Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 665 species
rattail
Kuronezumia macronema
A deep-sea rattail from the Philippines and the South China Sea, this fish cruises 600-800 m down where the water is cold and dark. It has that classic whiptail body and even a small light organ, picking off tiny crustaceans or scavenging what it finds. Super neat to learn about, but it is a look-only species for public aquariums, not something to keep at home.
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.
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.
Red Neon 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.
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.
Redseam dwarf cichlid
Apistogramma gephyra
A. gephyra is a tiny Rio Negro dwarf cichlid with crisp red seams on the fins and a sleek, agassizii-style body. It sticks close to leaf litter and small caves, where the female guards eggs and fry while the male patrols. Give it soft, acidic water and you get tons of color and personality from a very small fish.
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.