Evaluation of Stocking Density during Second‐Year Growth of Largemouth Bass, Micropterus salmoides, Raised Indoors in a Recirculating Aquaculture System

Abstract

Largemouth bass (LMB), Micropterus salmoides, are a highly desirable food fish especially among Asian populations in large cities throughout North America. The primary production method for food‐size LMB (>500 g) has been outdoor ponds that require two growing seasons (18 mo). Indoor, controlled‐environment production using recirculating aquaculture system (RAS) technologies could potentially reduce the growout period by maintaining ideal temperatures year‐round. Researchers conducted a 26‐wk study to evaluate optimal stocking densities for growout of second‐year LMB to food‐fish size in an indoor RAS. LMB fingerlings (112.0 ± 38.0 g) were randomly stocked into nine 900‐L tanks to achieve densities of 30, 60, or 120 fish/m3 with three replicate tanks per density. The RAS consisted of a 3000‐L sump, ¼ hp pump, bead filter for solids removal, mixed‐moving‐bed biofilter for nitrification, and a 400‐watt ultraviolet light for sterilization. Fish were fed a commercially available floating diet (45% protein and 16% lipid) once daily to apparent satiation. At harvest, all fish were counted, individually weighed, and measured. Total biomass densities significantly increased (P ≤ 0.05) with stocking rate achieving 6.2, 13.2, and 22.9 kg/m3 for fish stocked at 20, 60, and 120 fish/m3, respectively. The stocking densities evaluated had no significant impact (P > 0.05) on survival, average harvest weight, or feed conversion ratio which averaged 92.9 ± 5.8%, 294.5 ± 21.1 g, and 1.8 ± 0.3, respectively. After approximately 6 mo of culture, LMB did not attain target weights of >500 g. Observed competition among fish likely resulted in large size variability and overall poor growth compared to second‐year growth in ponds. Additional research is needed to better assess the suitability of LMB for culture in RAS.

Inhibiting fungus on largemouth bass eggs with copper sulfate and its toxicity to fry and juveniles

“…LMB have been cultured in the United States since at least the 1880s (Arnold Jr., ; Heidinger, ). LMB are the ultimate game fish for stocking ponds and lakes, but their culture has grown considerably as they are also a highly desirable food among ethnic populations in large U.S. cities (Heidinger, ; Watts, Bright, Coyle, & Tidwell, ). However, the legality of selling a game fish as a food fish is regulated by some states and is continuously in flux (Heidinger, ).…”

Farming largemouth bass (Micropterus salmoides) with lettuce (Lactuca sativa) and radicchio (Cichorium intybus) in aquaponics: effects of stocking density on fish growth and quality, and vegetable production

“…from 7 kg m -3 in indoor tanks (Guo et al, 2019) to 35 kg m -3 in in-pond raceway systems (Wang et al, 2019). Nevertheless, previous studies showed no effect of the stocking density on LMB performance (initial weight 36 g) farmed in in-pond raceway systems at two stocking densities (initial stocking density 2.45 vs. 4.10 kg m -3 ) (Wang et al, 2019) or in LMB (initial weight 112 g) reared in a recirculating aquaculture system and stocked at 2.24, 6.72 or 13.4 kg m -3 (Watts et al, 2016). No significant effect of stocking density was observed for LMB morphological indices or flesh quality (Table 3).…”

“…LMB farming showed a sharp increment (+88.1%) from 2012 to 2017 (Hussein et al, 2020), and it continues to expand. LMB is mainly farmed outdoor in raceway systems (Yuan et al, 2019) and high-density ponds (Sun et al, 2020), requiring 2 growing seasons (from 18 to 24 months) to reach the commercial size (approximately 0.5 kg live weight) (Watts et al, 2016). Due to its high growth rates, excellent flesh quality, and high tolerance to handling and water conditions (Hussein et al, 2020), LMB is a potential candidate for aquaponic systems.…”

Evaluation of alternative pond production systems for raising largemouth bass, Micropterus salmoides

“…The baitfish industry has also explored the possibility of bait fish production (e.g., golden shiners Notemigonus crysoleucas ) in split ponds, albeit with less success to date than the catfish industry (Smith & Stone, ). The culture of LMB during second‐year growout has also been explored in recirculating systems and determined to not be as viable as production in ponds (Watts, Bright, Coyle, & Tidwell, ). In Arkansas, there is one commercial LMB farm that is growing fish for the foodfish market using SPS.…”