Search results for "Oceano"

A continuous multi-millennial record of surficial bivalve mollusk shells from the São Paulo Bight, Brazilian shelf

2014

AbstractTo evaluate the potential of using surficial shell accumulations for paleoenvironmental studies, an extensive time series of individually dated specimens of the marine infaunal bivalve mollusk Semele casali was assembled using amino acid racemization (AAR) ratios (n = 270) calibrated against radiocarbon ages (n = 32). The shells were collected from surface sediments at multiple sites across a sediment-starved shelf in the shallow sub-tropical São Paulo Bight (São Paulo State, Brazil). The resulting 14C-calibrated AAR time series, one of the largest AAR datasets compiled to date, ranges from modern to 10,307 cal yr BP, is right skewed, and represents a remarkably complete time series…

2020

Ecology of the Atlantic black skipjack Euthynnus alletteratus (Osteichthyes: Scombridae) in the western Mediterranean Sea inferred by parasitological…

2016

Between 2008 and 2011, the head of 150 Euthynnus alletteratus (Osteichthyes: Scombridae) caught inshore off the southeastern Iberian coast (western Mediterranean Sea) were examined for parasites. Two monogeneans, four didymozoid trematodes and four copepods were found. Parasite abundance showed a positive relationship with the annual sea surface temperature, except for Pseudocycnus appendiculatus, but negative with the sea depth (Capsala manteri, Neonematobothrium cf. kawakawa and Caligus bonito). Prevalences and mean abundances differed significantly among sampling areas, except for C. manteri, Oesophagocystis sp. 2 and Ceratocolax euthynni, and sampling years (Melanocystis cf. kawakawa, N…

Nest-mediated parental care in a marine fish: Are large-scale nesting habitats selected and do these habitats respond to small-scale requirements?

2018

Fishes have evolved various reproductive strategies including mechanisms that involve parental care and demersal eggs laid into nests. Symphodus ocellatus has a seasonal reproduction period during which large, dominant males become territorial and build nests with fragments of algae, where they attract females to spawn and provide care to the developing eggs. Based on the hypothesis that the S. ocellatus males choose the reproductive habitat based on some characteristics of the substrate, here we assessed whether, on a coastal area scale, the distribution of this species changes during the reproductive period because of the selection of some suitable sites or substrates, and whether the nes…

Seasonal changes in morpho-functional aspects of two Anemonia sulcata (Pennant, 1777) wild populations

2017

Marine benthic organisms can be used as indicators of the quality of environmental status and as monitoring tools to detect natural or anthropogenic perturbations. In temperate waters, metabolic and biochemical responses may be governed by physiological changes driven by seasonal factors. Gathering baseline information on the mechanisms underlying seasonal acclimation patterns is therefore a critical step towards the understanding of the physiological responses of biological indicators. In poikilothermic metazoans, the production of regulatory metabolic enzymes can be used as tools for deciphering the acclimation potential. The aim of this study was to characterize the natural seasonal vari…

Morphological and molecular analysis of Henricia Gray, 1840 (Asteroidea: Echinodermata) from the Northern Atlantic Ocean

2017

Genetic structuring in Atlantic haddock contrasts with current management regimes

2020

AbstractThe advent of novel genetic methods has made it possible to investigate population structure and connectivity in mobile marine fish species: knowledge of which is essential to ensure a sustainable fishery. Haddock (Melanogrammus aeglefinus) is a highly exploited marine teleost distributed along the coast and continental shelf on both sides of the North Atlantic Ocean. However, little is known about its population structure. Here, we present the first study using single-nucleotide polymorphism (SNP) markers to assess the genetic population structure of haddock at multiple geographic scales, from the trans-Atlantic to the local (fjord) level. Genotyping 138 SNP loci in 1329 individual…

Genetic analysis of goldsinny wrasse reveals evolutionary insights into population connectivity and potentialevidence of inadverent translocationvia …

2017

The salmon industry is heavily dependent on wrasse for delousing infected fish. The goldsinny wrasse is numerically the most important, and each year, millions are harvested from the wild and transported large distances into fish farms. Population genetic knowledge is required to sustainably exploit this species. Here, 1051 goldsinny wrasses from 16 locations across Scandinavia, the British Isles, and Spain were genotyped with 14 microsatellite and 36 SNP markers. Within-population genetic diversity decreased towards north, and a genetic break was observed across the North Sea. Samples from Northern Norway differed from rest of the Scandinavian samples, and samples from the British Isles di…

Gastrointestinal parasites of two populations of Arctic foxes (Vulpes lagopus) from north-east Greenland

2017

Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps, Taenia serialis, Toxascaris leonina, Eucoleus boehmi, Physalopteridae and Ancylostomatidae, and Strongyloides-like larvae. As long-term ecological studies are conducted at both sampling locations, the present findings constitute a baseline data set for further parasitological monitoring.

When phenotypes fail to illuminate underlying genetic processes in fish and fisheries science

2019

Abstract Advances in genetic and genomic technologies have become widely available and have potential to provide novel insights into fish biology and fisheries science. In the present overview, we explore cases for which genomic analyses have proven instrumental in the rejection of hypotheses that have been well-motivated based on phenotypic and ecological properties of individuals and populations. We focus on study systems for which information derived using genomic tools contradicts conclusions drawn from traditional fisheries science methodologies and assumptions. We further illustrate the non-intuitive interplay of genomics and ecology in Atlantic salmon (Salmo salar L.) owing to the re…