Supplementation of rice husk activated charcoal in feed and its effects on growth and histology of the stomach and intestines from giant trevally, Caranx ignobilis

Background: Research on supplementing feed with rice husk activated charcoal was carried out to determine the effect of variations in the concentration of rice husk activated charcoal on the growth and histological features of the giant trevally  Caranx ignobilis intestine. Methods: This study used an experimental method with a completely randomized design consisting of six treatments and four replications, including adding activated charcoal to feed at concentrations of 0%, 1%, 1.5%, 2%, 2.5%, and 3% for 42 days. The measured parameters included daily growth rate (DGR), specific growth rate (SGR), absolute growth rate (AGR), feed conversion ratio (FCR), feed efficiency (FE), survival rate (SR), length of foveola gastrica, width of foveola gastrica, length of intestinal villi, and width of intestinal villi. Data were analyzed statistically using one-way analysis of variance and Duncan's test. Results: The results showed that supplementing fish feed with rice husk activated charcoal at different concentrations significantly affected the values of DGR, AGR, FCR, FE, SR, length of the foveola gastrica, length of the villous intestine, and width of the villous intestine, but did not significantly affect SGR or foveola gastrica width. Conclusion: The 2% rice husk activated charcoal treatment showed the best results for all parameters.

Supplementation of rice husk activated charcoal in feed and its effects on growth and histology of the stomach and intestines from giant trevally, Caranx ignobilis

Background: Research on supplementing feed with rice husk activated charcoal was carried out to determine the effect of variations in the concentration of rice husk activated charcoal on the growth and histological features of the Caranx ignobilis intestine. Methods: This study used an experimental method with a completely randomized design consisting of six treatments and four replications, including adding activated charcoal to feed at concentrations of 0%, 1%, 1.5%, 2%, 2.5%, and 3% for 42 days. The measured parameters included daily growth rate (DGR), specific growth rate (SGR), absolute growth rate (AGR), feed conversion ratio (FCR), feed efficiency (FE), survival rate (SR), length of foveola gastrica, width of foveola gastrica, length of intestinal villi, and width of intestinal villi. Data were analyzed statistically using one-way analysis of variance and Duncan's test. Results: The results showed that supplementing fish feed with rice husk activated charcoal at different concentrations significantly affected the values of DGR, AGR, FCR, FE, SR, length of the foveola gastrica, length of the villous intestine, and width of the villous intestine, but did not significantly affect SGR or foveola gastrica width. Conclusion: The 2% rice husk activated charcoal treatment showed the best results for all parameters.

Gut and intestinal biometrics of the giant trevally, Caranx ignobilis, fed an experimental diet with difference sources of activated charcoal

Background: The giant trevally, Caranx ignobilis, is a commercially important marine fish in Indonesia. This species was initially cultured in Aceh Province. Previous reports showed that charcoal has a positive effect on survival and feed utilization of the giant trevally. However, the effects of adding charcoal to the diet on gut and intestine biometrics has, to our knowledge, never been described.

Methods: Four activated charcoal sources were tested in this study using a completely randomized experimental design; coconut shell charcoal, mangrove wood charcoal, rice husk charcoal, and kernel palm shell charcoal. All treatments were performed with four replications. Juvenile giant trevally (average body weight, 16.52 ± 3.12 g; and average total length, 10.26 ± 0.64 cm) were stocked into the experimental tank at a density of 15 fish per tank. The fish were fed an experimental diet twice daily at 7 AM and 5 PM ad satiation for 42 days.

Results: Analysis of variance showed that adding charcoal to the diet had significant effects on the length and width of the foveola gastrica and villous intestine (P < 0.05). The greatest length and width of the foveola gastrica was recorded in fish fed an experimental diet of rice husk charcoal with average values of 311.811 ± 9.869 µm and 241.786 ± 10.394 µm, respectively. The greatest length of intestinal villous was found in fish fed the mangrove wood charcoal diet, with a value of 135.012 ± 5.147 µm, but this length was not significantly different to that in fish fed rice charcoal and kernel palm shell charcoal. However, the greatest width of intestinal villous was recorded in fish fed the control diet (without charcoal; P < 0.05).

