Indirect effects of eyestalk ablation | |
Considering that eyestalk ablation affects the hormone balance for numerous physiological processes in addition to stimulation of gonadal hypertrophy, what are the practical effects of this operation, and at what cost do we achieve induced ovarian development using eyestalk ablation? The following observations have been made concerning use of eyestalk ablation in captive reproduction, and may be related to either captive conditions, eyestalk ablation, or both:
There is strong circumstantial evidence that part of the problems seen with captive reproduction are related to a simple inability of current diets to supply required nutrients as rapidly as required for the gonadal hypertrophy stimulated by eyestalk ablation. In nature, an organism would not be anticipated to develop eggs, constituting some 10% of female body weight, unless nutrients are available for first, metabolism, second, growth, and third, reproduction. Eyestalk ablation accelerates the production of ova, regardless of whether the proper types and balance of nutrients are available, and regardless of whether those ova are even capable of fertilization. Dietary factors clearly have been shown to influence percentage hatch and percentage of females spawning (Bray & Lawrence, 1992). |