Interest from domestic and foreign markets in native North American fishes for ornamental use has provided a unique opportunity for expansion in the ornamental aquaculture industry. Developing aquaculture techniques for these animals not only supports novel economic aquaculture opportunities, but also provides a valuable foundation for potential restoration aquaculture endeavors for imperiled species. Two candidate species for ornamental aquaculture are the blackbanded sunfish Enneacanthus chaetodon and the flagfin shiner Pteronotropis signipinnis. E. chaetodon is a small, imperiled centrarchid native to the Eastern US, while P. signipinnis is an active, schooling cyprinid ranging throughout the gulf states. Both are currently traded as wild collected individuals in the ornamental fish industry. Here, we develop techniques for spawning, embryo incubation, embryo disinfection, larval rearing, as well as characterize larval development.
For P. signipinnis, spawning substrate preference was determined experimentally by providing three different types of spawning media to six replicate tanks stocked with eight individuals: gravel, a floating yarn mop to mimic floating vegetation, and a bottle brush to mimic submerged structure. Brood fish were allowed to volitionally spawn for 3 weeks, with eggs being collected every other day. P. signipinnis preferentially spawned on floating yarn mops, followed by bottle brushes, while showing the least preference for gravel. Evaluation of incubation techniques revealed that static and upwelling incubation are both viable strategies (P = 0.314), with an overall mean hatch rate of 81.6 ± 10%. Embryo disinfection was safe for multiple concentrations of formalin, hydrogen peroxide, and iodine, with hatch rates following disinfection being similar to the control in each group (P ≥ 0.104). P. signipinnis larvae survived best following 14 days of feeding with Otohime and Ziegler AP-100 microfeeds (57.5 ± 6.8% and 52.5 ± 3.9%, respectively) when compared to Golden Pearls and live Artemia nauplii (27.5 ± 4.9% and 17.5 ± 5.3%, respectively, P < 0.001).
E. chaetodon volitionally spawned in dense, submerged vegetation and resulting larvae only survived on Artemia nauplii with no larvae surviving following 14 days of feeding with microparticulate diets. Embryos were successfully incubated in situ in brood aquaria. Larval growth was characterized from hatch until 34 dph. In addition, gastrointestinal ontogenetic development was characterized using histology, histochemistry and digestive enzyme activity assays. In total, the results of these investigations provide preliminary culture techniques that will support commercial and restoration aquaculture endeavors for these native North American fishes.