Freshwater Fish Profiles

Explore our growing database of freshwater fish species. Each profile includes detailed care requirements, compatibility data, and environmental needs to help you build the perfect aquarium.

Showing 337 - 360 of 736 Fish Profiles

Gymnogeophagus meridionalis

Cichlids - South American

10 cm Semi-Aggressive

A stunning subtropical 'eartheater' cichlid native to the Uruguay River basin. Unlike typical Amazonian cichlids, they are temperate and benefit from a seasonal winter cooling period. As their name implies, they continuously sift the substrate for benthic invertebrates, making a soft sand substrate an absolute necessity to prevent mouth and gill damage. While generally peaceful for a cichlid, they become fiercely territorial during breeding.

Half Banded Spiny Eel

Macrognathus circumcinctus

Oddballs

20 cm Mostly Peaceful

A fascinating, peaceful bottom-dweller with a pointed snout and distinct banding. Like all spiny eels, they are notorious escape artists and require a tightly fitting lid. A soft sand substrate is absolutely mandatory to prevent skin abrasions and subsequent bacterial infections when they burrow. They are nocturnal micropredators that will hunt small shrimp and fry, but remain peaceful toward larger tank mates.

Haplochromis sp. 44 (Thick Skin)

Haplochromis sp. 44

Cichlids - African

12 cm Aggressive

A stunning but highly aggressive cichlid originating from the Lake Victoria basin. Known in the hobby as 'CH44', they are famous for the male's intense coloration featuring red, yellow, and blue with distinct black vertical barring. Due to their extreme territoriality, they require a spacious aquarium with plenty of rockwork (caves) to break line of sight, and must be kept in specific male-to-female ratios.

Harlequin Rasbora

Trigonostigma heteromorpha

Cyprinids

4.5 cm Peaceful

A highly popular, peaceful schooling fish recognizable by its metallic copper/orange body and the distinct black triangular 'porkchop' patch on its hindquarters. Originating from peat swamps and blackwater streams in Southeast Asia, they are active swimmers that thrive in heavily planted aquariums with gentle to moderate water flow.

Harlequin Shark

Labeo variegatus

Cyprinids

16 cm Aggressive

The Harlequin Shark (scientifically valid as Labeo cyclorhynchus, though commonly sold as L. variegatus) is a highly territorial, bottom-dwelling cyprinid native to the Congo River basin. Famous for the spectacular cream and black mottling of juveniles, their colors sadly fade to a darker tone as they mature. They are voracious algae and aufwuchs grazers that require high water flow, smooth substrate to protect their delicate barbels, and must absolutely be kept as a solitary specimen due to their extreme intolerance of conspecifics and other bottom-dwellers.

Head and Tail Light Tetra

Hemigrammus ocellifer

Characins

4.5 cm Peaceful

A peaceful, schooling characin named for the reflective copper/gold spots on its head and the base of its tail. These 'lights' evolved to help the school stay together in the dark, tannin-stained waters of the Amazon basin. They are hardy, active, and make excellent community fish for planted aquariums.

Helicopter Catfish

Wallagonia leerii

Catfish

150 cm Highly Aggressive

A massive, apex predator catfish native to Southeast Asia. Known for its enormous mouth and voracious appetite, this 'monster fish' is completely unsuitable for standard home aquariums. In the wild, they migrate through large rivers and flooded forests. They will consume any tankmate that fits in their massive mouth. Kept almost exclusively by specialized monster fish keepers or public aquaria.

Hi Fin Peppered Cory

Scleromystax macropterus

Catfish

9 cm Peaceful

A spectacular armored catfish native to the fast-flowing, cool-water streams of southern Brazil. Unlike most tropical catfish, it strictly requires sub-tropical temperatures (16-23°C) and high dissolved oxygen. Frequently confused with 'long-fin' mutations of the standard Peppered Cory (C. paleatus), this is a naturally occurring, highly sexually dimorphic species.

Highlands Rainbowfish

Chilatherina campsi

Rainbowfish

9 cm Peaceful

A rare and elegant species endemic to the central highlands of Papua New Guinea. Unlike many tropical rainbowfish, it thrives in slightly cooler, well-oxygenated water. They are very active, peaceful schooling fish characterized by an olive/mauve back, silvery reflections, and a distinct blackish-to-blue mid-lateral stripe.

Hillstream Loach

Beaufortia leveretti

Loaches

12 cm Peaceful

A fascinating bottom-dweller adapted to fast-flowing mountain streams in Asia. It features a unique, flattened body allowing it to cling to smooth rocks in heavy currents. It requires highly oxygenated, cooler water (18-24°C) with strong flow. Often confused or mislabeled in the trade with its smaller, more common cousin, Beaufortia kweichowensis. They are specialized grazers that feed heavily on biofilm and algae.

Honduran Red Point

Amatitlania sp. 'Honduran Red Point'

Cichlids - Central American

8 cm Semi-Aggressive

A beautiful, smaller relative of the Convict Cichlid. They boast an iridescent blue and purple body with red or orange fins. While significantly more peaceful than true Convicts, they are still Central American cichlids and become highly territorial when breeding. They love to dig, rearrange sand, and claim caves.

Honey Blue Eye

Pseudomugil mellis

Rainbowfish

3 cm Peaceful

A rare, stunning nano shoaling fish endemic to the acidic, tannin-stained 'wallum' heathlands of Queensland, Australia. Known for their honey-golden bodies and striking blue eyes, they are highly active but peaceful. They require mature, slightly acidic, soft water aquariums with dense planting. Listed as Endangered in the wild.

