Globally, amphibian populations are threatened by a diverse range of factors including habitat destruction and alteration. Forestry practices have been linked with low diversity and abundance of amphibians. The effect of exotic Eucalyptus spp. plantations on amphibian communities has been studied in a number of biodiversity hotspots, but little is known of its impact in the Mediterranean region...

The purpose of this study was to determine whether scale or otolith microstructures were more strongly related to fish growth. Scales and otoliths were sampled from 231 juvenile pink salmon (Oncorhynchus gorbuscha) collected from the marine waters of Southeast Alaska during two periods in 1993 and 1994. A computerized image analysis system was used to measure several periodic and non-periodic s...

The collapse of Caribbean coral reefs has been attributed in part to historic overfishing, but whether fish assemblages can recover and how such recovery might affect the benthic reef community has not been tested across appropriate scales. We surveyed the biomass of reef communities across a range in fish abundance from 14 to 593 g m(-2), a gradient exceeding that of any previously reported fo...

This study presents a model of an individual factory trawler conducting fishing operations off the west coast of North America in the Pacific hake (Merluccius productus) fishery. The model is used to explore several concepts that provide new insight into fishing behavior. A central theme of the model is the role of decisionmaking at different spatio-temporal scales. Decision-making occurs at tw...

Melanin-concentrating hormone (MCH) is a cyclic peptide originally identified as a 17-amino-acid circulating hormone in teleost fish, where it is secreted by the pituitary in response to stress and environmental stimuli. In fish, MCH lightens skin color by stimulating aggregation of melanosomes, pigment-containing granules in melanophores, cells of neuroectodermal origin found in fish scales. A...

Satellite tracking of large pelagic fish provides insights on free-ranging behaviour, distributions and population structuring. Up to now, such fish have been tracked remotely using two principal methods: direct positioning of transmitters by Argos polar-orbiting satellites, and satellite relay of tag-derived light-level data for post hoc track reconstruction. Error fields associated with posit...

A group of genes in the tumour necrosis factor signalling pathway are mutated in humans and mice with ectodermal dysplasias--a failure of hair and tooth development. A mutation has now been identified in one of these genes, ectodysplasin-A receptor, in the teleost fish Medaka, that results in a failure of scale formation.

In the present study, Mercury (Hg) accumulation in different tissues of Yellowfin seabream under different Hg concentrations in the medium were investigated. For this, PurPuse 45 fish specimen of the same size (19.2±1.8cm and 134.0±36.1 g) were caught from Musa Estuary, in northwest of the Persian Gulf and transferred to the laboratory. Fish were divided into five different groups of 9 fish ...

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish asse...

There is an increasing need to examine regional patterns of diversity in coral-reef systems since their biodiversity is declining globally. In this sense, additive partitioning might be useful since it quantifies the contribution of alpha and beta to total diversity across different scales. We applied this approach using an unbalanced design across four hierarchical scales (80 sites, 22 subregi...