Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 275 species
Southern Smiler
Opistognathus jacksoniensis
Australian jawfish found over sand/rubble near reefs where it constructs a burrow. Field references report it from ~20–30 m and often 30–50 m depths, suggesting it may be a deeper/temperate-affiliated species; aquarium care information appears limited compared to commonly kept tropical jawfishes. If attempted, provide deep mixed substrate with rubble/shell for burrow building and a tightly covered aquarium due to jumping risk.
Southwell's pipefish
Siokunichthys southwelli
A tiny tropical marine pipefish from Sri Lanka and the Philippines. Like many syngnathids, it is a slow, deliberate feeder that may require abundant small live foods and low-competition tankmates in captivity.
Spikefin goby
Discordipinna griessingeri
This is that tiny little reef goby with the crazy tall first dorsal spines and orange striping that makes it look like a living piece of candy. It spends a lot of time tucked into coral rubble and little crevices, then darts out to grab food, so giving it real hiding spots is the whole game. Also, it gets mixed up in the trade with the wrong name sometimes, so its worth double-checking the label before you buy.
Spinaker grenadier
Ventrifossa nigrodorsalis
This is a deep-sea rattail (grenadier) from the continental slope - long, tapering body, chin barbel, and that cool dark blotch on the first dorsal fin. Its natural home is hundreds of meters down, so its needs are basically the opposite of a typical home aquarium: cold, dark, very high pressure habitat, and a life built around picking off fish and squid in the deep.
Spine-tailed round ray
Urotrygon caudispinosus
This is a neat little round ray from Peruvian coastal waters that hangs out on sandy bottoms and noses around for crunchy snacks. It likes to bury itself with just the eyes showing, and it does best in cooler saltwater than most reef fish. Awesome to watch, but it really belongs with keepers who can dedicate a huge, chilled tank and meaty foods.
Spiny grenadier
Coelorinchus parallelus
A deep-sea rattail with a long whip tail and spiky head ridges, it cruises 600-1000 m down around Japan, the East China Sea, and the Philippines. It even has a tiny light organ near the belly, which is wild to see in photos. Super cool fish to read about, but not one to keep at home since it wants near-freezing saltwater and deep-ocean conditions.
Spiny lanternfish
Dasyscopelus spinosus
This is a small oceanic lanternfish (family Myctophidae) found in tropical and subtropical waters of the Atlantic, Indian, and Pacific oceans. It is high-oceanic and mesopelagic/bathypelagic, becoming near-surface at night (nyctoepipelagic). Adults reach about 9 cm standard length and have spined ctenoid scales at the anal-fin base.
Spotfin cardinal
Jaydia queketti
This is a small marine cardinalfish from the western Indian Ocean with a really recognizable black eyespot on the first dorsal fin and a pattern of brownish spots that line up into messy stripes. It is a nocturnal zooplankton feeder that hides in rocky areas by day, then comes out after lights-out, and males mouthbrood the eggs.
Spotfin cusk
Neobythites macrops
Neobythites macrops is a deep-slope cusk-eel from the Indo-West Pacific that hangs out way down on the shelf and upper slope. It is one of those long, eel-ish bottom fish with little eyespots (ocelli) on the dorsal fin - cool camouflage/decoy stuff for life in dim water. Not really an aquarium fish in any normal sense, since it is a true deepwater marine 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 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 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.