Different types of fish inhabit aquatic habitats with characteristics that allow them to swim, feed and reproduce. Fish species such as saltwater and freshwater fishes have different features that influence how they can be found, caught and consumed. Learning about the external parts of a fish may help you identify the fish you will encounter, as gills, fins and scales vary significantly in regards to their size, color and overall appearance. However, understanding the internal parts of a fish, which influence how it swims, breathes and eats, can assist you in locating and catching a fish in the first place.

Freshwater fishes can be found in streams, lakes, swamps and rivers, whereas saltwater fishes are typically found in sea shores, shallow seas, coral reefs, open oceans, ocean depths and estuarine habitats. To learn about how freshwater fish are different from saltwater fish in various ways, read the section below.

What are some types of saltwater fishes?

Saltwater fishes are able to survive in marine habitats such as seashores, estuaries, shallow seas, open oceans, ocean depths and coral reefs. Certain fish species spawn in freshwater but live most of their lifetimes in saltwater. However, other fishes of the world can only survive in saltwater. The following saltwater fish list includes some of the most regularly sought after types:

  • Amberjack – An amberjack is most identifiable by its large forked tail and long body, which is blue above and white below. Among its several variations, the most common amberjacks are the greater, lesser and yellowtail types, which can be found in the Atlantic or Pacific oceans.
  • Bass – Bass typically spawn in freshwater habitats and live most of their lifetimes in shallow coastal areas, lakes or ponds. Additionally, a bass can be classified as striped, white, yellow, rock, shadow or largemouth, which range in size and appearance. For instance, a striped bass can weigh as much as 125 pounds, whereas the average yellow bass weighs around half a pound.
  • Catfish – This fish species has several variations that range from herbivores to carnivorous. Additionally, despite being commonly associated with deep and/or slow-moving freshwater habitats, various types of catfish are found in saltwater, such as the hardhead catfish.
  • Grouper – Groupers typically have a robust body, which makes them slow swimmers. Moreover, this has a large mouth, which allows it to swallow prey rather than bite it off into pieces. However, certain types of grouper are considered endangered species, such as the gulf grouper.
  • Mahi-mahi – The mahi-mahi, also known as dolphinfish or dorado, is a vibrantly colored fish with a green and blue back and a yellow and white underside. Moreover, this saltwater fish is typically found in coastal areas or open oceans, and is considered a strong predator with high reproduction capabilities.
  • Red Snapper – A red snapper is a bottom-dwelling type of fish most commonly found in rocky habitats or coral reefs. Additionally, this fish typically has a red or pink pigmentation on its back and a white underside. In general, snappers feed on animals that have hard shells, such as crabs and sea urchins, and are able to crush the shells with their strong teeth.
  • Tuna – Tuna is among the very few species capable of maintaining a body temperature that is higher than the water temperature surrounding them. Thus, tunas are typically considered “warm-blooded” fish. Moreover, the most common types of tuna are the albacore, bluefin, bigeye, skipjack and yellowfin.

What are some types of freshwater fishes?

Freshwater fishes typically have an enhanced sense of touch in order to navigate dark or murky waters. Moreover, one of the most important external parts of a freshwater fish is its lateral line, which is used to detect pressure changes, orientate navigation and identify other surrounding animals. In general, there are several different types of freshwater fishes, but the following ones are the most commonly sought after by anglers:

  • Bass – Types of bass that are commonly found in lakes and ponds include yellow, largemouth and shadow basses.
  • Bluegill – A bluegill is a type of sunfish that is typically found in freshwater habitats and known for being a prolific breeder. Moreover, this freshwater fish is identifiable by its long and pointed pectoral fin and large black spot located at the rear of its dorsal fin.
  • Catfish – Catfish are typically found in deep and/or slow-moving freshwater habitats. This type of fish is easily identifiable by its long whisker-like barbel, which is used for orientation and the hunting of prey.
  • Salmon – Salmon are very popular freshwater fishes to eat in North America, and some species have cultural significance to Northern Pacific inhabitants. Thus, the most notable types of salmon are sockeye, pink, chinook, chum and coho. Despite spawning in rivers, these fish typically spend a considerable amount of time in open oceans.
  • Trout – Trout is a very popular fish in North America that has a varying appearance. For instance, a rainbow trout is distinguished by its caudal fin and black spots, and its color can vary from pink to red. Conversely, a cutthroat trout is most easily spotted by the red marks across its neck. Additionally, a brook trout may have slightly green lines and blue marks across its extension.
  • Walleye – A walleye, also known as glass-eye, marble-eye or pike-perch, is most identifiable by its large and reflective eyes. Additionally, this fish has a large mouth that is filled with canine teeth. Moreover, a walleye is considered the largest type of perch in North America, averaging 11 pounds.

