An intimidating ornament in a female pipefish
Brood pouches vary significantly among different species of pipefish, but all contain a small opening through which female eggs can be deposited.
The location of the brood pouch can be along the entire underside of the pipefish or just at the base of the tail, as with seahorses.
Courtship between male and female pipefish involves lengthy and complicated shows of display.
For example, in Syngnathus typhle, copulation is always preceded by a ritualized dance by both sexes.
In addition, when risk of predation is high, they copulate less frequently, dance less per copulation, and females transfer more eggs per copulation. thyphle males normally prefer to mate with larger females, they mate randomly when potentially threatened by predators.
Furthermore, in Corythoichthys haematopterus, similar ritualized mating dances were hypothesized to aid in reproductive synchronization, by allowing the female to assess male willingness to spawn so her eggs aren't wasted.
Our understanding of sexual selection comes largely from studies of competition among males for access to females and female choice, with the products of sexual selection including exaggerated male weapons and ornaments.
In contrast sexual selection acting on females is poorly understood, and indeed highly debated.
Most species of pipefish are usually 35–40 cm (14–15.5 in) in length and generally inhabit sheltered areas in coral reefs or seagrass beds.
Behavioral Ecology, 20(6): 1348-1355, https://doi.org/10.1093/beheco/arp140 Do exaggerated sexual swellings function in female mating competition in primates?
A comparative test of the reliable indicator hypothesis Behavioral Ecology, 26(4): 1030-1038, https://doi.org/10.1093/beheco/arv037 Cover Image: A female Common Glow-worm (Lampyris noctiluca). Females of this species move away from brightly glowing rivals to avoid appearing dull, see Borshagovski et al.
Pipefishes, like their seahorse relatives, leave most of the parenting duties to the male, which provides all of the postzygotic care for its offspring, supplying them with nutrients and oxygen through a placenta-like connection.
It broods the offspring either on distinct region of its body or in a brood pouch.