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Shoal & Stem

Flora & Fauna

673 entries — care guides, placement tips, and notes from the community

fish

Loxozonus Corydoras

Corydoras loxozonus

fishfreshwater
fish
easy

Lubbock's Fairy Wrasse

Cirrhilabrus lubbocki

fishsaltwater

Strikingly colourful — males flash vivid red, orange, and yellow with iridescent highlights during display. Peaceful and active; best kept as one male with several females. A jewel of the mid-water column.

plant
easy

Ludwigia Palustris

Ludwigia palustris

plantfreshwater

Ludwigia Palustris is one of the most accessible red stem plants, displaying green upper leaf surfaces and deep reddish-pink undersides that are visible as the stems wave in current. It is far less demanding than L. arcuata or Super Red Mini, making it an excellent entry-level red plant for tanks with moderate light. Fast growth means it requires regular pruning to maintain shape.

plant
medium

Ludwigia Super Red

Ludwigia sp. 'Super Red'

plantfreshwater

Ludwigia Super Red (also sold as Ludwigia sp. 'Red') is the full-size counterpart to Super Red Mini, producing larger oval leaves of intense blood-red to deep crimson coloration under high light and iron dosing. Its vivid, uniform red makes it one of the most striking background plants in aquascaping. Regular trimming and replanting of cuttings maintains colour intensity throughout the stem column.

plant
medium

Ludwigia Super Red Mini

Ludwigia sp. 'Super Red Mini'

plantfreshwater

Ludwigia Super Red Mini is a highly popular aquascape stem plant producing small, rounded leaves of an intense, uniform blood-red colour that few other plants can match. The compact leaf size and bushy growth habit make it more versatile than larger ludwigia species — it works equally well in nano tanks and as a detailed midground splash of colour in larger aquascapes. Adequate iron and CO2 are key to maintaining colour intensity.

algae
hard

Lyngbya

Lyngbya sp.

algaefreshwater

Dark, wiry filaments of cyanobacteria that form dense mats — often mistaken for BBA. Unlike true algae, it can fix atmospheric nitrogen, meaning low nitrogen levels do not suppress it. Produces toxins harmful to invertebrates. Requires the same treatment as blue-green algae: blackout, H₂O₂ treatment, and improved flow.

fish
medium

Lyretail Anthias

Pseudanthias squamipinnis

fishsaltwater

One of the most colourful reef fish — females orange-pink, males dazzling magenta-purple with elongated tail filaments. Best kept in a harem (one male, multiple females) with strong flow and frequent feeding.

fish

Macropterus Corydoras

Corydoras macropterus

fishfreshwater
fish
intermediate

Mahachai Betta

Betta mahachaiensis

fishfreshwater

Betta mahachaiensis is a wild betta discovered in 2012 in the brackish coastal habitats of Samut Sakhon, Thailand — making it unique among bettas in its tolerance for slightly saline conditions. Males display striking iridescent teal-blue scale edging similar to B. smaragdina. It builds bubble nests and is less aggressive than B. splendens toward other species. Its restricted wild range makes it important for conservation-minded hobbyists.

algae
medium

Maiden's Hair

Chlorodesmis fastigiata

algaesaltwater

Vivid blue-green turf-like tufts of very fine filaments — a common sight on Indo-Pacific reefs. In captivity it can spread across rockwork quickly. Produces terpene compounds that deter most grazers. Interesting as a biotope element but can become a nuisance if left unchecked.

fish

Malabar Danio

Devario malabaricus

fishfreshwater
snail
easy

Malaysian Trumpet Snail

Melanoides tuberculata

snailfreshwater

Malaysian trumpet snails are beneficial substrate dwellers that burrow through gravel and sand, aerating it and preventing the build-up of toxic anaerobic pockets. They are predominantly nocturnal and are often only seen at night. Populations can explode with excess food, but remain in check with controlled feeding.

fish
expert

Mandarin Dragonet

Synchiropus splendidus

fishsaltwater

Arguably the most beautiful fish in the hobby. Requires a mature reef with abundant copepods. Not for beginners. Will starve if not given live food.

fish
medium

Marble Angelfish

Pterophyllum scalare

fishfreshwater

A captive-bred variety with a swirling black-and-white marbled pattern caused by the marble gene. The pattern is unpredictable and no two fish look alike. One of the most widely kept angelfish morphs, well suited to planted scapes.

fish
easy

Marble Betta

Betta splendens 'Marble'

fishfreshwater

Marble Bettas carry a transposon-driven colour mutation discovered in the 1970s that causes random, irregular patches of pigmentation. One of their most fascinating traits is colour instability — a marble betta can spontaneously change colour pattern over its lifetime as the transposon activates or silences pigment genes. This unpredictability makes every individual unique and constantly surprising to their owners.

fish
medium

Marbled Hatchetfish

Carnegiella strigata

fishfreshwater

Smallest hatchetfish with intricate brown-and-gold marbled patterning. A delicate but fascinating surface fish. Needs a very tight-fitting lid as it can jump significant distances.

snail
easy

Margarita Snail

Margarites pupillus

snailsaltwater

Small, cold-water snail — an exceptional algae grazer often used in reef tanks as clean-up crew. Prefers cooler temperatures so it's ideal for FOWLR tanks or tanks below 74°F. Peaceful and prolific.

