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.
Faustino's lanternfish
Diaphus faustinoi
Diaphus faustinoi is a marine lanternfish (family Myctophidae) reported from the Philippines and the western-central Pacific. Like other myctophids it is a deep/mesopelagic open-ocean fish with photophores and diel vertical migration behavior, and it is not a practical home-aquarium species.
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.
Felix's elephantfish
Mormyrus felixi
Mormyrus felixi is a freshwater mormyrid (elephantfish) endemic to Cameroon, reaching about 14.3 cm standard length. Species-specific aquarium care information is limited; husbandry recommendations are typically inferred from general mormyrid requirements (dim lighting, soft substrate, high water quality, and appropriate foods).
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.
Fijian zebra dwarfgoby
Eviota pseudozebrina
This is a true micro-reef goby from Fiji that hangs tight to rockwork and algae-covered spots in super shallow water. It is one of those blink-and-you-miss-it fish, but once you start watching, you will see it perching, hopping, and picking at tiny foods all day. The big catch is keeping it well-fed and not letting bigger tankmates intimidate it or outcompete it at mealtime.
Finspot wrasse
Xenojulis margaritacea
This little wrasse is basically a nonstop grazer - it cruises the rockwork all day hunting tiny critters, then dives into the sand to sleep. Adults can get really flashy (especially males) with that signature black fin spot, and it is one of those fish that will absolutely remind you why lids matter because it can jump.
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.
Fish doctor
Gymnelus viridis
Gymnelus viridis (the fish doctor) is a cold-water Arctic eelpout with a long, scaleless, eel-like body that likes hugging the bottom in sand/mud and seaweed. It is a true marine fish from polar seas, feeding on crustaceans and other meaty bottom critters - basically a little benthic hunter built for chilly water.
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.
Flaccid catshark
Apristurus exsanguis
A ghostly deep-sea catshark from New Zealand, pale and kind of floppy-looking, that cruises 600-1200 m down where it is icy cold. It lays tough egg cases on the seafloor and grows to just under a meter. Super cool animal, but it is a deep, cold-water species that is totally unsuited to home aquariums.
Flagfin cardinalfish
Jaydia truncata
Jaydia truncata is a nocturnal reef-associated cardinalfish found in inshore waters of the continental shelf in the Indo-Pacific. It reaches about 15 cm total length and in aquaria should be provided with calm tankmates and ample shelter/overhangs.
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 galaxias
Galaxias rostratus
A small, slender Murray–Darling Basin galaxiid with a distinctly flattened head and large mouth. Occurs mid-water in still or gently flowing habitats such as billabongs, lagoons and backwaters, and schools in midwater. It is a threatened species in NSW and it is illegal to catch/keep/buy/sell/possess without a specific permit or approval.
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.
Fly River garfish
Zenarchopterus novaeguineae
This is a surface-cruising freshwater halfbeak from New Guinea and far north Australia that likes warm, weedy shallows and will hang near the top in little shoals. In the wild it grazes a lot of plant material but will also snap up insects, so it acts like a picky topwater grazer with a "snatch anything that lands" vibe. If you ever try one in a tank, think "tight lid, calm flow, lots of surface cover" first.