lancelets

The lancelets (from “lancet”) — also known as amphioxi (singular, amphioxus) — comprise some 32 species of fish-like marine chordates with a global distribution in shallow temperate (as far north as Scotland) and tropical seas, usually found half-buried in sand. They are the modern representatives of the subphylum Cephalochordata, formerly thought to be the sister group of the craniates. In Asia, they are harvested commercially as food for humans and domesticated animals. They are an important object of study in zoology as they provide indications about the evolutionary origins of the vertebrates. Lancelets serve as an intriguing comparison point for tracing how vertebrates have evolved and adapted. Although lancelets split from vertebrates more than 520 million years ago, their genomes hold clues about evolution, particularly how vertebrates have employed old genes for new functions. They are regarded as similar to the archetypal vertebrate form. The Amphioxiformes are often called “amphioxus” (from the Greek: “pointed on both sides “). Amphioxus is an obsolete synonym of the genus Branchiostoma. It is used as a common name along with “lancelet”, especially in the English language. The genome of the Florida lancelet (Branchiostoma floridae) has been sequenced.