The letter ‘R’ reveals a remarkable range of aquatic life, from the brilliantly colored Rainbow Trout of pristine mountain streams to the ancient Rays that glide silently over the ocean floor. This category is home to some of the most sought-after sport fish, like the powerful Redfish, and some of the most vibrant aquarium dwellers, like the shoaling Rasbora.
From the clever Remora with its suction-cup head to the aggressive Rockfish guarding its territory, this article explores the diverse and radiant fish that start with R.
Common Fish Names That Start With R
This section features the fish that have become famous under their common ‘R’ names.
Rainbow Trout (Oncorhynchus mykiss)
Habitat: Cold, clear freshwater streams, rivers, and lakes native to North America; now introduced worldwide.
Size: Typically 1 to 5 pounds, but can grow much larger.
Conservation Status: Least Concern (LC) by the IUCN, as it is one of the most widely farmed and stocked fish globally.
The Rainbow Trout is one of the most famous freshwater fish in the world, prized by anglers for its strong fight and beautiful appearance. Its name comes from its most stunning feature: a broad, iridescent pink or red stripe that runs along its lateral line. This stripe, along with its black spotted body, shimmers with different colors depending on the light, making it a truly dazzling sight.
This species is incredibly adaptable. While many live their entire lives in freshwater, some populations are anadromous, meaning they are born in freshwater, migrate to the ocean to mature, and then return to freshwater to spawn. When in the ocean, they are known as Steelhead and take on a more silvery appearance. As opportunistic predators, they feed on a wide variety of prey, from insects and crustaceans to smaller fish.
Red Drum (Sciaenops ocellatus)
Habitat: Coastal waters, estuaries, and brackish marshes in the Atlantic Ocean and Gulf of Mexico.
Size: Can grow over 4 feet long and weigh more than 90 pounds.
Conservation Status: Least Concern (LC) by the IUCN.
Also known as the Redfish, the Red Drum is a powerful and highly sought-after sport fish. Its most distinctive feature is one or more large, black eyespots located on its tail. This unique marking is a form of defensive mimicry, thought to confuse predators by tricking them into attacking the less vital tail instead of the head. The fish’s body has a beautiful coppery red or bronze coloration that gives it its common name.
The name “Red Drum” comes from the unique drumming or croaking sound the males make during spawning season. This sound is not vocal but is produced by vibrating specialized muscles against their swim bladder, which acts as an amplification chamber. As aggressive predators, they use their powerful jaws to crush crabs, shrimp, and small fish, making them a dominant force in their estuarine habitats.
Ray (Order Batoidea)
Habitat: Found in oceans worldwide, from shallow coastal waters to the deep sea; some species live in freshwater.
Size: Varies immensely, from a few inches across to over 20 feet for the Giant Manta Ray.
Conservation Status: Varies greatly; many species are common, but some, like the Giant Manta Ray, are listed as Endangered.
Rays are a huge and diverse group of fish defined by their close evolutionary relationship to sharks. Their most recognizable feature is a highly flattened body and enormous, wing-like pectoral fins that are fused to their head. They “fly” through the water by flapping these powerful fins, creating a graceful and silent form of propulsion. Like sharks, they have a cartilaginous skeleton instead of true bones.
Many rays, like the famous Stingray, possess a sharp, venomous barb on their tail that is used purely for self defense. Others, like the Manta Ray, are gentle giants that are completely harmless and filter feed on tiny plankton. Most rays are bottom dwellers, using their flattened shape to hide in the sand and hunt for mollusks and crustaceans, which they crush with powerful, plate like teeth.
Scientific Fish Names That Start With R
The fish that have become famous under their scientific ‘R’ name are mentioned in this section.
Rhinecanthus (Triggerfish)
Habitat: Coral reefs in the tropical Indo-Pacific region.
Size: Typically 8 to 12 inches long.
Conservation Status: Most species are listed as Least Concern (LC).
The genus Rhinecanthus contains some of the most recognizable and feisty fish on the reef. Their name comes from the Greek for “file snout,” but their most famous feature is their unique defensive mechanism. Their first dorsal fin is a large, thick spine that can be locked firmly into an erect position by a second, smaller spine—the “trigger.” When threatened, a Triggerfish will dive into a crevice and lock its spine, making it impossible for a predator to pull it out.
These fish are highly intelligent and notoriously territorial, known to aggressively charge at and bite divers who venture too close to their nests. They possess an incredibly powerful jaw and strong teeth, which they use to crush hard shelled prey like sea urchins, crabs, and mollusks. They are also known for their unique swimming style, propelling themselves primarily by undulating their dorsal and anal fins.
Rasbora (Rasboras)
Habitat: Freshwater streams, ponds, and swamps throughout South and Southeast Asia.
Size: Most are small, typically 1 to 4 inches long.
