One of the most common questions I get asked each day is, “What’s the difference between Fingerlings and Fry?” Now, there are a ton of different sites out there that’ll call anything a fingerling just to make more money. But what makes a tilapia fingerling truly a “Fingerling”? Well, it’s not about size or age. A true Tilapia fingerling has scales, working side fins, and has grown their sexual organs. Most of the time, they’re about 1 inch long and weigh 1 gram, typically around 25 -30 days old. But remember, it’s their development that turns them into fingerlings from fry.
Lets talk about scales on tilapia fingerlings. Tilapia have scales, which are thin, flexible and smooth edged. Scales grow constantly throughout their lives. Scales first show up shortly after the fry are hatched, starting at the caudal fin (tail) and lateral line. This forms the base of the scale which gets covered by the outer layer of skin. The scales will then grow outward, adding new layers of collagen and bony material. These layers are as visible and concentric rings on the scale, similar to tree rings, which can be used to tell us how old the tilapia are. Once the Tilapia are fully scaled, they are considered to be fingerlings.
How do you know if the side fins are operating properly? Well, it is quite simple. They are located on each side on the tilapia and are used for steering. By flexing the fins, the “Fingerlings” will be able to turn sideways or even upside down. They can also utilize their side fins as breaks. Tilapia need these functions for survival. When they are still considered fry, it’s because they are incapable of moving around well enough in any conditions other than a safe small tank.
During the first several weeks of life, tilapia fry are without gender, they do not have any visible sexual organs. Their genetic makeup holds the key to their future gender. Genes will decide whether they develop into males or females. Around the 3-week mark (25-30 days), the tilapia fry start to develop their genders. You cannot visually determine their gender until the tilapia mature into adolescent, which is usually about 4 months old and 3-4 inches long, and then they can be distinguished by examination.
In Summary, we have discussed the difference between tilapia fingerlings and fry, which are not determined by size or age, but by their development. We have described characteristics of fingerlings, such as scales, and how they grow. Side fins are crucial to the movement and even survival rate difference between Fingerlings and Fry. Lastly, we talked about sexual organs, and how the gender development of tilapia fry happens, which occurs around 3 weeks of age.