Carbon sources affect water quality and haemato‐biochemical responses ofLabeo rohitain zero‐water exchange biofloc system

Abstract

Biofloc technology degrades waste into useful resources exploiting microbes and can be used in zero‐water exchange systems. To study the effect of different biofloc systems on haematological and metabolic response of Labeo rohita fingerlings, a 60‐days experiment was conducted using four long lasting carbon sources. Seven hundred and fifty fingerlings having mean weight of 4.80 ± 0.12 g were randomly distributed into 15 tanks (n = 50 per tank). Five experimental groups were set in triplicate; T1 (Tapioca), T2 (Wheat), T3 (Corn) T4 (Sugar bagasse) and control (clear water). In‐situ biofloc was developed in 300 L fibre‐reinforced plastic (FRP) tanks and a C/N ratio of 15 was maintained. Water quality variables indicated ammonia immobilization by heterotrophic bacteria, as the dominant mechanism for the removal of toxic‐nitrogenous compounds in the biofloc systems. Results exhibited significantly higher floc volume (53.33 ± 7.88 ml/L), haemoglobin content (6.61 ± 0.03 g/dl) and total leucocyte count (109.66 ± 0.06 thousand cells/mm3) in tapioca biofloc system. Furthermore, the digestive and anti‐oxidative enzymes activities were also significantly higher in tapioca biofloc system. The lactate dehydrogenase and malate dehydrogenase enzyme assays showed a decreased level in tapioca biofloc system as compared with other biofloc systems and control group. Our observations indicate that tapioca biofloc system could improve the water quality, haematological and anti‐stress responses of L. rohita fingerlings in biofloc systems and thus can effectively replace other carbohydrate sources for the biofloc system.

Yam‐based biofloc system improves the growth, digestive enzyme activity, bacterial community structure and nutritional content in milkfish ( Chanos chanos )

“…A significantly higher nitrate value in biofloc treatment indicates the presence of nitrifiers and the occurrence of nitrification processes in the culture systems (Cohen et al, 2005; Ebeling et al, 2006). These results indicate that carbon source influences the different water quality parameters and similar results were reported by Ahmad et al (2019) in different carbon source‐based biofloc groups.…”

“…The increased digestive enzyme activities, particularly in the BFY group, improved nutrient utilization that contributed to better growth in these treatments. Previous studies also suggested that numerous extracellular/exogenous enzymes and unknown growth promoters present in microbial floc enhance the digestive activity in Labeo rohita (Ahmad et al, 2019) and Oreochromis niloticus (Long et al, 2015).…”

“…Likewise, source and type of carbon also influence the water quality, production of biofloc which in turn influence the growth and survival of the fish and it is preferred to use low‐cost, non‐conventional agro‐industrial products as carbon source (Caipang et al, 2015). Tuber crops such as tapioca (Ahmad et al, 2016, 2019), sweet potato (Caipang et al, 2015) and enzyme‐hydrolysed cassava dregs (Shang et al, 2018) were found suitable as source of carbon in maintaining biofloc‐based culture of finfish. Hence, in the present study, other tubers, that is potato and yam, were selected as source of carbon to know their potential in the development of biofloc for milkfish rearing.…”

Finger millet as a carbon source for biofloc, improved growth performance of Pangasianodon hypophthalmus (Sauvage, 1878) fingerlings

“…BFT-PM treatment groups recorded mean floc volume of 21.72±2.78 ml l -1 followed by BFT-S (20.52±4.50 ml l -1 ), BFT-T (19.61±0.28 ml l -1 ) and control (1.50±0.80 ml l -1 ). The results of this study concurred with that of the previous authors who reported supplementation of different carbon sources at varied levels could affect the biofoc volume, microbial and nutrient composition (Wang et al, 2015;Zhao et al, 2016;Dauda et al, 2017;Ahmad et al, 2019;Panigrahi et al, 2019). Furthermore, finger millet organic carbon source has the potential for higher biofloc production as well as to improve growth performance of pangasius fingerling culture in zero water exchange system.…”

Supplemental carbon sources applied in biofloc technology aquaculture systems: types, effects and future research

“…For example, Ahmad et al . (2019) tested the effectiveness of tapioca, corn, sugarcane bagasse and wheat as external carbon sources on the performance of Labeo rohita in a BFT system. The authors found that tapioca produced the best results in terms of haemoglobin content (6.61 ± 0.03 g dL −1 ), total leucocyte count (109.66 ± 0.06 thousand cells mm −1 ), antioxidant status, and lactate and malate dehydrogenase enzymes.…”