UCN-CEAZA
Effect of florfenicol and oxytetracycline treatments on the intensive larval culture of the Chilean scallop Argopecten purpuratus (Lamarck, 1819).
Miranda, C., Rojas, R., Abarca, A., & Hurtado, L.
The administration of antimicrobials to control bacterial pathologies in Chilean scallop hatcheries is a frequent practice, but their effects on these cultures remained unknown. This study was undertaken to obtain information on the effect of the administration of florfenicol and oxytetracycline on the growth, survival and bacterial content of scallop larvae under farming conditions. Florfenicol-treated cultures exhibited high survival rates (44% after 17 days of culture), whereas cultures not treated or treated with oxytetracycline collapsed after 11 days of culture. Surprisingly, no significant differences in the heterotrophic (Tukey test; P = 0.226) and Vibrio (Tukey test; P = 0.666) concentrations between the oxytetracycline-treated and untreated larval cultures were observed. Otherwise, florfenicol administered directly into rearing tanks produced significantly higher larval growth (Tukey test; P = 0.0001) and survival (Tukey test; P = 0.011) than bath treatment. When 2 and 4 mg L−1 of florfenicol were compared, no significant differences in growth (t-test; P = 0.4596) and survival (Tukey test; P = 0.057) were observed, suggesting that a concentration of 2 mg L−1 is sufficient to ensure larval production. The present results demonstrate the efficacy of florfenicol-based therapy to increase larval survival and growth at commercial scale and prompt the necessity to standardize its use in Chilean scallop hatcheries.
Año: 2013
Palabras claves: Bacteria; florfenicol; Chilean scallop; shellfish bacteriology; Argopecten purpuratus ; Chile.
Referencia APA: Miranda, C., Rojas, R., Abarca, A., & Hurtado, L. (2013). Effect of florfenicol and oxytetracycline treatments on the intensive larval culture of the Chilean scallop Argopecten purpuratus (Lamarck, 1819). Aquaculture Research, 45(1), 16-30.
Effects of isolation and fishing on the marine ecosystems of Easter Island and Salas y Gómez, Chile.
Friedlander, A., Ballesteros, E., Beets, J., Berkenpas, E., Gaymer, C., Gorny, M., & Sala, E.
An expedition to Salas y Gómez and Easter islands was conducted to develop a comprehensive baseline of the nearshore marine ecosystem, to survey seamounts of the recently created Motu Motiro Hiva Marine Park (MMHMP) – a no-take marine reserve of 150 000 km2 – and to compare these results with Easter Island where the marine ecosystem is similar but has no marine protection.
Live coral cover was surprisingly high at both Easter Island (53%) and Salas y Gómez (44%), especially considering their sub-tropical location, high wave energy environments, and geographic isolation.
Endemic and regionally-endemic species comprised 77% of the fish abundance at Easter Island and 73% at Salas y Gómez. Fish biomass at Salas y Gómez was relatively high (1.2 t ha-1) and included a large proportion of apex predators (43%), whereas at Easter Island it was almost three times lower (0.45 t ha-1) with large predators accounting for less than 2% of the biomass, despite good habitat quality.
The large cohort of small sharks and the absence of larger sharks at Salas y Gómez suggest mesopredator release consistent with recent shark fishing. The fish fauna at the seamounts between Easter Island and Salas y Gómez, outside of MMHMP, harboured 46% endemic species, including a new species of damselfish (Chromis sp. nov.) and probably a new species of Chimaera (Hydrolagus). Numerous seamounts adjacent to Salas y Gómez are currently not included in the MMHMP.
This expedition highlights the high biodiversity value of this remote part of the Pacific owing to the uniqueness (endemicity) of the fauna, large apex predator biomass, and geographic isolation.
Año: 2013
Palabras claves: Coral; biodiversity; no-take marine reserve; algae; fish; fishing.
Referencia APA: Friedlander, A., Ballesteros, E., Beets, J., Berkenpas, E., Gaymer, C., Gorny, M., & Sala, E. (2013). Effects of isolation and fishing on the marine ecosystems of Easter Island and Salas y Gómez, Chile. Aquatic Conserv: Mar. Freshw. Ecosyst., 23(4), 515-531.
Sea urchin Tetrapygus niger distribution on elevated surfaces represents a strategy for avoiding predatory sea stars
Urriago, J., Himmelman, J., & Gaymer, C.
