Half a century of rising extinction risk of coral reef sharks and rays.

Sharks and rays are key functional components of coral reef ecosystems, yet many populations of a few species exhibit signs of depletion and local extinctions. The question is whether these declines forewarn of a global extinction crisis. We use IUCN Red List to quantify the status, trajectory, and threats to all coral reef sharks and rays worldwide.

Mitochondrial DNA genome evidence for the existence of a third divergent lineage in the western Atlantic Ocean for the bull shark (Carcharhinus leucas).

We report for the first time a highly divergent lineage in the Caribbean Sea for the bull shark (Carcharhinus leucas) based on the analysis of 51 mitochondrial DNA genomes of individuals collected in the western North Atlantic. When comparing the mtDNA control region obtained from the mitogenomes to sequences reported previously for Brazil, the Caribbean lineage remained highly divergent. These results support the existence of a discrete population in Central America due to a phylogeographic break separating the Caribbean Sea from the western North Atlantic, Gulf of Mexico and South America.

Strong population structure and shallow mitochondrial phylogeny in the banded guitarfish, Zapteryx exasperata (Jordan y Gilbert, 1880), from the Northern Mexican Pacific.

The northern Mexican Pacific (NMP), the Gulf of California (GC), and Baja California have been recognized as an ecological and evolutionarily dynamic region having experienced significant tectonic and climatic changes leading to the diversification of terrestrial and marine biotas. Zapteryx exasperata is a predominant ray caught in the artisanal fisheries of the NMP. Morphometric and reproductive differences between rays from the GC and the Pacific coast of Baja California (PCBC) regions suggest the presence of distinct populations.

[Diet and reproduction of the main fish species from the Mesay river (Colombian Amazon region) during the flooding season].

The diet and reproduction of fish communities in three biotopes (river, stream, and lake) of the Mesay floodplain-river complex (Puerto Abeja, Serrania de Chiribiquete National Natural Park, Caquetá, Colombia) were sampled during the "high water" level or flooding period. A total of 79 species of fishes from 15 families and four orders were collected between July and September 2000. The most important items in their diet were fruits and seeds.