Fish That Start With R
Browse all aquarium fish species with common names beginning with "R". Each profile includes care requirements, water parameters, tank size recommendations, and compatibility information for freshwater, marine, and brackish species.
Welcome to the species index for the letter 'R', where you will find a unique variety of aquarium fish. One highlight is the White-cheeked goby (Rhinogobius duospilus), a fascinating species known for its adaptability and charm. While this letter features a limited selection, it showcases intriguing options for both community aquariums and specialized habitats.
Raconda
Raconda russeliana
A pelagic-neritic pristigasterid (longfin herring) occurring in marine coastal waters and often in estuaries; elongate, compressed body with a sharp keel of scutes and a very long anal fin; feeds mainly on prawns (especially Acetes) and also copepods.
Radiated puffer
Takifugu radiatus
Takifugu radiatus is a temperate, demersal marine puffer from the Northwest Pacific (Kyushu, Japan to the East China Sea) reaching about 20 cm standard length.
Rainford's goby
Koumansetta rainfordi
This little goby is a tiny striped hoverer that spends its day scooting between rock crevices and pecking at the sand and micro-stuff on the rocks. In the right setup its a super chill, reef-safe character fish, but the big trick is keeping it well-fed in a mature tank so it doesnt slowly waste away.
Ram cichlid (German blue ram / butterfly cichlid)
Mikrogeophagus ramirezi
Rams are tiny little cichlids with big-time attitude (in the cutest way) and insane sparkle-those blues, yellows, and that black face bar really pop when they're happy. They're also one of the warmer-water dwarf cichlids, and they'll show off pair behavior and even spawn on flat stones if you keep the tank clean and calm.
Randall’s shrimp goby
Amblyeleotris randalli
Randall's shrimp goby is that little candy-cane striped goby you'll see parked at the entrance of a burrow, doing sentry duty like it's getting paid for it. The really fun part is the partnership with a pistol shrimp-goby keeps watch, shrimp does the digging, and they basically run a tiny construction site in your sand bed. Give it a cozy sand area and a few rubble bits and it'll settle in and start acting like it owns the place (in the cutest way).
Rapanui flagtail
Kuhlia nutabunda
Kuhlia nutabunda is an endemic flagtail from Easter Island (Rapa Nui) in the Southeast Pacific, recorded from exposed rocky shores and large tide pools. It is a silvery fish that reaches about 24.2 cm and is adapted to active swimming in nearshore habitats.
Rattail (grenadier)
Ventrifossa rhipidodorsalis
Deep-water marine rattail (family Macrouridae) from the Western Pacific (reported from southern Japan, northeastern Taiwan, the South China Sea, and the Philippines) occurring around ~500–535 m depth. Notable ID features include a relatively large ventral luminous organ (photophore) between the pelvic-fin bases and a mostly dark first dorsal fin with pale/white areas basally and distally. This is a deep-sea species and is not an appropriate/realistic home-aquarium fish.
Rausu sculpin
Icelus sekii
A tiny cold-water sculpin from Hokkaido, Japan, it tucks into rock cracks along the Shiretoko coast and stays near the bottom. Males grow little blade-like flaps on the first dorsal fin, which is a wild detail you only notice up close. Super niche in the hobby, and it absolutely needs chilled, full-strength seawater.
Red Neon Blue-eye (Luminatus Blue-eye)
Pseudomugil luminatus
This little blue-eye is basically a tiny fireworks show-males flash electric blue eyes and red/orange fins and spend half the day showing off to each other. Keep them in a nice-sized group and you'll see constant "dancing" and fin-flaring in the open water, especially over dark substrate and plants.
Redback dragonet
Synchiropus tudorjonesi
This is a tiny deepwater scooter dragonet from Indonesia/Papua New Guinea that spends its whole day glued to the bottom, pecking at micro-crustaceans in the sand and rubble. The cool part is the male's little "flag" dorsal fin display and that rich red banding - but it is absolutely the kind of fish that does best in a mature, pod-rich reef where it can hunt constantly. If you like watching behavior more than a fish "doing laps," this one is a total vibe.
Redbanded seabream
Pagrus auriga
This is a large sparid from the eastern Atlantic and Mediterranean that lives over rocky/mixed bottoms and feeds on hard-shelled invertebrates (crustaceans, bivalves) and cephalopods. Due to its eventual size, it is generally considered suitable only for very large display/public aquaria rather than typical home systems.
