Search results for "Yellowfin tuna"
showing 6 items of 6 documents
Genomic Differentiation and Demographic Histories of Atlantic and Indo-Pacific Yellowfin Tuna (Thunnus albacares) Populations.
2017
Recent developments in the field of genomics have provided new and powerful insights into population structure and dynamics that are essential for the conservation of biological diversity. As a commercially highly valuable species, the yellowfin tuna (Thunnus albacares) is intensely exploited throughout its distribution in tropical oceans around the world, and is currently classified as near threatened. However, conservation efforts for this species have so far been hampered by limited knowledge of its population structure, due to incongruent results of previous investigations. Here, we use whole-genome sequencing in concert with a draft genome assembly to decipher the global population str…
Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models
2016
Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares) in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fis…
Illegal fishing in Isla del Coco National Park: Spatial-temporal distribution and the economic trade-offs
2020
Abstract The Isla del Coco National Park, located on the Pacific coast of Costa Rica, is rich in biodiversity and has a high concentration of pelagic species. This high marine biodiversity makes the Isla del Coco National Park (PNIC) a very attractive place for illegal fishers. We analyzed a dataset covering 8 years (2003–2010) of patrol records from PNIC with the aim of determining, a) the spatial-temporal distribution of illegal fishing, b) other areas that could be prone to illegal fishing but are currently undetected, c) the most profitable areas for this activity and d) the economic trade-offs of this illegal activity in relation to potential gains and the costs. Residuals Autocovariat…
Statistical Validation of the Identification of Tuna Species: Bootstrap Analysis of Mitochondrial DNA Sequences
2002
Sequencing of the mitochondrial cytochrome b gene has been used to differentiate three tuna species: Thunnus albacares (yellowfin tuna), Thunnus obesus (bigeye tuna), and Katsuwonus pelamis (skipjack). A PCR amplified 528 bp fragment from 30 frozen samples and a 171 bp fragment from 26 canned samples of the three species were analyzed to determine the intraspecific variation and the positions with diagnostic value. Polymorphic sites between the species that did not present intraspecific variation were given a diagnostic value. The genetic distance between the sequences was calculated, and a phylogenetic tree was constructed, showing that the sequences belonging to the same species clustered…
Molecular evidence for cosmopolitan distribution of platyhelminth parasites of tunas (Thunnus spp.)
2007
Global distribution of platyhelminth parasites and their host specificities are not well known. Our hypothesis was that platyhelminth parasites of large pelagic fishes are common around the world. We analysed molecular variation in three different taxa of platyhelminth parasites infecting four species of tunas: yellowfin tuna (Thunnus albacares, Scombridae) from Western Australia, southern bluefin tuna (Thunnus maccoyii, Scombridae) from South Australia, Pacific bluefin tuna (Thunnus orientalis, Scombridae) from Pacific Mexico and northern bluefin tuna (T. thynnus, Scombridae) from two localities in the Mediterranean (Spain and Croatia). Comparisons of ITS2 and partial 28S rDNA demonstrated…
Mercury in fish products: what’s the best for consumers between bluefin tuna and yellowfin tuna?
2017
A total of 205 bluefin and yellowfin tuna samples were examined for mercury detection in order to verify possible differences and have a detailed risk assessment of the two tuna species. The results showed significant higher mercury concentration in muscle tissue of bluefin tuna respect yellowfin tuna (p < 0.001) with mean concentration of 0.84 mg/kg and maximum value of 1.94 mg/kg. These differences can be due the different biological and ecological aspects of the two tuna species and to different oceanographic aspects between Atlantic Ocean and Mediterranean sea. The results obtained in this study suggest an advisable containment of the sources of pollution and further studies on the c…