How do the gonads of Branchiostoma differ from those of Epigonichthys?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

In the subphylum Cephalochordata, the arrangement of gonads serves as a primary distinction between the two main families:12

Branchiostomatidae (Branchiostoma): Members of this family possess a double row of gonads, meaning they are present on both sides of the body.1
Epigonichthyidae (Epigonichthys): Members of this family are characterized by having gonads restricted to the right side of the body only.123

Both genera are dioecious and lack specialized ducts; instead, their gonads develop in the wall of the atrium, where they eventually rupture to release gametes into the cavity to be carried out into the sea.4