Synaptid

Synaptid is a common name for members of the family Synaptidae, a group of marine echinoderms within the class Holothuroidea (sea cucumbers). They are typically slender, worm-like, and soft-bodied, with a reduced calcareous skeleton compared with other echinoderms.

The body is elongated with faint annulations; most species lack prominent dermal ossicles and have a simple integument. Feeding tentacles around the mouth are present in many species, though their number and form vary.

Synaptids occur worldwide in a range of habitats from shallow tropical reefs to deep-sea bottoms. Some species reach several decimeters to meters in length, notably the genus Synapta, which includes the giant Synapta maculata.

They are primarily detritivores, ingesting sediment and organic matter. Their movement and feeding influence sediment structure and nutrient cycling on the seafloor.

Reproduction is typically sexual, with external fertilization in spawning events; some species brood embryos or have direct development.

While some holothurians are exploited for beche-de-mer, synaptids are not generally the main target; however, overharvesting and habitat degradation can affect local populations.

Notable species include Synapta maculata, the giant synaptid sea cucumber.