Skin or scales
a coral
The primary function of external gills in aquatic animals is to exchanges gases. However, gas exchange is more difficult with external gills.
Some animals that have external fertilization include fish, frogs, sea urchins, and certain aquatic invertebrates like jellyfish and corals.
Actually, Cold-blooded animals do not maintain a constant body temperature so their body fluctuates based on external temperature.Answer: It is considered as external (if that's what you mean).
spiders
There is a great importance of identifying the external anatomy of a farm animals. This will make it easy for you to notice any unusual behaviors by the animals and attend to them as required.
A toad goes through external fertilisation/fertilization
external
external
Snakes and fish are examples of animals that lack external ears.
They are aquatic.
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