| pipefish | |
|---|---|
| Alligator Pipefish Syngnathoides biaculeatus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Syngnathiformes |
| Family: | Syngnathidae |
| Subfamily: | Syngnathinae |
| Genera | |
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See text. |
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Pipefishes or pipe-fishes (Syngnathinae) are a subfamily of small fishes, which, together with the seahorses, form the family Syngnathidae.
Contents |
Pipefish look like straight-bodied seahorses with tiny mouths. The name is derived from the peculiar form of their snout, which is like a long tube, ending in a narrow and small mouth which opens upwards and is toothless. The body and tail are long, thin, and snake-like. They have a highly modified skeleton formed into armored plating. This dermal skeleton has several longitudinal ridges, so that a vertical section through the body looks angular, not round or oval as in the majority of other fishes.
A dorsal fin is always present, and is the principal (in some species, the only) organ of locomotion. The ventral fins are constantly absent, and the other fins may or may not be developed. The gill openings are extremely small and placed near the upper posterior angle of the gill cover.
Many are very weak swimmers in open water, moving slowly by means of rapid movements of the dorsal fin. Some species of pipefish have tails that are prehensile, as in seahorses. The majority of pipefishes have some form of a caudal fin (unlike seahorses), which can be used for locomotion. See fish anatomy for fin descriptions. There are species of pipefish with more developed caudal fins, such as the group collectively known as flagtail pipefish, which are quite strong swimmers.
Most pipefish are marine dwellers; only a few are freshwater species. Pipefishes are abundant on coasts of the tropical and temperate zones. Most species of pipefish are usually 35–40 cm in length and generally inhabit sheltered areas in coral reefs, seagrass beds and sandy lagoons. There are approximately 200 species of pipefish.
Pipefishes, like their seahorse relatives, leave most of the parenting duties to the male. 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 not.
Male pipefishes have a specially developed area to carry eggs, which are deposited by the female. 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. Many species exhibit polyandry, a breeding system in which one female mates with two or more males. This tends to occur with greater frequency in internal brooding species of pipefishes than with external brooding species.
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.