The Captain fish will repopulate the Cundinamarca-Boyacá Provinces high plateau water bodies
UN/DICYT The captain fish (Eremophilus mutisii) is a solitary, calm and endemic fish which was lost from the memory of Colombians, especially the inhabitants of the Savannah of Bogotá.
The tributaries of the Negro, Frío, Chicú, Balsillas, Juan Amarillo, Fucha, Tunjuelo and Soacha Rivers were formerly the natural habitat of the cold water guardian and was one of the main food sources of the region.
The transformation of bodies of water, especially the Bogotá River due to industrial tannery processes as well as use of fungicides, herbicides and other chemicals in crops and dairy farms displaced this fish which in the past had important populations in the high basin of the Bogotá River near the towns of Suesca, Fúquene, Guasca, Tominé and La Copa.
Therefore Professors Miguel Ángel Landines, Director of the UNal Zootechnics program and Camilo Prieto, Director of Zootechnics of the University of Applied and Environmental Sciences (UDCA, for its Spanish acronym), began a research project with the purpose of trying to recover the species. Their task focused on several topics, including identifying bodies of water and a repopulation program also including a captivity reproduction program.
During the 2 years of the research project, they carried out 6 to 8 monthly sampling field tours completing a total sampling of 90 species collected from the higher lakes of the Bogotá River Basin mainly near the town of Suesca.
Then they performed an analysis of the gonad maturation status and biochemical blood studies with the purpose of obtaining information of the reproductive behavior and a hormonal profile. This helped them determine that the captain fish reproduces during the whole year, although with peaks which coincide with the rainy seasons. Their egg count ranges between 10,000 and 50,000 ova per female.
In order to begin a captivity reproduction program, they chose the best males and carried out a hormonal induction as it may take the fish some time to produce these hormones in captivity. They tested several hormonal dosages and the time needed for the best treatment response.
When ovulation took place the researchers captured the females and extracted the ova and then captured males and obtained a considerable amount of semen in order to carry out an in vitro fertilization.
Afterwards they incubated the embryos and waited for approximately 100 hours, the time needed for development. The fry develop with a yolk sac, which is the first source of nutrients and oxygen for the embryo. This food absorption process lasts approximately 3 to 4 days until they begin to eat external nutrients close to six days of development. The whole reproduction process takes between 2 to 3 weeks.
A learning experience
At the same time the researchers carried out a genetic study with the purpose of identifying the species present in each body of water and try to understand their attributes to become cognizant of which species adapted better to different environments.
Professor Landines says that although Colombia is the country with the second most ictiologic biodiversity after Brazil, captain fish are the only cold water fish in the country.
When they have a considerable amount of fry they will begin to reintroduce the fish to bodies of water and try to create awareness among the communities. They will also teach communities to reproduce these fish in order to have a source of protein lost with time and lack of environmental awareness to preserve the hydric resources of rivers such as the Bogotá River.
Currently the average Colombian consumer only eats imported fish, including tilapia and trout. Professor Landines added that captain fish are a native species of the Bogotá savannah and has greater potential than trout and needs less water to reproduce.