Sutchi catfish is one of the important freshwater fish commodities in Indonesia. In 2011, Sutchi catfish production reached 229,267 tons or around 16.1% of total world production. Sutchi catfish are famous for its high prices, fast growth rates, easy cultivation, and delicious taste.
Unfortunately, Sucthi catfish are not always available at all times because the spawning pattern only occurs once a year (October to April), so availability is limited in meeting market demand. One solution is the application of cryopreservation.
Cryopreservation is the preservation of cells and tissues using liquid nitrogen at a temperature of -196 ° C for long periods without reducing biological functions. Cryopreservation is used to store spermatozoa in optimal conditions so that it can be used at any time for artificial spawning. Cryopreservation has been used in the world of biotechnology to solve various problems, such as fish transportation, limited parent fish, gametes storage, and also spermatozoa.
The main factor that influences the success of cryopreservation is the extender material. Extenders are needed for dilution of fish spermatozoa before cryopreservation and are generally designed to fit the physiochemical composition of seminal fish plasma. The most important function of an extender is to protect cells from the formation of ice crystals during freezing and thawing, so they are not damaged quickly.
Honey, a natural extender for improving sperm quality of Siamese catfish
Who does not like honey? Honey is one of the natural ingredients that have many benefits. Honey has many important nutrients, such as minerals and vitamins, which are obtained from flower nectar collected by bees. Interestingly, honey can also be used to improve the quality of spermatozoa in sutchi catfish in the process of cryopreservation because it contains 41% fructose and 35% glucose which can be used as an energy source for spermatozoa during the formation of ice crystals.
Furthermore, honey also contains salt ions which are used to maintain cells during the cryopreservation process, so they are not easily damaged. Some enzymes are also found in honey, such as the diastase, invertase, glucose oxidase, peroxidase, and lipase. All these enzymes are useful for the body’s metabolic processes.
Method and Results
The first thing to do in this study is sperm collection. Sperm of sutchi catfish from IBAT Mojokerto weigh 2 kg with ripe gonads were collected through stripping (pressing on the urogenital part of the fish manually / by hand). The obtained sperm is mixed with NaCl, honey, and glycerol for cryopreservation.
The cryopreservation process is done by inserting a mixture of sperm into the mini straw and deep-freezing it for 15 minutes. Then, the mini straw is transferred to the sperm storage with a temperature of -196 o C for 30 days. After 30 days, the sperm is thawed at 30 o C for 30 seconds. The sperm is then tested for its motility, viability, abnormality, hatchability, and fertilization of the eggs to determine the effect of honey on sperm quality.
The results showed that the addition of honey in the cryopreservation process could improve the quality of Sutchi catfish spermatozoa. Judging from motility, viability, and hatchability, egg fertilization rates and abnormalities of spermatozoa, 0.6% addition of honey can increase the success rate of cryopreservation in spermatozoa.
Interestingly, this study also showed that excessive honey could also reduce the quality of sperm during the cryopreservation process. It happens because too much honey can have a toxic effect on spermatozoa. This toxicity occurs in the changing osmotic pressure in the diluent, which causes damage to the plasma membrane cells in the spermatozoa.
The study concluded that 0.6% of honey could be used in the cryopreservation process to support the availability of Sutchi catfish seeds and accelerate the progress of Indonesian fisheries. (*)
Author: Muhammad Browijoyo Santanumurti
Details of research available at:
Fanni, NA, Santanumurti, MB, Suprayogi, TW, Bendryman, SS (2019). Quality enhancement of cryopreserved spermatozoa of sutchi catfish (Pangasianodon hypophthalmus) with addition. Iraqi Journal of Veterinary Sciences, 32 (2), 231-236.
https://vetmedmosul.com/?_action=article&au=400430&_au=Suprayogi,+T.+w.
