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
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 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.
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.
Blueband goby
Valenciennea strigata
This is that classic gold/yellow-headed sand-sifting goby with the little blue cheek stripe-always busy, always rearranging your sandbed. In a reef tank it'll spend the day taking mouthfuls of sand, filtering out tiny critters/foods, then "snowing" clean sand back out, and it'll usually claim a burrow area (often as a pair in the wild). It's super cool behavior-wise, but you really do need a mature tank with a proper sandbed and a lid because they can jump.
Blue dorsal Borneo sucker
Gastromyzon ctenocephalus
This is one of the little Borneo hillstream loaches that scoots around like a tiny living suction cup, spending most of its day grazing on biofilm off smooth rocks. The cool part is the fin patterning - the caudal fin has bold pale-blue striping, and they do those quick little territorial "flaring" displays with each other without usually doing real damage. Keep it in a high-oxygen, high-flow setup and it just settles in and does its thing.
Blue Green Chromis (Green Chromis)
Chromis viridis
Blue Green Chromis are those shimmery little green-blue darts you'll see zipping around the top of a reef tank, always looking like they're catching the light just right. They're super fun in a group because they hover and cruise together, but they've got a bit of a "pecking order" thing going on if the tank's tight or the group's too small.
Blue gularis
Fundulopanchax sjostedti
This is the big, flashy West African killifish with the ridiculous triple-point tail and electric blue-green body covered in red spotting. Males can be real attitude machines with each other, but if you give them room, cover, and a tight lid, they make an awesome centerpiece fish that will absolutely demolish live and frozen foods.
Blueline demoiselle
Chrysiptera caeruleolineata
This is one of those damsels that looks like it should be a little terror, but its vibe is way more chill than the classic blue devils. You get that bright blue body with a clean line detail, and it spends a lot of time zipping low around the rockwork like it owns a tiny little neighborhood.
Blue skate
Notoraja azurea
Gorgeous fish, but strictly a look-dont-keep species: a metallic-blue deepwater skate from southern Australia that glides along the continental slope 765-1440 m down in about 3-6 C water. It tops out around 65 cm and occasionally turns up in deep-sea trawls, but conditions that cold and pressurized put it way outside home-aquarium territory. ([fishbase.se](https://fishbase.se/summary/SpeciesSummary.php?id=63978))