Fish That Start With M - Page 2 of 3
Browse all aquarium fish species with common names beginning with "M". Each profile includes care requirements, water parameters, tank size recommendations, and compatibility information for freshwater, marine, and brackish species.
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.
Menderes garra
Garra menderesensis
A small-bodied cyprinid endemic to Lake Işıklı and the Büyük Menderes River system (Turkey). Described in 2015 (originally as Hemigrammocapoeta menderesensis) and currently treated as Garra menderesensis. Aquarium husbandry information appears scarce; avoid extrapolating care requirements from unrelated Garra species without species-specific sources.
Mexican stargazer
Dactyloscopus metoecus
This is a teeny sand-stargazer that spends its time buried with just the eyes poking out, waiting to ambush tiny prey. Super cool little "sand-periscope" behavior, but its whole lifestyle is basically built around being in clean marine sand, so it is not a typical aquarium fish at all.
Midas blenny
Ecsenius midas
Midas blennies are those weirdly "blenny-but-also-open-water" fish that zip around the tank like a tiny golden torpedo, then duck into a hole like nothing happened. They'll even color-shift and loosely school with anthias in the wild, which is honestly one of the coolest behaviors you'll see in a reef fish.
Milkspotted puffer
Chelonodontops patoca
This is that chunky, curious puffer with the milky white spots and big "what are you doing?" eyes that follows you around the glass like a little water puppy. It's a super fun fish to watch-always cruising, inspecting everything, and begging for food-but it's also one of those puffers that really needs the right setup as it grows (and it grows a lot).
Milkspotted puffer
Chelonodon patoca
This is the big milk-spotted brackish puffer that cruises estuaries and mangroves and sometimes wanders a little way into fresh water. It gets chunky (over a foot) with those clean white spots, and it has that classic puffer personality - curious, food-motivated, and sometimes a bit too interested in other fish's fins. Long-term it really does best as a brackish-to-marine fish with hard, alkaline water and lots of crunchy shell-on foods to keep the beak worn down.
Min County plateau loach
Triplophysa minxianensis
This is a coldwater, fast-river Triplophysa from Gansu, China - a little bottom loach built for current, with that classic 'stone loach' shape and a life spent hugging the substrate. Its wild range seems pretty localized (Taohe River and upper Weihe), and in the hobby its care gets tricky mostly because it really wants cool, super-oxygenated water and a clean, river-style setup.
Minerim banjo catfish
Bunocephalus minerim
This is a tiny little banjo catfish from Brazil that basically lives the stealth life - it melts into leaf litter and sand and you can go days thinking it vanished. Super chill fish, but it is one of those bottom hiders you feed with intention (sinking foods after lights-out), and it really appreciates a soft substrate to burrow into.
Mini zebra loach
Yunnanilus pulcherrimus
This is a tiny Chinese stone loach with a really crisp, zebra-like stripe pattern, and it spends most of its time nosing around the bottom like a little aquatic mouse. It does best in a mature, well-oxygenated tank with lots of cover and smooth sand or rounded gravel so it can cruise and forage without beating up its barbels.
Mo River killifish
Fundulopanchax moensis
Fundulopanchax moensis is one of those West African stream killies where the males just light up once they settle in, especially in a dim, plant-packed tank. It is a non-annual killi (so not a "live fast, die young" puddle fish) and it really rewards you if you keep it covered and calm - they can be jumpy little rockets.
Moenkhausia aurantia
Moenkhausia aurantia
This is a little Brazilian Moenkhausia tetra described in 2011 from clear, shallow streams in the upper rio Tocantins basin. In the wild it turns up around rocky/sandy bottoms with riparian vegetation, and its name (aurantia) is literally a nod to an orangish tone. It is not a common aquarium fish, so most keepers end up treating it like a small, schooling South American tetra and focusing on stability and a calm setup.
Mojarita
Knodus breviceps
Knodus breviceps is a small freshwater characin from South America, reported from the Tocantins River basin. FishBase lists it as a benthopelagic freshwater species.
Moluccas snake eel
Yirrkala moluccensis
Yirrkala moluccensis is a tropical snake eel (Ophichthidae) from Indonesia in the western central Pacific. Like most of its relatives its whole vibe is hiding and burrowing, so it is way more of a secretive, sand-loving predator than a "swimming around for display" fish.
Mongolia bitterling
Rhodeus monguonensis
Rhodeus monguonensis is a little temperate bitterling from China, and its whole claim to fame (like other bitterlings) is the wild breeding trick of laying eggs into freshwater mussels. Its actual aquarium care is basically "cool, clean water and a planted setup," but the real challenge is that species-specific hobby info is scarce, so you end up keeping it like other Rhodeus and watching behavior closely.
Monte's croaker
Plagioscion montei
Plagioscion montei is a freshwater croaker from the Amazon basin (Brazil and Peru) that grows into a sleek, silvery predator with that classic Sciaenidae shape. Its whole family is famous for making croaking/drumming sounds (swim bladder stuff), so its close relatives are pretty fun fish behavior-wise even if this exact species is rarely seen in the aquarium trade.
Moore's sand eel
Yirrkala moorei
Yirrkala moorei is a marine tropical snake eel (family Ophichthidae) known from the western central Pacific (Marquesas and American Samoa). It is reported from at least ~25 m depth and is known mainly from collected specimens; aquarium husbandry is not well documented.
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.
Motatan pencil catfish
Trichomycterus motatanensis
Trichomycterus motatanensis is a little Venezuelan pencil catfish from the Lake Maracaibo basin area, the kind that likes hugging the bottom and poking around in crevices. Its not really a mainstream aquarium fish, so a lot of its exact care details in captivity are basically undocumented - if you ever ran into one, you would treat it like a cool-water, high-oxygen stream catfish and keep things super clean.
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.
Mottled triplefin
Forsterygion malcolmi
This is a little New Zealand temperate reef triplefin that spends its time parked on rockwork, peeking out from overhangs and holes like a tiny goby-meets-blenny. It is a crustacean-and-snail picker in the wild, and its whole vibe is "hang close to cover and watch everything" - super cool if you like natural behavior more than flashy open-water swimming.
Mountain Erethistoides catfish
Erethistoides montana
This is a tiny little South Asian river catfish that lives down in fast, clean streamlets, where it hugs the bottom and lets the current do its thing. In a tank it is basically a stealthy pebble-cat that comes alive at feeding time, and it really appreciates lots of oxygen and places to tuck in.
Mountain swordtail
Xiphophorus nezahualcoyotl
This is a cool little wild-type swordtail from Mexico that likes it a bit cooler than the typical pet-store swordtail. Males can do a quirky "headstand" display during courtship and squabbles, and in a roomy tank they stay active and busy without being total jerks.
Mozambique large-eye bream
Wattsia mossambica
This is a deep-water emperor bream that hangs around rocky/coral reef edges on the outer continental shelf. It gets big (around 22 inches max) and is a benthic hunter that cruises the bottom for invertebrates and small fish - super cool fish, but it is absolutely not an aquarium species for typical home setups.
Mozambique silverbiddy
Gerres mozambiquensis
Small gerreid (silverbiddy/mojarra) described from Larde Estuary, Mozambique (holotype and paratype). Natural history details beyond the type locality are limited in readily available references; like other Gerreidae, it likely forages on benthic invertebrates in shallow estuarine/coastal habitats.