15 May 2015

The term "warm-blooded" is passe

Same with "cold-blooded," as per a comment quibbling with the title of a report on the discovery of the first warm-blooded fish:
"Just in case anybody doesn't know, warm-blooded and cold-blooded are now defunct terms in biology. This is because "cold-blooded" animals can actually have very hot blood e.g. lizards in the desert, and "warm-blooded" animals can actually have relatively cold blood e.g. bats during torpor. The terms I am aware of are homeotherm (maintains a steady body temperature e.g. humans) and poikilotherms (body temperature fluctuates with ambient temperature). It seems endotherm and ectotherm are two other terms that can be used, those being animals that generate their own internal heat and those that don't respectively. As far as I can tell endotherm, homeotherm and warm-blooded are synonymous, as are ectotherm, poikilotherm and cold-blooded. There may be subtleties that I am not aware of that distinguish endotherm from homeotherm etc."

7 comments:

  1. Endothermic and homeothermic are not synonymous (nor are ectothermic and poikilothermic). Bats in torpor (and hummingbirds, which similarly "shut down" at night) would be endothermic and poikilothermic. An animal that was capable of maintaining steady temperature by virtue of size (increased volume:surface area ratio, also called gigantothermy), as some have hypothesized sauropod dinosaurs to be, could be ectothermic and homeothermic.

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    Replies
    1. The leatherback sea turtle is a modern-day example of an animal that is ectothermic and homeothermic due to gigantothermy.

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  2. And there was an article in the Washington Post today about a warm-blooded fish, the opah, found on the West Coast.

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    Replies
    1. That's the story this comment is from (see the first sentence), just a different site's copy of it.

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  3. I don't know why all the reports are saying that the Opah is the first "warm-blooded" fish. Check the Wikipedia article on the Pacific bluefin tuna. It says tuna and mackerel sharks have this ability. I first read about tuna being warm-blooded a few years ago. I don't know how long it's been known, but the opah isn't the first found.

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  4. Great White Sharks also increase their blood temperature.

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