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Genotype by environment interactions, heritabilities and genetic correlations for productive traits of Haliotis rufescens

Autores:

Farías, W., Winkler, F., & Brokordt, K.

Resumen:

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.

Año: 2017

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.

Autores:

Friedlander, A. M., Wagner, D., Gaymer, C. F., Wilhelm, T. A., Lewis, N. A., Brooke, S., Kikiloi, K. & Varmer, O.

Resumen:

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.

Año: 2016

Palabras claves:

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).

Autores:

Pappalardo, P., Pitombo, F., Wares, J., & Haye, P.

Resumen:

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.

Año: 2016

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.

Autores:

Stotz, W., Aburto, J., Caillaux, L., & González, S.

Resumen:

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.

Año: 2016

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.

Autores:

Palaoro, A., del Valle, E., & Thiel, M.

Resumen:

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.

Año: 2016

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.

Autores:

Lizée-Prynne, D., López, B., Tala, F., & Thiel, M.

Resumen:

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.

Año: 2016

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.

Autores:

Koch, K., Thiel, M., Hagen, W., Graeve, M., Gómez, I., & Jofre, D. et al.

Resumen:

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.

Año: 2016

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.

Characterization and pathogenicity of Vibrio splendidus strains associated with massive mortalities of commercial hatchery-reared larvae of scallop Argopecten purpuratus (Lamarck, 1819)

Autores:

Rojas, R., Miranda, C., Opazo, R., & Romero, J.

Resumen:

Three strains (VPAP16, VPAP18 and VPAP23 strains) were isolated as the most predominant organisms from 3 different episodes of massive mortalities of larval cultures of the Chilean scallop Argopecten purpuratus occurred in different commercial hatcheries located in northern Chile. The main aims of this study were to identify the pathogenic strains and investigate their pathogenic activity. Based on selected phenotypic features and sequence identity of the 16S rRNA gene and the housekeeping gene, RNA polymerase α-chain rpoA, all pathogenic strains were identified as Vibrio splendidus. Healthy 10–day–old scallop larvae cultures exhibited mortality percentages of 69.61 ± 3.35%, 79.78 ± 6.11% and 61.73 ± 3.71% after 48 h when were inoculated with 1 × 106 CFU (colony forming units) mL−1 of VPAP16, VPAP18 and VPAP23 strains, respectively, and evidenced that concentrations ⩾104 CFU mL−1 would probably be detrimental for the larval culture. The main clinical signs observed in challenged larvae for 24 h were bacterial swarms on the margins of the larvae, extension and disruption of the velum, detachment of velum cilia cells and digestive tissue necrosis. Otherwise, challenge assays using pathogenic strains stained with 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein hydrochloride (5-DTAF) evidenced that after 1 h stained bacteria were detected in high density in the digestive gland and the margin of the shell. When larval cultures were inoculated with cell-free extracellular products (ECP) of V. splendidus strains, exhibited larval mortalities higher than 70% (VPAP16), 80% (VPAP18) and 50% (VPAP23) after 24 h, even when ECP were treated with proteinase K or heat, indicating that extracellular pathogenic activity is mainly mediated by non-proteic thermostable compounds. In this study all Koch’s postulates were fulfilled and it was demonstrated for the first time the pathogenic activity of V. splendidus strains on reared-larvae of scallop A. purpuratus and prompt the necessity to maintain this species at concentrations lower than 104 CFU mL−1 to avoid episodes of mass mortalities in scallop hatcheries.

Año: 2015

Palabras claves: Bacteria; Vibrio splendidus; Scallop larvae; Vibriosis; Shellfish pathology; Argopecten purpuratus.

Referencia APA: Rojas, R., Miranda, C., Opazo, R., & Romero, J. (2015). Characterization and pathogenicity of Vibrio splendidus strains associated with massive mortalities of commercial hatchery-reared larvae of scallop Argopecten purpuratus (Lamarck, 1819). Journal Of Invertebrate Pathology, 124, 61-69.

First Records of Striped Boarfish Evistias acutirostris and Ornate Butterflyfish Chaetodon ornatissimus from Easter Island 1.

Autores:

Hernández, S., García, M., Gaymer, C., & Friedlander;, A.

Resumen:

Here we report on two new reef fish species from the remote and isolated Easter Island—the striped boarfish Evistias acutirostris and the ornate butterflyfish Chaetodon ornatissimus were observed during scuba dives and underwater video around Easter Island, as well as at nearby Apolo Seamount. These observations are the first records of these species for the southeastern Pacific, which represents a major extension to their distributions and raises questions about the origins and persistence of reef fishes in remote subtropical locations.

Año: 2015

Palabras claves:

Referencia APA: Hernández, S., García, M., Gaymer, C., & Friedlander, A. (2015). First Records of Striped Boarfish Evistias acutirostris and Ornate Butterflyfish Chaetodon ornatissimus from Easter Island1. Pacific Science, 69(4), 525-529.

Analysis of Life-History Traits in a Sex-Changing Marine Shrimp (Decapoda: Caridea: Rhynchocinetidae).