We ran field experiments to examine whether the micro-distribution of the sea urchin Tetrapygus niger on elevated surfaces represents a strategy for limiting predation by the sea stars Heliaster helianthus and Meyenaster gelatinosus. Several lines of evidence supported this hypothesis. (1) A survey of the distribution of the urchin and the 2 sea stars showed that urchins occur mainly on elevated surfaces, and sea stars on low surfaces. (2) In trials involving simulated attacks, the time needed by the urchin to sever contact with the sea stars was 48% less on elevated surfaces than on the bottom. (3) In trials involving sustained simulated attacks (high predatory risk) the urchins could detach themselves from the elevated surfaces to avoid being eaten. Finally, tethering experiments indicated that the urchin had a higher survival rate on elevated than low surfaces. Our observations indicate that M. gelatinosus represents a stronger predatory threat to T. niger than H. helianthus.
Año: 2012
Palabras claves: Tetrapygus niger · Heliaster helianthus · Meyenaster gelatinosus · Predator−prey interactions · Aggregation · Distribution · Tethering
Referencia APA: Urriago, J., Himmelman, J., & Gaymer, C. (2012). Sea urchin Tetrapygus niger distribution on elevated surfaces represents a strategy for avoiding predatory sea stars. Marine Ecology Progress Series, 444, 85-95.
Effects of patch size and position above the substratum during early succession of subtidal soft-bottom communities.
Pacheco, A., Thiel, M., Oliva, M., & Riascos, J.
Early macrobenthos succession in small, disturbed patches on subtidal soft bottoms is facilitated by the arrival of post-larval colonizers, in particular by active and passive dispersers along the seafloor or through the water column. Using a field experiment at two contrasting sites (protected vs. exposed to wave action), we evaluated the role of (a) active and passive dispersal through the water column and (b) the influence of small-scale spatial variability during succession of subtidal macrobenthic communities in northern Chile. Containers of two sizes (surface area: small—0.12 m2 and large—0.28 m2) at two positions above the natural substratum (height: low—3 cm and high—26 cm) were filled with defaunated sediment, installed at two sandy sublittoral sites (7–9 m water depth) and sampled after 7, 15, 30, 60 and 90 days, together with the natural bottom sediment. The experiment took place during austral fall (from late March to early July 2010), when both larval and post-larval stages are abundant. At the exposed site, early succession was driven by similar proportions of active and passive dispersers. A sequence from early, late and reference communities was also evident, but container position and size affected the proportional abundance of dispersal types. At the protected site, the successional process started with abundant colonization of active dispersers, but toward the end of the experiment, the proportion of swimmer/crawlers increased, thus resembling the dispersal types found in the natural community. At this site, the position above the sediment affected the proportional abundance of dispersal types, but patch size had no effect. This study highlights that macrobenthic post-larvae can reach at least 26 cm high above the bottom (actively or passively, depending on site exposure), thus playing an important role during early succession of sublittoral soft bottoms. The active or passive use of the sediment–water interphase may also play an important role in the connectivity of benthic populations and in the recovery after large-scale disturbances of sublittoral habitats.
Año: 2012
Palabras claves: Colonization, Disturbance, Macrobenthos, Size effects, Recruitment, Active and passive dispersal, Humboldt, Current, System.
Referencia APA: Pacheco, A., Thiel, M., Oliva, M., & Riascos, J. (2012). Effects of patch size and position above the substratum during early succession of subtidal soft-bottom communities. Helgoland Marine Research, 66(4), 523-536.
Effects of predation and habitat structure on the abundance and population structure of the rock shrimp Rhynchocinetes typus (Caridea) on temperate rocky reefs.
Ory, N., Dudgeon, D., Dumont, C., Miranda, L., & Thiel, M.
