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
Maltzan's goby
Wheelerigobius maltzani
This is a tiny West African coastal goby that lives right down on the bottom in warm, shallow inshore water. Its big appeal is the "little predator" vibe - it perches, scoots, and hugs structure like a classic goby, but its real-world habitat is marine shoreline rather than a typical freshwater community setup.
Mandarinfish
Synchiropus splendidus
This is the classic mandarin dragonet-the little reef crawler that looks like someone hand-painted neon blue and orange squiggles onto a fish. It spends basically all day pecking at live rock for tiny pods, and at dusk you can sometimes catch the pair-spawning "rise" if you keep a bonded male/female. Absolutely reef-safe, but it's one of those fish that does amazing only when the tank is truly mature and full of microfauna.
Marlin-spike grenadier
Nezumia bairdii
Marlin-spike grenadier is a deep-sea rat-tail with a long whip tail and big eyes, cruising over soft bottoms on the Atlantic slope. You see it from Newfoundland down to Florida in near-freezing water hundreds of meters down, picking off krill, amphipods, and worms. Super cool to spot on ROV dives, but not a fish for home aquariums.
Marquesas dwarf flounder
Engyprosopon marquisense
This is a tiny deepwater lefteye flounder from the Marquesas Islands - one of those little sand-hugging ambush fish that looks like a leaf until it moves. Super cool biologically, but honestly not a realistic home-aquarium fish since it comes from 108-408 m depths and there is basically no established hobby care info for the species.
Marshall's grenadier
Coryphaenoides marshalli
This is a deep-sea grenadier (rattail) from the Gulf of Guinea - think big head, huge eyes for the dark, and that classic long tapering tail. It lives way down on the slope, so it's not an aquarium fish in any realistic sense, but it's a really neat example of how fish are built for cold, high-pressure life.
McCosker's coralbrotula
Ogilbia mccoskeri
This is a tiny, super-secretive little reef brotula from the SW Caribbean that spends its life tucked into coral rubble and crevices. It is a bottom-hugging carnivore that picks off small mobile crustaceans, and you will mostly see it at dusk or when food hits the water. Cool fish, but it is absolutely not a typical aquarium species, so most "care" info out there is guesswork or confused with McCosker's flasher wrasse (totally different fish).
Mekran ponyfish
Deveximentum mekranense
This is a small ponyfish from the Gulf of Oman off Iran, and like other ponyfishes its whole vibe is being a little bottom-hugging, silvery coastal fish. It is a pretty recent species description (2021), and its natural range is very localized, so you are not going to see it come through the aquarium trade in any normal way. If you ever did encounter one, you would treat it like a delicate wild marine schooling fish rather than a typical hardy "saltwater beginner" fish.
Memorable rearspined fin prickleback
Kasatkia memorabilis
Kasatkia memorabilis is a tiny, eel-shaped marine prickleback from the Sea of Japan area that spends its life down on the bottom in nearshore water. Its whole vibe is "hide in cracks and hug the rocks," so if you ever did keep one, you would treat it more like a coldwater tidepool fish than a tropical reef fish.
Miracle triplefin
Enneapterygius mirabilis
This is a tiny reef perch that hops around the rockwork and flashes big pectoral fins and a tall first dorsal when it is fired up. It sticks to outer reef slopes in the Southwest Pacific and tops out around 3 cm, so think micro-reef showpiece rather than community fish. Give it mature live rock full of pods and it becomes a fun little hunter to watch.
Moon-spotted shrimp goby
Vanderhorstia nannai
This little shrimp-goby rocks bright moon-yellow spots and loves living with a pistol shrimp, sharing a sand burrow and acting like the lookout. Give it a sandy bed and peaceful tankmates and it will perch at the entrance, dash for meaty bites, and show tons of personality. Use a snug lid - they can launch if startled.
Moorish idol
Zanclus cornutus
Moorish idols are that black-white-yellow reef fish with the long streamer off the dorsal fin - they look like theyre floating more than swimming. In the wild they cruise reefs in pairs or little groups and pick at sponges and other encrusting critters all day. Theyre gorgeous, but the big challenge in aquariums is getting them eating well long-term.
Mottled mojarra
Ulaema lefroyi
Ulaema lefroyi is that shiny silver beach mojarra with the crazy-protrusible mouth, always nosing around sandy bottoms for little critters. Adults hang out along sandy shores and inlets and they can show a neat mottled/banded look that helps them blend over sand. Its a true saltwater fish, so think marine setup, not a community freshwater tank.