, were used. Replicates of each FS family of the 2007 cohort were distributed in two farms in the northern region of the country and were evaluated after 1 and 2 years of cultivation. For the 2009 cohort, replicates of each family were distributed in a farm in the northern region and a farm in the southern region of the country. The estimated h2 values were significant for all traits, with the length and width of the shell and total weight varying primarily by cohort between 0.22–0.62, 0.16–0.58 and 0.40–0.53, respectively. The genetic correlations (rG) between traits were all higher than 0.82. The expected correlated responses for improving the total weight using the shell length as a selection criterion predict a selection gain (14–51%) similar to what would be obtained by selecting directly for weight (16–51%) in all environments examined. Thus, indirect selection by shell length and the direct use of total weight as a selection criterion would yield similar effects in terms of the increase in weight. High rG, not significantly different from 1, were observed for the analyzed traits between replicates of the families in any of the farms compared, both within the northern region and between the northern and southern regions of the country. These high rG were indicative of non-significant GEI for the analyzed traits. Therefore, results suggest that one selective breeding program could provide improved red abalone for the industry in Chile with consistent results between farms located in different environments.
Palabras claves: Abalone, Aquaculture, Breeding, Heritability, Genetic correlation, Genotype by environment interaction
Referencia APA: Farías, W., Winkler, F., & Brokordt, K. (2017). Genotype by environment interactions, heritabilities and genetic correlations for productive traits of Haliotis rufescens. Aquaculture, 473, 407-416. http://dx.doi.org/10.1016/j.aquaculture.2017.02.030
Co‐operation between large‐scale MPAs: successful experiences from the Pacific Ocean.
Friedlander, A. M., Wagner, D., Gaymer, C. F., Wilhelm, T. A., Lewis, N. A., Brooke, S., Kikiloi, K. & Varmer, O.
Nations have recently committed to protecting 20–30% of the ocean at various global summits; however, marine protected areas currently cover <3% of the ocean. Large-scale marine protected areas (LSMPAs, >100 000 km2) are a new concept in global marine conservation that offer real hope in achieving global conservation targets.
Many of the existing LSMPAs are remote islands in the Pacific that share common natural history, threats, culture, as well as scientific and management needs.
As a result of their common ancestry, many Pacific cultures have a long history of collaboration, including sharing resources, information and expertise to ensure the long-term sustainability of their resources.
Management, governance and research capacity limitations are magnified in LSMPAs, therefore highlighting the need to return to these prior forms of collaboration to achieve conservation objectives.
Several LSMPAs in the Pacific have collaborated to achieve their management and scientific goals, including documented collaborations among the Papahānaumokuākea Marine National Monument, the Phoenix Islands Protected Area, the Pacific Remote Islands Marine National Monument, the Marianas Trench Marine National Monument, the Motu Motiru Hiva Marine Park, the Natural Park of the Coral Sea, and the Cook Islands Marine Park.
Collaborations among LSMPAs in the Pacific include bilateral agreements, learning exchanges, as well as research, monitoring and enforcement activities. By working together, Pacific LSMPAs have been able to overcome some of the management and scientific challenges associated with conserving vast areas of the oceans.
Referencia APA: Friedlander, A. M., Wagner, D., Gaymer, C. F., Wilhelm, T. A., Lewis, N. A., Brooke, S., Kikiloi, K. & Varmer, O. (2016). Co‐operation between large‐scale MPAs: successful experiences from the Pacific Ocean. Aquatic Conservation: Marine and Freshwater Ecosystems, 26(S2), 126-141.
A rose by any other name: systematics and diversity in the Chilean giant barnacle Austromegabalanus psittacus (Molina, 1782) (Cirripedia).
Pappalardo, P., Pitombo, F., Wares, J., & Haye, P.