Human disturbances, such as overfishing, may disrupt predator–prey interactions and modify food webs. Underwater surveys were carried out at six shallow-water reef barrens in temperate waters of northern-central Chile from October to December 2010 to describe the effects of predation, habitat complexity (low, medium and high) and refuge availability on the abundance and population structure of the rock shrimp Rhynchocinetes typus (Rhynchocinetidae), an important mesoconsumer on subtidal hard substrata. Three sites were within managed (restricted access) areas for fishermen, and three were unmanaged (open-access). Field observations and tethering experiments were conducted to examine the relationship between fish and shrimp abundances, and the relative predation rates on shrimps. Direct effects of predation on R. typus body-size distribution were examined from shrimps collected in the field and fish stomachs. The presence and the abundance of R. typus increased with habitat reef complexity and refuge availability. Shrimp abundance was negatively related to fish abundance in managed areas, but not in open-access areas, where shrimp densities were the highest. Also, predation rates and body-size distribution of shrimps were unrelated, although fish consumed more large shrimps than should be expected from their distribution in the field. R. typus occurred most often in shelters with wide openings, offering limited protection against predators, but providing potential aggregation sites for shrimps. Overall, direct effects of predation on shrimp densities and population structure were weak, but indirect effects on shrimp distribution within reefs appear to have been mediated through behavioural responses. Our study highlights the need to assess both numerical and behavioural responses of prey to determine the effects of predator loss on mesoconsumer populations.
Año: 2012
Palabras claves:
Referencia APA: Ory, N., Dudgeon, D., Dumont, C., Miranda, L., & Thiel, M. (2012). Effects of predation and habitat structure on the abundance and population structure of the rock shrimp Rhynchocinetes typus (Caridea) on temperate rocky reefs. Marine Biology, 159(9), 2075-2089.
Floating kelps in Patagonian Fjords: an important vehicle for rafting invertebrates and its relevance for biogeography.
Wichmann, C., Hinojosa, I., & Thiel, M.
Floating macroalgae are common dispersal vehicles for associated benthic invertebrates. In order to investigate the importance of kelp rafts for species dispersal in the Patagonian Fjord Region (PFR), the abundance and distribution pattern of floating kelps (Macrocystis pyrifera, Durvillaea antarctica) and of the invertebrate fauna associated with M. pyrifera were evaluated during austral spring of 2002–2005, 2008 and 2010. In the southernmost Magellan Region (MR), benthic M. pyrifera were additionally sampled to compare the community structures in both conditions. Floating kelps were abundant throughout the entire PFR, harbouring a diverse and abundant invertebrate fauna. The density of floating kelps increased towards the south. In the MR, a loss of species was observed between benthic and floating condition (e.g. decapods, echinoderms, several peracarid species), but a high diversity of organisms from all major phyla were observed on rafts. Throughout the PFR, the predominant rafting species belonged to the peracarids, molluscs and annelids, but the community composition differed between floating samples from the northern and southern zones of the PFR. Relative abundances of peracarids were higher in northern zones, whereas molluscs and annelids dominated in the southern areas. Species of the peracarid genera Peramphithoe, Gondogeneia, Bircenna and Limnoria were shared between all areas. The results suggest that kelp rafts not only contribute to local population connectivity in the PFR, but could also be an important dispersal vehicle for rafting species along the PFR in north–south direction, crossing the biogeographic boundary around Taitao Peninsula. Furthermore, the MR appears to be an important stepping stone for species dispersal via kelp rafting in the subantarctic region.
Año: 2012
Palabras claves:
Referencia APA: Wichmann, C., Hinojosa, I., & Thiel, M. (2012). Floating kelps in Patagonian Fjords: an important vehicle for rafting invertebrates and its relevance for biogeography. Marine Biology, 159(9), 2035-2049.
Reproductive biology of two species of squat lobsters – female receptivity and interbrood intervals.
Espinoza-Fuenzalida, N., Acuña, E., Hinojosa, I., & Thiel, M.
The reproductive biology of many species of anomuran crabs is only poorly known. Herein we studied the reproductive biology of two species of squat lobsters, Cervimunida johni Porter, 1903 and Pleuroncodes monodon (H. Milne Edwards, 1837), which are target of a trawl fishery operating on the continental margin along the Chilean coast. During the reproductive period (May-November) we maintained squat lobsters in the laboratory to examine whether mating is related to the reproductive molt of the female and to determine the interbrood interval between successive broods. In both species females mated during the intermolt period. Females became receptive shortly after having released larvae from a previous brood, when they formed pairs with males. The interbrood interval (from larval release until having a subsequent brood) lasted <72<72 hour in the majority of female C. johni, but was longer in P. monodon, where most females took 72-144 hours before producing a new brood. Despite longer interbrood intervals, copulatory mate-guarding was substantially shorter in P. monodon than in C. johni. These differences in reproductive behavior might be due to differences in the general biology of the two species, including mobility and intraspecific aggression. Mating during the intermolt period may have several advantages, namely reducing the risk of cannibalism and energy costs of molting during the reproductive season.
