Fish That Start With M - Page 2 of 2
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.
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.
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.
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 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.
Murray Island bandfish
Owstonia merensis
Owstonia merensis is a tiny deepwater bandfish from the western Pacific - think slope/reef-edge trawl depths, not a reef tank fish. It stays small (around 5.7 cm standard length in the literature) and lives way down where water is cool, dark, and super stable, which is why it is basically never a realistic home-aquarium species.