1. School of Life Sciences, Xiamen University, Xiamen 361005, China; 2. College of Life Sciences, Fujian Normal University, Fuzhou 350007, China; 3. Fujian Institute of Oceanology, Xiamen 361012, China
Amphioxus is expected to be a model laboratory animal in the near future because of its important position in evolution, simplified internal organ systems and transparent body. In order to develop the animal into a new laboratory model, we sampled two species of amphioxus (Branchiostoma belcheri and B. japonicum) from Xiamen in September 2003 and April 2004. The captive lancelets were cultured in the laboratory and fed daily with unicellular algae. After three years of laboratory culturing, we successfully obtained a second filial generation of both species, meaning that a full reproductive cycle was achieved in the laboratory. Preliminary observations on the growth of the progeny indicated that warmer water temperature will speed up the growth and development of amphioxus. This hints that amphioxus probably spawns more often in the laboratory, where water temperature is controlled, than in the wild. Most of the second generation lancelets have now metamorphosed into the early sub-adult stage, and their maximum full body lengths were up to 14.6 mm (B. japonicum) and 6.5 mm (B. belcheri), respectively.