Año: 2012
Palabras claves: female receptivity, mating, reproduction, squat lobsters, trawl fishery.
Referencia APA: Espinoza-Fuenzalida, N., Acuña, E., Hinojosa, I., & Thiel, M. (2012). Reproductive biology of two species of squat lobsters – female receptivity and interbrood intervals. Journal Of Crustacean Biology, 32(4), 565-574
Microplastics in the Marine Environment: A Review of the Methods Used for Identification and Quantification.
Hidalgo-Ruz, V., Gutow, L., Thompson, R., & Thiel, M.
This review of 68 studies compares the methodologies used for the identification and quantification of microplastics from the marine environment. Three main sampling strategies were identified: selective, volume-reduced, and bulk sampling. Most sediment samples came from sandy beaches at the high tide line, and most seawater samples were taken at the sea surface using neuston nets. Four steps were distinguished during sample processing: density separation, filtration, sieving, and visual sorting of microplastics. Visual sorting was one of the most commonly used methods for the identification of microplastics (using type, shape, degradation stage, and color as criteria). Chemical and physical characteristics (e.g., specific density) were also used. The most reliable method to identify the chemical composition of microplastics is by infrared spectroscopy. Most studies reported that plastic fragments were polyethylene and polypropylene polymers. Units commonly used for abundance estimates are “items per m2” for sediment and sea surface studies and “items per m3” for water column studies. Mesh size of sieves and filters used during sampling or sample processing influence abundance estimates. Most studies reported two main size ranges of microplastics: (i) 500 μm–5 mm, which are retained by a 500 μm sieve/net, and (ii) 1–500 μm, or fractions thereof that are retained on filters. We recommend that future programs of monitoring continue to distinguish these size fractions, but we suggest standardized sampling procedures which allow the spatiotemporal comparison of microplastic abundance across marine environments.
Año: 2012
Palabras claves:
Referencia APA: Hidalgo-Ruz, V., Gutow, L., Thompson, R., & Thiel, M. (2012). Microplastics in the Marine Environment: A Review of the Methods Used for Identification and Quantification. Environmental Science & Technology, 46(6), 3060-3075.
Asociacion del color de la concha de reproductores de Argopecten purpuratus (Lamarck, 1819) con la supervivencia, crecimiento y desarrollo larval de sus progenies.
Garcia, R. & Winkler, F.
Las conchas de moluscos bivalvos marinos son extremadamente diversas en sus patrones de pigmentación y riqueza de colores. Tal diversidad se debe a factores ambientales y genéticos. En bivalvos marinos adultos, individuos con coloraciones de concha poco comunes en las poblaciones silvestres suelen presentar tasas de crecimiento y supervivencia menores que aquellos con colores de concha más frecuentes. Conociendo que la variación del color de la concha en Argopecten purpuratus está bajo control genético, en este trabajo se pone a prueba la hipótesis de que los loci responsables de dicha variación pueden afectar el crecimiento, la supervivencia y la tasa de desarrollo de las larvas de esta especie. Se estimó la supervivencia y el crecimiento en progenies de cruzamientos dirigidos entre individuos de A. purpuratus con colores de concha blanco, naranja y marrón, y se verificó la existencia de diferencias en las tasas de desarrollo. El crecimiento de las larvas producidas en cruzamientos que incluyeron individuos marrones o blancos con naranja no mostraron diferencias entre sí. En cambio, las progenies producto de autofecundaciones de individuos naranja y blancos presentaron tasas de crecimiento significativamente menores que las anteriores y distintas entre sí. Las tasas de desarrollo y de supervivencia, en cambio, no mostraron diferencias entre las progenies de los distintos tipos de cruzamientos. Los resultados sugieren que los genes que controlan la variación del color en las conchas de juveniles y adultos de A. purpuratus afectarían la tasa de crecimiento de sus larvas, pero no la tasa de desarrollo ni su supervivencia.
Año: 2012
Palabras claves: Argopecten purpuratus, ostión del norte, pectinidos, cultivo, desarrollo larval, color, Chile.