We analyzed the population structure of the edible barnacle Austromegabalanus psittacus (Molina, 1782) along most of the coast of Chile. The analysis of population structure was based on nucleotide sequences of the mitochondrial cytochrome oxidase I (COI) gene region. We also tested for differences between the regions to the north and south of 30-33°S, as these latitudes represent a recognized biogeographic break and important oceanographic transitions occur in that area. No geographic differentiation was evident when using Hudson’s nearest-neighbor (S nn) statistic to analyze genetic differences between all populations. F st values nevertheless showed overall genetic structure among sites. Significant geographic structure was found using S nn and analysis of molecular variance (AMOVA) when locations were separated into northern and southern regions, with a stronger signal when the geographic division is set at 33°S. Our results support the idea that oceanographic transitions can affect the genetic structure in species with pelagic larvae. We also discuss observations on size structure differences within the natural range of A. psittacus and this barnacle’s sympatric occurrence with another barnacle, Megabalanus concinnus (Darwin, 1854) in its northern range.
Palabras claves: Genetic diversity; genetic structure; picoroco; phylogeography; larval dispersal.
Referencia APA: Pappalardo, P., Pitombo, F., Wares, J., & Haye, P. (2016). A rose by any other name: systematics and diversity in the Chilean giant barnacle Austromegabalanus psittacus (Molina, 1782) (Cirripedia). Journal Of Crustacean Biology, 36(2), 180-188.
Vertical distribution of rocky subtidal assemblages along the exposed coast of north-central Chile.
Stotz, W., Aburto, J., Caillaux, L., & González, S.
Through a systematic study of a stretch of coast in north central Chile, the variety and vertical zonation patterns of the rocky subtidal communities are described, thereby revising apparent uniformity and lack of vertical zonation of the rocky subtidal of southeastern Pacific shores previously reported in the literature. Over the 600 km of coast studied, the following pattern of depth-zonation is described: an upper fringe (lower part of the sublittoral fringe) characterized by barren grounds dominated by calcareous encrusting algae and the sea urchin Tetrapygus niger; an intermediate fringe (upper Infralittoral sub-zone) characterized either by deep barren grounds similar to the former, or kelp beds of Lessonia trabeculata, or an assemblage of suspension feeding organisms, as the big barnacle Austromegabalanus psittacus and/or the tunicate Pyura chilensis; and a deep fringe (Circalittoral sub-zone) dominated by small encrusting or mobile invertebrates. This basic vertical zonation pattern of the shallow rocky subtidal communities seems to be common to most of the temperate coasts of the world. The analysis, first of the occurrence of the general zonation pattern and second of the species composition within the assemblages corresponding to each sub-zone, offers a useful framework for the assessment of the eventual impacts and changes within the shallow rocky subtidal habitat, for example within environmental monitoring programs.
Palabras claves: Chile; Community monitoring; Southeastern Pacific; Subtidal; Zonation pattern.
Referencia APA: Stotz, W., Aburto, J., Caillaux, L., & González, S. (2016). Vertical distribution of rocky subtidal assemblages along the exposed coast of north-central Chile. Journal Of Sea Research, 107, 34-47.
Life history patterns are correlated with predictable fluctuations in highly seasonal environments of semi-terrestrial burrowing crayfish.
Palaoro, A., del Valle, E., & Thiel, M.
Animals living in extreme environments with predictable seasonality may have important life history events correlated to favourable periods. These animals pass critical life stages in protected habitats, especially during early life, often receiving parental care. It is thus hypothesized that juveniles rely on protective microhabitats provided by their parents, becoming independent only during favourable seasons. Semi-terrestrial crayfish Parastacus pugnax inhabit burrows in highly seasonal and predictable environments, thus being well suited to test this hypothesis. Following marked burrows and individual crayfish we examined the life history patterns of P. pugnax in their natural environment to test the predictions that (i) burrowing activity is higher during the wet season, (ii) reproductive events occur during favourable seasons and (iii) juveniles only disperse after reaching larger sizes. There was little or no burrowing activity during the dry season, when soil was more compact, but burrows became wider and had more openings during the wet season. After hatching, juveniles cohabited with adults for at least 4 months during the dry season. During this period juveniles grew considerably, starting independent lives during the wet season. These results suggest that the prolonged parent-offspring cohabitation evolved in response to the predictable seasonal variations in the crayfish habitat.
Palabras claves: Behavioural adaptations, Fossorial species, Parastacus pugnax, Parental care, Seasonality.
