Utilizing Cell Transplantation Methods, A Group of IPB Students of IPB Produced Single Sex Tilapia
The growing demand for food sources, particularly protein, has made aquaculture to be one of the fastest growing food sectors in the world. A variety of freshwater fish, such as carp, tilapia and catfish has been cultured in many parts of the world to meet the demands and preferences of consumers. Red tilapia (Oreochromis sp.), however, is a not a species of tilapia, it is instead a name used for several different manmade tilapia variants that sport and attractive red colouration. These variants are the result of continuous selective breeding. Many farmers prefer to cultivate red tilapia since it is much sought after in certain markets, as Red tilapia (Oreochromis sp.) have high economic potential. In addition, this species is rich in high ratios of omega-6 to omega-3 fatty acid. This hybrids species, red tilapia (Oreochromis sp.), are becoming important for export commodity to Middle East, Japan, Singapore and America. As production techniques improved and off-flavors were controlled, tilapia moved into the mainstream seafood markets of Indonesia. The growing popularity of tilapia among consumers and the ever increasing need to improve food production, impose the need to seek production alternatives to culture tilapia.
Seeing the immense possibility, a group of students of the Faculty of Fisheries and Marine Sciences of Bogor Agricultural University (FPIK IPB) consisting of Muhammad Lutfi Abdurrachman, Afif Abdurrahman, Dede Priyadi, Meri Alvina Taufik and Siska Aliyas Sandra, under the sponsorship of Program Kreativitas Mahasiswa bidang Penelitian (PKM-P – Creativity Student Research Program for research) 2017 designed the research program to investigate the increased production of tilapia from synthetic indigo engineering.
The title of the group research program is "Nila Merah Sintetis (Hasil Transplantasi Sel Testikular): Transplantasi Sel Testicular Ikan Nila Merah pada Ikan Nila Hitam = Synthetic Red Nila (Result of Testicular Cell Transplant): Testicular Cell Transplantation of Red Tilapia on Black Tilapia). This study used a transplant cell testicular technique to produce a parent nila supermale fish (YY) which will be used as a parent stock to produce single sex tilapia larvae (producing all-male fry). There are several ways of obtaining single sex fingerlings, but for commercial culture, methyltestosterone treatment to cause sex reversal or reliance on YY male brood stock are commonly used to produce all-male fingerlings. The production of fingerlings of a single sex is an important method for controlling reproduction during culture. Many tilapia (Oreochromis spp.) farmers produce all-male populations because of the superior growth rate of males compared to females. "Normally the masculinization of Oreochromis niloticus is by oral administration of 17α-methyltestosterone (17α-MT), but its residual impacts due to the artificial hormone administration will cause environmental degradatiion," explained Muhammad Lutfi Abdurrachman explaining the reasons for using the transplant method.
A transplant or grafting is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. In fisheries methods, this this transplantation is by inserting spermatogonia cells into the larvae of the fish larvae, then the cells will turn into eggs or sperm inside the fish. Generally, this transplantation technique is carried out for genetic conservation activities of endangered fish and as a surrogate parent in seed production. "This technology is suitable for producing all-male fry male of tilapia," he added.
The Research was conducted in the Laboratory of Reproduction and Genetics of Fish Department of Aquaculture of IPB, Bogor. The three-day sterile black tilapia larvae (Oreochromis niloticus) were utilized for this research. The larvae are then injected with testicular cells of red tilapia which have been artificially coloured for easy handling and observation under the microscope. After that the fish are kept and fed by live artemia and silk worms until they are ready for breeding (reproduction).
According to Muhammad, the reason the team chose the tilapia as the object of research because these fish can live in a variety of environmental conditions, even in low-quality water though. In addition, tilapia are popular as a culture species because of their ability to efficiently use both natural organisms and manufactured feed efficiently under crowded conditions allowing high levels of production. "Tilapia fish will spawn in the rainy season, so it is suitable with the Indonesian a country having a very high level of rainfall," said student from Cianjur.
The group expected that their research program would be a pioneer for the tilapia industry in improving its output. Tilapias have traditionally been important in capture fisheries, but the culture of these species has increased and now exceeds the wild catch. They have high nutritional value can and have become established outside their native range. (Wied)
