Penelitian Pendahuluan Bioekologi Ikan Terubuk di Perairan Bengkalis, Riau

Terubuk (Tenualosa macrura)is an endangered and under protected species in Riau Province. A series survey activity was conducted at least one time in a week (in May to November 2016) at Bengkalis regency waters for knowing the development of gametes and fish oocytes. However, the survey activities were not carried out in June to August. The result shows that the T. macrura was not spawning simultaneously among individuals; however when removing eggs and sperm were carried out simultaneously or totally released between oocytes and sperm, with the most spawning occurs in September each year.

Polluted water exacerbates Barbus callensis oocyte oxidative status

The deleterious effects of environmental pollutants on cellular components and tissues damage in fish have been studied extensively. However, there is no data about the oxidative status of fish oocytes once released into water. This study aimed to investigate the effects of polluted (Soummam River) and unpolluted (Agrioun River) fresh water on the oxidative biomarkers of Barbus callensis (=Lucibarbus callensis) (Val.) oocytes. The experimental design consisted of collecting fish oocytes from polluted and unpolluted rivers and then activating these oocytes separately in water collected from each site. Four groups were considered: oocytes from the Agrioun River activated in Agrioun fresh water (A-oocytes/A-fresh water); oocytes from the Agrioun River activated in Soummam fresh water (A-oocytes/S-fresh water); oocytes from the Soummam River activated in Agrioun fresh water (S-oocytes/A-fresh water); and oocytes from the Soummam River activated in Soummam fresh water (S-oocytes/S-fresh water). Oxidative stress biomarkers were evaluated by measuring total antioxidant status (TAS), catalase (CAT) activity, and cell-free hemoglobin (Hb) concentrations. The results showed that the oxidative status of fish oocytes was significantly affected by the quality of fresh water. Unpolluted fresh water improved the antioxidant activity of the fish oocytes. The results of this study suggest that once oocytes are released into polluted water, antioxidant protection is affected with subsequent cellular oxidative damage and potential reproduction impairment.

Assessing species and stage specific effects of preservation on fish oocytes over different temporal scales

This study assessed the effect of 10% neutral buffered formalin and of three ethanol solutions of different concentration on Mediterranean sardine and European anchovy oocytes over several temporal scales (days, weeks, months). The two species exhibit differences both in the elemental composition and the shape of their oocytes which further allowed an appraisal of oocyte shrinkage dynamics in relation to oocyte shape, developmental stage and composition. We showed that the effect of the preservative on oocyte size is stage specific while different preservation periods of ovarian material might lead to discrepancies among studies.