UCN-CEAZA
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Analysis of Life-History Traits in a Sex-Changing Marine Shrimp (Decapoda: Caridea: Rhynchocinetidae).
Osawa, Y., Aoki, M., Thiel, M., & Bauer, R.
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.
Petit, I., Gaymer, C., Palma, Á., & Wahle, R.
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.
Koch, K, Thiel, M., Tellier, F., Hagen, W., Graeve, M., Tala, F., Laeseke, P., and Bischof K.
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.
Transcriptome characterization of the ascidian Pyura chilensis using 454-pyrosequencing data from two distant localities on the southeast Pacific.
Haye, P. & Gallardo-Escárate, C.
This study describes the results from transcriptomes sequenced by 454-pyrosequencing from two populations separated by 10° of latitude of the endemic tunicate Pyura chilensis. Most transcripts were assembled in 43,972 contigs with an average length of 842 nucleotides. De novo assembly revealed that less than 30% of the contigs were annotated to Gene Ontology terms. A total of 71,662 single nucleotide polymorphisms (SNPs) were detected in 14,712 contigs. In silico differential expression of contigs annotated for SNPs revealed several genes differentially expressed in individuals collected from both populations. The present genomic resource will provide the basis to perform functional genomics on the species via the localization of genomic markers that can aid in determining levels of local adaptation, overall genetic structure and the genetic assessment of restocking programs for this species.
Año: 2015
Palabras claves: RNA-Seq; SNP; Pyura chilensis; Tunicates; Transcriptome; Pyrosequencing.
Referencia APA: Haye, P. & Gallardo-Escárate, C. (2015). Transcriptome characterization of the ascidian Pyura chilensis using 454-pyrosequencing data from two distant localities on the southeast Pacific. Marine Genomics, 20, 19-22.
High variability of levels of Aliivibrio and lactic acid bacteria in the intestinal microbiota of farmed Atlantic salmon Salmo salar L.
Godoy, F., Miranda, C., Wittwer, G., Aranda, C., & Calderón, R.
In the present study, the structure of the intestinal microbiota of Atlantic salmon (Salmo salar L.) was studied using culture and culture-independent methods. Three adult specimens of S. salar were collected from a commercial salmon farm in Chile, and their intestinal microbiota were studied by partial sequencing of the 16S rRNA gene of pure cultures as well as of clone libraries. Out of the 74 bacterial isolates, Pseudomonas was the most predominant genus among cultured microbiota. In clone libraries, 325 clones were obtained from three adult fish, and a total of 36 operational taxonomic units (OTUs) were identified. This indicated that lactic acid bacteria (Weissella, Leuconostoc, and Lactococcus genera) comprised more than 50 % of identified clones in two fishes. This was in contrast with the high dominance of a single OTU (99 sequences) of Aliivibrio sp. related to the pathogenic Aliivibrio salmonicida species and the absence of lactic acid bacteria in the third fish, suggesting a condition of an asymptomatic non-healthy carrier. It is clear that molecular identification of 16S rRNA gene libraries obtained from intestinal content samples is effective in determining the overall structure of the intestinal microbiota of farmed Atlantic salmon enabling detection of a minority of taxa not previously reported as part of the intestinal microbiota of salmonids, including the genera Hydrogenophilus, Propionibacterium, Cronobacter, Enhydrobacter, Veillonella, Prevotella, and Atopostipes, as well as to evaluate the health status of farmed fish when evaluating the dominance of potential pathogenic species and the incidence of lactic acid bacteria.
Año: 2015
Palabras claves: Aquaculture, Intestinal microbiota, Aliivibrio, Salmon farming, Salmo salar.
Referencia APA: Godoy, F., Miranda, C., Wittwer, G., Aranda, C., & Calderón, R. (2015). High variability of levels of Aliivibrio and lactic acid bacteria in the intestinal microbiota of farmed Atlantic salmon Salmo salar L. Ann Microbiol, 65(4), 2343-2353