Spectral effects on rearing fish

Hello, my name is Cypress Hansen and I am from Tucson Arizona, studying Marine Science, Spanish and Chemistry at Eckerd College in Saint Petersburg Florida. I am working at the Fisheries and Mariculture Lab (FAML) this summer for the UTMSI REU program. My research project is led by Dr. Lee Fuiman, director of FAML, and we will be testing brand new lighting technology on a commonly used fish in aquaculture, the Red Drum (Sciaenops ocellatus). Below is my initial synopsis for our research and some defining terms to aid in understanding.

Teleost- a class of bony fish, consisting of more than 26,000 species
Exogenous feeding- consumption of other organisms, as opposed to autotrophy or yolk-feeding
Spectra/wavelength– with regard to visible light, these characteristics determine the color of light



Aquaculture is an essential and expanding science, becoming more important as wild caught fish stocks shrink and human populations grow. Several fish species are now grown indoors, but many of them experience huge bottlenecks in survival at the earliest stages of life. Most larval teleosts require live food as they transition to exogenous feeding, however, under the dim fluorescent lighting typical of indoor fisheries, their ability to see prey could be greatly compromised. For Red Drum larvae (Sciaenops ocellatus) a survival rate of 30% during the dietary shift from the yolk to plankton is considered very high in culture tanks. Past research has suggested that certain light wavelengths are important to teleost larvae predatory ability due in part to the overwhelming color sensitivity that larval fish eyes exhibit. It is understood that retinal design in larvae is much different than in adults, however, there is little research on the specific effects of different wavelengths on larval survival and growth. To further complicate this issue, larval spectral photosensitivity is quite different among species depending on their ecology; the spectral output that one species benefits from, may increase mortality in another. New LED technology could offer brighter, more flexible lighting able to be tuned to the photosensitivity of the species grown. This project will be testing the effectiveness of high spectral output lighting vs. traditional fluorescent lights. Results will be based on growth measurements and survival rates of Red Drum larvae (Sciaenops ocellatus) grown separately under six different lighting spectra for the first 10 days post hatch. It is expected that the whitest, most supplemDSC_0920ented light will allow larvae to detect and capture prey best, which can be measured through growth rate and survival (clear functions of successful feeding). If there is a significant increase in larvae survival and development with this new technology, farmers will be able to tune the lighting conditions for their stocks depending on the seasons, fish age, species, etc. with just one fixture. Fish production could become more economically efficient not just for red drum, but for several other species of marine and freshwater fish as well. As knowledge expands on larval response to and requirements for various lighting conditions, new protocols of larval rearing could contribute to increased production, efficiency and survival in aquaculture everywhere.

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