algae
easy

Marimo Moss Ball

Aegagropila linnaei

algaefreshwater

Beloved velvety-green spheres of filamentous green algae — not a moss at all. Forms naturally in cold lakes where wave action rolls colonies into balls over decades. A low-maintenance aquarium icon that grows extremely slowly. Rotate occasionally for even light exposure.

fish
easy

Maroon Clownfish

Premnas biaculeatus

fishsaltwater

The largest clownfish species, maroon-red with bold white stripes. Highly aggressive — best kept as a single specimen or bonded pair. One of the most striking reef fish available.

plant
easy

Marsilea Crenata

Marsilea crenata

plantfreshwater

The most popular carpeting Marsilea in the hobby, producing tiny two- or four-leaf clovers on short petioles that hug the substrate to form a dense, bright green carpet. Significantly smaller than M. hirsuta, making it better suited to nano tanks and foreground work in larger scapes. Grows reliably with good light and CO₂ but is surprisingly tolerant of lower-tech conditions compared to HC Cuba. The clover-shaped leaves are charming and create an instantly recognisable, naturalistic foreground.

plant
easy

Marsilea Minuta

Marsilea minuta

plantfreshwater

The smallest Marsilea species commonly available, producing miniscule two-leaf forms when submerged that create an incredibly fine, lawn-like carpet. Its wide geographic distribution makes it very adaptable to different water conditions. Under high light it carpets tightly to the substrate; in lower light, petioles elongate as the plant reaches for the surface. One of the most low-maintenance carpeting options available — more forgiving than HC Cuba or E. Belem.

plant
medium

Mato Grosso Milfoil

Myriophyllum mattogrossense

plantfreshwater

Lush, feathery stem plant with fine bright-green whorled leaves. Faster-growing and more forgiving than its red cousin. Creates a spectacular soft texture in the background of planted tanks.

plant
intermediate

Mayaca Fluviatilis

Mayaca fluviatilis

plantfreshwater

A beautiful, moss-like stem plant with densely packed, fine, bright green leaves that give stems a cylindrical, fluffy appearance. It grows in flowing, well-oxygenated water in the wild. Prefers soft, slightly acidic conditions and benefits from CO2. Often used in Dutch scapes as a light green accent column.

coral
easy

Maze Brain Coral

Platygyra daedalea

coralsaltwater

Iconic labyrinthine-patterned brain coral — the classic reef centrepiece. Hardy, slow-growing, and tolerant of moderate conditions. Green fluorescent under actinic lighting. A timeless display piece.

fish

Melanistius Corydoras

Corydoras melanistius

fishfreshwater
fish
easy

Melanurus Wrasse

Halichoeres melanurus

fishsaltwater

Dazzling rainbow colouration — females green-blue, males sporting a vivid magenta-and-green pattern. A sand-diver that buries to sleep. Natural predator of flatworms and pyramid snails.

plant
intermediate

Mermaid Weed

Proserpinaca palustris

plantfreshwater

Mermaid Weed is a unique stem plant that changes leaf shape depending on whether it is emersed or submersed — submerged leaves are deeply serrated and comb-like, while emersed leaves are broader and simple. Under high light the deeply lobed leaves turn intense shades of orange and red, making it a striking colour accent in Dutch and Nature Aquarium layouts.

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.

plant
easy

Mexican Oak Leaf

Shinnersia rivularis

plantfreshwater

Fast-growing stem plant with distinctive oak-leaf-shaped leaves. Extremely easy and undemanding — grows well without CO2. The unusual leaf shape adds variety to planted tank backgrounds.

plant
easy

Micrantha Lily

Nymphaea micrantha

plantfreshwater

Small water lily that propagates prolifically from plantlets on its floating leaves. Produces striking red-spotted green pads. Remove surface leaves regularly to keep the plant growing compact submersed growth.

plant
easy

Microsorum Trident

Microsorum pteropus 'Trident'

plantfreshwater

The trident java fern is a cultivar with deeply lobed, multi-pronged fronds that create an elegant, fern-like silhouette. Like all java ferns it attaches to hardscape and requires no substrate. Very low-maintenance and suitable for low-tech tanks.

fish
easy

Midas Blenny

Ecsenius midas

fishsaltwater

Brilliant golden-yellow with a flowing, eel-like body. Often mimics Lyretail Anthias in colour. Perches on rockwork and darts into crevices when startled — reef-safe and entertaining to watch.

plant
intermediate

Mini Bolbitis

Bolbitis difformis

plantfreshwater

Sometimes sold as 'Baby Bolbitis' or 'Mini Bolbitis', this small aquatic fern produces deeply divided fronds similar to the full-size Bolbitis heudelotii but significantly more compact and fine-textured. It attaches to driftwood and rock and grows well in moderate flow. One of the finest detail ferns in the hobby for Iwagumi and Nature Aquarium style.

plant
easy

Mini Christmas Moss

Vesicularia montagnei

plantfreshwater

A smaller, more delicate version of Christmas Moss with finer fronds arranged in the same classic triangular pattern. The smaller frond size allows for more detailed, intricate-looking moss walls and carpets compared to standard Christmas Moss. Like other Vesicularia species, it attaches readily to hardscape and can be tied, glued, or pressed onto mesh panels. Works especially well in nano tanks and detailed scapes where a finer texture is desired.

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.