Aquaculture is the husbandry of an
aquatic organism in a controlled environment. The aquaculture
industry in Florida has been dominated for decades by production
of freshwater ornamental fishes. The purpose of my research program
is to diversify aquaculture production by developing culture methods
for new aquatic organisms and determining their potential for
commercial production. To diversify the number of species produced
in Florida I have focused my research efforts on three areas:
the culture of marine baitfish, the culture of copepods and utilizing
them as a first feed for larval marine fish, and development of
diets and methods to condition and spawn brood fish. Each of these
areas increases the potential for culture of new species by defining
methods to alleviate critical bottlenecks which have prevented
successful culture and commercialization.
Marine Baitfish Culture
My research defines culture methods
to close the life cycle of several fish species commonly used
as bait by the $6.6 billion saltwater fishing industry in Florida.
Currently, almost all marine baitfish are harvested from the wild.
The supply is seasonal, and for most of the year the demanded
species and/or sizes of baitfish are not available. There is no
special marketing effort needed because established retail markets
exist in every coastal county and marine baitfish are in high
demand. My research has defined culture methods of three new species
and my lab was the first to close the lifecycle of two species.
Continued research will refine culture methods of these species
and define methods for year round and low salinity production.
One attractive attribute of some marine
fish is their ability to survive and grow in low saline waters.
This facilitates marine aquaculture to occur in inland low saline
waters where high-valued marine organisms can be cultured away
from expensive and developed coastal property.
Larval Culture Using Live Feeds
There is a great desire to culture
many species of high valued marine food fish and hundreds of species
of marine ornamentals. Currently, the bottleneck to their production
is the larval stage. This stage requires very small live food
organisms to be fed to the larval fish. For the past decade, larval
culture methods have used rotifers and brine shrimp (Artemia sp.)
for live food, but successful culture is limited to a few species.
Neither of these organisms are the natural prey of marine fish
and are used because they are commercially available. Additionally,
their nutritional composition will not support the growth and
survival of larval fish unless they are enriched with nutritional
additives. The natural prey of larval marine fish is copepods.
There are 24,000 species of copepods identified and they are so
numerous in the oceans that they represent the greatest biomass
of any organism in all of the world’s oceans, even though their
size ranges from 60 to 1000 µm. There is a growing research effort
worldwide to isolate and culture individual species of copepods
in tanks to produce the necessary small naupliar stage to feed
larval marine fish.
My research on copepods includes isolating
and evaluating new species and determining if they are conducive
to culture in tanks, then the optimal culture conditions for each
species are defined. Additionally, we are feeding copepods to
marine fish larvae and comparing their performance to larvae fed
rotifers and Artemia sp. The long-term objective is to allow many
marine fish, including ornamental, bait and food species, to be
produced commercially because the larvae can be successfully cultured
Reproduction and nutrition of brood fish
I am PI of a research project evaluating
brood nutrition of two commercially important freshwater ornamental
fish, Redtail Black Shark (Epalzeorhynchos bicolor) and Mono Sebae
(Monodactylus sebae). This project is funded by a USDA grant which
is part of a larger regional project to investigate broodstock
nutrition of fish. For most species of fish, there is minimal
information on broodstock nutrition. It is known that brood fish
require additional nutrition during egg and sperm development.
However, the effects different levels of fatty acids have on ornamental
fish reproduction are unknown. So, we formulated diets to measure
the effects of altering the fatty acid composition of brood diets.
My lab is conducting research to define
the optimal spawning protocol of pinfish (Lagodon rhomboides)
and pigfish (Orthopristis chrysoptera), both marine baitfishes.
Additionally, we are evaluating the effects of different hormones
on fecundity, egg and larval quality, and survival of larvae.
The results of this research will clearly define when to dose
fish with each spawning hormone, how much to use, and the efficacy
of the hormones. Additionally, my lab conducts research on the
Seminole killifish (Fundulus seminolis), a candidate marine baitfish,
to determine how it reproduces in captivity and what is the reproductive
potential. My lab was the first to show that the Seminole killifish
could reproduce in tanks and they deposit their eggs on substrate
materials suspended within the tank, additionally their eggs do
not need to be submersed in water and must only remain in a humid
environment to develop.