Fish That Start With F
Browse all aquarium fish species with common names beginning with "F". Each profile includes care requirements, water parameters, tank size recommendations, and compatibility information for freshwater, marine, and brackish species.
In this section, you'll find a variety of fascinating species that begin with the letter 'F.' Although we currently don't have specific entries, notable examples are the popular Fantail Goldfish (Carassius auratus), vibrant Flame Tetra (Hyphessobrycon flammeus), and striking Frontosa Cichlid (Cyphotilapia frontosa). Whether you're looking for community-friendly options or unique cichlids, the 'F' species index may hold exciting prospects for your aquarium.
Falcate snailfish
Careproctus cypselurus
Careproctus cypselurus (falcate snailfish) is a marine, bathydemersal snailfish (Liparidae) from the North Pacific (off Japan and from the Sea of Okhotsk to off Washington, USA), recorded from deep water (about 35–1993 m). It is not a typical aquarium species due to its deep-sea/coldwater ecology and specialized life-support needs.
Fat sleeper
Dormitator maculatus
Dormitator maculatus is that chunky "sleeper goby" type fish with the bulldog head and the attitude of a little vacuum cleaner-always sifting and nosing around the bottom. It'll do freshwater or brackish and it can get way bigger than most people expect, so it's one of those fish that's awesome... as long as you plan the tank around the adult size, not the baby you bought.
Feathered river-garfish
Zenarchopterus dispar
Zenarchopterus dispar is a surface-hanging halfbeak from mangroves and sheltered bays, with that classic long lower jaw for snapping up insects and other floaty foods. Males get those funky elongated fin rays (the "feathered" look), and they are livebearers, so once they settle in you can occasionally get surprise babies. Biggest thing with this fish is giving it calm water up top, room to cruise, and a tight lid because halfbeaks can rocket-jump.
Fedorov eelpout
Zoarces fedorovi
Zoarces fedorovi is a cold-water eelpout from the northern Sea of Okhotsk - an eel-shaped, bottom-hugging fish that hides under rocks and cruises around the bottom. Its claim to fame is being livebearing (viviparous), which is pretty wild for a marine fish, but its exact day-to-day habits in the wild are still not super well documented.
Fenestratum cichlid
Vieja fenestrata
Vieja fenestrata is a big, chunky Central American cichlid that spends a lot of its time cruising the lower half of the tank and redecorating by digging. Give it room, strong filtration, and some tough hardscape, and you get a really interactive fish with that classic Vieja attitude.
Few-pored wriggler
Xenisthmus oligoporus
This is a teeny little Red Sea reef wriggler that lives down in sandy spots and stays pretty secretive. At barely around an inch long, its whole vibe is "blink and you miss it" - more of a cool oddball micro-predator than a display fish.
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Figure 8 Puffer (Eyespot puffer)
Dichotomyctere ocellatus (syn. Tetraodon biocellatus)
This is the small "Figure 8"/eyespot puffer with two bold eyespots and a yellow-green maze-like pattern. They're interactive and can be fin-nippy and territorial, especially toward other puffers. Husbandry advice on salinity varies by source: FishBase lists it as a freshwater species, while many aquarium references recommend low-end brackish (often around SG ~1.005-1.008) for long-term keeping, with very clean, stable water.
Fire eel
Mastacembelus erythrotaenia
Fire eels are those big, snake-y "spiny eels" with the red/orange flame striping that really pops once they settle in and color up. They love to wedge themselves under wood or burrow into sand and then come out at dusk to cruise around and beg for food-super personable once they trust you, but they get huge and can absolutely inhale small tankmates.
Fire-eyed loach
Barbucca diabolica
This is one of those tiny, oddball loaches that spends its whole day scooting along wood and rocks like a little vacuum cleaner, and those glowing red eyes are the whole vibe. It is peaceful and shy, but it gets way more confident in a dim, cover-filled tank with leaf litter and lots of little hideouts. Biggest thing people miss is feeding - it is a bottom grazer and pretty much will not chase food up in the water column.
Firefish (Fire Goby / Fire Dartfish)
Nemateleotris magnifica
This is that little "hover-and-dart" reef fish with the yellow face and the white-to-red fade that looks like it was airbrushed on. It'll pick a bolt-hole in the rockwork, hang in the water column facing the current, and do that cute little flag-flick with the tall first dorsal fin when it's feeling bold.
Flabby sculpin
Zesticelus profundorum
This is a tiny deepwater sculpin from the North Pacific that lives way down on the bottom, not cruising around the reefs like typical “aquarium marines”. The wild habitat is cold, dark, and high-pressure (down to around 2580 m), so it is basically a “look up in a museum database” fish rather than something you can realistically keep at home.
