Unlike vertebrates, the notochord persists in the adult, in the form of a simple dorsal neural tube slightly thickened in the anterior part (the cerebral vesicle).

Gas exchange takes place as water passes through gill slits in the mid region, and segmented gonads lie just behind these.

Its range has expanded through the Suez Canal to the northerly parts of the Indian Ocean and the coasts of East Africa.

Each evening they rise to near the surface of the sea and in the morning they sink through the water column, feeding on phytoplankton, copepods and detritus as they descend.

[5] Toll-like receptors (TLR's) act as important mediators of the inflammatory pathways for creating an innate immune response in chordates.

[6] The mitochondrial genome of Branchiostoma lanceolatum has been sequenced,[7][4] and the species serves as a model organism for studying the development of vertebrates.

[4] Since 2015, a merged effort from different labs working on this species, the Amphiencode consortium, provides a centralized platform on which genomic data is publicly accessible.