Conservation Status: Most species are Least Concern (LC), but some are threatened by habitat loss.
The genus Rasbora is a cornerstone of the aquarium hobby, containing dozens of small, peaceful, and active species. Their most important behavioral trait is their strong shoaling instinct. They are most comfortable and display their best colors when kept in large groups, where they move as a coordinated unit. This behavior is a natural defense against predation, as the flashing, moving mass of fish makes it difficult for a predator to target a single individual.
In an aquarium setting, they are often used as “dither fish.” Their constant, confident swimming in the open water signals to shyer, more timid fish (like dwarf cichlids) that the environment is safe, encouraging them to come out of hiding. As micropredators, they have small mouths and feed on tiny insects, crustaceans, and zooplankton.
Other Fish Species That Start with R
- Rabbitfish (Siganidae)
- Raccoon Butterfly fish (Chaetodon lunula)
- Rainbow Shark (Epalzeorhynchos frenatus)
- Ratfish (Chimaeriformes)
- Rattail (Macrouridae)
- Razorback sucker (Xyrauchen texanus)
- Red Devil Cichlid (Amphilophus labiatus)
- Red Lionfish (Pterois volitans)
- Red Tailed Shark (Epalzeorhynchos bicolor)
- Red-eye Tetra (Moenkhausia sanctaefilomenae)
- Redfin Perch (Perca fluviatilis)
- Redhorse Sucker (Moxostoma spp.)
- Remora (Echeneidae)
- Ribbon Eel (Rhinomuraena quaesita)
- Ribbonfish (Trachipteridae)
- Ricefish (Oryzias spp.)
- Roach (Rutilus rutilus)
- Rock Bass (Ambloplites rupestris)
- Rock Beauty (Holacanthus tricolor)
- Rock Cod (Epinephelus spp.)
- Rockfish (Sebastes spp.)
- Rockling (Gaidropsarus spp.)
- Rockweed Gunnel (Pholis spp.)
- Roosterfish (Nematistius pectoralis)
- Rosefish (Sebastes norvegicus)
- Rosy Barb (Pethia conchonius)
- Rough Scad (Trachurus lathami)
- Rough Sculpin (Cottus spp.)
- Roughy (Trachichthyidae)
- Round Goby (Neogobius melanostomus)
- Round Stingray (Urobatis halleri)
- Roundhead (Pseudaphritis urvillii)
- Royal Gramma (Gramma loreto)
- Ruby Snapper (Etelis carbunculus)
- Rudd (Scardinius erythrophthalmus)
- Ruffe (Gymnocephalus cernua)
- Russian Bitterling (Rhodeus sericeus amarus)
- Russian Sturgeon (Acipenser gueldenstaedtii)
- Red Grouper (Epinephelus morio)
- Red Pike Cichlid (Crenicichla spp.)
- Red Snapper (Lutjanus campechanus)
- Red Velvetfish (Gnathanacanthus goetzeei)
- Red Zebra Cichlid (Maylandia estherae)
- Redear Sunfish (Lepomis microlophus)
- Redlip Blenny (Ophioblennius atlanticus)
- Redmouth Whalefish (Rondeletia bicolor)
- Redspotted Sunfish (Lepomis miniatus)
- Redtooth Triggerfish (Odonus niger)
- Red Salmon (Oncorhynchus nerka)
- Red Rainbowfish (Glossolepis incisus)
- Requiem Shark (Carcharhinidae)
- Ribbonfish (family Trachipteridae)
- Ribbon Sawtail Fish (Idiacanthus fasciola)
- Rio Grande Perch (Herichthys cyanoguttatus)
- River Loach (Balitoridae)
- River Stingray (Potamotrygonidae)
- Royal Gramma (Gramma loreto)
FAQs
How does a Remora stick to sharks and other large animals?
The Remora has a truly unique adaptation: its first dorsal fin has evolved into a powerful suction disc on the top of its head. This oval-shaped organ has slat-like structures that the remora can raise or lower to create powerful suction, allowing it to attach firmly to a host animal without causing it any harm.
Why are so many different fish called “Rockfish”?
“Rockfish” is a common name given to dozens of different species in the genus Sebastes. It’s a descriptive name that perfectly captures their lifestyle: they are spiny, bottom-dwelling fish that almost always live in and around rocky outcrops and reefs for protection.
What gives the Roosterfish its name?
The Roosterfish gets its name from its most spectacular feature: seven extremely long spines that make up its dorsal fin. When the fish is excited or chasing prey, it can raise these spines high into the air, looking just like a rooster’s comb, making it one of the most unique and recognizable game fish in the world.
Which fish with R changes its gender and its color?
Ribbon eels are protandric hermaphrodites, meaning they start life as males and can later change into females. This change is accompanied by a dramatic color shift: juveniles are black, mature males are brilliant electric blue, and large, terminal females are vibrant yellow.
