Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 563 species
Spothead lantern fish
Diaphus metopoclampus
This is a deep-sea lanternfish with rows of photophores (little light organs) that it uses down in the dark, and it does that classic up-at-night, down-by-day vertical migration. Super cool animal, but its whole lifestyle is built around cold, high-pressure midwater life, so its not really an aquarium fish in any normal sense.
Spotted blue-eye
Pseudomugil gertrudae
This little blue-eye is one of those fish that looks "cute" at first glance, then you notice the electric-blue eyes and the males flashing those spotted fins at each other all day. They're happiest in a planted, kind of shady tank with gentle flow, where they'll cruise in a loose group and do constant mini courtship displays.
Spotted Mandarin Dragonet (Picturesque/Psychedelic Mandarin)
Synchiropus picturatus
This little dragonet is basically a living piece of reef art-chunky fins, goofy "hovering" swimming, and those crazy psychedelic spots that look painted on. The big thing with them is they're constant pickers, cruising rockwork all day hunting tiny critters, so they're happiest in a mature tank with tons of pods (or a keeper who's ready to meet them halfway on food). If you like chill fish with tons of personality that don't bother anyone, mandarin time is hard to beat.
Spotted scat
Scatophagus argus
Spotted scats are those chunky, disc-shaped brackish fish with the peppered "polka dot" pattern that changes a lot as they grow. They cruise around in groups, eat basically anything you offer, and they're tough as nails-just don't fall into the super common trap of keeping them in straight freshwater long-term.
Spotted spikefish
Hollardia meadi
Hollardia meadi is a tiny deepwater spikefish from the western Atlantic with a super cool pink-and-spot pattern and those lockable spines that make the whole family look like little armored oddballs. Its a rocky-bottom, reef-associated fish that lives way deeper than typical reef tank temps, so its basically a no-go for normal home aquariums unless youre set up for chilled deepwater marine.
Spottedfin sand cichlid
Xenotilapia spiloptera
Xenotilapia spilopterus is a Lake Tanganyika sand-sifter that spends its day cruising over open sand, scooping mouthfuls and filtering out tasty bits like insect larvae. They are at their best in a small group where you get to watch the schooling vibe, then pairs peel off to mouthbrood when they are ready. Give them fine sand and stable, hard alkaline water and they really settle in.
Starhead topminnow
Fundulus dispar
Fundulus dispar is a small native U.S. topminnow associated with vegetated standing waters and quiet pools/backwaters. It is known for reflective "star" spots on the head, and FishBase notes it can be difficult to maintain in aquaria long-term.
Stellate tadpole-goby
Benthophilus stellatus
This is one of those weird little bottom-huggers from the Black Sea/Azov/Caspian region - big head, narrow tail, and a body covered in tiny bony bumps. It spends its time on mud and sand in cooler water, picking at small invertebrates, and it is way more of a coldwater/brackish oddball than a typical tropical aquarium goby.
Stream catfish
Pseudobagarius macronemus
This is a tiny little akysid stream catfish from eastern Sumatra that spends its time down low, poking around the bottom (benthopelagic). The weird part with this one is the name - a lot of sources treat it as Pseudobagarius macronema, and you will see it sold or listed under either spelling.
Striped clingfish
Derilissus vittiger
This is a tiny little Western Atlantic clingfish that lives down on deeper reefs and clings to hard stuff with its belly suction disk. Its whole vibe is cryptic and hidey, more like a micro-predator you would spot while peering into reef rockwork than a fish that cruises around the tank. Honestly, it is super cool biologically, but it is not a realistic home-aquarium species for most people.
Striped goby
Gobius vittatus
A small Mediterranean marine goby found mainly on coralligenous/rocky bottoms (often ~15-50+ m), known for its pale body with a dark lateral stripe; it is shy and retreats quickly to crevices. In aquaria it is a cool-water Mediterranean species rather than a typical tropical reef goby.
Stripe-face Calamiana
Eugnathogobius mindora
This is a teeny-tiny estuary goby that hangs out on the bottom in mangrove and tidal creek habitats. Its little striped face and speckly fins are the main "wow" factor, but the real charm is watching it perch and scoot around like a mini dragon. Not something you see in the aquarium trade much, and it is easy to mis-ID as other small brackish gobies.