Fish, as almost everyone knows, are almost always hatched from eggs that range from almost microscopic, about a millimeter in size, to the size of a small orange pea in the case of some salmon eggs. In most cases, the female fish deposits eggs in a semi-protected location, where they continue to develop for from two to seven days, or up to two weeks depending on the species, before hatching.
Hatchlings
Fish larvae that first emerge from their fertilized egg sacs are known as hatchlings. They are not yet recognizable as fish and haven’t yet developed the ability to feed themselves. At this point of their life cycle, they are sustained by the “yolk” that is typically still attached for a period of two to five days. Even under the best of conditions, most hatchlings do not survive to maturity.
Fry
Once the nutrition from the yolk is consumed, the young fish have a basic ability to feed themselves. Even though they have not yet developed all the characteristics of mature fish, within seven to 10 days they begin to develop fins and will soon resemble miniature versions of their species. At this stage of development, they are known as “fry.” Once the fry start to feed on their own, they can be introduced into stocking ponds -- sometimes by the truckload -- and left to fend for themselves.
Fingerlings
After approximately 30 to 60 days, the small fry will have grown sufficiently to be classified as fingerlings. Depending on the breed, a fingerling can measure from an inch or two up to five or six inches in length, can swim efficiently using its fins and has begun to develop scales. Most commercial breeders sell fingerlings, because they have a greater chance of survival than fry, although they are correspondingly more expensive as well.
Catchables
Sometimes, pond owners prefer to stock more mature fish in advance of the fishing season, in preparation for a tournament, or simply to have a better chance of snagging a fish for dinner. Typically, most breeds of fish can be expected to gain weight and grow about three inches a year until they reach maturity. Even smaller fish can be challenging for a dedicated angler and catch-and-release fishing is often as popular as catching and keeping.
About those Eggs
Roe, as the fish eggs are called, is harvested and prized by many different cultures, particularly Oriental, Asian and Northern European. Caviar is a term applied only to the roe from the Sturgeon family. Although there are many different types of caviar, no other fish roe can claim that name. All roe is highly nutritious, known for its beneficial levels of Vitamin D and Omega-3 fatty acids, as well as for concentrated levels of Vitamin B-12. Bright salmon eggs are also used as bait, particularly for trout.