Flabby whalefish
Gyrinomimus grahami
Gyrinomimus grahami is a deep-sea flabby whalefish from the Southern Ocean-ish parts of the world - big head, huge mouth, tiny eyes, and a super soft-bodied look. Its adult females are described as dark with reddish tones and orangey fins, and it lives crazy-deep in the bathypelagic zone, so its whole vibe is built around life in perpetual darkness.
Flag-tailed glass perchlet
Ambassis miops
Ambassis miops is a small, see-through little perchlet from Indo-Pacific estuaries and river mouths - you can often see the silvery organs and spine line inside the body when it turns just right. They tend to hang out in loose groups along weedy edges in slow-to-moderate flow, and that flag-like tail pattern is the quick giveaway once you spot it.
Flame cardinalfish
Fowleria amblyuroptera
Fowleria amblyuroptera is a very small Indo-Pacific/Western Pacific cardinalfish (to about 4 cm SL) associated with coastal reefs/bays and is primarily nocturnal. Like many cardinalfishes, the male mouthbroods the eggs; in captivity it should be provided with ample shelter and offered appropriately sized meaty foods/planktonic items.
Flathead long-whiskered catfish
Megalonema platycephalum
This is a real-deal South American pimelodid catfish that stays in that "big but not monster" range - around a foot long - with that wide, bulldog-ish head and long whiskers. Its natural diet includes insect larvae and even fish scales, so it has that sneaky bottom-predator vibe and will absolutely inhale meaty foods once it settles in. The big "gotcha" is that it sometimes shows up mislabeled in shops (even as other catfish species), so you want to buy it assuming you'll be housing a 12-inch predator.
Foersch's killifish
Nothobranchius foerschi
Nothobranchius foerschi is an annual killifish from coastal Tanzania that lives in temporary pools, so it is basically built to grow up fast, spawn hard, and not hang around forever. The males are ridiculously colorful and do a lot of little sparring and display posturing, which is half the fun of keeping them in a species tank.
Fork-tailed Yunnan loach
Yunnanilus forkicaudalis
This is a tiny Chinese stone loach that sticks close to the bottom and cruises around like a little mouse, poking into sand and between small rocks. Its wild home is pretty localized in Yunnan, so its more of a "cool oddball" than something you will reliably see at every fish shop. Treat it like a small, peaceful stream/edge-of-lake loach and it will reward you with nonstop foraging behavior.
Fork-tailed loach
Vaillantella maassi
This is one of those weird, awesome loaches with a long sail-like dorsal fin and a deeply forked tail that looks way too fast for a bottom fish. It comes from dark, tannin-stained blackwater streams and tends to be shy by day but more active once the lights are low. Keep the lid tight because they can be serious escape artists when they get the loach wanderlust.
Forktail blue-eye (Forktail rainbowfish)
Pseudomugil furcatus
Pseudomugil furcatus is one of those little fish that never sits still-in a good way. When you keep a proper group, the males do these harmless fin-flaring "showdowns" and the forked tail + blue eyes really pop, especially in a planted tank with some open swimming room. It's a peaceful, small schooling fish from Papua New Guinea rainforest streams, and it's an easy way to add constant movement to a tank.
Four-Eyed Fish
Anableps anableps
This is that wild-looking surface cruiser with the "four eyes" - each eye is split so it can watch above and below the water at the same time. It's super active and always patrolling the top, and it really shines in a long tank with room to zoom. Just don't treat it like a regular freshwater fish; it's way happier in brackish water and needs open surface space.
Four-eyed sleeper
Bostrychus sinensis
This is one of those chunky "sit-and-watch" gobies that looks like it's always plotting something-big head, tough little body, and a real ambush-predator vibe. It'll perch on the bottom like a log and then suddenly lunge when food comes by, which is honestly super fun to watch. Just don't expect it to play nice with tiny tankmates-anything that fits in its mouth is basically on the menu.
Fowler's large-toothed conger
Bathyuroconger fowleri
Bathyuroconger fowleri is a deepwater conger eel, the kind of fish that spends its life down on the slope rather than cruising a reef. Think secretive, bottom-oriented, and very much not an aquarium species - it is more of a cool ID-only eel than something you would ever plan a home setup around.
Foxface Rabbitfish
Siganus vulpinus
Siganus vulpinus is that bright yellow "fox-masked" rabbitfish you see cruising around picking at algae all day. It's generally chill with other fish, but it can get a little bossy with similar-shaped grazers-and those dorsal spines are venomous, so nets and hands need to be treated with respect.
Freshwater angelfish
Pterophyllum scalare
Pterophyllum scalare is that classic tall, triangle-shaped cichlid that just glides around like it owns the midwater. Give it some vertical space, plants/wood to weave through, and it'll reward you with tons of personality-especially once a pair forms and starts guarding a spawn site.