Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 563 species
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.
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.
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.
River garfish
Zenarchopterus xiphophorus
This is a slim, surface-hugging halfbeak from the mouth of a river in Sumatra, and it has that classic "half-beak" look where the lower jaw sticks out. Its biology is way more "wild fish" than "pet shop fish" - think open-water cruising up top and spooking easily if the tank is busy or uncovered.
River garfish (halfbeak)
Zenarchopterus clarus
Zenarchopterus clarus is a true halfbeak - that long lower jaw is built for picking stuff off the surface. Its a tropical, surface-cruising fish from the Western Central Pacific (Thailand and Borneo), and it reproduces via internal fertilization with ovoviviparous young.
Robust assfish
Bassozetus robustus
Bassozetus robustus (robust assfish) is a deep-sea marine cusk-eel (Ophidiidae) with a circumglobal distribution in tropical to temperate waters. It occurs at great depths (reported to >1000 m and to over 4000 m). Reproduction is oviparous and has been described as producing buoyant/pelagic eggs (reported as occurring in a gelatinous egg mass in some references). It is not an aquarium species, as its habitat conditions (depth/pressure and deep-sea environment) cannot be replicated in typical home systems.
Rosen's Hybrid Platy
Xiphophorus roseni
Xiphophorus roseni is a Mexican livebearer that shows up in the hobby mostly as a "weird/obscure Xiphophorus" rather than a mainstream platy or swordtail. The big twist is that a lot of sources treat it as a natural hybrid form (often discussed as variatus x couchianus), so it is more of a "locality oddball" than a clearly distinct, widely traded species.
Rosy Tetra
Hyphessobrycon bentosi
Rosy tetras are those little coppery-pink characins that look kinda "glowy" when the light hits them right, and the males can get nice extended fins when they're settled in. Keep a small group and you'll see them do their little pecking-order sparring and flashing-nothing scary, just classic tetra drama that looks awesome in a planted tank.