ZOOL313 Animal Temperature Physiology Module

Terms for the first lecture block

Endotherm

An animal that can generate its own body heat.

Ectotherm

An animal that relies on its environment for their body heat.

Homeotherm

An animal with a stable body temperature that varies very little.

Poikilotherm

An animal with a body temperature that varies a lot.

Heterotherm

An animal in the middle between homeotherms and poikilotherms, so body temperature varies a bit.

Thermal Performance Curve (TPC)

A model showing how temperature impacts ectotherm physiology and behaviour. Varies between individuals, populations, and species. Also, by life history and habitat

Acclimation

TPC variations in a controlled environment (like a lab), happens within a few days/weeks/months

Acclimatisation

TPC variations in the natural environment (ex. seasons), happens within an individual’s lifetime

Adaptation

TPC variations via mutations and natural selection process, happens over many generations

Regional Endothermy

Certain fish species maintain elevated temperatures in specific parts of their bodies. Muscles can get up to 12 degrees Celsius warmer than the water.

Retia

Retains heat produced by red swimming muscles and organs.

Cryoprotectants

Substances that prevents cell tissue from freezing or prevents damage to cells during freezing (ex. glycerol, glucose).

Supercooling Point (SCP)

Ice formation nucleated at the SCP (supercooling point), thaws when the temperature is above the melting point

Lower Lethal Temperature (LLT)

Varies for different species and life stages of insects.

Recrystallization-inhibiting proteins (RIPs)

Stabilize ice crystals.

Ice Nucleating Agents INAs

Trigger ice formation (ex. some proteins) or food in gut.

hot eyes

keep eyes and brain warm of some fish that are apex predators in the epipelagic zone to enhance visual acuity and hunting success.

freezing avoidance

evasion of freezing by lowering the temperature at which water freezes the body, which often involves lowering the supercooling point through physiological adaptations such as the production of antifreeze proteins.

freezing tolerance

ability to tolerate frozen tissues by limiting the location of ice in the body. This often involves the use of cryoprotectants to protect cellular structures and function during freezing.

What makes reptiles vulnerable to climate change?

species can be exposed, sensitive, and/or unadaptable to shifts in temperature and habitat resulting from changing climates, impacting their physiology and survival.