Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 654 species
Blackfin pygmy skate
Fenestraja atripinna
Fenestraja atripinna is a small, deepwater (upper slope) bathydemersal pygmy skate from the Western Central Atlantic (e.g., Bahamas/Cuba/Florida region) reported from ~310–870 m (often deeper than ~440 m). Biology is poorly known; like other skates it is oviparous (egg cases).
Blackfin slatey
Diagramma melanacrum
This is a big Indo-West Pacific sweetlips/grunt that cruises reefs and hangs in caves, and it gets that cool yellow-and-silver look sprinkled with dark spots plus the really obvious black on the lower tail and the pelvic/anal fins. Juveniles show up in murkier estuary and silty reef areas, then the adults shift deeper and often sit in small groups until they go hunting at night. In aquariums its size is the whole story - it is a public-aquarium kind of fish once grown.
Blackflash ribbonfish
Trachipterus jacksonensis
This is one of those true open-ocean ribbonfish - long, silvery, and super weird-looking in the best way, with a tall red dorsal fin when its in good shape. Its a deepwater, roaming marine species that occasionally turns up nearshore or even in estuaries, but its not something you can realistically keep in a home aquarium.
Black-Lined Loach
Ambastaia nigrolineata
Ambastaia nigrolineata is a little river-loach with two clean black stripes that turns into a really cool barred pattern as it grows. Keep it in a proper gang and you will see all the fun loach stuff - shadowing, clicking, and the occasional goofy "greying out" dominance squabble. It likes clean, well-oxygenated water and lots of nooks to cram into.
Black loach
Eonemachilus niger
This is a tiny, deep-velvet-black stone loach from Yunnan, China, with the odd detail that the tail fin is not black like the rest of the fish. Its wild range is extremely limited, so its aquarium presence is basically nil - this is more of a conservation-interest species than something you will actually see for sale.
Black morpho tetra
Poecilocharax weitzmani
Poecilocharax weitzmani is one of those tiny blackwater oddballs that acts more like a little darter than a typical tetra - it hangs low, darts between cover, and the males can get pretty showy with fin-flares. The really cool part is they are cave breeders with male brood care, which is not what most people expect from a small characin. Give them very soft, acidic, super-clean water and lots of leaf litter and hidey holes, and they settle in and start showing their best colors.
Black Neon Tetra
Hyphessobrycon herbertaxelrodi
Black neons are one of those little tetras that look kinda understated until the light hits them-then that bright stripe pops and they shimmer when the school turns together. They're super chill, always cruising mid-water, and they make a tank feel "alive" without being hectic. If you keep a nice group, they get bolder and you'll see way more of their personality.
Black redhorse
Moxostoma duquesnei
Black redhorse are sleek river suckers that really come alive in clean, fast-flowing runs and riffles - they are basically a living indicator that the water quality is good. They cruise the bottom in little groups and pick at insect larvae and tiny crustaceans, and in spring the males can show pink and dark striping when they are in spawning mode.
Black River madtom
Noturus maydeni
Noturus maydeni is a tiny little riffle catfish from the Ozarks that lives tucked into cool, clear, fast water over gravel and rocks. Its claim to fame is being super range-limited (Black and St. Francis river drainages), and like other madtoms its pectoral spines can give you a nasty poke if you grab it wrong.
Black Skirt Tetra (Black Widow Tetra)
Gymnocorymbus ternetzi
Black skirts are those little "suit-and-tie" tetras with the dark bands and flowing fins that look way fancier than they should for how tough they are. They're super active midwater fish, and when you keep a proper group they do that tight, zippy schooling thing that makes the whole tank feel alive. Just give them enough buddies and finny tankmates they won't be tempted to nip.
Blackspot razorfish
Iniistius dea
This is one of the coolest "knife-bodied" wrasses - it hangs over open sand and, when it gets spooked or wants to sleep, it literally torpedoes straight into the sand. Give it a deep, fine sand bed and it will act totally different (and way more natural) than a typical rock-hugging reef wrasse. Adults are usually shy and cruisy with tankmates, but they are not forgiving about rough handling or sketchy setups.
Blacktip rasbora
Rasbora dorsinotata
This is a slim little Southeast Asian rasbora with a clean dark lateral stripe and a neat black tip on the dorsal fin. In a group it gets way more confident and you will see that tight midwater schooling behavior, especially in a planted tank with some flow.