Water quality,Vibriodensity and growth of Pacific white shrimpLitopenaeus vannamei(Boone) in an integrated biofloc system with red seaweedGracilaria birdiae(Greville)

Abstract

An indoor trial was conducted for 42 days to evaluate water quality, Vibrio density and growth of Litopenaeus vannamei in an integrated biofloc system (IBS) with Gracilaria birdiae. Four treatments were used, each in triplicate: Control (monoculture shrimp); IBS 2.5 (L. vannamei and 2.5 kg wet weight seaweed m À3 ); IBS 5.0 (L. vannamei and 5.0 kg wet weight seaweed m À3 ) and IBS 7.5 (L. vannamei and 7.5 wet weight seaweed m À3 ). Shrimp individuals (0.34 AE 0.01 g) were stocked at a density of 500 shrimp m À3 . No water exchange was carried out during the experimental period. Molasses was added once a day as an organic carbon source to maintain the C:N ratio at 12:1. The IBS significantly decreased (P < 0.05) dissolved inorganic nitrogen (DIN) ranging from 19% to 34% (3.12-3.83 mg L À1 ), NO 3 -N ranging from 19% to 38% (2.40-3.16 mg L À1 ), Vibrio density ranging from by 8-83% (0.40-2.20 log 10 3 colony-forming units mL À1 ), and FCR ranging from by 20-30% (1.20-1.37), as compared to the control (4.73 mg L À1 , 3.93 mg L À1 , 2.40 log 10 3 colony-forming units mL À1 , and 1.74 respectively). Moreover, the IBS significantly increased (P < 0.05) crude protein in whole body shrimp, ranging from 8% to 13% (13.2-13.7% wet weight basis); as well as final weight, ranging from 25% to 32% (3.90-4.12 g), weekly growth ranging from 25% to 34% (0.59-0.63 g), and shrimp yield by 22-39% (1.72-1.96 kg m À3 ), as compared to control (12.1% wet weight basis, 3.12 g, 0.47 g, and 1.41 kg m À3 respectively). It can thus be concluded that cultivating Gracilaria birdiae in an IBS with L. vannamei can contribute to DIN and NO 3 -N removal, lower Vibrio density, increased crude protein in whole body shrimp, higher growth and yield parameters in shrimp culture.

Effects of two commercial feeds with high and low crude protein content on the performance of white shrimp Litopenaeus vannamei raised in an integrated biofloc system with the seaweed Gracilaria birdiae

“…orthophosphate levels from use of an integrated biofloc system, corroborating similar results observed by Brito et al (2014Brito et al ( , 2016. Du et al (2013) found better phosphate removal by G. asiatica at a 10:1 N:P ratio, however, in this study a lower N:P (2:1) ratio in the water was observed.…”

“…Similar results for higher concentrations of nitrate, as compared to nitrite and TAN, were also observed in other studies of integrated biofloc systems (using seaweed and shrimp) (Brito et al, 2016(Brito et al, , 2014, thus indicating that nitrifying bacteria were also present in the system. No effect from the use of an integrated biofloc system was observed on dissolved inorganic nitrogen removal, probably due to a lower photoperiod (12:12 light/dark), and lower biomass rate of shrimp:seaweed (1.27 -1.79) than those used by Sánchez-Romero et al (2013) (12:12 light/dark and shrimp:seaweed 1:8), and higher TSS levels of about 500 mg/L as compared to Brito et al (2016), who used 223 to 253 mg/L.…”

“…No effect from the use of an integrated biofloc system was observed on dissolved inorganic nitrogen removal, probably due to a lower photoperiod (12:12 light/dark), and lower biomass rate of shrimp:seaweed (1.27 -1.79) than those used by Sánchez-Romero et al (2013) (12:12 light/dark and shrimp:seaweed 1:8), and higher TSS levels of about 500 mg/L as compared to Brito et al (2016), who used 223 to 253 mg/L.…”

“…Shrimp growth variables are highly sensitive to protein quality, especially to adequate supply of essential amino acids (Tacon, 1987). Brito et al (2016) recorded increased crude protein levels in shrimp (in whole bodies) reared in integrated biofloc systems. However, Jatobá et al (2014) and Yun et al (2016) did not find significantly different (p > 0.05) results for protein in whole bodies and muscle tissue in juvenile shrimp reared in a biofloc monoculture system and fed diets containing varying levels of protein.…”

“…According to Angell et al (2016), seaweeds have relatively high quality proteins (essential amino acids as a proportion of total amino acids) compared to fishmeal and soybean meal. Moreover, Brito et al (2016) showed that G. birdiae tissue in a biofloc system had high crude protein levels. These beneficial nutrition components of seaweed may act as nutritional supplements and/or improve the shrimps' utilization of nutrients and can therefore partially substitute artificial feed (Cruz-Suárez et al, 2010;Gamboa-Delgado et al, 2011;Pallaoro et al, 2016;Peña-Rodríguez et al, 2017).…”