As you’ve already read, fish can go to great lengths to ensure the survival of the next generation. Nest-building is a common phenomenon amongst fish, with some even creating a floating nest of bubbles in which to place their eggs, such as the Osphronemidae family which includes some of our favourites like the Siamese fighter and gouramis. However, a nest does tie a fish into a particular location waiting while the eggs develop and hatch. If only there way a way to carry your eggs around with you? The medaka or Japanese rice fish (Oryzias latipes) does just this. After fertilisation, the female fish carries the eggs between her pelvic fins. However, she will sooner or later gradually deposit them on submerged leaves or twigs. Famously, seahorses go an extra step with the male looking after the eggs in a brood pouch until they are fully developed. Let’s not forget our favourite, the guppy (and other live bearers). Females retain the eggs internally giving their offspring about a month’s worth of development before having to face the challenges of the big, wide, aquatic world.
Image credit: Ryu Uchiyama / Nature Production / Minden Pictures.
Tagged in: Aquatic Adaptations