Synapseidae
Synapseidae is not a widely recognized taxon; the name is a misspelling of Synaptidae, a family of sea cucumbers (holothurians) within the phylum Echinodermata and the class Holothuroidea. The correct name is Synaptidae, and the type genus is Synapta. The family includes several genera of slender, worm-like holothurians. Members typically have elongated bodies, with reduced or absent tube feet along most of the body, and a mouth surrounded by feeding tentacles adapted for deposit or suspension feeding. The skin is often smooth or lightly papillae-covered; calcareous plates are reduced in many species, giving a soft appearance. The best-known member is Synapta maculata, the giant sea cucumber, among the longest echinoderms.
Synaptids have a cosmopolitan distribution, found from shallow tropical seas to deeper temperate habitats, often in
Reproduction is sexual, with external fertilization in many species, and development includes free-swimming larval stages typical
Synaptidae comprises numerous genera and species, and taxonomic work continues to resolve species boundaries and distribution.