I n Kentucky State University’s Division of Aquaculture, Dr. Boris Gomelsky studies fish genetics and reproduction. He has nearly 40 years of experience in this area, conducting research in the U.S., Israel, and Russia. He has worked with koi, goldfish, tilapia, crappie, paddlefish, and striped bass. In recent years, his research has focused on cyprinid fish (carp family) including ornamental koi carp to be stocked in water bodies to prevent the growth of algae and submerged weeds. Currently, working with Dr. Noel Novelo and graduate student Jeffrey Warner, Dr. Gomelsky performs studies on fish genetics in the following areas:
First, Dr. Gomelsky develops methods for production of sterile fish, or fish that are unable to reproduce. It is known that the stocking of some cyprinid fish, for example ornamental koi carp or goldfish, to ponds or other water bodies can prevent development of filamentous algae and submerged weeds. The mechanism of this positive influence is that cyprinid fish make water more turbid and less transparent for sunlight. These conditions stimulate development of desirable microscopic algae (phytoplankton) but not the expansion of annoying filamentous algae and submerged weeds.
In order to be successfully used for weed control, stocked fish should be genetically sterile for prevention of uncontrolled reproduction and overcrowding. Dr. Gomelsky investigates using two different genetic methods for production of sterile fish. The first method is induced triploidy. Triploid fish have an additional set of chromosomes in their genomes. The presence of this extra chromosome set makes it impossible for fish to develop eggs and spermatozoa and therefore the fish are sterile. Induced triploidy is used not only for producing sterile fish but also for plants. For example, seedless watermelons, which we buy in grocery stores, originate from sterile triploid plants. Another genetic method, which he applies in his studies for obtaining sterile fish, is interspecies hybridization or production of hybrids between two different fish species. Distant hybridization is a common method for production of sterile animals. The most well-known example is sterility of mule, which is hybrid between a donkey and a horse. In Dr. Gomelsky's studies, he produces and investigates hybrids between two common ornamental fish: koi and goldfish. A second focus of genetic studies that Dr. Gomelsky explores is the investigation of inheritance of color and other traits in ornamental koi carp. Koi is a very popular decorative fish in many countries including the United States. Koi were developed in Japan approximately two centuries ago. In spite of relatively long history of koi, the inheritance of many traits is not yet understood. As a result of our studies performed at Kentucky State University, Dr. Gomelsky obtains data on inheritance of different traits in koi including long fins, sparkling scales and red eyes. Currently he is investigating inheritance of trait “transparent scales” in koi. Available information on koi genetics will help to improve quality of fish produced by U.S. koi cultivars.
of chromosomes in their genomes. The presence of this extra chromosome set makes it impossible for fish to develop eggs and spermatozoa and therefore the fish are sterile. Induced triploidy is used not only for producing sterile fish but also for plants. For example, seedless watermelons, which we buy in grocery stores, originate from sterile triploid plants. Another genetic method, which he applies in his studies for obtaining sterile fish, is interspecies hybridization or production of hybrids between two different fish species. Distant hybridization is a common method for production of sterile animals. The most well-known example is sterility of mule, which is hybrid between a donkey and a horse. In Dr. Gomelsky's studies, he produces and investigates hybrids between two common ornamental fish: koi and goldfish.
A second focus of genetic studies that Dr. Gomelsky explores is the investigation of inheritance of color and other traits in ornamental koi carp. Koi is a very popular decorative fish in many countries including the United States. Koi were developed in Japan approximately two centuries ago. In spite of relatively long history of koi, the inheritance of many traits is not yet understood. As a result of our studies performed at Kentucky State University, Dr. Gomelsky obtains data on inheritance of different traits in koi including long fins, sparkling scales and red eyes. Currently he is investigating inheritance of trait “transparent scales” in koi. Available information on koi genetics will help to improve quality of fish produced by U.S. koi cultivars.
Dr. Boris Gomelsky, Professor in Aquaculture Genetics and Reproduction
23