Aquatic mammals

Mammals that live in water are known aquatic mammals. On the other words, aquatic mammals is a diverse group of mammals which completes their life-cycle (all or most) in water.

Example: Dolphin, Whales, Manatee, Seals, >>>

Aquatic animal

Animals that live in water are known aquatic animals. On the other words, an aquatic animal is an animal which completes their life-cycle (all or most) in water.

Example: Fishes, Turtles, Crocodiles, Dolphins, Whales etc. >>>

Aquatic birds

Birds that live (feeding, breeding, staying) on or around water (aquatic environment) are known aquatic birds. On the other hand, birds that depend on aquatic environment to complete their life-cycle are called aquatic birds.

They >>>


Aestivation (also spelled “estivation”) is a situation of inactivity and a lowered metabolic rate of animal during summer as well as dry season.

Most of all coldblooded (also known poikilothermic or ectothermic) animals take position >>>


Amphibians (singular: amphibian) are cold-blooded vertebrates (usually tetrapod/four-footed, carnivorous and oviparous) which young are commonly under go metamorphosis from water-breathing larva with gills to an air-breathing adult with lungs.

They use their soft, moist, glandular >>>


Amphibia is the group (Class) of vertebrates that includes amphibians (singular: amphibian).

The word Amphibia consists of Greek word “amphi” meaning “on both side” and “bios” meaning life.

Amphibians (singular: amphibian) are cold-blooded vertebrates (usually >>>


Acoelomata is the group that includes acoelomates.

Acoelomates (singular: acoelomate) means a group of animals that lacks fluid filled body cavity named coelom.

Body cavity (the space between outer side of alimentary canal and >>>


Acoelom means a body cavity which is filled with cell and tissue in place of body fluid. It is lacking of body fluid and also lacking of peritoneum.

An animal having acoelom (means having no >>>

Accessory respiratory organ

An organ that allows some fishes (air breathing fishes) to takes oxygen directly from the air. Such as skin of Anguilla anguilla, pharyngeal diverticula of snakeheads, tubular air sac and arborescent organ of some catfishes, >>>

Arrector pili

Arrector pili (plural: arrectores pilorum) is a small fan-shaped smooth muscle attached to each hair follicle in mammals. The hair stands on end when the muscle contracts.



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