Optimal breeding circumstances of larvae and juvenile of the Korean Bullhead, Pseudobagrus fulvidraco(Richardson)

초록

The present study on the optimal breeding circumstances of the Korean bullhead, Pseudobagrus fulvidraco was investigated for the purpose to obtain the fundamental data for the aquaculture and the reinforcement of natural population of the Korean bullhead. It was experimented in three types of artificial conditions as followed : grain size of substrates in aquarium(0.5, 2, 5, 10, 20mm), aquarium color(white, yellow, red, light blue, black), and light intensity(10, 50, 100, 1000, 5000lux). In observations of situations in the movement of larvae and young fish with the time lapse under a different circumstance, larvae and juvenile showed thier highest appearence rate at the 20mm-grain-size area where the grain size of the substrate was largest, and at the black-aquarium area where the brightness was lowest. Also, they showed thier highest appearence rate at the 10lux-area where the light intensity was lowest(p<0.05). However, juvenile were distributed more widely and equally at each experimental area than were larvae. It is because that the complex phenomenon from biological characteristics that juvenile tend to occupy more territories between individuals and distribution patterns that juvenile migrate to preferable environment by the time lapse is thought to be appeared.