Referencia APA: Garcia, R. & Winkler, F. (2012). Asociacion del color de la concha de reproductores de Argopecten purpuratus (Lamarck, 1819) con la supervivencia, crecimiento y desarrollo larval de sus progenies. Latin American Journal Of Aquatic Research, 40(2), 367-375.
The Lessonia nigrescens fishery in northern Chile: “how you harvest is more important than how much you harvest”
Vásquez, J., Piaget, N., & Vega, J.
In Chile, management of natural resources usually starts right before its imminent collapse or after evident declination. In the northern area of the country, the fishery of brown seaweeds has an enormous social, ecological, and economical importance. More than 11,000 people depend directly or indirectly on the collection and harvesting of this resource. Ecologically, kelps constitute areas for food, reproduction, and refuge for hundreds of invertebrates and fish species. Economically, landings up to 300,000 dry tons per year represent close to US $60 million for the industry. Until 2002, the Chilean brown seaweed fishery was mainly sustained by natural mortality, where plants cast ashore were collected by artisanal fishermen. Since then, three brown seaweed species of economic importance (Lessonia nigrescens, Lessonia trabeculata, and Macrocystis pyrifera) have been intensively harvested in coastal areas between 18° and 32° S. To manage kelp populations along the northern Chilean coast, regulations have been based on the principle “how you harvest is more important than how much you harvest”. This exploitation strategy has been adopted in consensus between fishermen, industries, governmental entities, and scientists. Since L. nigrescens represents more than 70% of total brown seaweed landings, this study tests the effects of L. nigrescens harvesting on the following population variables: (1) abundance, (2) distribution, (3) juvenile recruitment, (4) plant morphology, (5) frequency of reproductive plants, and (6) biodiversity of the macroinvertebrate community associated to kelp holdfasts. Our results show that, despite the enormous harvesting pressure on Lessonia density and biomass, the associated macroinvertebrate richness has been maintained, due to normal plant growth and high recruitment all year round.
Año: 2012
Palabras claves: Kelp fishery, Natural populations, Intertidal, Management, Harvesting, Conservation, Administrative policies.
Referencia APA: Vásquez, J., Piaget, N., & Vega, J. (2012). The Lessonia nigrescens fishery in northern Chile: “how you harvest is more important than how much you harvest". J Appl Phycol, 24(3), 417-426.
Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2011-30 September 2011.
A’hara, S. W., Amouroux, P., Argo, E. E., Avand-Faghih, A., Barat, A., Barbieri, L., Bert, T. M., Blatrix, R., Blin, A., Bouktila, D., Broome, A., Burban, C., Capdevielle-Dulac, C., Casse, N., Chandra, S., Cho, K. J., Cottrell, J. E., Crawford, C. R., Davis, M. C., Delatte, H., Desneux, N., Djieto-lordon, C., Dubois, M. P., El-Mergawy, R. A. A. M., Gallardo-Escárate, C., Garcia, M., Gardiner, M.M., Guillemaud, T., Haye, P. A., Hellemans, B., Hinrichsen, P., Jeon, J. H., Kerdelhué, C., Kharrat, I., Kim, K. H., Kim, Y. Y., Kwan, Y.-S., Labbe, E. M., Lahood, E., Lee, K. M., Lee, W.-O., Lee, Y.-H., Legoff, I., Li, H., Lin, C.-P., Liu, S. S., Liu, Y. G., Long, D., Maes, G. E., Magnoux, E., Mahanta, P. C., Makni, H., Makni, M., Malausa, T., Matura, R., Mckey, D., Mcmillen Jackson, A. L., Méndez, M. A., Mezghani-Khemakhem, M., Michel, A. P., Paul, M., Murielcunha, J., Nibouche, S., Normand, F., Palkovacs, E. P., Pande, V., Parmentier, K., Peccoud, J., Piatscheck, F., Puchulutegui, C., Ramos, R., Ravest, G., Richner, H., Robbens, J., Rochat, D., Rousselet, J., Saladin, V., Sauve, M., Schlei, O., Schultz, T. F., Scobie, A. R., Segovia, N. I., Seyoum, S., Silvain, J.-f., Tabone, E., Van Houdt, J. K. J., Vandamme, S. G., Volckaert, F. A. M., Wenburg, J., Willis, T. V., Won, Y.-J., Ye, N. H., Zhang, W. and Zhang, Y. X.
