## 2 Material and Methods
### Shrimp Husbandry  
Post-larvae shrimp (PL 15) were obtained from a commercial farm in northern Queensland. Animals (\(\approx\)220-250 individuals, \(\approx\)15 animals L\({}^{-1}\)) were transported for 2 h in \(\approx\)35 ppt seawater in a plastic bag (15 L volume) with an oxygen-enriched atmosphere. The bag was contained within a polystyrene box to stabilise the water temperature. Upon arrival at the experimental facility, the animals and the transport water were treated with formalin (0.2 g L\({}^{-1}\) for 1 h in an aerated bucket) as a quarantine requirement. At the time of the experiment, no animal ethics approval was required for shrimp trials in Australia. Animals were housed in rectangular plastic tanks within an isolated environmentally controlled recirculating aquaculture system (RAS). The system consisted of a total of 40 rectangular plastic tanks (working volume \(\approx\) 43 L), two biofilters (\(\approx\)100 L each), two UV filters (Emperor Aquatics 25 W UVC filter, Pentair, Florida, USA), and two sums (\(\approx\)350 L each). The total system volume was \(\approx\) 2600 L. A 12:12 h light regime was used throughout the trial, with four red fluorescent tubes used to dimly light the room during the 12 h light period. Water quality parameters were measured daily using commercial \begin{table}
\begin{tabular}{l l l l l} \hline \multirow{2}{*}{**Diet**} & \multicolumn{1}{l}{**Polygain**} & \multirow{2}{*}{**Sucrose (g kg\({}^{-1}\) DM) 2**} & \multicolumn{1}{l}{**Dry Mash**} & \multicolumn{1}{l}{**Total Additional Dietary Polyphenol**} \\  & **(g kg\({}^{-1}\) Diet) 1** & & **(g kg\({}^{-1}\) DM) 3** & **Addition (mg kg\({}^{-1}\) DM)** \\ \hline Control & 0 & 3.6 & 996.4 & 0 \\
0.2\% Polysgain & 2 & 2.4 & 995.6 & 60.8 \\
0.4\% Polysgain & 4 & 1.2 & 994.8 & 121.6 \\
0.6\% Polysgain & 6 & 0 & 994.0 & 182.4 \\ \hline \end{tabular}  
* The Product Makers, Melbourne, Vic, Australia. Polysgain additions were of the unaltered liquid supplied by the manufacturer; 2 Chem-supply, Port Adelaide, SA, Australia. Sucrose additions as a filler for Polysgain were based on Polysgain’s estimated 60% DM content by weight. 3 Shrimp dry mash, Ridley Aquafeeds Ltd., Narangba, QLD, Australia.  
\end{table} 
Table 1: Experimental diet compositions used to evaluate the effect of adding a polyphenol-rich sugarcane extract (PolygainTM) to the diet of the black tiger shrimp, _Penaus mondon_. kits for NH\({}_{3}\)/NH\({}_{4}\)+, NO\({}_{2}\)\({}^{-}\), NO\({}_{3}\)\({}^{-}\) (Aquasonic Pty Ltd., Wauchope, NSW, Australia), and pH (API high range pH test kit, Mars Fishcare North America Inc., Chalfont, PA, USA), or a probe (YSI 556 MPS, Yellow Springs, OH, USA) for DO, salinity, and temperature. Water parameters over the length of the trial were within the optimal range for _P. monodon_; 29.2 \(\pm\) 0.04 \({}^{\circ}\)C, pH 8.2 \(\pm\) 0.02, 96.5 \(\pm\) 6.3 DO (% saturation), <0.01 mg NH\({}_{3}\)/NH\({}_{4}\)+ L\({}^{-1}\), <0.05 mg NO\({}_{2}\)\({}^{-}\) L\({}^{-1}\), 10.5 \(\pm\) 4.4 mg NO\({}_{3}\)\({}^{-}\) L\({}^{-1}\) (mean \(\pm\) SEM, \(n\) = 75). Salinity was gradually decreased from 31 to 20 g L\({}^{-1}\) over a 10-day period after the introduction of the shrimp to the system, from which time it was maintained at 20.1 \(\pm\) 0.02 g L\({}^{-1}\) (mean \(\pm\) SEM, \(n\) = 75) for the trial period. Filtered (1 \(\upmu\)m) seawater was obtained from the open ocean (AIMS, Townsville, QLD, Australia), while the freshwater used to reduce the salinity was carbon-filtered tap water. A commercial blend of cultured bacteria (Stability, Seachem Laboratories Inc., Madison, GA, USA; Batch 77,975 4/20) was added to the system at the rate of 250 mL/day (0.1 mL L\({}^{-1}\)) for two consecutive days starting on the day that the shrimp were added to the system. Shrimp were stocked at 25-30 animals per tank (\(\approx\)0.6 shrimp L\({}^{-1}\)). The density was decreased to \(\approx\) 15 shrimp per tank from PL 40 to minimise cannibalism during moulting.