Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 541 species
Xenochromis hecqui (often listed without a stable aquarium common name; avoid confusing with Hecq's shell-dweller)
Xenochromis hecqui
Xenochromis hecqui is a Lake Tanganyika cichlid associated with deep-water habitats (reported captures to ~100 m). It is a specialized scale-eater (historically placed in Perissodus as P. hecqui).
Xingu spotted catfish
Zungaropsis multimaculatus
This is a super obscure pimelodid catfish from Brazil's Rio Xingu, and it is basically a mystery fish in the hobby - you almost never see real, confirmed aquarium care info for it. Taxonomy-wise it is even considered "uncertain" and has been suggested as a possible synonym of the much larger jau catfish (Zungaro zungaro), so I would treat anything sold under this name with extra caution and verify the ID hard before you plan a tank around it.
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.
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.
Yellowcheek carp
Elopichthys bambusa
Massive, torpedo-shaped predator from East Asia that cruises big rivers and lakes and inhales smaller fish like a vacuum. Juveniles look harmless, but this thing grows into a legit river monster, so think pond-scale water and serious filtration if you ever see one for sale.
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.
Yellowfin gambusia
Gambusia alvarezi
Tiny spring-dwellers from Chihuahua, these little livebearers zip around the surface and the males flash buttery-yellow fins when they are feeling bold. They thrive in warm, hard, alkaline water and do best as a lively species group, since they can pester slower or long-finned fish. If you like active, always-hungry top swimmers with personality, this one is a fun project fish.
Yellowfin madtom
Noturus flavipinnis
Yellowfin madtoms are tiny, secretive native catfish from the upper Tennessee River system, and they act exactly like little river goblins - hiding under flat rocks all day and cruising around at night. The cool part is the male guards the eggs under cover, and they really appreciate clean, well-oxygenated current and a rock-and-leaf-litter kind of setup.
Yellow kribensis
Wallaceochromis humilis
A large ‘krib’ from West Africa (Guinea to Liberia), Wallaceochromis humilis is the biggest member of its group, forming pairs and defending caves for spawning. In soft to medium, slightly acidic–neutral water it becomes strongly territorial around a chosen cave and exhibits classic biparental cave-spawning behaviour.