The effect of feeding frequency, water temperature, and stocking density on the growth of river puffer Takifugu obscurus reared in a zero-exchange water system

Abstract

The effects of daily feeding frequency (Exp I), water temperature (Exp II), and stocking density (Exp III) on the growth of river puffer, Takifugu obscurus, juvenile fish of 10 and 40 g in body weight were examined to develop effective techniques to produce river puffer in a non-exchange water system. In Exp I, fish were fed commercial floating feed with 45 % protein one to five times per day to apparent satiation each by hand daily for 8 weeks at 25°C. In both the 10-and 40-g size groups, the final body weight, daily feed consumption, and weight gain of fish fed one meal per day were significantly lower than those of fish fed five meals per day (P < 0.05). However, there were no significant differences in the final body weight, daily feed consumption, and weight gain among fish fed two, three, and five meals per day. Feed efficiency showed decreasing tendency with increasing size of fish. In Exp II, fish of 10 and 40 g in initial body weight were reared with the commercial feed at 15-30°C for 8 weeks. The weight gain of fish increased with raising water temperature up to 25°C and decreased drastically at 30°C for both sizes. The Q10 of specific growth rate was decreased with raising water temperature from 5.04 (temperature interval, 15-20°C) to 0.66 (25-30°C) for the 10-g fish and from 4.98 to 0.31 for the 40-g fish. In Exp III, the effect of stocking density on growth was examined with fish of 10 and 40 g in initial body weight. The final body weight for initial stocking densities of 4, 8, and 12 kg/m 3 was significantly higher than that of 20 kg/m 3 for the 10-g fish, and the final stocking density reached 10. 1, 19.2, 28.7, and 39.9 kg/m 3 , respectively. For the 40-g fish, the final body weight for initial stocking densities of 3 and 6 kg/m 3 was significantly higher than that of 9 and 15 kg/m 3 and the final stocking density reached 7.38, 13.5, 17.1, and 27.5 kg/m 3 , respectively (P < 0.05). In both groups, weight gain tended to decrease with increasing stocking density; however, survival showed no significant difference.

Effect of Garcinia kola seeds supplemented diet on growth performance and gonadal development of Oreochromis niloticus juveniles breed in ponds

“…The average values of water quality parameters such as temperature, transparency, pH, dissolved oxygen, nitrite, nitrate, and ammonia monitored throughout the trials were considered as suitable for the survival, normal growth, as well as good general physiology of O. niloticus. These values were in accordance with the findings of Yoo and Lee, 2016, Makori et al 2017and Nyadjeu et al (2018 and could partially justify the absence of mortality observed throughout the study, coupled with experimental fish's apparent good health observed through the results on both the growth and feed utilization.…”

Effects of&nbsp;Stocking&nbsp;Density and FeedingfFrequency on the Growth Performance,&nbsp;Digestive Enzyme Activity, and Tissues Histology of&nbsp;Hybrid Grouper (Epinephelus Fuscoguttatus♀×E. Lanceolatus♂)

“…This suggested that the growth performance of the sh in the 1.10 kg and 1.65 kg per tank stocking densities was better than that of the other groups with the same feeding frequency. In other words, feeding frequency and stocking density in uenced the growth performance of this species, which was consistent with previous studies [27,28]. The poor growth performance observed in the high stocking density was likely due to crowding stress [29].…”

Integrated application of multi-omics provides insights into cold stress responses in pufferfish Takifugu fasciatus

“…Taking experiment needs and the suitable culture density of juvenile T. fasciatus into consideration [28], a total of 120 juvenile T. fasciatus (13 ± 1.76 cm in length, 22 ± 2.85 g in weight), supplied from Zhongyang Group Co., Ltd. (Jiangsu Province, China), were randomly transferred to six aquaria with biofiltered water recirculation systems (equipped with cooling and heating functions; volume 200 L; flow rate 5 L/min), and were divided into the control group (G1, G2 and G3; total of 60 individuals; 2.2 ± 0.3 g/L) and the experimental group (Ga, Gb and Gc; total of 60 individuals; 2.2 ± 0.3 g/L). These individuals were acclimated at 26 ± 1 °C for 2 weeks.…”

“…Furthermore, the pufferfish is also popular in Korea [26] and Japan [27]: pufferfish sashimi is widely known. As a kind of warm-water fish [28], T. fasciatus has an optimum growing temperature between 23 °C and 32 °C [29]. However, in farms as well as rivers, the water temperature in winter is far below that optimal growth temperature, which causes massive deaths of T. fasciatus and leads to large economic losses.…”