What are the parts of a fish?

A fish anatomy is composed of various internal and external parts that sustain its ability to swim, breathe, feed and reproduce. Among the external parts of a fish, the most significant are:

  • Gills – Fish gills are external tissue surfaces that exchange oxygen and carbon dioxide. Thus, gills allow fish to extract respiratory gases from water. Additionally, the structure that opens and closes a gill aperture is called an operculum.
  • Fins – Most species of fish have an average of four paired fins and three single fins, all of which contribute to the swimming of a fish. Moreover, the four paired fins consist of the pectoral and pelvic fins. Conversely, the three single fins consist of the dorsal, anal and caudal fin. Among the parts of a fish that yield swimming motions, the caudal fin is considered the most important of all.
  • Scales – Scales serve as an added layer over the skin for fish to protect themselves. Additionally, scales can feel hard or smooth to the touch, depending on the size and nature of the fish. For instance, a salmon has relatively soft scales in comparison to a perch.

Internal parts of a fish are also important for the maintenance of a fish’s overall livelihood. A fish anatomy is internally composed of the:

  • Bladder.
  • Gonad.
  • Heart.
  • Intestine.
  • Kidney.
  • Liver.
  • Stomach.

What types of fish do you need a license to catch?

Fishing licenses are issued by states in an effort to gather information about anglers and help fund the maintenance and upkeep of public fishing areas. Thus, both saltwater and freshwater fishes require licenses in order to be caught. However, fishing regulations vary according to the following factors:

  • Environment – Regulations are significantly different in each state due to the particularities of each region. For instance, states such as California have generally strict daily bag limits for anglers, whereas states such as Florida only enforce strict rules for certain habitats. Additionally, a fishing license for saltwater environments is typically distinguished from freshwater fishing licenses.
  • Residency – Most states offer cheaper fishing licenses to state residents. Conversely, anglers visiting from out of state are typically charged a higher price to obtain licenses. For example, an annual fishing license in Ohio costs $19 for residents and $43.50 for nonresidents. Additionally, in states such as New York, resident children and seniors are exempt from the requirement of obtaining a fishing license.
  • Purpose – Fishing license rules vary depending on the purpose of an angler, which can be recreational or commercial. In general, obtaining a recreational license is cheaper and easier than the process to acquire a commercial license.
  • Location – Typically, if fishing takes place at a private property with the authorization of the property owner, the state does not interfere. However, certain conservation guidelines regarding fish and waters still apply, regardless of where the activity takes place.

What are the easiest types of fish to catch?

A generally easy fish to catch is a fish that is found in abundance, enticed by several types of bait and located near land. Among the most common freshwater species, the following are the easiest to catch:

  • Bluegill – Some of the easiest freshwater fish to catch are from the sunfish family, such as the bluegill. In general, these fish are enticed by nearly any kind of bait. Additionally, a bluegill is among the easiest freshwater fish to catch for kids due to its typically small body, which averages 12 inches in length and four and a half pounds.
  • Catfish – A catfish is also generally considered easy to catch. However, a catfish may be considered a less easy catch in comparison to a bluegill when fishing with kids, as catfish species tend to have larger and heavier bodies.

When it comes to easy to catch saltwater fish, each angler’s experience can be vastly different. For instance, fly-fishing enthusiasts are known for easily catching redfish and tarpon. On the other hand, surf casters typically have better chances of catching striped bass and bluefish.

What are the hardest types of fish to catch?

The most difficult fish to catch are those that require a particular skill and/or equipment in order to be caught. Watch out for these hard fish to catch during your next trip:

  • Bonefish – A bonefish tends to inhabit shallow waters and feed on crabs and worms located on the seabed. However, this fish can be incredibly sensitive to sounds and will disappear upon hearing any voice, bang or splash. Thus, it is generally tough to catch fishes that require anglers to be silent and still for an extended period of time.
  • Blue Marlin – Blue marlins are hard to catch saltwater fish due to their speed, endurance and strength. Thus, this fish can swim long distances and take high leaps over the water surface. Additionally, a blue marlin prefers open oceans and deep waters, making it a hard fish to spot.
  • Muskellunge – A muskellunge, also known as musky, is one of the hardest freshwater fish to catch due to its heavy weight and ability to hide.

What types of fish can break lines?

Fishes that break lines are generally heavy or strong fishes that are able to outweigh an angler’s line pull. In general, some fish are able to escape and go on to live normal lives, whereas other fish are unable to survive after being hooked. When identifying the common fish that break lines, keep the following species in mind:

  • Muskellunge – A muskellunge averages 66 pounds and six feet, thus being one of the heaviest and strongest fish to be caught in a freshwater habitat.
  • Pike – Despite not being as heavy as a muskellunge, a pike can still weigh as much as 53 pounds. Additionally, a pike’s large mouth is known for being its strongest asset to catching prey and breaking lines.