Referencia APA: Palaoro, A., del Valle, E., & Thiel, M. (2016). Life history patterns are correlated with predictable fluctuations in highly seasonal environments of semi-terrestrial burrowing crayfish. Hydrobiologia, 767(1), 51-63.
No sex-related dispersal limitation in a dioecious, oceanic long-distance traveller: the bull kelp Durvillaea antarctica.
Lizée-Prynne, D., López, B., Tala, F., & Thiel, M.
Dispersal of dioecious floating seaweeds could be limited due to biological constraints. This study examined for benthic and floating populations (stranded individuals) of the rafting kelp Durvillaea antarctica whether male and female individuals cohabit within one holdfast. As a previous study had indicated colour differences between sexes, we also examined whether these colour differences are consistent and possibly related to pigment and phlorotannin concentrations. Our large-scale survey of rafted holdfasts and a small-scale survey of benthic holdfasts at two sites found that reproductive males and females do travel together in coalesced holdfasts, although this proportion is relatively low (5–17%). There were no sex-specific differences in pigment and phlorotannin concentrations, but there were significant differences between the two benthic populations. There was no relationship between the colouration of thalli and the concentration of pigments but there was a slight colour difference between vegetative and reproductive sexual stages. Based on these results we conclude that biological conditions are not the cause for the lack of genetic connectivity between D. antarctica populations from central Chile. Instead, we suggest that ecological processes, such as density-blocking and physical factors (i.e. currents and winds), limit the potential for successful rafting dispersal.
Palabras claves: Chemical composition; dioecious seaweeds; dispersal potential; phlorotannins; pigments; rafting.
Referencia APA: Lizée-Prynne, D., López, B., Tala, F., & Thiel, M. (2016). No sex-related dispersal limitation in a dioecious, oceanic long-distance traveller: the bull kelp Durvillaea antarctica. Botanica Marina, 59(1).
Short- and long-term acclimation patterns of the giant kelp Macrocystis pyrifera(Laminariales, Phaeophyceae) along a depth gradient.
Koch, K., Thiel, M., Hagen, W., Graeve, M., Gómez, I., & Jofre, D. et al.
The giant kelp, Macrocystis pyrifera, is exposed to highly variable irradiance and temperature regimes across its geographic and vertical depth gradients. The objective of this study was to extend our understanding of algal acclimation strategies on different temporal scales to those varying abiotic conditions at various water depths. Different acclimation strategies to various water depths (0.2 and 4 m) between different sampling times (Jan/Feb and Aug/Sept 2012; long-term acclimation) and more rapid adjustments to different depths (0.2, 2 and 4 m; short-term acclimation) during 14 d of transplantation were found. Adjustments of variable Chl a fluorescence, pigment composition (Chl c, fucoxanthin), and the de-epoxidation state of the xanthophyll cycle pigments were responsible for the development of different physiological states with respect to various solar radiation and temperature climates. Interestingly, the results indicated that phlorotannins are important during long-term acclimation while antioxidants have a crucial role during short-term acclimation. Furthermore, the results suggested that modifications in total lipids and fatty acid compositions apparently also might play a role in depth acclimation. In Aug/Sept (austral winter), M. pyrifera responded to the transplantation from 4 m to 0.2 m depth with a rise in the degree of saturation and a switch from shorter- to longer-chain fatty acids. These changes seem to be essential for the readjustment of thylakoid membranes and might, thus, facilitate efficient photosynthesis under changing irradiances and temperatures. Further experiments are needed to disentangle the relative contribution of solar radiation, temperature and also other abiotic parameters in the observed physiological changes.
Palabras claves: Acclimation; antioxidants; Chile; fatty acid composition; PAR ; phlorotannins; temperature; total lipids.
Referencia APA: Koch, K., Thiel, M., Hagen, W., Graeve, M., Gómez, I., & Jofre, D. et al. (2016). Short -and long- term acclimation patterns of the giant kelp Macrocystis pyrifera (Laminariales, Phaeophyceae) along a depth gradient. Journal Of Phycology, 52(2), 260-273.
On the advantage of sharing a holdfast: effects of density and occurrence of kin aggregation in the kelp Lessonia berteroana.
Segovia, N., Vásquez, J., Faugeron, S., & Haye, P.
