Introduction Do billfish and tuna distinguish colours? This question has captivated both fishermen and scientists for years. Proving colour vision in this group of fish is particularly difficult since behavioural colour discrimination experiments—the “final proof” of colour vision ability in any animal—are impossible to undertake with such large open ocean fish. Instead, scientists have aimed t...

Recently we demonstrated that the capacity of isolated muscle mitochondria to produce reactive oxygen species, measured as H2O2 efflux, is temperature-sensitive in isolated muscle mitochondria of ectothermic fish and the rat, a representative endothermic mammal. However, at physiological temperatures (15° and 37°C for the fish and rat, respectively), the fraction of total mitochondrial electron...

Urgent measures to save falling stocks of tuna in the world's second biggest tuna fishery — the eastern Pacific— have failed to be implemented, according to several environmental groups. Closure of the fishery, both by area and by time, was demanded by the groups to protect rapidly decreasing Pacific populations of yellowfin and bigeye tuna. But the annual meeting of the Inter American Tropical...

Overexploitation threatens the future of many large vertebrates. In the ocean, tunas and sea turtles are current conservation concerns because of this intense pressure. The status of most shark species, in contrast, remains uncertain. Using the largest data set in the Northwest Atlantic, we show rapid large declines in large coastal and oceanic shark populations. Scalloped hammerhead, white, an...

The gills of 31 skipjack tuna Katsuwonus pelamis (L.) caught in the Alboran Sea (western Mediterranean Sea) were examined for metazoan parasites, and the gills of 4 specimens from the Balearic Sea (also western Mediterranean Sea) were analysed for comparative purposes. Nine -species of parasites were found, including 8 didymozoid trematodes (Atalostrophion cf. bio-varium, Didymocylindrus filifo...

Tropical tuna fisheries are among the largest worldwide, with some having significant bycatch issues. However, pole-and-line tuna fisheries are widely believed to have low bycatch rates, although these have rarely been quantified. The Maldives has an important pole-and-line fishery, targeting skipjack tuna (Katsuwonus pelamis). In the Maldives, 106 pole-and-line tuna fishing days were observed ...

BACKGROUND Ecologists are collecting extensive data concerning movements of animals in marine ecosystems. Such data need to be analysed with valid statistical methods to yield meaningful conclusions. PRINCIPAL FINDINGS We demonstrate methodological issues in two recent studies that reached similar conclusions concerning movements of marine animals (Nature 451:1098; Science 332:1551). The firs...

Are pelagic species such as sharks and tuna distributed homogenously or heterogeneously in the oceans? Large assemblages of these species have been observed at seamounts and offshore islands in the eastern tropical Pacific, which are considered hotspots of pelagic biodiversity. Is the species distribution uniform at these hotspots or do species aggregate at a finer spatial scale at these sites?...

Numerous reports on existence of white cysts in musculature of skipjack tuna Katsuwonus pelamis and lack of information about the quality of cysts and individual responses of fish to them led the authors to focus on this fish as a commercially valuable species. This study investigated the histopathologic responses of skipjack tuna to highly prevalent cystic larval stages of Trypanorhyncha. Some...

One of the mainly popular consumed colloid protein materials in pharmaceutics, medical, food and military industries is Gelatin. Especially from warm-water fish gelatin report poss similar characteristics to mammalian’s gelatin .Yellow fin tuna (Thunnus albacares) gelatin skin, lots of waste in form of skin and bones of the fish are produced every day. Analysis factors were extracted alkaline g...