Shark & Skate Eggs
Most sharks and skates lay eggs sometimes called a 'devil's purse' or a 'mermaid's purse.' It's an egg case in a thin capsule made of collagen. Most are shaped like this. A few sharks like the port jackson shark have helical egg cases which are secured into the sand like a drill bit. They are generally hand sized but have been recorded as large as 2m long. They can contain more than one baby who cannibalize each other before hatching.
Octopus Eggs
Octopuses string their soft, translucent eggs on overhangs of rocks or coral. Hundreds of thousands are laid at a time and the female guards them until they hatch. This can take so long that she begins to starve and some will eat their own arms to survive. Once her thousands of tiny offspring are hatched the mother will generally be eaten by a predator once she leaves her lair because she has grown too weak to defend herself.
Fish Eggs
Millions of soft eggs are laid at once, so even hungry predators will not destroy all of them before they hatch. Some eggs are laid on secure surfaces like rocks whereas others drift freely in the water, sometimes for up to hundreds of km. Free-floating eggs are called ichthyoplankton and some are able to swim even before they hatch.
Sponge & Jelly Eggs
These organisms are not gendered. Instead they have both male and female organs which release the eggs and sperm into the water.
Amphibian Eggs
Most amphibians begin the first parts of their lives in water but as adults live on land. Their eggs are often laid in water, surrounded by a gel to keep them all together. When they hatch, the offspring are called ‘tadpoles’ and have gills but no legs. They swim around like fish, although initially they also lack a mouth and live directly off the yolk left over from their egg by absorbing it through their skin. Eventually, tadpoles grow mouths, legs, lungs, lose their tail, and become fully adult. Some frogs carry their eggs about to protect them or if there is not enough water around. A small number of amphibians become tadpoles and grow into tiny adults before they even hatch, so they do not need to live in the water at all.
Monotreme Eggs
Monotremes are thought to have evolved from reptiles and were the ancestors of modern mammals. The only living monotremes today are platypuses and echidnas. They are warm-blooded, have hair, and produce milk, so they are mammals. However, not like other mammals, they lay eggs. Unlike most birds and reptiles, while the egg is still inside a mother monotreme, she supplies it with a small amount of nutrition from her own body, similar to other mammals. Monotreme eggs are small and spherical. They are laid in small numbers and are fastidiously cared for by their mother in her burrow until 4 to 6 months after hatching. Platypuses keep their eggs warm by curling their tail over them whereas echidnas warm them by tucking them in a small fold of skin across their stomachs. Monotremes do not have nipples to produce milk from, so instead they sweat milk which their newly-hatched young drink.
Most sharks and skates lay eggs sometimes called a 'devil's purse' or a 'mermaid's purse.' It's an egg case in a thin capsule made of collagen. Most are shaped like this. A few sharks like the port jackson shark have helical egg cases which are secured into the sand like a drill bit. They are generally hand sized but have been recorded as large as 2m long. They can contain more than one baby who cannibalize each other before hatching.
Octopus Eggs
Octopuses string their soft, translucent eggs on overhangs of rocks or coral. Hundreds of thousands are laid at a time and the female guards them until they hatch. This can take so long that she begins to starve and some will eat their own arms to survive. Once her thousands of tiny offspring are hatched the mother will generally be eaten by a predator once she leaves her lair because she has grown too weak to defend herself.
Fish Eggs
Millions of soft eggs are laid at once, so even hungry predators will not destroy all of them before they hatch. Some eggs are laid on secure surfaces like rocks whereas others drift freely in the water, sometimes for up to hundreds of km. Free-floating eggs are called ichthyoplankton and some are able to swim even before they hatch.
Sponge & Jelly Eggs
These organisms are not gendered. Instead they have both male and female organs which release the eggs and sperm into the water.
Amphibian Eggs
Most amphibians begin the first parts of their lives in water but as adults live on land. Their eggs are often laid in water, surrounded by a gel to keep them all together. When they hatch, the offspring are called ‘tadpoles’ and have gills but no legs. They swim around like fish, although initially they also lack a mouth and live directly off the yolk left over from their egg by absorbing it through their skin. Eventually, tadpoles grow mouths, legs, lungs, lose their tail, and become fully adult. Some frogs carry their eggs about to protect them or if there is not enough water around. A small number of amphibians become tadpoles and grow into tiny adults before they even hatch, so they do not need to live in the water at all.
Monotreme Eggs
Monotremes are thought to have evolved from reptiles and were the ancestors of modern mammals. The only living monotremes today are platypuses and echidnas. They are warm-blooded, have hair, and produce milk, so they are mammals. However, not like other mammals, they lay eggs. Unlike most birds and reptiles, while the egg is still inside a mother monotreme, she supplies it with a small amount of nutrition from her own body, similar to other mammals. Monotreme eggs are small and spherical. They are laid in small numbers and are fastidiously cared for by their mother in her burrow until 4 to 6 months after hatching. Platypuses keep their eggs warm by curling their tail over them whereas echidnas warm them by tucking them in a small fold of skin across their stomachs. Monotremes do not have nipples to produce milk from, so instead they sweat milk which their newly-hatched young drink.