Autores:

Osawa, Y., Aoki, M., Thiel, M., & Bauer, R.

Resumen:

The hypothesis of protandrous (male to female) sex change was tested for the first time in a rhynchocinetid shrimp, Rhynchocinetes uritai, with an analysis of life-history traits. Samples were taken monthly for 2 years in Oura Bay, Japan, using a combination of bait and refuge traps. Breeding was seasonal but extended from spring through autumn, with female-phase individuals (FPs) producing broods successively, with their ovaries maturing for a new spawn during incubation of a previous brood. Females incubated numerous (∼500–4000) embryos that suffered insignificant mortality before hatching. Recruitment of juveniles after planktonic larval development began in summer and peaked during the autumn, with negligible recruitment during winter and spring. Cohort analysis confirmed the hypothesis of protandric sex change in this species, with juveniles maturing into the male phase (MP) during their first reproductive season at an age of 6–10 mon, depending on the time of recruitment. Sex change occurred during the following winter when transitional individuals matured into FPs during their second reproductive season at an age of ≥18 mon. Two cohorts were followed from recruitment until the end of the study, indicating a life span of 21–25 mon. Aside from its sexual system, this sex-changing species showed no obvious differences in reproductive and other life-history traits from those of gonochoric species from similar latitudes and habitats.

Año: 2015

Palabras claves:

Referencia APA: Osawa, Y., Aoki, M., Thiel, M., & Bauer, R. (2015). Analysis of Life-History Traits in a Sex-Changing Marine Shrimp (Decapoda: Caridea: Rhynchocinetidae). The Biological Bulletin, 228(2), 125-136.

Predation of Juvenile Jasus frontalis : An Endemic Spiny Lobster of the Juan Fernández Archipelago, Chile.

Autores:

Petit, I., Gaymer, C., Palma, Á., & Wahle, R.

Resumen:

This study identified and quantified in the field the natural predators of juvenile spiny lobster Jasus frontalis, an endemic, ecologically relevant species, and the most valuable local commercial catch of Robinson Crusoe Island. It also assessed the predation pressure that these predators exerted on juveniles lobsters and whether they showed preferences for particular body sizes within the juvenile size range. A series of tethering experiments were performed in three coastal sites of Robinson Crusoe Island (Juan Fernández archipelago. Chile). In overnight experiments, survival of juveniles decreased over time in all three sites, reaching ∼50% at the end of the experiment. The evidence suggests that fish were relevant predators since mortality of lobsters was proportional to their abundance. Although video surveillances depicted numerous octopus attacks, their abundance did not exhibit a statistically significant relationship with lobster mortality. Predatory events were not selective of juvenile sizes. These results are fundamental to understand one of the key factor (i.e., predation) that affects the juvenile (and more vulnerable) benthic phase of J. frontalis.

Año: 2015

Palabras claves: Predation, oceanic island, juveniles, lobsters, Jasus frontalis.

Referencia APA: Petit, I., Gaymer, C., Palma, Á., & Wahle, R. (2015). Predation of Juvenile Jasus frontalis: An Endemic Spiny Lobster of the Juan Fernández Archipelago, Chile. Journal Of Shellfish Research, 34(3), 1085-1089.

Species separation within the Lessonianigrescens complex (Phaeophyceae, Laminariales) is mirrored by ecophysiological traits.

Autores:

Koch, K, Thiel, M., Tellier, F., Hagen, W., Graeve, M., Tala, F., Laeseke, P., and Bischof K.

Resumen:

Lessonia nigrescens used to be an abundant kelp species along the Chilean coast, but recent molecular studies revealed the existence of a L. nigrescens species complex, which includes the two cryptic species Lessonia berteroana and Lessonia spicata. Since these species have different distributions (16°S–30°S for L. berteroana and 29°S–42°S for L. spicata), they experience differences in environmental conditions, such as solar irradiance, seawater temperature and air exposure during low tide. This study tested to what extent the genetic distinctness of each of the two species [identified by a mitochondrial marker (atp8/trnS)] is reflected by ecophysiological traits (total lipids, fatty acid composition, phlorotannins, pigments and variable chlorophyll a fluorescence of PSII) in response to the respective environmental conditions, prevailing along the latitudinal gradient. We studied algal individuals from eight populations (27°S–32°S, including the species overlapping zone). Phlorotannins, pigments and Chl a fluorescence of PSII were most crucial for species-specific adaptations at the respective growth sites, whereas changes in total lipids and fatty acid compositions were negligible. Hence, species differentiation within the L. nigrescens complex is also manifested at the ecophysiological level. These findings may help to predict kelp responses towards future environmental changes.

Año: 2015

Palabras claves: Chile; fatty acid composition; Lessonia nigrescens complex; phlorotannins; photosynthetic pigments.

Referencia APA: Koch, K, Thiel, M., Tellier, F., Hagen, W., Graeve, M., Tala, F., Laeseke, P., and Bischof K. (2015). Species separation within the Lessonia nigrescens complex (Phaeophyceae, Laminariales) is mirrored by ecophysiological traits. Botanica Marina 2015; 58(2): 81–92.