Shoal & Stem

Species Catalogue

1,376 species — care guides, community photos, water parameters, and tank-mate compatibility.

fish
Mmedium

Twostripe Aphyosemion

Aphyosemion bivittatum

fishfreshwater
1.5″·10+ gal·semi-aggr.
fish
advanced

Uaru

Uaru amphiacanthoides

fishfreshwater
10″·75+ gal·peaceful
plant
intermediate

Umbrella Hairgrass

Eleocharis vivipara

plantfreshwater

Eleocharis Vivipara, Umbrella Hairgrass, is uniquely different from other hairgrass species — when grown submerged its slender stems branch repeatedly into arching, umbrella-like tufts rather than simple grass blades, creating a highly textural midground accent. Each stem tip can produce plantlets that anchor to substrate, aiding natural propagation. It needs moderate light and benefits from CO2.

fish
beginner

Upside-Down Catfish

Synodontis nigriventris

fishfreshwater
4″·20+ gal·group 4+·peaceful
plant
advanced

Utricularia Graminifolia

Utricularia graminifolia

plantfreshwater

Carnivorous aquatic plant used as a fine-leaved carpet alternative. Forms a delicate bright-green lawn. Requires CO2, high light, and soft water. Rewarding when established.

fish
intermediate

Valentini Puffer

Canthigaster valentini

fishsaltwater
4″·40+ gal·semi-aggr.
plant
beginner

Vallisneria Americana

Vallisneria americana

plantfreshwater

A tall, ribbon-leaved background plant that spreads aggressively by runners to create natural-looking grass beds. Leaves can reach 50–100 cm, making it ideal for very tall tanks or ponds. Very adaptable and grows without CO2 injection in moderate to hard water. An excellent fish habitat plant that oxygenates the water actively.

plant
beginner

Vallisneria Caulescens

Vallisneria caulescens

plantfreshwater

Unique Vallisneria that grows from a stem rather than a rosette. Long, narrow leaves cascade from branching stems. Unusual and attractive.

plant
beginner

Vallisneria Nana

Vallisneria nana

plantfreshwater

Vallisneria nana is a dwarf vallisneria with narrow, grass-like leaves that stay much shorter than spiral vallisneria. It spreads prolifically via runners and creates natural-looking meadow backgrounds. Excellent for tanks with moderate lighting and no CO2.

plant
beginner

Vallisneria Spiralis

Vallisneria spiralis

plantfreshwater

Vallisneria spiralis is a fast-growing ribbon grass that produces long, narrow, strap-like leaves that spiral slightly as they grow, creating a graceful waving motion in moderate current. It is one of the easiest and most forgiving background plants available, tolerating hard, alkaline water that challenges most aquatic plants. It spreads rapidly via runners and can quickly fill the background of large aquariums without CO2 injection.

plant
beginner

Vallisneria Tortifolia

Vallisneria tortifolia

plantfreshwater

The corkscrew Vallisneria produces striking, tightly twisted ribbon leaves that spiral as they grow. Unlike straight Vallisneria species it stays at a medium height (20–40 cm), making it more versatile in mid-sized tanks. A distinctive textural element in planted tank backgrounds, especially effective in Dutch Style rows.

