Fish and Coral Information
Pipefish (Syngnathidae) are small fish, which with the seahorses, form a distinct family. Pipefish look like straight-bodied seahorses with tiny mouths.
Pipefish, like their seahorse relatives, leave most of the parenting duties to the males. Courtship tends to be elaborately choreographed displays between the males and females. Pair bonding varies wildly between different species of pipefish. While some are monogamous or seasonally monogamous, others are quite gregarious. Many species exhibit polyandry, a breeding system in which one female mates with two or more males, and are thus sex-role reversed. This occurs because males invest more energy in the offspring than do females, as a result of male pregnancy. This tends to occur with greater frequency in internal brooding species of pipefish than with external brooding species. Male pipefish have a specially developed area to carry eggs, which are deposited by the female pipefish. In some species this is just a patch of spongy skin that the eggs adhere to until hatching. Other species have a partial or even fully developed pouch to carry the eggs. The location of the brood patch or pouch can be along the entire underside of the pipefish or just at the base of the tail, as with seahorses. Young are born freeswimming with relatively little or no yolk sac, and begin feeding immediately. From the time they hatch they are independent of their parents, who at that time may choose to view them as food. Some fry have short larval stages and live as plankton for a short while. Others are fully developed but miniature versions of their parents, assuming the same behaviors as their parents immediately.
It is the case that pipefish possess a swimbladder. The literature on its size and positioning is very scant, with an aged volume dating from 1934 the only known publication containing specific information. The laterally-flattened spheroidal swimbladder is approximately 1/25 the length of the whole animal and apparently highly acoustically reflective at commercially important frequencies. This appears to apply to juveniles also.