🟢 Green Severum – (Heros efasciatus) – Amazon Basin South American Cichlid

The Green Severum (Heros efasciatus) is a large, deep-bodied South American cichlid known for its olive-green coloration, dark vertical bars, intelligent behavior, and generally calmer temperament compared with many similarly sized cichlids.

Healthy adults can develop attractive combinations of:

• Olive green
• Blue-green
• Gold
• Bronze
• Yellow
• Turquoise
• Orange
• Red facial markings

depending on the individual, age, sex, mood, and aquarium conditions.

Green Severums are native to the:

AMAZON RIVER BASIN

of South America.

They occur in river channels, flooded areas, lagoons, vegetated margins, and slower sections of the Amazon system.

Although often called a relatively peaceful cichlid, the Green Severum is still a:

LARGE CICHLID

that can become territorial during breeding and may eat fish small enough to fit into its mouth.

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🔎 Quick Facts – Green Severum

• 📛 Common Name: Green Severum
• 📛 Other Names: Severum, Banded Severum
• 🔬 Scientific Name: Heros efasciatus
• 📅 Originally Described: 1840
• 🐟 Family: Cichlidae
• 🧬 Subfamily: Cichlinae
• 🌎 Origin: South America
• 🌊 Native Drainage: Amazon River Basin
• 🇧🇷 Countries: Brazil
• 🇵🇪 Countries: Peru
• 🇪🇨 Countries: Ecuador
• 🇨🇴 Countries: Colombia
• 🇧🇴 Countries: Bolivia
• 💧 Water Type: Freshwater
• 📏 Scientific Maximum: Approximately 17 cm / 6.7 inches standard length
• 📏 Adult Planning Size: Approximately 8–10 inches total length
• 🏠 Recommended Aquarium: Approximately 75 gallons or larger for one adult
• 🏠 Pair / Community Aquarium: Approximately 90–125+ gallons preferred
• 🌡️ Temperature: Approximately 76–84°F
• 💧 pH: Approximately 5.5–7.5
• 💦 Water: Soft to moderately mineralized
• 🌊 Water Movement: Low to Moderate
• 💨 Oxygenation: Good
• 🍽️ Diet: Omnivore with Strong Plant / Fruit Component
• 🌿 Plant Foods: Very Important
• 🦐 Animal / Insect Protein: Supplemental
• 😌 Temperament: Relatively peaceful for a large cichlid
• ⚠️ Breeding Temperament: Territorial
• 🐠 Small Fish: May be eaten
• 🌿 Live Plants: May be eaten or uprooted
• 🥚 Breeding: Open Substrate Spawner
• 👨‍👩‍👧 Parental Care: Biparental
• 🚫 Mouthbrooder: No
• ⭐ Care Level: Intermediate
• 🌎 IUCN Status: Least Concern
• 📦 Current Listing Size: Approximately 7–8 inches
• 📦 Current Shipping Requirement: Special Bag Required

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🧬 Valid Scientific Species

The currently accepted scientific name is:

Heros efasciatus Heckel, 1840

The current Catalog of Fishes continues to recognize:

Heros efasciatus

as a valid species.

It belongs to the South American cichlid genus:

Heros

which contains several similar-looking species that have historically been confused in both scientific literature and the aquarium trade.

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⚠️ Severum Identification Has a Complicated History

The common name:

SEVERUM

has been used loosely for multiple members of the genus Heros.

Older aquarium literature frequently labeled many Severums as:

Heros severus

even when they were not actually that species.

This has created decades of confusion involving:

• Heros efasciatus
• Heros severus
• Heros liberifer
• Other regional Heros forms
• Aquarium color strains
• Locality populations

For this product:

GREEN SEVERUM = Heros efasciatus

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⚠️ Green Severum Is Not the Mouthbrooding Severum

This is an important correction.

You may find older aquarium sources claiming that:

SEVERUMS ARE MOUTHBROODERS

That statement should not be applied to Heros efasciatus.

The Green Severum:

HEROS EFASCIATUS

is an:

OPEN-SUBSTRATE SPAWNER

that deposits adhesive eggs on surfaces such as:

• Flat rocks
• Roots
• Wood
• Other cleaned surfaces

Both parents guard:

• Eggs
• Larvae
• Fry

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🆚 Heros liberifer

The unusual mouthbrooding behavior historically associated with some “Severums” belongs especially to:

Heros liberifer

a species formally described from the:

RIO ORINOCO DRAINAGE

in 2015.