What types of fish can you catch in competitions?

Fishing competitions vary significantly according to the scale of the competition and the region where it is being held. However, fish tournaments generally award anglers who are able to catch the fish that is deemed the hardest to be caught.

The types of fish to catch in competitions should be the ones that award you the most points based on the criteria established by the organizers. Additionally, the International Game Fish Association (IGFA) publishes an annual World Record Game Fishes book that details the fishing records that were set during a given year. Thus, this publication can give you an idea of which species are perceived as more valuable in competitions.

What types of fish can be caught from shore?

Shore fish typically feed on animals such as crabs and urchins, which are located in shallow saltwater habitats. In general, shore fishing must take into consideration several elements, such as weather, the constant flux of waves and the rocky nature of certain coastlines. The following types of fish caught from shore are the most common:

  • Bluefish
  • Certain types of snappers
  • Certain types of trout
  • Flounder
  • Redfish
  • Sharks
  • Snook

What types of fish are poisonous?

Poisonous fish contain venomous toxins that can be very harmful to humans by means of a bite or sting. Otherwise, venomous fishes can also be harmful to a human’s digestive system once ingested. Thus, some of the deadliest fish species are:

  • Boxfish – Otherwise known as cowfish or trunkfish, this species’ body is encased in a box-like armor formed by rough scales. When threatened, a boxfish can expel toxins that poison the waters surrounding it.
  • Lionfish – A lionfish’s dorsal fin contains glands that are capable of excreting venom. Thus, this is an extremely poisonous fish that is typically found during night fishing.
  • Pufferfish – Pufferfish are most commonly known for being able to inflate, or puff, their bodies. This inflation is a pufferfish’s strategy to threaten enemies or make itself harder to swallow. Additionally, a pufferfish is considered one of the most poisonous fish in the ocean due to the tetrodotoxins contained in their organs.
  • Stingray – Certain types of stingrays can be extremely venomous to humans. Because these fish typically bury themselves under the seabed, they are often stepped on by casual divers.
  • Stonefish – A stonefish is named after its stone-like appearance and stillness. Moreover, a stonefish is generally considered one of the most venomous fishes in the entire ocean and has been known to kill humans who accidentally stumbled upon it.

What are the types of dangerous fish?

Dangerous fish do not necessarily have to be poisonous. Thus, some of the scariest fish are capable of harming humans without excreting any venom. Moreover, be mindful of the following extremely dangerous fish in the world:

  • Candiru – The candiru is a well-known fish found in the Amazon region. This species is able to enter the urethras of bathers and open its gills once deep inside. Moreover, this action can cause inflammation or hemorrhage in victims and possibly lead them to even more serious harm.
  • Electric eel – An electric eel produces electric discharges to stun its prey, which is typically another fish. However, an electric eel can also use these electric shocks to escape from humans who are perceived as predators. In general, these eels are commonly found in South American waters.
  • Great white shark – Made famous by the 1975 film “Jaws,” a great white shark is one of the ocean’s fiercest predators. Thus, great white sharks are dangerous fish that may attack swimmers even if left unprovoked.
  • Moray eel – Moray eels are fish with sharp teeth and large mouths that can seize their enemies and inflict deep wounds. Despite generally requiring some sort of provocation, moray eels can be vicious attackers when they feel threatened.

What types of fish can I catch in each season?

Fishing seasons play a significant role regarding the species that anglers are able to catch over time. Thus, consider the following types of fish by season of the year:

  • Spring – During spring, fishing enthusiasts can catch freshwater fishes such as bluegill, bass and specks. Additionally, saltwater species such as trout and mackerel are found in abundance.
  • Summer – Summertime offers the optimal weather for anglers to catch saltwater fishes such as tuna, trout, marlin and mackerel. Moreover, freshwater species such as bass and catfish are commonly caught during summer.
  • Fall – As summer ends and fall begins, the variety of saltwater and freshwater fishes begins to decline. However, fishing during early fall still allows anglers to catch most of the fish that were available during the summer.
  • Winter – Winter is the weakest among the fishing seasons when it comes to fishing opportunities. However, species such as stripers and speaks are typically found year-round, including winter months.

What types of fish can be used as bait?

