UCN-CEAZA
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
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.
Año: 2014
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.
Año: 2015
Palabras claves:
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.
Año: 2015
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.
Año: 2015
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.
Año: 2015
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.
Numbers and sizes of the shrimp Rhynchocinetes uritaiKubo, 1942 (Decapoda: Caridea) caught in bait and refuge traps.
Osawa, Y., Bauer, R., Aoki, M., & Thiel, M.
Catch rates and sizes of hingebeak shrimp Rhynchocinetes uritaiKubo, 1942 were studied with two types of traps: bait traps that were exposed for 1-2 days and unbaited “refuge traps” exposed for 2-4 weeks. Shrimp were collected twice a month from June 2010 to May 2012 on rocky substrata in Oura Bay, Shimoda, Japan. Overall the numbers of shrimp caught did not differ between the two trap types, but when adjusted for soak times, the bait traps had substantially higher catch rates than the refuge traps. Addition of light to the bait traps had no significant effect on catch rates. However, shrimp in the baited traps were significantly larger than those in the refuge traps. The results show that size distribution can be greatly affected by trap type. Consequently, using two types of traps simultaneously increases not only the catch efficiency but also ensures that all sizes of the reproductively mature shrimp population are sampled in adequate numbers, which is especially important in protandric hermaphrodites.
Año: 2015
Palabras claves: Hingebeak shrimp; bait traps; catch efficiency; refuge traps.
Referencia APA: Osawa, Y., Bauer, R., Aoki, M., & Thiel, M. (2015). Numbers and sizes of the shrimp Rhynchocinetes uritai Kubo, 1942 (Decapoda: Caridea) caught in bait and refuge traps. Journal Of Crustacean Biology, 35(6), 768-775
First record of the sea anemone Diadumene lineata (Verrill, 1869)from the Chilean coast.
Häussermann, V., Spano, C., Thiel, M., & Lohrmann, K.B.
The orange-striped green sea anemone Diadumene lineata (Verrill 1871) was originally described from Japan but has been recorded as an invasive species from temperate and tropical coasts all over the world, being presumably transported on ship hulls or with seafood shipments. Here, we report the occurrence of this species for the first time from the South East Pacific, specifically on the coast of Coquimbo, northern Chile. Two specimens were spotted in 2012 and approximately 15 individuals were collected and examined in 2014. Most specimens were identified both externally and internally, confirming the cnidome described for the species in several individuals. Generally, the greenish-brown specimens had a pedal disc diameter of up to 7 mm and possessed between 2 and 11 irregularly distributedorange stripes. Since D. lineata is known to proliferate quickly, it is strongly recommended to start monitoring the area for possible outbreaks.
Año: 2015
Palabras claves:
Referencia APA: Häussermann, V., Spano, C., Thiel, M., & Lohrmann, K.B. (2015). First record of the sea anemone Diadumene lineata (Verrill, 1869) from the Chilean coast. In Spixiana, Zeitschrift Für Zoologie. Editor Gerhard Haszprunar. Bavarian State Collection Of Zoology (zoologische Staatssammlung München). pp. 39-42.
Genetic diversity in Chilean populations of rainbow trout, Oncorhynchus mykiss.
Carcamo, C., Diaz, N., & Winkler, F.
The rainbow trout Oncorhynchus mykiss, was first introduced in Chile between 1905 and 1920 and is currently widely distributed in Chile from Antofagasta (23°S) to Patagonia (55ºS). The broad range of the geographic and climatic distributions of this species in Chile offers a unique opportunity to study the effect of naturalization of an introduced species on its genetic variability. It is of particular importance to observe the genetic variability of populations in the northern range of this species distribution, in a transition zone where a Mediterranean-type climate changes to an arid climate. The present study analyzed allozymic variability and distribution within and between populations of O. mykiss from the river basins of Elqui and Limarí rivers, and six culture strains, using starch-gel protein electrophoresis. Populations were found to be in Hardy-Weinberg equilibrium and the average values of He (0.045), polymorphism (13.9%) and allele per locus (1.19) are similar to rainbow trout in its native distributional range. About 77.8% of the genetic variability was within population, similar to the variability reported for wild populations in the northern hemisphere. However, a marked genetic differentiation between wild populations was also found. This is likely to be the consequence of initial founder effects followed by subsequent introgression of resident populations caused by reseeding with trout of different origins in both basins.
Año: 2015
Palabras claves: Oncorhynchus mykiss, rainbow trout, Salmonidae, genetic variation, aquaculture, conservation.
Referencia APA: Carcamo, C., Diaz, N., & Winkler, F. (2015). Genetic diversity in Chilean populations of rainbow trout, Oncorhynchus mykiss. Latin American Journal Of Aquatic Research, 43(1), 59-70.
Management of marine resources through a local governance perspective: Re-implementation of traditions for marine resource recovery on Easter Island.
Aburto, J., Gaymer, C., Haoa, S., & González, L.
Easter Island (Rapa Nui) is one of the most isolated places in the world. The local Rapanui people have noticed an extreme decline in marine resources, which is due to the exploitation of these resources. Top-down regulations (e.g. fisherman and boat registrations and restrictions on catch-length and fishing season and location) implemented by the central fishery authorities located ∼4000 km from the island do not represent the cultural heritage and interests of the Rapanui people. According to the local people, one of the traditional ways to protect marine resources was the taboo (or tapu in Rapa Nui) that regulated the fish harvest. Key informants were interviewed to assess what they knew about the tapu in fisheries and so that the feasibility of its implementation could be assessed based on current local conditions. The tapu that had the greatest potential impact on regulating open water resources, especially tuna, was the traditional belief that consumption of open-water fish during winter months would cause asthma. According to the interviewees, the real reason for this tapu was to protect the fish during its reproductive period, and the asthma threat was only a way to enforce the restriction. At present, tapu is not respected because of the high economic activity related to the tourism that demands fish like tuna all year. Even though many Rapanui people agree that tapu re-implementation would be the best alternative to recover marine resources, people also think it is difficult to implement under modern conditions. We propose to promote a participatory process for development of a local governance structure that will use local traditions and beliefs, including tapu, to support the local decision-making process for reverting the decline of marine resources.
Año: 2015
Palabras claves: Easter Island; Resource management; TEK; Taboo; Local governance.
Referencia APA: Aburto, J., Gaymer, C., Haoa, S., & González, L. (2015). Management of marine resources through a local governance perspective: Re-implementation of traditions for marine resource recovery on Easter Island. Ocean & Coastal Management, 116, 108-115.
Citizen scientists and marine research: volunteer participants, their contributions, and projection for the future.
Thiel, M., Penna-Díaz, M. A., Luna-Jorquera, G., Salas, S., Sellanes, J., & Stotz, W.
Año: 2014
Palabras claves:
Referencia APA: Thiel, M., Penna-Díaz, M. A., Luna-Jorquera, G., Salas, S., Sellanes, J., & Stotz, W. (2014). Citizen scientists and marine research: volunteer participants, their contributions, and projection for the future. Oceanography and Marine Biology: An Annual Review, 52, 257-314. DOI: 10.1201/b17143-6