Galapagos tortoises are divided into 15 species. The Chelonoidis abingdonii species became extinct on June 24, 2012 with the last male specimen which was given the name George, still today a symbol for the fight against the conservation of our planet's animal species.
The Galapagos tortoises reside scattered among 6 of the 14 islands of the homonymous archipelago which is precisely called Galapago which in Spanish stands for Tartaruga, name given by the Spaniards who discovered it. Chelonoidis niger went extinct in 2017.
The Galapagos tortoises are the largest land tortoises in the world, with a carapace length of around 150 centimeters and a weight that can reach 300 kg.
Depending on the environment in which they grow, they can develop two different types of carapaces called a saddle and dome, in the specimens found in the flat and arid islands the classic saddle carapace occurs, given the drier vegetation, sparse and growing upwards, such as the opuntia plants that grow in these driest islands of the
Galapagos, all this is aimed at facilitating the extension of the animal so that it can easily reach the succulent vegetation from which they derive hydration and minerals, while the domed carapace is typical of the wetter islands where the vegetation is more luxuriant and easily accessible.
It is one of the longest-lived animals in the world, it can easily exceed 150 years. Extinction occurred during the 1840s or 1850s following overexploitation for food by sailors and settlers, as well as predation and habitat degradation from introduced species, including goats, pigs, dogs, cats, donkeys, and rodents.
However, several hybrids between this species and Chelonoidis becki were discovered around Wolf Volcano on Isabela Island, apparently from some of the Floreana tortoises being transported there in the early 19th century.
Green sea turtle: what are the current threats?
The IUCN Red List classifies Green sea turtle as an endangered species.
In recent decades, sea turtles have moved from unrestricted exploitation to global protection, with individual countries providing additional protection, although serious threats remain unabated. All populations are considered threatened.
More dangerous are unintentional threats, including boat strikes, fishermen's nets that lack turtle excluder devices, pollution and habitat destruction. Chemical pollution may create tumors, effluent from harbors near nesting sites may create disturbances; and light pollution may disorient hatchlings.
With chemical pollution present, there is a development of tar balls that is often eaten by green sea turtles in a confusion of their food. Tar balls cause the green sea turtle to intake toxins that can block their guts, displace the liver and intestines causing swelling of the tissue.
Habitat loss usually occurs due to human development of nesting areas. Beach-front construction, land reclamation and increased tourism are examples of such development. An infectious tumor-causing disease, fibropapillomatosis, is also a problem in some populations. The disease kills a sizeable fraction of those it infects, though some individuals seem to resist the disease.