Conclusion: The optimal sizes of the foveola gastrica and villous intestine were found in fish fed an experimental diet with rice husk charcoal.

Gut and intestinal biometrics of the giant trevally, Caranx ignobilis, fed an experimental diet with difference sources of activated charcoal

Background: The giant trevally, Caranx ignobilis, is a commercially important marine fish in Indonesia. This species was initially cultured in Aceh Province. Previous reports showed that charcoal has a positive effect on survival and feed utilization of the giant trevally. However, the effects of adding charcoal to the diet on gut and intestine biometrics has, to our knowledge, never been described. Methods: Four activated charcoal sources were tested in this study using a completely randomized experimental design; coconut shell charcoal, mangrove wood charcoal, rice husk charcoal, and kernel palm shell charcoal. All treatments were performed with four replications. Juvenile giant trevally (average body weight, 16.52 ± 3.12 g; and average total length, 10.26 ± 0.64 cm) were stocked into the experimental tank at a density of 15 fish per tank. The fish were fed an experimental diet twice daily at 7 AM and 5 PM ad satiation for 42 days. Results: Analysis of variance showed that adding charcoal to the diet had significant effects on the length and width of the foveola gastrica and villous intestine (P < 0.05). The greatest length and width of the foveola gastrica was recorded in fish fed an experimental diet of rice husk charcoal with average values of 311.811 ± 9.869 µm and 241.786 ± 10.394 µm, respectively. The greatest length of intestinal villous was found in fish fed the mangrove wood charcoal diet, with a value of 135.012 ± 5.147 µm, but this length was not significantly different to that in fish fed rice charcoal and kernel palm shell charcoal. However, the greatest width of intestinal villous was recorded in fish fed the control diet (without charcoal; P < 0.05). Conclusion: The optimal sizes of the foveola gastrica and villous intestine were found in fish fed an experimental diet with rice husk charcoal.

Length-weight relationships and condition factors of mullets Liza macrolepis and Moolgarda engeli (Pisces: Mugilidae) harvested from Lambada Lhok waters in Aceh Besar, Indonesia

Background: The mullets fish Liza macrolepis and Moolgarda engeli are predominant in the Lambada Lhok waters in Aceh province. At present, no scientific report on this species in Aceh waters is available. Therefore, the objective of the present study is to examine the growth pattern and condition factor of the species of mullets L. macrolepis and M. engeli harvested from the aforementioned coastal waters. Methods: The sampling was done in three locations in the Lambada Lhok waters from July to November 2018. The fish were captured using gillnets from 6:00 AM to 3:00 PM four times a month for five months.  A total of 242 L. macrolepis and 109 M. engeli were used for the analysis. The growth pattern was analyzed using linear allometric model; then, two condition factors, Fulton's and relative weight, were calculated. Results: The study revealed a b value of 2.49 for the male L. macrolepis and 1.81 for the female. The b value was 3.22 for the male M. engeli and 3.41 for the female. The b value of the fish was higher during the dry season. The Fulton's condition factor of the male L. macrolepis was 1.19, and that of the female was 1.19. The relative condition factor of this species was 100.11 and 100.01 for males and females, respectively. The Fulton condition factor of male M. engeli was 1.05 and that of the female was 1.06. The relative weight condition factors were 101.08 and 100.61 for the male and female, respectively.   Conclusions: The growth pattern of  M. engeli tends to be isometric, whereas that of  L. macrolepis has a negative allometric growth pattern. The condition factors indicate that the Lambada Lhok waters are still in good condition and support the growth of the mullets, but  M. engeli is more adaptable than  L. macrolepis.