Pipefish
Pipefish belong to the Syngnathidae family, the same family as both seahorses and pygmy seahorses.
Pipefish share many qualities with seahorses, such as similar morphology as well as a sex-role reversal.
Pipefish look very similar to seahorses if a seahorse’s tail is uncurled. Many species are weak swimmers, as the only consistent fin between all pipefish species is the dorsal fin, although some do possess caudal.
They can usually be found in the seagrasses of coastal marine waters, but there are also freshwater species of pipefish and symbiotic cleaning pipefish.
Their overall weakness in the water tends to limit them to shallower waters with weaker currents resulting in a particular vulnerability to runoff and human recreational activities.
Pipefish is also popular in traditional Chinese remedies despite no effectiveness beyond a placebo effect.
Pipefish are a species that are sexually role reversed, which means the male is the one to ‘get pregnant’.
Male pipefish possess a subcaudal pouch (some species have a soft, adhesive bit of skin to stick eggs to) which is a small opening into which the females will deposit their eggs, after which the male will fertilise them.
This is believed to provide one very distinct advantage for the eggs: immunity information from both parents, rather than just the mother like in most species.
The sex-role reversal also results in males being the limiting sex as the females produce too many eggs to store in the males’ pouch.
This also leads to females competing for the males. Studies have shown that male pipefish prefer females that have a more ornamental display and show more confidence and dominance in the showing of their ornament.