Common Fish Names Beginning With O

1. Ocean sunfish

The ocean sunfish, also known as the mola, is one of the heaviest known bony fishes in the world. They can grow up to 10 feet long and weigh over 2,000 pounds. They are found in temperate and tropical oceans around the world.

2. Opah

The opah, also known as moonfish or sunfish, is a deep-sea fish that is prized for its meat. They have a unique circular body shape and are known for their reddish-orange flesh. They are found in oceans around the world but are most commonly found in the Pacific.

3. Oilfish

The oilfish, also known as escolar, is a deep-sea fish that is often mistaken for tuna or mackerel. It has a high oil content, which can cause digestive issues in some people. They are found in tropical and temperate waters around the world.

4. Orange roughy

The orange roughy is a deep-sea fish that is prized for its delicate flavor and texture. They are found in the waters around New Zealand and Australia and are known for their long lifespan, with some individuals living up to 150 years.

5. Oscar

The Oscar is a freshwater fish that is popular among aquarium hobbyists. They are native to South America and are known for their vibrant colors and aggressive behavior.

Freshwater fish that starts with O

• Oakleaf fish (Pteronotropis euryzonus): The oakleaf fish is a small freshwater fish that is native to the southeastern United States. It has a distinctive oakleaf-shaped spot on its side, which gives it its name.

• Ocellated knifefish (Sternopygus macrurus): The ocellated knife fish is a freshwater fish that is found in South America. It has a long, eel-like body and is known for its ability to generate an electrical field to help it navigate and communicate with other fish.

• Old world bichir (Polypterus senegalus): The old world bichir is a primitive freshwater fish that is native to Africa. It has a distinctive armored appearance and can breathe air through a modified swim bladder, allowing it to survive in oxygen-poor environments.

• Olive cichlid (Satanoperca jurupari): The olive cichlid is a freshwater fish that is found in South America. It is known for its olive-green coloration and is popular among aquarium hobbyists.

• Orange chromide (Etroplus maculatus): The orange chromide is a freshwater fish that is found in India and Sri Lanka. It has a bright orange coloration and is popular among aquarium hobbyists.

• Oscar (Astronotus ocellatus): The oscar is a popular freshwater fish that is native to South America. It is known for its aggressive behavior and is often kept in large aquariums.

Tropical fish that starts with O

• Ocellaris clownfish (Amphiprion ocellaris): The ocellaris clownfish, also known as the false percula clownfish, is a popular tropical fish that is found in the Indo-Pacific region. It is known for its bright orange coloration and distinctive white stripes.

• Odessa barb (Pethia padamya): The Odessa barb is a tropical freshwater fish that is native to Southeast Asia. It has a distinctive, iridescent blue-green coloration and is popular among aquarium hobbyists.

• Oranda goldfish (Carassius auratus): The oranda goldfish is a popular tropical fish that is native to China. It is known for its distinctive, round body shape and the large, bumpy growth on its head.

• Otocinclus catfish (Otocinclus affinis): The otocinclus catfish is a small tropical fish that is native to South America. It is known for its ability to eat algae and is popular among aquarium hobbyists as a natural way to control algae growth.

• Otohime (Chromis nitida): The otohime is a tropical marine fish that is found in the Indo-Pacific region. It has a bright blue coloration and is popular among aquarium hobbyists.

• Orange chromide (Etroplus maculatus): The orange chromide is a tropical freshwater fish that is found in India and Sri Lanka. It has a bright orange coloration and is popular among aquarium hobbyists.

Saltwater fish that starts with O

• Ocean surgeonfish (Acanthurus bahianus): The ocean surgeonfish is a saltwater fish that is found in the Western Atlantic. It is known for its striking blue coloration and sharp spines on its tail, which it uses for protection.

• Ocellaris angelfish (Centropyge ocellatus): The ocellaris angelfish is a popular saltwater fish that is found in the Indo-Pacific region. It is known for its bright orange coloration and blue ring around its eyes.

• Orangespine unicornfish (Naso lituratus): The orange spine unicornfish is a saltwater fish that is found in the Pacific Ocean. It is known for its distinctive unicorn-like horn on its forehead and bright orange coloration.

• Orange-striped triggerfish (Balistapus undulatus): The orange-striped triggerfish is a saltwater fish that is found in the Indo-Pacific region. It is known for its vibrant orange coloration and the distinctive, wavy stripes on its body.

• Oyster blenny (Omobranchus punctatus): The oyster blenny is a saltwater fish that is found in the Western Pacific Ocean. It is known for its ability to live in oyster shells and other small crevices.

• Oyster toadfish (Opsanus tau): The oyster toadfish is a saltwater fish that is found along the eastern coast of North America. It is known for its distinctive appearance, with a broad head and a large mouth full of sharp teeth.