A prickly solution for stress


SERETEC is your powerful tool for stress control in aquatic production

SERETEC is a total extract of the fruit of Opuntia ficus indica, the prickly pear cactus. It accelerates the synthesis and enables the elevated levels of Heat Shock Proteins (HSP) in fish for three days following a stress episode. Studies that have been carried out showing how SERETEC enhances HSP performance yielding beneficial effects in aquatic species.

In one study, Atlantic salmon smolts were transferred to an offshore site via wellboat over a 10-day period. SERETEC and a control group were utilized and the two populations were kept separate throughout the trial. Salmon were kept in containment tanks prior to transport. SERETEC was applied by immersion between two and eight hours prior to handling. 50,000 salmon were preconditioned with SERETEC and 300,000 salmon were used as a control population. Mortalities were observed during transportation and six-weeks post-transfer. There was 7% mortality in the control population and 2.3% mortality in the SERETEC preconditioned population demonstrating effective reduction in mortalities during transfer of smolts to sea.

Adult gilthead seabream, with an average weight of 350g (transport density 35kg/m3; transport time approximately five hours) were used in a transport trial. Stress biomarkers (cortisol, glucose and lactate) were measured in blood plasma and epidermal mucus prior and post-transfer to assess fish allostatic load and recovery to the stress episode. Survival and presence of external lesions were recorded. Results show that stress biomarkers were significantly lower in plasma and mucus, (Figure 3) upon arrival and during the post-transport period, compared with control fish. Evidence of stress such as a darker fish skin color, erratic swimming, and higher incidence of skin lesions (85%) were observed in control fish. (Featured). The use of SERETEC demonstrated a positive strategy to attenuate transport-derived stress in adult gilthead seabream.

A study was carried out to determine the effect of using SERETEC during transport of wild-caught rasbora harlequin fish. Three thousand rasbora were collected from their natural habitat in Riau Province, Indonesia. Fish were allowed to acclimatise for one week in six 45-litre aquariums. Twelve hours prior the start of transport, five aquariums were preconditioned with SERETEC, applied by immersion while one aquarium acted as control. All the fish from each aquarium (500 fish) were then placed in transport bags. After the 12h-transport by road and plane to Depok, the fish were placed into six ponds. Mortality was recorded on arrival and for a period of six days post-transfer. Due to the large number of deaths in the control fish, SERETEC was applied to both groups, preconditioned and control fish on the fourth day (Figure 2). The results show a reduction in mortality of delicate wild-caught ornamental species and the prolonged three-day protection of SERETEC.

Results from various trials including the ones described, demonstrate the importance of mitigating stress, in order to alleviate both mortality and morbidity in aquaculture. The use of effective health management through the application of natural solutions can support sustainable aquaculture practices. SERETEC has proven to be a powerful tool for stress control in aquatic production. www.tecnovit.net

Featured: Control group showed skin peeling and presence of small petechial areas throughout the lateral line and caudal peduncle
Figure 2: Wild caught rasbora harlequin fish mortality record at arrival and during six days post transfer. SERETEC was applied 12h prior to transport and at the fourth day to preconditioned and control fish, where a significant decrease in mortality was observed for both groups. The prolonged 3 day protection of SERETEC is demonstrated
Figure 3: Skin mucus stress biomarkers for gilthead seabream transported with SERETEC or without (control). Asterisks indicate significant differences between experimental conditions (*P < 0.05, **P < 0.01; t-test). Basal health status of fish was evaluated before initiating the transport. Stress biomarkers were recorded at arrival (0h) and 3, 19 and 38h post-transport.


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