Shifting the natural fission plane of Holothuria atra (Aspidochirotida, Holothuroidea, Echinodermata)

Fission stimulation involves the fission plane as the division area. In natural fission of Aspidochirote and Dendrochirotida, only a single fission plane is present. This paper present successful assay of shifting the natural fission plane. The experiment was conducted in July 2007, when two stimulated area were applied on each of 20 individuals of Holothuria atra. new tentacles and new anal pores started to appear in week 7 after division in anterior group (A) and posterior group (P), respectively. The middle group (M), which did not carry both mouth and anal complex, regenerated slightly slower than the A and P group. Eleven individual of the M group developed both tentacles and anal pore in week 9, and the number increased subsequently. When the experiment was terminated in week 12, the survival rate reached 96.67 persen. In induced fission, the natural fission plane was unlikely to be as definitive area of body division; therefore in such experiments, the great potential of regeneration was expressed more than the phenomenon of induced asexual reproduction. Beche-de-mer Information bulletin, 2009. Vol. 29. P: 16-19