Therefore:

DO NOT DESCRIBE H. EFASCIATUS AS A MOUTHBROODER

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🌎 Native Distribution – Important Correction

The older Green Severum page lists:

Amazon, Orinoco and Essequibo Basins

I would remove that.

Current taxonomic references place Heros efasciatus within the:

AMAZON RIVER BASIN

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🌊 Amazon Basin Distribution

Current records recognize Heros efasciatus from the Amazon basin across portions of:

• Brazil
• Peru
• Ecuador
• Colombia
• Bolivia

More specific historical records include portions of the:

• Rio Negro
• Ucayali River
• Marañón River
• Nanay River
• Solimões
• Amazon River

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⚠️ Do Not List the Orinoco as the Main Range

The:

RIO ORINOCO

contains other members of the genus Heros.

For example:

• Heros liberifer
• Heros severus

are associated with the Orinoco system.

For the Green Severum product page:

AMAZON RIVER BASIN

is the appropriate origin.

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🌿 Natural Habitat

Green Severums are associated with freshwater environments including:

• River margins
• Flooded areas
• Floodplain habitats
• Lagoons
• Slow-moving sections
• Areas with heavy riverbank vegetation
• Submerged roots
• Woody structure

They are not specialized high-current river fish.

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🌊 Water Movement

Unlike many rheophilic plecos:

GREEN SEVERUMS DO NOT REQUIRE STRONG CURRENT

A better aquarium environment provides:

LOW TO MODERATE WATER MOVEMENT

with good filtration and adequate oxygenation.

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🌿 Flooded Forest Influence

The Amazon experiences large seasonal changes in water level.

Flooded areas provide access to:

• Plant matter
• Fruits
• Seeds
• Insects
• Small aquatic animals
• Organic material

This helps explain the species' unusual natural diet.

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🍽️ Diet – Omnivorous but Mainly Frugivorous in Nature

One of the most interesting scientific facts about Heros efasciatus is that it is described as:

OMNIVOROUS BUT MAINLY FRUGIVOROUS

in nature.

That means fruit and other plant material form an important part of its natural feeding ecology.

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🌿 Plant Foods Are Important

A healthy captive diet should include regular plant-based foods.

Good options include:

• Spirulina-containing pellets
• Vegetable-based cichlid pellets
• Quality omnivore pellets
• Blanched spinach
• Romaine lettuce
• Green peas
• Zucchini
• Squash
• Green beans

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🍎 Fruit in the Natural Diet

Wild Green Severums can consume fruit available during seasonal flooding.

Fruit can be used occasionally in captivity, but it should be:

A SMALL PART OF A BALANCED AQUARIUM DIET

rather than fed heavily because uneaten fruit can quickly deteriorate water quality.

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🦐 Animal & Insect Foods

Green Severums will also readily consume:

• Mysis shrimp
• Brine shrimp
• Krill
• Bloodworms
• Insect larvae
• Quality cichlid pellets
• Appropriate frozen foods

These provide useful:

SUPPLEMENTAL PROTEIN

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⚖️ Balanced Feeding

A good captive feeding program combines:

QUALITY CICHLID FOOD + PLANT FOODS + MODERATE ANIMAL PROTEIN

rather than using an extremely meat-heavy diet.

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🚫 Avoid an All-Protein Diet

Green Severums should not be maintained primarily on:

• Shrimp
• Krill
• Bloodworms
• Fish meat
• High-protein carnivore pellets

The natural diet contains an important plant and fruit component.

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🚫 Beef Heart Is Unnecessary

There is no biological need to feed Green Severums:

BEEF HEART

A varied diet based on quality aquatic foods and plant material is a better long-term choice.

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🎨 Natural Appearance

The wild-type Green Severum generally has a:

• Olive-green
• Gray-green
• Blue-green
• Golden-green

body.

Dark vertical bands may appear across the sides.

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⚫ Vertical Bars

Depending on:

• Mood
• Stress
• Dominance
• Breeding condition
• Lighting
• Background

the vertical bars can become:

• Very dark
• Moderately visible
• Nearly invisible

This color change is normal.

