Two feeding experiments were conducted to study the effects of different levels of solvent-extracted soybean meal on the growth and body composition of juvenile southern flounder Paralichthys lethostigma. In experiment 1, seven diets were formulated, replacing menhaden fish meal protein (FMP) with soybean meal protein (SBP) at 0, 10, 20, 30, 40, 50, and 60% without supplementing amino acids. In experiment 2, eight diets were formulated, replacing FMP with SBP at 0, 10, 20, 30, 40, 50, 60, and 70% and supplementing with L-methionine and L-lysine. In the test diets, L-methionine and L-lysine were supplemented to approximate the methionine and lysine level found in the 45% whole-body protein of southern flounder. All diets were formulated to have the same crude protein (45%) and lipid levels (12%), and all diets contained 9% squid meal and 5% krill meal to improve palatability. Each of the test diets was fed two times a day to triplicate groups of flounder (average weight = 0.61 g for experiment 1 and 1.63 g for experiment 2). Experiments 1 and 2 were conducted for 42 and 60 d, respectively. Fish were held in 75-L recirculating seawater tanks at 15 fish per tank. In both experiments, no significant differences were observed in body weight gain (WG), specific growth rate, feed intake, feed conversion and protein efficiency ratios, and the whole-body proximate composition among fish fed diets replacing 0-40% of FMP with SBP. When compared with fish fed 0% SBP, WG decreased significantly for the fish fed more than 40% SBP. Broken-line regression showed that the optimum levels of FMP replacement with SBP in the diet of southern flounder without and with supplemental methionine and lysine were 35.1% and 38.9%, respectively, when diets contained 9% squid meal and 5% krill meal.The southern flounder Paralichthys lethostigma (family Bothidae) is a flatfish found in coastal waters from North Carolina through the South Atlantic states to Texas, except for South Florida (Wenner et al. 1990). Their euryhaline character, tolerance of a wide range of temperatures, and status as a highly desirable food and recreational species make southern flounder an ideal candidate for aquaculture. Declining commercial and recreational landings has also stimulated interest in culturing

Three experiments were conducted to evaluate the effects of micro-bound diets (MBD) on southern flounder larvae. In experiment 1, four MBDs were formulated with different protein sources as follows: MBD 1: herring meal, MBD 2: menhaden meal, MBD 3: menhaden and squid meal; MBD 4: menhaden, squid and herring meal. In experiment 2, four MBDs were formulated as follows: MBD 5: menhaden, squid and herring meal; MBD 6: menhaden, squid, herring and attractants; MBD 7: menhaden, squid, herring and casein, and MBD 8: menhaden, squid, herring, casein and attractants. In experiment 3, three groups were maintained as follows: Group 1: live feed; Group 2: co-fed with MBD 6; and Group 3: MBD 6. In experiment 1 on 35 dph, survival and body weight (BW) of the fish fed MBD 4 was significantly higher than the MBDs 1 and 2. In experiment 2 on 34 dph, fish fed MBD 6 had significantly higher BW than the commercial microdiets. In experiment 3 on 21 dph, fish receiving only MBD had significantly lower survival than the other groups. Growth, survival and larval fatty acid composition suggested that co-feeding MBD 6, a mixture of marine protein sources plus attractants was more effective than the other MBDs.

Ages of schoolmaster (n = 136) from the southeastern Florida coast from 1981–2015 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming March–July (peaking in May–June). Schoolmaster ranged in age from 1–42 years; the largest fish measured 505 mm total length (TL) and was 19 years old. The oldest fish measured 440 mm TL. Estimated body size relationships for schoolmaster were: W = 9.26 × 10−6 TL3.11 (n = 256, r2 = 0.95); W = 2.13 × 10−5 FL2.99 (n = 161, r2 = 0.95); TL = 1.03 FL + 10.36 (n = 143, r2 = 0.99); and FL = 0.96 TL − 8.41 (n = 143, r2 = 0.99), where W = whole weight in g, FL = fork length in mm, and TL in mm. The fitted von Bertalanffy growth equation was: Lt = 482 (1 − e−0.12(t+2.79)) (n = 136). Based on published life history relationships, a point estimate of natural mortality for schoolmaster was M = 0.10, while age-specific estimates of M ranged from 1.57–0.18 for ages 1–42.

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