Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 423 species
Skipper halfbeak
Hyporhamphus snyderi
This is a sleek little open-water halfbeak from the Tropical Eastern Pacific, with that classic underbite beak and a silvery body with dark lines along the back. Its whole vibe is cruising the surface in a school, so if you ever tried keeping one you would be planning around swimming room and a seriously escape-proof lid.
Slender abyssal cusk-eel
Sciadonus pedicellaris
Sciadonus pedicellaris is a rare deep-sea livebearing brotula (family Bythitidae) with a very slender body, small deep-set eyes, and loose translucent skin; it occurs at bathyal to abyssal depths and is not suited to typical aquarium care. The name refers to the stalk-like (“pedicellate”) pectoral-fin base.
Slender grenadier
Ventrifossa teres
Ventrifossa teres is a deep-slope rattail (grenadier) from the southeast Pacific, built like a skinny little torpedo with that classic big-head-tapering-tail grenadier look. Its whole deal is living way down in the dark (hundreds of meters deep), so its "aquarium care" is basically a public-aquarium-only kind of fish, not a home tank species.
Slender lightfish
Vinciguerria attenuata
This is a tiny deep-water lightfish that spends its life way out in the ocean twilight zone, cruising up and down the water column each day. It has rows of photophores (little light organs) on the underside, plus those slightly tubular eyes that are built for looking up in the dark. Super cool biology, but realistically its not an aquarium fish at all.
Slender sunfish
Ranzania laevis
This is the little, weird cousin of the big ocean sunfishes - kind of an oval, squished-looking pelagic fish that literally loses the normal tail fin as it grows and ends up with a clavus instead. It cruises open water in warm-temperate to tropical seas, usually solo, picking off zooplankton and other small drifting prey.
Slime skate
Dipturus pullopunctatus
This is a South African deep-water skate that lives way out on the shelf/upper slope, not something that belongs anywhere near a home aquarium. It gets big (around 1.3 m max reported) and is a bottom-dwelling predator, so it needs cold, high-oxygen marine conditions and huge space to swim and rest properly.
Small lanternfish
Diaphus roei
Diaphus roei is a tiny deep-sea lanternfish (a myctophid) that lives out in open ocean water and uses rows of photophores (light organs) for camouflage and communication. It is not really an aquarium species - it is a mesopelagic fish adapted to cold, high-pressure life and many individuals migrate upward at night.
Smalleye conger
Gnathophis microps
Gnathophis microps is a deepwater marine conger eel from off Western Australia, and its little eyes make a lot of sense once you realize it lives way down around 200-320 m. Cool fish on paper, but its deep, cold-ish habitat means it is basically not a realistic home-aquarium species (think public-aquarium level life support).
Small-mouth croaker
Johnius hypostoma
Johnius hypostoma is a small marine croaker (family Sciaenidae) reported from the eastern Indian Ocean (Sumatra, Indonesia) and listed by FishBase as Indo-Pacific in distribution; it is primarily a fisheries species rather than an aquarium-trade fish.
Smith's witch eel
Facciolella smithi
This is a deep-water witch eel (duckbill eel) that was only described recently, from off the Kerala coast in the Arabian Sea. It's a long, ribbon-bodied, soft-sediment bottom-dweller with that weird duckbill snout and small deep-sea eyes - super cool, but not something you can realistically keep in a normal home aquarium.
Smooth bandfish
Owstonia psilos
Owstonia psilos is a deepwater bandfish from off northwestern Australia - long, ribbon-bodied, reddish, and it has that neat black blotch up front on the dorsal fin. Its home turf is way down around 360-446 m, so its "cool factor" is real, but its natural lifestyle is totally a deep-reef, low-light thing rather than a normal home-aquarium fish.
Snake eel
Cirrhimuraena cheilopogon
A shy sand-burrower from Papua New Guinea, this snake eel spends most of the day hidden with just its head poking out like a little periscope. It is a specialist predator and a serious escape artist, so it needs deep sand and a rock-solid lid if anyone ever attempts it in a tank.