Honey Gourami

Trichogaster chuna

Anabantoids

5 cm Peaceful

The smallest and most peaceful member of the Trichogaster genus. Ideally suited for planted nano aquariums. Unlike the aggressive Dwarf Gourami (*T. lalius*), Honey Gouramis are timid and gentle. True Honey Gouramis rarely exceed 5cm. Note: Many bright red fish sold as 'Red Honey' or 'Red Robin' are actually Thick-lipped Gouramis (*T. labiosa*), which grow larger.

Hongsloi Apistogramma

Apistogramma hongsloi

Cichlids - South American

6 cm Semi-Aggressive

A striking dwarf cichlid native to the Orinoco River basin in South America. They are popular for their vivid red, yellow, and blue colors. Best kept in blackwater setups with soft, acidic water and plenty of leaf litter. They form harems and require sand substrate, as they sift sand through their gills to find food.

Horei Cichlid

Ctenochromis horei

Cichlids - African

18 cm Aggressive

A robust and highly aggressive haplochromine cichlid native to Lake Tanganyika. Known for its striking coloration and dynamic, albeit violent, territorial behavior. Adults are opportunistic predators and piscivores. They are maternal mouthbrooders, and males are fiercely intolerant of other males. They require hard, alkaline water.

Horned Nerite Snail

Clithon corona

Invertebrates

1.5 cm Peaceful

A highly effective and tiny algae-eating snail characterized by the horn-like spikes on its shell. It is completely peaceful and will not reproduce in freshwater (though it may lay unsightly white eggs on decor). It requires an established tank with plenty of algae and hard, alkaline water to prevent shell erosion. Known to climb out of aquariums if a lid is not secure.

Humpbacked Limia

Limia nigrofasciata

Livebearers

6 cm Peaceful

An active, hardy livebearer endemic to Lake Miragoane in Haiti. They are renowned for their striking sexual dimorphism and enthusiastic grazing on algae. Being from a specific rift-style lake, they strongly require hard, alkaline water to thrive and prevent disease.

Hystrix Stingray (Porcupine Ray)

Potamotrygon hystrix

Oddballs

40 cm Semi-Aggressive

One of the smaller species of freshwater stingray, yet it still requires a massive aquarium with a vast floor footprint. They are bottom-dwelling predators that absolutely require a fine sand substrate to bury themselves; coarse gravel will cause fatal infections to their soft underbellies. They possess a venomous tail barb and demand extreme filtration due to their massive bioload.

Incolicana Corydoras

Corydoras incolicana

Catfish

6.5 cm Peaceful

The Incolicana Corydoras (also designated as C001 in the DATZ system) is a peaceful, armored catfish originating from the Rio Içana in the Rio Negro basin. It features a classic Corydoras shape with a cream-colored body adorned with horizontal bands of brown spots and a distinctive orange patch on its head. As an obligate schooling fish and bottom-dweller, it requires a soft, sandy substrate to prevent damage to its delicate sensory barbels.

Indian Glassfish

Parambassis ranga

Oddballs

8 cm Peaceful

The Indian Glassfish is a fascinating schooling fish famous for its completely transparent body, allowing you to see its skeletal structure and internal organs. Originally from South Asia, they are highly adaptable but thrive best in hard, alkaline freshwater or low-end brackish setups. They are timid and must be kept in groups. Note: Artificially injected 'Painted Glassfish' suffer severely reduced immune systems and lifespans; supporting the natural, clear form is strongly recommended.

Indonesian Datnoid (Tiger Fish)

Datnioides microlepis

Oddballs

40 cm Semi-Aggressive

A massive, deep-bodied ambush predator highly prized by monster fish keepers for its striking black and gold 'tiger' stripes. Native to the freshwater rivers of Southeast Asia, they possess huge mouths and will consume any fish small enough to fit. They are notoriously shy when young but grow into bold, impressive centerpieces. Due to intense conspecific aggression, they should be kept entirely solitary or in groups of 4 or more to disperse bullying.

Indonesian Giant Snakehead

Channa micropeltes

Oddballs

100 cm Highly Aggressive

One of the largest, most aggressive, and predatory freshwater fish in the world. The Giant Snakehead is an apex predator equipped with a labyrinth organ, allowing it to breathe atmospheric air. In captivity, they require massive, heavily secured indoor ponds or custom ultra-large aquariums. They possess crushing jaw strength and will consume or brutally attack almost any tank mate.

Intermedius Cichlid

Tramitichromis intermedius

Cichlids - African

16 cm Semi-Aggressive

A peaceful to semi-aggressive 'earth-eating' cichlid endemic to the sandy shores of Lake Malawi. They continuously sift fine sand through their gills to forage for small invertebrates. While relatively peaceful compared to Mbuna, they require hard, alkaline water, ample floor space, and a strictly sandy substrate to prevent damage to their delicate gills.

Irian Jaya Rainbowfish

Melanotaenia irianjaya

Rainbowfish

10 cm Peaceful

A beautiful, highly active shoaling fish native to the rainforest streams of West Papua, Indonesia. Known for their striking mauve bodies, bold blue lateral bands, and red fins with white margins. They are fast, robust swimmers that require plenty of open horizontal space and a tight-fitting lid to prevent jumping. While peaceful, their voracious eating habits and speed can easily outcompete shy or slow-moving tank mates.