Redblotch razorfish
Iniistius twistii
Iniistius twistii is a razor-thin little wrasse that lives over sandy patches next to reefs, and it will absolutely vanish into the sand when it spooks - its whole body shape is built for that trick. It tops out around 20 cm and is usually seen alone or in loose groups in the wild, so in a tank it does best as a single showpiece fish with plenty of open sand to cruise over.
Red-lipped Wallaceochromis
Wallaceochromis rubrolabiatus
This is a tiny West African river cichlid that stays around 2.5 inches, and the adults get that really neat reddish-purple color around the lips that gives it its name. In a tank it acts more like a shy little cave cichlid than a bruiser - give it sand, leaf litter, and a couple tight caves and it settles in and starts doing the whole pair-bond and territory routine.
Redlips Darter
Etheostoma maydeni
This is a tiny Cumberland River drainage darter with a really neat telltale feature: the red pigment right on the lips. Its whole vibe is hanging out on the bottom in calmer pools along big creeks and rivers, tucked around boulders and woody cover.
Redrump blenny
Xenomedea rhodopyga
This is a tiny, bottom-hugging blenny from the Gulf of California that lives around rocky, weedy reef and tidepool habitat. The cool bit is how it spends its time tucked into rocks and algae, picking at little meaty critters, and it can show a neat pinkish body with darker bars and that red area near the rear that the name is calling out.
Redsaddled snake eel
Quassiremus nothochir
This is a big, sand-loving snake eel from the eastern Pacific that spends a lot of its time tucked into the bottom with just the head showing. The cream-and-tan body with those dark-edged reddish saddle marks is the giveaway, and it is built for backing into the sand fast when it feels spooked. Cool animal, but realistically more of a public-aquarium fish than a home-tank project because of size and escape-artist vibes.
Redspotted snakehead
Channa andrao
Channa andrao is one of those "how is this real?" dwarf snakeheads-tiny, super colorful, and way more personable than you'd expect from a predator. It's a mouthbrooder, hangs near the surface a lot (air-breather), and it's happiest in a plant-choked, hidey-hole setup with a tight-fitting lid because, yep, it can jump.
Regan's dwarf pike cichlid
Wallaciia regani
This is one of the smaller pike cichlids, with that sleek, torpedo shape and the attitude to match - super fun to watch when it cruises and "stalks" around wood and leaf litter. It's a cave-spawning little predator that will absolutely snack on tiny fish, but compared to big pikes its size it can be surprisingly manageable if you give it space and lots of cover.
Renny's ricefish
Oryzias hadiatyae
Endemic to Lake Masapi (Malili Lakes system), Central Sulawesi, Indonesia; reported from shallow shoreline habitats and associated with shoreline root/vegetation structure. Diagnostic morphology includes a snout concavity (not unique within the genus).
Reticulate clingfish
Tomicodon lavettsmithi
This is a tiny little clingfish from the NW Caribbean that spends its life plastered to rubble and shells in super-shallow water. It has that classic clingfish suction disc, so it can hang on in surge and pick at small prey right on the bottom. Not really a "community tank" fish - its whole vibe is cryptic, rock-hugging micro-predator in a saltwater nano.
Reticulate round ray
Urotrygon reticulata
A small, demersal round ray endemic to the Gulf of Panama that inhabits shallow sandy bottoms. Like other stingrays it has a venomous tail spine, and it is assessed as Critically Endangered (IUCN, assessed 24 Jan 2020), so it should not be targeted for aquarium trade.
Reticulated hillstream loach
Sewellia lineolata
This is the little "stingray-shaped" loach that parks itself on rocks and glass like it's magnetized, then cruises around in the current like a tiny river skate. Give it cool, super-oxygenated, fast-moving water and lots of smooth stones with biofilm, and it'll spend all day grazing and doing hilarious little dominance shuffles with its own kind.
Riggenbach's ctenopoma
Ctenopoma riggenbachi
Ctenopoma riggenbachi is a small African anabantid (labyrinth fish) in the genus Ctenopoma. Like other labyrinth fishes it can breathe atmospheric air via a labyrinth organ; provide cover and ensure access to warm, humid air above the water with a secure lid.
Rikuzen flounder
Dexistes rikuzenius
Dexistes rikuzenius is a demersal right-eyed flounder (Pleuronectidae) from the NW Pacific (Japan/Korea), living on sandy/muddy bottoms at ~42–200 m and feeding on benthic invertebrates.