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Details van artikel 18 van 29 gevonden artikelen
| Titel: |
Gonad histology in post fingerling of Tilapia guineensis exposed to Parateq |
| Auteur: |
Ijeoma VINCENT AKPU Alex Chuks CHINDAH |
| Verschenen in: |
Revista cientÃfica UDO agrÃcola |
| Paginering: | Jaargang 9 (2009) nr. 3 pagina's 672-680 |
| Jaar: |
2009 |
| Inhoud: |
The study investigated the effect of Parateq on gonad morphology and changes in gonadosomatic index of post fingerlings of Tilapia guineensis exposed to sublethal Parateq concentrations for 12 weeks. Initial short- term static toxicity tests were run to determine 96 hr LC50 of Parateq in T. guineensis which was 5.47%. The Parateq concentrations used were 0.32%, 0.63%, 1.25 % and 2.5% vol/vol parateq/ water. The histological changes noted in the gonads of the exposed fish were inhibition of maturation in oocytes or delay in spermatogenesis which resulted in lack of spawning. In contrary, the four stages of spermatogenesis or oocytogenesis were present in the control and spawning occurred. The increasing degeneration of maturing eggs resulted in complete absence of matured egg in the female gonads of fish exposed to the highest concentration (2.5%) of the drilling fluid. The gonadal somatic index values were recorded in a decreasing order toward the higher tested concentrations. The gonadal somatic index values ranged from 2.34 to 1.25% in the female and from 0.32 to 0.09% in male, whereas in the control, it was 2.85% for female and 0.41% for male. The results revealed that discharge of drilling fluid such as parateq into the environment can lead to impairment in the reproductive success of aquatic organisms in the Niger Delta. |
| Uitgever: |
Universidad de Oriente Press (provided by DOAJ) |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 18 van 29 gevonden artikelen
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