This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis, Menippe mercenaria, Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagüensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana.
Año: 2012
Palabras claves:
Referencia APA: Molecular Ecology Resources Primer Development Consortium, A’hara, S. W., Amouroux, P., Argo, E. E., Avand-Faghih, A., Barat, A., Barbieri, L., Bert, T. M., Blatrix, R., Blin, A., Bouktila, D., Broome, A., Burban, C., Capdevielle-Dulac, C., Casse, N., Chandra, S., Cho, K. J., Cottrell, J. E., Crawford, C. R., Davis, M. C., Delatte, H., Desneux, N., Djieto-lordon, C., Dubois, M. P., El-Mergawy, R. A. A. M., Gallardo-Escárate, C., Garcia, M., Gardiner, M.M., Guillemaud, T., Haye, P. A., Hellemans, B., Hinrichsen, P., Jeon, J. H., Kerdelhué, C., Kharrat, I., Kim, K. H., Kim, Y. Y., Kwan, Y.-S., Labbe, E. M., Lahood, E., Lee, K. M., Lee, W.-O., Lee, Y.-H., Legoff, I., Li, H., Lin, C.-P., Liu, S. S., Liu, Y. G., Long, D., Maes, G. E., Magnoux, E., Mahanta, P. C., Makni, H., Makni, M., Malausa, T., Matura, R., Mckey, D., Mcmillen Jackson, A. L., Méndez, M. A., Mezghani-Khemakhem, M., Michel, A. P., Paul, M., Murielcunha, J., Nibouche, S., Normand, F., Palkovacs, E. P., Pande, V., Parmentier, K., Peccoud, J., Piatscheck, F., Puchulutegui, C., Ramos, R., Ravest, G., Richner, H., Robbens, J., Rochat, D., Rousselet, J., Saladin, V., Sauve, M., Schlei, O., Schultz, T. F., Scobie, A. R., Segovia, N. I., Seyoum, S., Silvain, J.-f., Tabone, E., Van Houdt, J. K. J., Vandamme, S. G., Volckaert, F. A. M., Wenburg, J., Willis, T. V., Won, Y.-J., Ye, N. H., Zhang, W. and Zhang, Y. X. (2012). Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2011–30 September 2011. Molecular Ecology Resources, 12: 185–189.
Plasticity in feeding selectivity and trophic structure of kelp forest associated fishes from northern Chile.
Pérez-Matus, A., Pledger, S., Díaz, F., Ferry, L., & Vásquez, J.
One of the primary ways in which species interact with their environment is through foraging; thereby directly consuming some fraction of their surrounding habitat. The habitat itself, in turn, may dictate the types of foraging opportunities that are available to the inhabitants. To investigate the relationship between habitat availability and diet composition of habitat-associated fishes, we estimated the relative abundance of the potential sessile and mobile prey items and the diet of the fish species assemblage associated to kelp forest. Specifically, diet and feeding selectivity of the kelp-forest associated fish assemblage were determined by calculating Manly's alpha selectivity index. We determined the diet of kelp forest associated fishes and their foraging behavior by comparing prey availability with those items present in the stomachs of fishes captured by gill net and spear gun. We calculated the degree of dietary overlap among fishes from four locations along the northern coast of Chile. Results indicate that utilization of prey by predators is predominantly affected by potential prey availability. With the exception of the two carnivorous species such as Pinguipes chilensis (Valenciennes, 1883) and Paralabrax humeralis (Cuvier & Valenciennes, 1828), whose diet did not change among sites, all other kelp-associated fishes changed their dietary habitats to consistent with the availability of local resources. Benthic resources changed among the different study sites, which led to differing diets even in the same species from different locations. Eleven of the 12 kelp forest fishes also showed some selectively for benthic prey. We conclude that the ability of fishes to be plastic in their feeding preference and, therefore, partition the benthic resources may set adaptations to co-exist in a dynamic environment such as kelp forest.
Año: 2012
Palabras claves: Chile, Manly α, predation, trophic guilds, understory.
Referencia APA: Pérez-Matus, A., Pledger, S., Díaz, F., Ferry, L., & Vásquez, J. (2012). Plasticity in feeding selectivity and trophic structure of kelp forest associated fishes from northern Chile. Rev. Chil. Hist. Nat., 85(1), 29-48.