Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 556 species
Wicker-work sole
Zebrias craticulus
This is a small striped sole from northern Australia that basically lives life glued to the sand, doing that classic flatfish thing where it vanishes the second it settles in. Those tight cross-bands that run right onto the fins are the whole vibe - it really does look like wicker-work up close. Not an aquarium fish for most people, but it is a super cool species if you are into oddball bottom-dwellers.
Williaminae glass fish
Parachela williaminae
Parachela williaminae is one of those sleek, silvery river "glass fish" types from the Mekong/Chao Phraya systems - built for current and open-water cruising. It is not a tiny rasbora-style fish at all (it can hit around 12 cm/4.7 in), so think "active river minnow" and plan space and flow accordingly.
Wouter's pygmygoby
Trimma woutsi
Trimma woutsi is a true pygmy reef goby - maxing out around an inch - that spends its life perched close to the rockwork in shallow reef zones. Its tiny size is the whole game here: it is perfect for a peaceful nano reef where it can pick at micro-foods all day and not get bullied off meals.
Wry snailfish
Careproctus staufferi
Careproctus staufferi is a deepwater snailfish (family Liparidae) described from the central Aleutian Islands, Alaska (North Pacific) in 2016. The original description notes an overall red/pale coloration and a distinct lateral yellow slash across the dorsal part of the abdomen and posterior. It is a bathydemersal deep-sea species and is not a typical aquarium fish.
Wu's goby
Wuhanlinigobius polylepis
This is a tiny mangrove-and-mudflat goby from the western Pacific that spends its time on the bottom, often in really shallow brackish areas. The cool part is how "muddy" its lifestyle is - it gets found in puddles on exposed mud at low tide and can even be partly buried, so it appreciates a soft substrate and lots of cover if you ever try one.
Xingyun Lake Yunnan loach
Yunnanilus analis
Yunnanilus analis is a little bottom-hugging stone loach from China, originally described from Xingyun Lake in Yunnan. Its species name is literally about the anal fin - it has six branched anal-fin rays, which is a weirdly specific ID feature. This one is not an aquarium regular, so if you ever actually see true Y. analis for sale, it would be a pretty unusual find.
Xiuren torrent catfish
Xiurenbagrus xiurenensis
This is a tiny little Chinese torrent catfish from the Pearl River drainage - think bottom-hugging, hidey fish that wants clean, oxygen-rich water. It stays around 10 cm/4 inches and is more of a nighttime rock-and-crevice cruiser than a "front glass" pet. If you set it up like a cool, fast stream with lots of cover, it should act way more confident.
Xixi high-plateau loach
Triplophysa xiqiensis
Triplophysa xiqiensis is a little Chinese stone loach from cool, flowing hill-stream type water, and it lives right on the bottom picking around the substrate. It is the kind of fish that spends its day cruising and perching on rocks, so it is way more about behavior and habitat vibes than flashy color.
X-ray tetra
Pristella maxillaris
This is that little see-through tetra where you can kinda make out the spine inside the body, and then it tops it off with those sharp black/yellow/white fin markings and a reddish tail. Super chill schooling fish, and it's one of those rare tetras that doesn't freak out if your water isn't "perfect Amazon blackwater" 24/7.
Yaluwak armored catfish
Yaluwak primus
This is a super rare, fast-water loricariid from the upper Ireng River system in Guyana - the kind of fish most hobbyists will only ever see in a scientific paper. Its neat party trick (for an armored catfish) is a big cluster of evertible cheek odontodes and it even lacks a normal adipose fin, replacing it with a low ridge of plates.
Yangi loach
Yunnanilus yangi
Yunnanilus yangi is a small freshwater stone loach (Nemacheilidae) described in 2024 from Yunnan, China (upper Pearl River/Nanpanjiang drainage). Species-specific aquarium guidance is limited in the literature; husbandry is typically inferred from related small Yunnanilus/Micronemacheilus-type loaches, emphasizing clean, well-oxygenated water, cover, and small foods.
Yellow enteromis
Enteromius cerinus
Enteromius cerinus is a tiny Congo Basin barb that stays under 2 inches and shows a neat pattern of three dark flank spots with a darker midline. It was described in 2024, so it is basically unheard of in the aquarium trade right now, but it reads like a classic little schooling river barb if it ever shows up.