World Aquaculture Magazine - September 2021

WWW.WA S .ORG • WORLD AQUACULTURE • SEP TEMBER 2021 33 IRREC-AL when nearly all died as a result of infections with Cryptocaryon irritans and other pathogens. Broodstock were also collected by a commercial crab fisher in KeyWest. Fish were collected from traps during the beginning of stone crab season. Fish collected by this method were kept in live wells of the fishing boat, transported to the dock, and placed in a submerged net pen at the marina. Fish were held for two days and transported in Bonar boxes to the UF-IRREC-AL. All fish survived and the fish were 5-12 inches in length. When all fish arrived at the UF-IRREC-AL they were placed in quarantine for two weeks before initiation of harem formation. Due to the large size of the fish collected by angling, they were placed immediately into 1,500-gal broodstock tanks. These fish were quarantined for two months before being divided as needed for desired harems. Due to spatial limitations at the facility, fish were initially held at an imbalanced sexual ratio as new fish were continually being collected. During initial quarantine, fish tended to be reclusive and did not consume food items for up to two weeks. Male-to-male aggression was only observed once between two large males that had been captured from the wild together and held as a cohort. This led to the subsequent death of both males from aggression and reduced body condition. Harem Formation Once a sufficient number of adults of both sexes were collected and had completed quarantine, three harems were established based only on visible physical distinctions between male and female hogfish (Fig. 4). No fish were excluded from harems; therefore, the likelihood of harems containing a single male with multiple females was very low. Fish were stocked into three 1500-gal tanks and some fish were moved between tanks as needed. One tank contained one large fish assumed to be a male and five smaller fish under 12 inches in length. A second tank contained six fish that were greater than 12 inches in length. A third tank contained eight fish from the same collection trip cohort and had the largest average body size of the three harems. After establishment of the three harems, there was no further aggression seen, regardless of how the sexes had been divided, until months later. The two cohorts collected from the Florida Keys were stocked into two 2000- gal recirculating systems consisting of four 500-gal tanks each and held for a two-week quarantine period. The first cohort collected by scuba divers with nets had high mortality rates as mentioned previously and only four fish survived and were subsequently moved into a separate recirculating system located in the facility. The second cohort fromKey West survived a two-week quarantine period and was divided by size and placed into existing harems and four of the smallest fish were isolated in a separate smaller recirculating tank system. The four surviving fish collected by divers with nets were mixed with the four smallest fish from the Key West cohort and stocked into two 500-gal tanks. The remaining fish from the Key West cohort were stocked into a 1500-gal recirculating system tank that served as a non- photothermally manipulated control. These fish ranged in size from 12-22 inches in length. Hogfish collected by angling and from the first Florida Keys cohort did not accept feeds for two weeks upon arrival to the UF- IRREC-AL. The KeyWest cohort was fed and accepted frozen food items immediately after being transported to the facility. Fish ( C O N T I N U E D O N P A G E 3 4 ) FIGURE 5. Head of a male hogfish displaying mating coloration. FIGURE 6. Feeding hogfish broodstock. Note shelters on tank bottom. Hogfish are highly prized for the quality and taste of their fillets and have been described as the “filet mignon of fish” for their delicate white meat with almost no “fishy” flavor. Hogfish are often marketed as “hog snapper” and sold fresh or frozen, whole or filleted.