crab
Mmedium

Vampire Crab

Geosesarma dennerle

crabfreshwater
0.75″·5+ gal·peaceful
shrimp
intermediate

Vampire Shrimp

Atya gabonensis

shrimpfreshwater
3″·20+ gal·group 2+·peaceful
fish
intermediate

Veil Angelfish

Pterophyllum scalare

fishfreshwater
6″·30+ gal·group 2+·semi-aggr.
fish
beginner

Veiltail Betta

Betta splendens

fishfreshwater
3″·5+ gal·semi-aggr.
fish
beginner

Venezuelan Corydoras

Corydoras venezuelanus

fishfreshwater
2.5″·15+ gal·group 6+·peaceful
fish
intermediate

Venustus Cichlid

Nimbochromis venustus

fishfreshwater
10″·75+ gal·aggressive
fish
intermediate

Viejita Dwarf Cichlid

Apistogramma viejita

fishfreshwater
2.5″·20+ gal·semi-aggr.
fish
beginner

Vietnamese Cardinal Minnow

Tanichthys micagemmae

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

Volitans Lionfish

Pterois volitans

fishsaltwater
15″·120+ gal·semi-aggr.
fish
beginner

Von Rio Tetra

Hyphessobrycon flammeus

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

Wagtail Platy

Xiphophorus maculatus

fishfreshwater
2.5″·10+ gal·group 3+·peaceful
fish
Mmedium

Walker's Killifish

Fundulopanchax walkeri

fishfreshwater
1.5″·10+ gal·peaceful
plant
intermediate

Water Caltrop

Trapa natans

plantfreshwater

Unusual floating plant with diamond-shaped surface leaves and feathery submerged leaves. Historically important food plant in Asia.

plant
beginner

Water Lettuce

Pistia stratiotes

plantfreshwater

Water lettuce is a floating rosette plant with velvety, pale green leaves and a substantial root system. It provides excellent shade, nutrient export, and shelter for surface-shy fish. It grows rapidly in bright conditions and may become invasive outdoors.

algae
advanced

Water Net Algae

Hydrodictyon reticulatum

algaefreshwater

Remarkable bright green net-like colonies — a tessellated honeycomb of cells visible to the naked eye. Beautiful under a microscope but a serious nuisance in garden ponds. Thrives in warm, nutrient-rich water. Manual removal is the primary method as few animals eat it effectively.

plant
beginner

Water Sprite

Ceratopteris thalictroides

plantfreshwater

Water Sprite is a versatile aquatic fern that can be grown both floating and rooted. The finely dissected, lacy fronds give it a delicate, feathery appearance. Floating specimens develop broader, more deeply lobed leaves and provide excellent surface cover and fry refuge. A classic, beginner-friendly plant that grows vigorously.

plant
advanced

Water Violet

Hottonia palustris

plantfreshwater

Stunning cold-water stem plant with whorls of feathery leaves. One of the most beautiful temperate aquarium plants. Challenging to keep in tropical tanks — prefers cool, clear, well-oxygenated water.

plant
beginner

Water Wisteria

Hygrophila difformis

plantfreshwater

Water wisteria is a fast-growing stem plant with deeply lobed, feathery leaves that vary in form depending on light intensity. It is an excellent nutrient sponge that helps control algae in new setups. Cuttings root readily and it adapts to a wide range of water parameters.

plant
Xexpert

Waterwort

Elatine triandra

plantfreshwater

One of the finest-leaved carpet plants in existence — creates an almost moss-like lawn of tiny round leaves. Extremely challenging; requires CO2, very high light, and excellent nutrient control. The pinnacle of carpeting plants.

plant
beginner

Weeping Moss

Vesicularia ferriei

plantfreshwater

Weeping Moss is prized for the elegant downward-drooping habit of its fine fronds, which cascade gracefully off driftwood and rocks like a willow tree in miniature. This weeping growth pattern is most pronounced in moderate flow and makes it one of the most aesthetically distinct mosses for aquascaping. It is slightly slower growing than Java Moss but creates a more refined, delicate textural effect.

fish
intermediate

Weitzmani Corydoras

Corydoras weitzmani

fishfreshwater
2″·15+ gal·group 6+·peaceful
fish
beginner

Western Rainbowfish

Melanotaenia australis

fishfreshwater
4″·30+ gal·group 4+·peaceful
fish
beginner

Whiptail Catfish

Rineloricaria lanceolata

fishfreshwater
5″·30+ gal·peaceful
shrimp
Mmedium

Whisker Shrimp

Macrobrachium lanchesteri

shrimpfreshwater
8″·30+ gal·semi-aggr.
White Cloud Mountain Minnowbeginner

White Cloud Mountain Minnow

Tanichthys albonubes

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