Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 424 species
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.
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.
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.
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.