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
Tequila splitfin
Zoogoneticus tequila
This is a little Mexican goodeid livebearer where the males get that awesome orange crescent in the tail and will spar and posture like tiny cichlids. They do best in a planted tank where they can duck into roots and stems, and once they're settled they'll breed steadily and you'll see lots of interesting social behavior.
Tetracamphilius pectinatus
Tetracamphilius pectinatus
A tiny African loach catfish with chocolate-and-cream banding, Tetracamphilius pectinatus tops out around an inch and hides in and around fine sand. It has a neat serrated pectoral spine without a locking mechanism, and behaves like other sand-loving catlets, so a soft sandy bed and gentle flow really brings it out. It is rare in the hobby, so think of it as a fun niche project rather than a first catfish.
Thracian shemaya
Alburnus istanbulensis
Endemic to Turkey, occurring in coastal streams of Thrace (Marmara to SW Black Sea drainages) and Lake Sapanca; a small, silvery pelagic cyprinid (bleak/shemaya type).
Threadfin rainbowfish
Iriatherina werneri
This is the little rainbowfish with the ridiculous, delicate streamers - especially on the males, who love to posture and "dance" at each other in a calm planted tank. Keep them in a real group and they get way braver, cruising the top/midwater under floaters and showing off those thread-like fins. They are peaceful, but they really hate fast flow and rough tankmates that shred fins or outcompete them at feeding time.
Threadfin seasnail
Rhodichthys regina
This is a deep-sea snailfish from the Arctic and far North Atlantic - not an aquarium fish at all, but a really neat oddball from way down in the cold and dark. It lives on or right above the bottom and cruises around picking off crustaceans, and in life it can be bright red which is wild for something from 1000+ meters down.
Three-lined aphyosemion (three-lined killifish)
Aphyosemion trilineatus
Aphyosemion trilineatus is a small West African killifish from Cameroon that does best in a calm, plant-heavy setup with gentle filtration and a tight lid (they can jump). Males top out around 5.1 cm and look way flashier than females, and like most Aphyosemion they are happiest when you keep things on the soft, slightly acidic side and do changes slowly.
Three-spined stickleback
Gasterosteus aculeatus
The three-spined stickleback is a small, armored fish with bony lateral plates and three prominent dorsal spines used for defense. Males become striking in breeding condition, often developing a red throat/belly and intensified coloration while they build and guard nests. It is highly active and behaviorally interesting, but can be nippy and territorial, especially during breeding.
Three-spot righteye flounder
Samariscus triocellatus
This is a tiny little Indo-Pacific flounder that lives right on sand and rubble around reefs, and it can be ridiculously hard to spot once it settles in. The coolest part is the three eye-like spots (ocelli) and the way it kind of creeps along the bottom hunting small benthic critters at dusk.
Tibetan garra
Garra tibetana
A rugged little hill-stream grazer from the cold, fast water of Tibet's Yarlung Tsangpo. It uses a sucker-like mouth to cling to rocks and rasp biofilm, and it really shines in a high-oxygen, high-flow setup. Think cool temps, clean water, and lots of hard surfaces to pick at.
Tidepool snailfish
Liparis florae
This is a little coldwater snailfish that literally lives in tide pools on exposed Pacific coast rock, hiding under algae and stones when the surf is crashing. It has that classic soft, tadpole-ish snailfish look and a suction-disk belly, so it can cling in place instead of getting tossed around. Super cool fish biologically, but it is absolutely not a normal home-aquarium species unless youre set up for a chilled marine system.
Tidewater mojarra
Eucinostomus harengulus
Tidewater mojarras are those sleek, silvery little estuary fish with the crazy-protrusible mouth they use to pick and vacuum tiny critters out of sand and mud. They show up around seagrass, mangroves, and shallow muddy flats, and theyll even push up into lower-salinity creeks and tributaries when conditions are right.
Tiger dwarf goby
Mugilogobius tigrinus
This is a tiny little mangrove goby with crisp black banding that really does look tiger-striped when it colors up. In a calm brackish setup with sand and lots of little hides, the males will posture and flare at each other like they own the place, which is half the fun of keeping them.