We investigated the density-dependent and genetic relatedness that regulate the occurrence of inter-individual (genet) fusion forming plurigenotypic organisms in the brown alga Lessonia berteroana. Recruitment generally occurs at high densities in the inter-tidal, allowing contact of neighbouring holdfasts as they grow and expand on the substrate. Algal density, by contrast, is regulated by the effects of herbivory and wave impact, which often lead to low holdfast density. Herein, we investigated whether the occurrence of plurigenotypic organisms and their genotypic composition (number of genotypes per plurigenotypic organism) are density dependent and affected by kin selection in the inter-tidal kelp L. berteroana. Four microsatellite loci were used to analyse DNA from 260 samples obtained from shared and non-shared holdfasts, at two sites with high and two site with low holdfast density. Analyses showed that fusions forming plurigenotypic organisms are extremely common. Interestingly, the frequency of fusions was higher in low-density sites, in which 100% of the plants had at least two genotypes and the average was 3.5. In high-density sites, 62% of plants were plurigenotypic, with an average of 2.8 genotypes per plant. Additionally, we found that genotypes that shared a holdfast had a significantly higher genetic relatedness than the average in the population, compatible with a kin structure. Density dependence and kin structure suggest that the occurrence of plurigenotypic organisms is linked to environmental quality, and that kin or multilevel selection may be favouring the fusion of genetically related genets.
Palabras claves: Density dependence; fusion of individuals; genetic relatedness; kelp; kin aggregation; kin selection; microsatellites.
Referencia APA: Segovia, N., Vásquez, J., Faugeron, S., & Haye, P. (2015). On the advantage of sharing a holdfast: effects of density and occurrence of kin aggregation in the kelp Lessonia berteroana. Mar Ecol, 36(4), 1107-1117
Growth Inhibition of Bacterial Fish Pathogens and Quorum-Sensing Blocking by Bacteria Recovered from Chilean Salmonid Farms.
Fuente, M., Miranda, C., Jopia, P., González-Rocha, G., Guiliani, N., Sossa, K., & Urrutia, H.
The main goal of this study was to find bacterial isolates with the ability to inhibit the growth of the fish pathogens Aeromonas hydrophila, Vibrio anguillarum, and Flavobacterium psychrophilum and to inhibit the blockage of the quorum-sensing (QS) system. A total of 80 gram-negative strains isolated from various freshwater Chilean salmonid farms were studied. We determined that 10 strains belonging to the genus Pseudomonas inhibited at least one of the assayed fish pathogens. Of these, nine strains were able to produce siderophores and two strains were able to inhibit the growth of all assayed pathogenic species. When the 80 strains were examined for QS-blocking activity, only the strains Pseudomonas sp. FF16 and Raoultella planticola R5B1 were identified as QS blockers. When the QS-blocker strains were analyzed for their ability to produce homoserine lactone (HSL) molecules, thin-layer chromatography analysis showed that both strains were able to produce C6-HSL– and C8-HSL–type molecules. Strain R5B1 did not show growth inhibition properties, but strain FF16 also led to inhibition of growth in A. hydrophila and F. psychrophilum as well as to siderophore production. Pseudomonas sp. FF16 exhibited potentially useful antagonistic properties and could be a probiotic candidate for the salmon farming industry.
Referencia APA: Fuente, M., Miranda, C., Jopia, P., González-Rocha, G., Guiliani, N., Sossa, K., & Urrutia, H. (2015). Growth Inhibition of Bacterial Fish Pathogens and Quorum-Sensing Blocking by Bacteria Recovered from Chilean Salmonid Farms. Journal Of Aquatic Animal Health, 27(2), 112-122.
Scallop larvae hatcheries as source of bacteria carrying genes encoding for non-enzymatic phenicol resistance.
Miranda, C., Rojas, R., Geisse, J., Romero, J., & González-Rocha, G.
