Histological analysis of ovary development in narrow-clawed crayfish Astacus leptodactylus Esch. 1823 (Crustaceae, Decapoda, Astacidae), reared in ponds in South Bulgaria
Journal Title: Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society - Year 2009, Vol 2, Issue 3
Abstract
The study was carried out for determination the age and body weight in which the females of freshwater narrow-clawed crayfish Astacus leptodactylus Esch. reached maturity, as well as of the duration of the different stages of the annual reproduction cycles of the matured individuals in the conditions of carp ponds. The study was carried out on juvenile and matured female crayfish. As a result of the study it was found that female narrow-clawed crayfish reaches sexual maturity during the first year of its life (6-7 months old), at body weight above 9.5 g and body length above 7 cm. The annual ovarian cycle of sexually mature females in the region of South Bulgaria, is following: January-May - eggs incubation, resorption of unovulated oocytes in the ovary, presence of previtellogenic and early vitellogenic oocytes, endogenic vitellogenesis; June-November - exogenic vitellogenesis, active accumulation of vitellogenin into the oocytes from August till November; November-December - copulation, ovulation, fertilization of the eggs.
Authors and Affiliations
Tania Hubenova, Penka Vasileva, Angel Zaikov
Production and characterization of phytase from Bacillus spp. as feed additive in aquacultur
Phytases are phosphohydrolases that catalyze the release of phosphate from phytate (myoinositol hexakisphosphate), the major phosphorus (P) form mostly occurring in animal feeds of plant origin. These enzymes can be supp...
Fish community structure in rivers located in the Capanema municipality, Pará State, Brazi
Fish fauna species can show spatial and temporal patterns, which can be revealed by species association or species groups as well as by species preference to certain habitats. A study was conducted in 2010 in the Capan...
Researches regarding the influence of royal jelly on sex reversal in zebra fishes (Danio rerio).
In this study we observed the influence of royal jelly on sex reversal in zebra fishes (Danio rerio). Experiments were made in the laboratories of aquaculture from Faculty of Animal Science and Biotechnologies, Timișoara...
Disease resistance effect of sea-buckthorn (Hippophae rhamnoides L.) added in the fish diet.
In this paper, we approached a research theme regarding the effects of sea-buckthorn Hippophae rhamnoides L. added in the diet the common carp Cyprinus carpio upon the disease resistance in case of the imminent disease o...
Instruments for an equitable management of shared waters.
Concepts of Integrated Water Resources and River Basins Management are considered as key points to the question of how conflict can be avoided and international waters be managed. Over the last fifty years, countries hav...