Aquaculture 2025

March 6 - 10, 2025

New Orleans, Louisiana USA

Add To Calendar 08/03/2025 15:15:0008/03/2025 15:35:00America/ChicagoAquaculture 2025INVESTIGATING THE EFFICACY OF CALCEIN MARKING TECHNIQUES FOR HOGFISH Lachnolaimus maximusSalon DThe World Aquaculture Societyjohnc@was.orgfalseDD/MM/YYYYanrl65yqlzh3g1q0dme13067

INVESTIGATING THE EFFICACY OF CALCEIN MARKING TECHNIQUES FOR HOGFISH Lachnolaimus maximus

Casey A. Murray*, Brandon C. Ray, Olivia I. Markham, Cortney L. Ohs, Joshua T. Patterson, Angela B. Collins, and Matthew A. DiMaggio

 

Tropical Aquaculture Laboratory

Fisheries and Aquatic Sciences

Institute of Food and Agricultural Sciences

University of Florida

Ruskin, FL 33570

casey.murray@ufl.edu

 



Hogfish (Lachnolaimus maximus), popular sport and food fish, have historically experienced overfishing throughout portions of their range prompting desire for intervention from management agencies to support impacted populations. Aquaculture and subsequent stock enhancement are potential opportunities that can support impacted populations, but evaluation of stocking success first requires effective assessment tools (e.g., mark-recapture experiments). Various marking methods exist but utility may be limited by cost, labor intensity, and species-specific sensitivity. Calcein is an efficient, non-lethal, batch fluorescent chemical marker that has potential to avoid some of the problems associated with more traditional marking methods. Standard calcein marking practices use osmotic induction, however, induction protocols, marking efficacy, and retention may be specific to species and environment. Four trials were conducted to evaluate the efficacy of calcein marking for hogfish. First, a trial was completed to determine the most efficient salinity pre-treatment for osmotic induction of calcein. A second trial determined the calcein concentration that resulted in the brightest mark. Two subsequent trials examined the effects of time and lighting scenarios on mark-retention of calcein. Osmotic induction experiments showed positive correlations between mark brightness, calcein concentration, and salinity pretreatment (Fig. 1). Retention experiments suggested vulnerability of marks, with rapid degradation of mark brightness over three to eight weeks. These results, alongside its current regulatory status, cast doubt on the viability of calcein as an external mark for stock assessment studies in hogfish, although more research is needed to assess its viability in natural settings. Results from this research will help guide future aquaculture and stock enhancement efforts for hogfish and add to the growing body of literature for this valuable marine species.