ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Abstract Two-year-old blue tilapia, Oreochromis aureus (Steindachner), were stocked into five replicate breeding hapas (1·2 m × 1·2 m × 2·7 m) at a density of six males and six females per hapa. At stocking, males and females averaged 415 and 225g respectively. During the 50-day trial (July-August), 62900 seed (eggs and sac-fry) representing 78 spawns, were collected from 30 females. In comparative treatments, prestocking surgical removal of the male's maxillary bone did not influence hatchery productivity. However, removal of the female's maxillary bone significantly reduced frequency of repeat spawning and clutch size (P 〈 0·05). Removal of the maxillary bone also influenced weight gain of broodstock. It is hypothesized that these significant responses were due to the surgical removal of the maxillary bone and the subsequent breakdown in dominance hierarchies.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-2109.1993.tb00546.x
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