Bait fish are very small species of fish that can be used to attract larger predatory game fish. Thus, the following types of bait fish are the most common among saltwater fishes:

  • Anchovies
  • Ballyhoo
  • Gudgeon
  • Ladyfish
  • Scad

Besides the common bait fish that come from saltwater, there are also freshwater species that are used to attract game fish. Therefore, be mindful of the following freshwater bait fish:

  • Carp
  • Minnow
  • Sculpin
  • Shads
  • Suckers

What types of fish can I eat?

Many people around the world see fish as food, making these species some of the most significant sources of animal protein in the world. Thus, there are several types of fish to eat, such as:

  • Amberjack – The amberjack’s soft pink flesh has a sweet flavor. Moreover, this is a small and tasty fish that contains a firm texture and has a fat content that is similar to a salmon.
  • Bass – A bass is most commonly grilled, baked, broiled or pan-fried. When cooked with its skin, the bass tends to take on a strong fish flavor. Conversely, this fish presents a more delicate taste when cooked without its skin.
  • Bluegill – A bluegill has a buttery meat that is accompanied by small but hard bones. This fish can be grilled, fried, baked or broiled.
  • Catfish – A catfish is commonly cut into small fillets and fried. However, it can also be boiled, baked, broiled, used in stews or consumed as a fish cake.
  • Grouper – The grouper has a lean meat with a mild taste. Additionally, its meat is firm enough to be prepared on a grill. However, because a grouper is considered a tasty fish with a flavor comparable to a halibut, it is a relatively expensive fish.
  • Mahi-mahi – A mahi-mahi is a very popular dish in Hawaii that is typically served in fillets. Because it has a thick skin, the mahi-mahi is more suitable to being grilled than several other fish.
  • Red Snapper – The red snapper has a distinctive mild flavor that is hardly drowned by added seasoning. Because it is a small fish, a red snapper can be pan-fried, which is a great alternative to grilling.
  • Salmon – A salmon is among the most popular types of fish to eat due to its flavorful meat and easy to remove bones. Moreover, a salmon can have a crispy taste if pan-fried with its skin. Conversely, this fish can be poached after the removal of its skin.
  • Trout – A trout can be grilled, fried, broiled, baked or used in stews.
  • Tuna – The tuna has a very strong fish flavor in comparison to other types of In general, this fish is consumed raw or grilled. When grilled, a tuna changes its color, which serves as an indicator of its readiness.
  • Walleye – A walleye’s meat is typically white and possesses a strong, sweet taste. Moreover, consumers enjoy the fact that walleyes have fewer bones than most freshwater fish. Additionally, these fish are small enough to be pan-fried.

What types of fish are the healthiest to eat?

Not all edible fishes can be used on healthy fish recipes. Thus, certain fish are considered flavorful but are not entirely nourishing. On the other hand, some of the healthiest fish to eat include:

  • Mackerel – A mackerel is high in protein and omega-fatty acids. Thus, it is a flavorful fish that also yields significant health benefits. Because the mackerel can repopulate easily, it is also a fish that can be caught in large quantities.
  • Salmon – The salmon is included in some of the most popular healthy fish recipes around the world. Additionally, the Atlantic salmon is particularly common in North America, where it is generally caught through sustainable methods.
  • Sardines – Sardines are very high in vitamin D and omega-fatty acids. Thus, they are considered some of the best fish to eat when it comes to health benefits. Additionally, their small sizes typically yield smaller portions.
  • Trout – A trout has a high level of omega-fatty acids, which are beneficial to reducing memory loss, preventing inflammations and lowering triglyceride levels. Additionally, trout are typically high in protein and low in fat.
  • Tuna – Tuna has high levels of protein. Additionally, this fish serves as a great alternative to individuals who enjoy meat with a strong taste but want to avoid red meat. However, despite being one of the healthiest fish to eat, tuna should not be consumed regularly or in excess.

What types of fish can I sell?

Selling fish is generally prohibited to anglers who have recreational licenses. However, if appropriately licensed, a commercial angler may find it easy to sell fish that have a high demand in the region where he or she lives. Thus, the availability and demand of fish vary depending on each location, which may also determine how much fish can be sold for. Additionally, live fish for sale can be found in pet stores, but anglers are not generally allowed to sell fish to these retailers.

What is the difference between white fish and pink fish?

The difference between white and pink fish typically has to do with a protein called myoglobin. In general, the main purpose of this protein is to store oxygen for muscles. However, this protein also determines the color of fish meat. To learn what determines the color of fish flesh, consider the following factors:

  • White fish – A fish that has rested or remained inactive for most of its life typically has white meat. The inactivity in a white fish causes it to not require a high level of oxygen to be regularly stored in its body.
  • Pink fish – Pink, orange or red meat is typically an indicator that the fish has had to swim long distances and required high levels of oxygen in order to survive. Thus, pink fish require a regular use of myoglobin, which causes their flesh to change colors.