Question

Which one of the two, stenothermal or eurythermal, show a wide range of distribution on earth and why?

Answer 1

Hint:Temperature affects growth, metabolism, reproduction, sex ratio distribution and morphology. Organisms that can tolerate wide ranges of temperature are called eurythermal, whereas those restricted to the narrow range are called stenothermals.

Complete step by step answer:Temperature is the degree of hotness and coldness of substance. It is the most ecologically relevant environment factor. It is affected by altitude,
latitude, topography and vegetation.

Tropical zone	Megatherm
Subtropical zone	Mesotherm
Temperate zone	Microtherm
Arctic/Antarctic	Hekistotherm

Temperature varies seasonally, decreases progressively from the equator towards the poles and from plains to the mountain top. Temperature governs the geographical distribution, metabolism, growth, reproduction, and behavior of many plants and animals. Example- Mango trees do not and cannot grow in temperate countries like Canada and Germany. Tuna fish are rarely found beyond tropical latitudes in oceans. Temperature greatly affects living organisms, because it affects the kinetics of enzymes and through it the basic metabolism, activity, and other physiological functions of the organisms. Organisms which can tolerate large fluctuations in temperature and can tolerate a wide range of temperature are called eurythermal. Example- Artemesia, plants of temperate regions. Organisms that are restricted to a narrow range of temperature, are called stenothermal. Example- Palms, Plants in warm tropics. In recent years, as the average global temperature is gradually increasing it is going to affect the distributional range of the species particularly – stenothermal.
So, eurythermal animals can tolerate a wide range of temperatures and are widely distributed because they can adapt to the environment with fluctuations as well.

Note: Organisms that can tolerate a wide range of salinities are called euryhaline and the ones that are adapted to a narrow range of salinities are called stenohaline.