Jaguar in the context of "Piscivorous"

A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf and lion, are also apex predators.

The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity.It became a popular concept in conservation biology, alongside flagship and umbrella species. Although the concept is valued as a descriptor for particularly strong inter-species interactions, and has allowed easier communication between ecologists and conservation policy-makers, it has been criticized for oversimplifying complex ecological systems.

The Amazon Delta (Portuguese: delta do Amazonas) is a vast river delta formed by the Amazon River and the Tocantins River (through the Pará River distributary channel) in northern South America. It is located in the Brazilian states of Amapá and Pará and encompasses the Marajó Archipelago, with Marajó Island as its largest island. The main cities located in the vicinity are Belém and Macapá, each with its respective metropolitan area.

The Amazon Delta has a tropical climate with high humidity and high temperatures. It has a wet season with frequent flooding and a dry season where the delta dries out. These seasons shape the environment of the Amazon Delta and the life in it, such as the water buffalo for which Marajó Island is well known, three-toed sloth, capybara, giant anteater, giant otter, jaguar and pink river dolphins.

The term "big cat" is used by zoologists to mean any of the five living members of the genus Panthera (the tiger, lion, jaguar, leopard, and snow leopard). In non-scientific contexts, "big cat" can also mean any member of the cat family that is considered "big", including animals like cheetahs and cougars that taxonomically fall under the small cats.

All cats are members of the Felidae family, sharing similar musculature, cardiovascular systems, skeletal frames, and behaviour. Both the cheetah and cougar differ physically from fellow big cats, and to a greater extent, other small cats. As obligate carnivores, big cats are considered apex predators, topping their food chain without natural predators of their own. Native ranges include the Americas, Africa, and Asia; the ranges of the leopard and tiger also extend into Europe, specifically in Russia.

A piscivore (/ˈpɪsɪvɔːr/) is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory.

Almost all predatory fish (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lions, and crocodilians, are not completely piscivorous; often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish, while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, cetaceans, spiders, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fish as significant if not dominant portions of their diets. Humans can live on fish-based diets, as can their carnivorous domesticated pets such as dogs and cats.

Tupi–Guarani (/tuːˈpiː ɡwɑˈrɑːni/ /ɡwɑˈɾɑ-/; Tupi-Guarani: [tuˈpi ɡwaɾaˈni]; pronunciation) is the most widely distributed subfamily of the Tupian languages of South America. It consists of about fifty languages, including Guarani and Old Tupi. The most widely spoken in modern times by far is Guarani, which is one of the two official languages of Paraguay.

The words petunia, jaguar, piranha, ipecac, tapioca, jacaranda, anhinga, carioca, and capoeira are of Tupi–Guarani origin.

Panthera is a genus within the family Felidae, and one of two extant genera in the subfamily Pantherinae. It contains the largest living members of the cat family. There are five living species: the jaguar, leopard, lion, snow leopard and tiger. Numerous extinct species are also named, including the cave lion and American lion.