The main aim of the study was to evaluate the role of scallop hatcheries as source of the floR and cmlA genes. A number of 133 and 121 florfenicol-resistant strains were isolated from scallop larval cultures prior to their transfer to seawater and from effluent samples from 2 commercial hatcheries and identified by 16S rRNA gene sequence analysis, observing a predominance of the Pseudomonas, Pseudoalteromonas and Halomonas genera and exhibiting an important incidence of co-resistance to streptomycin, oxytetracycline and co-trimoxazole. A high percentage of strains from both hatcheries carried the floR gene (68.4% and 89.3% of strains), whereas a lower carriage of the cmlA gene was detected (27.1% and 54.5% of strains). The high prevalence of floR-carrying bacteria in reared scallop larvae and hatchery effluents contributes to enrich the marine resistome in marine environments, prompting the need of a continuous surveillance of these genes in the mariculture environments.
Palabras claves: Florfenicol; Antimicrobial resistance; floR; Scallop hatchery; Chile.
Referencia APA: Miranda, C., Rojas, R., Geisse, J., Romero, J., & González-Rocha, G. (2015). Scallop larvae hatcheries as source of bacteria carrying genes encoding for non-enzymatic phenicol resistance. Marine Pollution Bulletin, 95(1), 173-182.
Litter and seabirds found across a longitudinal gradient in the South Pacific Ocean.
Miranda-Urbina, D., Thiel, M., & Luna-Jorquera, G.
Abundances and composition of marine litter and seabirds were estimated in the central South Pacific (SP) Ocean between the Chilean continental coast and the Easter Island Ecoregion. Litter was dominated by plastics throughout the study area, but the proportion of plastics was higher at sea and on the oceanic islands than in coastal waters and on continental beaches. Litter densities were higher close to the center of the SP subtropical gyre compared to the continental coast. The seabird assemblage was diverse (28 species), and several endemic species were recorded. Seabird abundances were higher in the coastal waters and around Juan Fernández Islands off the continental coast than in the Oceanic and Polynesian sectors. Endangered species breeding on Salas & Gómez Island were observed in the Polynesian sector, which suggests a high potential for negative interactions between seabirds and floating litter, both occurring in high densities in this sector.
Palabras claves: Litter; Seabirds; South Pacific Subtropical gyre; Oceanic islands; Motu Motiro Hiva Marine Park.
Referencia APA: Miranda-Urbina, D., Thiel, M., & Luna-Jorquera, G. (2015). Litter and seabirds found across a longitudinal gradient in the South Pacific Ocean. Marine Pollution Bulletin, 96(1-2), 235-244.
Mating rock shrimp hedge their bets: old males take greater risk, but only after careful assessment of the investment scenario.
Ory, N., van Son, T., & Thiel, M.
Mature organisms often have to trade reproductive opportunities against the need to survive, especially in species with exaggerated, sexually selected traits. Life history theory predicts that old males with low residual reproductive value (RRV) would accept greater risk for current reproduction than their younger counterparts. Accordingly, we tested the prediction that, under predation risk, old males of the rock shrimp Rhynchocinetes typus pair with females faster and for a longer time than young males do. We exposed young and old dominant males (in the final ontogenetic stage, called “robustus”) to a female in the absence and presence of a predator. As predicted, older robustus males modified their mating behavior when exposed to a predator. However, in contrast to the prediction, they delayed female seizure under predation risk, possibly to carefully assess the actual threat before initiating female guarding. Once they had established the mate-guarding position, old robustus males did not interrupt it until the end of female spawning and, in the presence of predators, even guarded the female significantly longer than in predator-free treatments. In contrast, younger robustus males did not delay female seizure but abandoned the female repeatedly when a predator was present, suggesting that they perceived and responded to the predation risk. Our results suggest that older robustus males have the experience to assess threats before engaging in risky behaviors that bolster their reproductive success. Although consistent with the theory that low RRV individuals should accept greater reproductive risk, we suggest that old individuals do not recklessly engage in risky behaviors but rather cautiously evaluate the threats before investing in a potentially terminal reproductive event.
Palabras claves: AgeMate-guarding, Mating behavior,Predation risk,Residual reproductive value,Risk-taking strategies.
Referencia APA: Ory, N., van Son, T., & Thiel, M. (2015). Mating rock shrimp hedge their bets: old males take greater risk, but only after careful assessment of the investment scenario. Behavioral Ecology And Sociobiology, 69(12), 1975-1984.