TorporTorpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time a hibernator spends at low body temperature, lasting days to weeks, or it can refer to a period of low body temperature and metabolism lasting less than 24 hours, as in "daily torpor".
ThermoregulationThermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation. The internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology).
HomeothermyHomeothermy, homothermy or homoiothermy is thermoregulation that maintains a stable internal body temperature regardless of external influence. This internal body temperature is often, though not necessarily, higher than the immediate environment (from Greek ὅμοιος homoios "similar" and θέρμη thermē "heat"). Homeothermy is one of the three types of thermoregulation in warm-blooded animal species. Homeothermy's opposite is poikilothermy.
HibernationHibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature.
FishA fish (: fish or fishes) is an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period.
Warm-bloodedWarm-blooded is an informal term referring to animal species whose bodies maintain a temperature higher than that of their environment. In particular, homeothermic species (including birds and mammals) maintain a stable body temperature by regulating metabolic processes. Other species have various degrees of thermoregulation. As there are more than two categories of temperature control utilized by animals, the terms warm-blooded and cold-blooded have been deprecated in the scientific field.
EctothermAn ectotherm (from the Greek ἐκτός () "outside" and θερμός () "heat"), more commonly referred to as a "cold-blooded animal", is an animal in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature. Such organisms (for example frogs) rely on environmental heat sources, which permit them to operate at very economical metabolic rates. Some of these animals live in environments where temperatures are practically constant, as is typical of regions of the abyssal ocean and hence can be regarded as homeothermic ectotherms.
BlubberBlubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians. Lipid-rich, collagen fiber-laced blubber comprises the hypodermis and covers the whole body, except for parts of the appendages. It is strongly attached to the musculature and skeleton by highly organized, fan-shaped networks of tendons and ligaments, can comprise up to 50% of the body mass of some marine mammals during some points in their lives, and can range from thick in dolphins and smaller whales, to more than thick in some bigger whales, such as right and bowhead whales.
FeatherFeathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier example of a complex evolutionary novelty. They are among the characteristics that distinguish the extant birds from other living groups. Although feathers cover most of the bird's body, they arise only from certain well-defined tracts on the skin.
PlesiosaurThe Plesiosauria (ˌpliːsiəˈsɔːriə,_-zi-; Greek: πλησίος, plesios, meaning "near to" and sauros, meaning "lizard") or Plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago. They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago.
