A baby fish is commonly called a fry. The term “fry” refers to the early developmental stage of fish after they hatch from their eggs. As the fry grow and develop further, they may be referred to using different terms based on their specific stage of development or the species they belong to.

The general names for fish in the early stages of development are larva, fry, and fingerling.

Keep in mind that the terms used to describe fish in developmental stages can vary depending on the species and context.

The Stages of Juvenile Fish Growth

While “fry” is a commonly used term for baby fish, there are specific designations used for the early stages of fish development.

Here are some of the general terms used to describe immature fish:

1. Larva: This is the earliest stage of fish development after hatching from the eggs. Larvae are typically characterized by their distinct body shape and feeding habits.
2. Fry: Fry is the term used for young fish that have reached a stage where they can actively feed on their own. They are usually larger than larvae and have more developed body features.
3. Fingerling: Fingerling is a term used to describe a juvenile fish that has grown beyond the fry stage but is still relatively small. It generally refers to fish that have developed finger-like proportions.
4. Juvenile: Juvenile fish are young individuals that have developed further from the fingerling stage. They are typically larger and have more advanced characteristics compared to fry or fingerlings, but they are not yet sexually mature.
5. Subadult: Subadult fish are in an intermediate stage of development between juveniles and adults. They are approaching maturity but may still exhibit some juvenile features.
6. Adult: Adult fish have reached sexual maturity and have fully developed reproductive organs. They have acquired the physical characteristics of their species and are capable of reproducing.

Larvae or hatchlings

You can refer to fish in the early stages of development after hatching as “larvae” or “hatchlings.” 

Larvae or hatchlings are typically characterized by their small size, distinct body shapes and often have specific adaptations for feeding and survival in their respective environments. Depending on the species, as they grow and develop further, they may progress into the fry or juvenile stages.

The larval fish look very different from their parent. Their axial spines have just begun to develop, and they still have an Embryonic median fin fold, which will disappear at the end of the larval stage.

Later in the larval process, the fish begins to feed itself from picoplankton, zooplankton, or a mixture of the two.

The larval stage can vary in duration; in carps, it lasts one or two days; in sardines, one to two weeks and eels have a larval phase of several months.

The Fry Stage

“Fry” is a term used to describe young fish that have reached a stage where they can actively feed on their own. 

Fry are typically larger and more developed than larvae and may exhibit more recognizable features of the adult fish species they belong to. They have usually absorbed their yolk sac and developed their swim bladder, so they can swim and find their own food. 

The term “fry” is commonly used in the context of fish farming, fisheries, and aquaculture to refer to young fish at this specific stage of development.

The Fingerling Stage

“Fingerling” is a term used to describe juvenile fish that have grown beyond the fry stage but are still relatively small in size. The name “fingerling” originates from the notion that these fish are approximately the size of a finger.

Fingerlings have developed scales, fins, and a more recognizable body shape compared to fry. They are less dependent and have better swimming abilities. Fingerling fish are often sought after for stocking ponds, lakes, or aquaculture operations as they have a higher chance of survival compared to smaller, more vulnerable fry.

The specific size at which a fish is considered a fingerling can vary depending on the species.

The Juvenile Stage

The juvenile fish stage refers to a phase in the life cycle of fish that occurs after the larval or fry stage and before reaching adulthood.

Juvenile fish have grown and developed beyond the early stages and exhibit characteristics similar to adult fish, although they are not yet sexually mature. 

During this stage, juvenile fish continue to grow, refine their feeding strategies, and develop their swimming abilities. They may also undergo habitat transitions, adapt to changing environmental conditions, and face various challenges and predators.

The duration of the juvenile stage varies widely among fish species, ranging from weeks to several years. Ultimately, the juvenile stage prepares the fish for the next phase of its life cycle, which is the subadult and adult stages.

What is a Group of Baby Fish Called?

A group of baby fish is commonly called a “school” or “shoal” of fish. These terms describe a gathering or aggregation of fish, including both adult and young individuals.

In the case of baby fish, they often stay together in a school or shoal for protection and to increase their chances of survival against predators. The collective behavior of swimming in a group provides safety in numbers and enhances their ability to find food and navigate their environment.

So, while there isn’t a specific term exclusively for a group of baby fish, they generally join the larger groups of fish called schools or shoals.

What is a Juvenile Salmon Called?

A juvenile salmon is commonly referred to as a “smolt.” The term “smolt” specifically applies to salmon during a specific stage of their life cycle when they undergo physiological changes and prepare to migrate from freshwater to the ocean.

Smolts are typically characterized by their silver coloration and increased tolerance to saltwater. This transformation enables them to survive and adapt to the marine environment.

During this stage, smolts undergo physical and internal changes that allow them to migrate and live in saltwater for a period before returning to freshwater as adults for spawning.

Baby Fish Names Based on Species

Eels 

Baby eels are commonly referred to as “elvers.” Elvers are the early life stage of eels and are characterized by their slender, transparent bodies. They are typically small in size and exhibit adaptations for their unique life cycle.

Elvers undergo a long migration from the ocean to freshwater rivers, where they grow and develop into adult eels. During this migration, elvers face various challenges and obstacles, including navigating upstream and overcoming barriers such as dams or waterfalls.

Elvers are highly valued in some culinary traditions and are caught for consumption in certain regions.

Sharks

Baby sharks are often referred to as “pups” or “shark pups.” Shark pups are typically miniature versions of adult sharks but are smaller in size and still developing.

They exhibit similar body structures and characteristics as adult sharks, including their distinct shape and toothy jaws.

Some shark species give birth to live young, while others lay fish eggs that hatch outside the mother’s body. The term “pups” is used regardless of the method of reproduction for baby sharks.

Whales

Baby whales are referred to as “calves.” The term “calf” is used to describe the young offspring of whales, similar to how “calf” is used for the young of other large mammals.

Whale calves are born live; their size and appearance can vary depending on the species. They are generally smaller than mature adult whales but still considerably large compared to many other marine mammals.

These are just a few examples, and each fish species may have its own specific term for their young. It’s always a good idea to research the particular species you are interested in to learn the specific name for their baby fish.

To sum up

Different species of fish have specific names for their baby or young offspring. However, The general names for fish in the early stages of development are larva, fry, and fingerling.