Shoal & Stem

Species Catalogue

1,492 species — care guides, community photos, water parameters, and tank-mate compatibility.

plant
easy

Marsilea Hirsuta

Marsilea hirsuta

plantfreshwater
Carpet·Medium–High light·Moderate growth
plant
easy

Marsilea Minuta

Marsilea minuta

plantfreshwater
Carpet·Low to high light·Medium growth
plant
easy

Marsilea Quadrifolia

Marsilea quadrifolia

plantfreshwater
Foreground·Low–High light·Moderate growth
plant
medium

Mayaca Fluviatilis

Mayaca fluviatilis

plantfreshwater
Background·Medium–High light·Moderate growth
coral
easy

Maze Brain Coral

Platygyra daedalea

coralsaltwater
2″·30+ gal·peaceful
fish
expert

Mbu Puffer

Tetraodon mbu

fishfreshwater
26″·300+ gal·aggressive
fish
easy

McCosker's Flasher Wrasse

Paracheilinus mccoskeri

fishsaltwater
3.5″·55+ gal·peaceful
fish
easy

Medaka

Oryzias latipes

fishfreshwater
1.5″·10+ gal·group 6+·peaceful
fish
easy

Melanistius Corydoras

Corydoras melanistius

fishfreshwater
2″·15+ gal·group 6+·peaceful
amphibian
medium

Melanoid Axolotl

Ambystoma mexicanum

amphibianfreshwater
10″·20+ gal·peaceful
fish
easy

Melanurus Wrasse

Halichoeres melanurus

fishsaltwater
5″·30+ gal·semi-aggr.
fish
easy

Melon Barb

Haludaria fasciata

fishfreshwater
3″·30+ gal·group 6+·semi-aggr.
plant
medium

Melon Sword

Echinodorus osiris

plantfreshwater
Midground·Medium growth
algae
medium

Mermaid's Fan

Udotea flabellum

algaesaltwater

Elegant fan-shaped calcified macroalgae on a slender white stalk. Grows in sandy areas near reefs and seagrass beds. A beautiful decorative species for low-flow areas of the display tank. Like Penicillus, it anchors in deep sand and has a natural lifespan of several months.

algae
medium

Mermaid's Wine Glass

Acetabularia acetabulum

algaesaltwater

One of the most extraordinary organisms in biology — a single giant cell shaped like a wine glass on a slender stalk. Each 'plant' is a single cell that can grow to 10 cm. Famous in cell biology research. In aquariums it anchors in sand and is a remarkable conversation piece. Prefers cooler, calcium-rich water.

invertebrate
easy

Mexican Dwarf Crayfish

Cambarellus patzcuarensis

invertebratefreshwater
1.6″·10+ gal·peaceful
plant
easy

Mexican Oak Leaf

Shinnersia rivularis

plantfreshwater
Background
fish
easy

Mickey Mouse Platy

Xiphophorus maculatus

fishfreshwater
2.5″·10+ gal·group 3+·peaceful
plant
easy

Micrantha Lily

Nymphaea micrantha

plantfreshwater
Midground
plant
easy

Micranthemum Umbrosum

Micranthemum umbrosum

plantfreshwater
Floating·Medium–High light·Fast growth
plant
easy

Microsorum Pteropus Needle Leaf

Microsorum pteropus 'Needle Leaf'

plantfreshwater
Epiphyte·Low–Medium light·Slow growth
fish
easy

Midas Blenny

Ecsenius midas

fishsaltwater
5″·30+ gal·semi-aggr.
fish
medium

Midas Cichlid

Amphilophus citrinellus

fishfreshwater
15″·75+ gal·aggressive
fish
medium

Midnight Catfish

Auchenipterichthys thoracatus

fishfreshwater
4.5″·30+ gal·group 3+·semi-aggr.
fish
medium

Millennium Rainbowfish

Glossolepis pseudoincisus

fishfreshwater
4″·30+ gal·group 6+·peaceful
fish
medium

Mimic Tang

Acanthurus pyroferus

fishsaltwater
10″·75+ gal·semi-aggr.
plant
easy

Mini Christmas Moss

Vesicularia sp. 'Mini Christmas'

plantfreshwater
Epiphyte·Slow growth
plant
expert

Mini Eriocaulon

Eriocaulon cinereum

plantfreshwater

Tiny rosette plant forming grass-like tufts. One of the most challenging aquarium plants to keep long-term. Needs very soft, acidic water, strong light, and CO2.

moss
expert

Mini Fissidens

Fissidens splachnobryoides

mossfreshwater

Mini Fissidens is a delicate, slow-growing moss with tiny, feathery fronds that create an intricate, lacy appearance. It features small, finely divided leaves arranged in a distinctive two-ranked pattern, giving it a refined aesthetic ideal for detailed aquascaping. This moss is prized for its ability to attach to hardscape and create natural-looking moss walls or carpets in foreground and midground areas.

fish
medium

Mirabilis Killifish

Fundulopanchax mirabilis

fishfreshwater
2.5″·20+ gal·semi-aggr.
shrimp
medium

Mischling Shrimp

Caridina sp. (Mischling)

shrimpfreshwater
1.5″·5+ gal·group 10+·peaceful
plant
medium

Monte Carlo

Micranthemum tweediei

plantfreshwater
Carpet·Medium to high light·Moderate growth
coral
hard

Montipora

Montipora sp.

coralsaltwater
2″·40+ gal·peaceful
fish
easy

Moonlight Gourami

Trichopodus microlepis

fishfreshwater
6″·30+ gal·peaceful
fish
hard

Moorish Idol

Zanclus cornutus

fishsaltwater
9″·100+ gal·peaceful
amphibian
medium

Mosaic Axolotl

Ambystoma mexicanum

amphibianfreshwater
10″·20+ gal·peaceful