Fish use outer fertilization because they are not Mammals , which use inner fertilization . Mammals generally bear live young , with few exeptions . Fish and other cold blooded animals lay eggs which are fertilized outside the body , again with few exeptions .
what two classes of vertebrates use external fertilisation
Most fish use external fertilization. But not all, guppies and other livebearers use internal fertilization. Of the external fertilizers, some are broadcast spawners, whereas others are not.
spiders
Ants, beetles, fish and frogs are the main ones.
Mosquitoes have **internal fertilisation**. The male mosquito transfers sperm to the female during mating, and the eggs are fertilised **inside the female’s body**. After that, the female lays the fertilised eggs in water, where they hatch and grow. So yeah, fertilisation happens inside—but the development (eggs → larvae → adult) happens outside in water.
The 2 fertilisation's are external fertilisation, or internal fertilisation. External fertilisation is the type frogs do.
Yes
Yes.
yes,sometimes
Like most fish, external. The female lays eggs in a nest then the male fertilizes them.
A toad goes through external fertilisation/fertilization
internal