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🔴 Facial Markings

Mature specimens, particularly males, may develop attractive:

• Red
• Orange
• Brown-red
• Turquoise

markings across the:

• Face
• Cheeks
• Gill covers

These worm-like markings are often called:

VERMICULATIONS

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♂️ Mature Male Appearance

Mature males often develop:

• More facial vermiculation
• Longer dorsal-fin extensions
• Longer anal-fin extensions
• More pointed fins
• Larger overall body size
• Occasionally a modest nuchal hump

However:

NONE OF THESE FEATURES IS 100% RELIABLE BY ITSELF

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♀️ Mature Female Appearance

Mature females may:

• Have fewer facial markings
• Retain more visible dark body bars
• Have rounder fin tips
• Develop a fuller abdominal profile when carrying eggs

Again:

SEXING BY APPEARANCE ALONE IS NOT FOOLPROOF

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🧬 Green Severum vs. Gold & Red Strains

The natural Green Severum should not automatically be confused with aquarium strains such as:

• Gold Severum
• Red Spot Gold Severum
• Super Red Severum
• Red Shoulder Severum / Rotkeil

Some are:

• Color mutations
• Selectively bred lines
• Distinct locality forms
• Different Heros populations

They should retain their own accurate product identification.

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📏 Adult Size

FishBase documents a maximum of approximately:

17 CM / 6.7 INCHES STANDARD LENGTH

for Heros efasciatus.

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⚠️ Standard Length Does Not Include the Full Tail

Standard length is measured from:

THE SNOUT TO THE BASE OF THE CAUDAL FIN

The tail fin itself is excluded.

Therefore, aquarium fish can have a larger:

TOTAL LENGTH

than the scientific standard-length measurement suggests.

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📏 Responsible Adult Planning Size

Aquarium references commonly report mature Severums around:

8–10 INCHES TOTAL LENGTH

For long-term housing:

PLAN FOR APPROXIMATELY 8–10 INCHES

rather than assuming every fish will stop at exactly 8 inches.

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🏠 Aquarium Size

The older product page recommends:

55 GALLONS

I would consider that too tight as the normal permanent recommendation for a full-grown Green Severum.

For one mature adult:

75 GALLONS OR LARGER

is more appropriate.

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🏠 Pair or Community Aquarium

For a bonded pair or a Green Severum kept with other substantial fish:

90–125+ GALLONS

is preferable.

Larger aquariums provide:

• More swimming room
• Better water stability
• Greater territory separation
• More tankmate options
• Better breeding management

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📐 Aquarium Footprint

Severums have:

• Deep bodies
• Large adult dimensions
• Significant territorial requirements

so aquarium:

LENGTH + WIDTH

are important.

A long aquarium is preferable to a tall, narrow display tank.

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🪵 Aquarium Setup

A good Green Severum aquarium can include:

• Large driftwood
• Roots
• Smooth rocks
• Large open swimming areas
• Sand or smooth gravel
• Sheltered areas
• Strong filtration

The aquascape should provide both:

OPEN SPACE + STRUCTURE

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🌿 Live Plants – Important Warning

Green Severums are:

NOT RELIABLY PLANT-SAFE

They may:

• Eat leaves
• Tear plants
• Uproot plants
• Bite new growth
• Rearrange planted areas

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🌱 Tough Plants

If live plants are attempted, better choices are generally:

• Tough-leaved species
• Plants attached to wood
• Plants attached to rocks

Even then:

NO PLANT IS GUARANTEED TO BE SEVERUM-PROOF

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🪵 Driftwood & Roots

Driftwood is excellent for:

• Visual barriers
• Territory boundaries
• Natural appearance
• Shelter
• Spawning options

Large branching wood also helps create an Amazon-style environment.

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⚠️ Secure Aquarium Décor

Large Severums are strong fish.

Make sure:

• Rocks are stable
• Wood cannot fall
• Decorations cannot trap the fish

Breeding pairs may rearrange the aquarium.

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🌡️ Temperature

FishBase documents a broad tropical environmental range around:

24–32°C / 75–90°F

That does not mean the fish should routinely be maintained at 90°F.

A practical aquarium maintenance range is:

76–84°F

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💧 pH

Green Severums are adaptable in captivity.

A practical range is approximately:

pH 5.5–7.5

They generally do especially well in:

• Slightly acidic
• Neutral
• Moderately soft

water.

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⚠️ Stability Is More Important Than Chasing a Number

Avoid repeatedly altering the aquarium with chemicals simply to hit an exact pH.

Healthy Severums do better with:

STABLE WATER CONDITIONS

than with constantly fluctuating chemistry.

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💧 Water Parameters

A practical long-term range is:

• 🌡️ Temperature: Approximately 76–84°F
• 💧 pH: Approximately 5.5–7.5
• 💦 Hardness: Soft to Moderately Mineralized
• 🌊 Water Movement: Low to Moderate
• 💨 Oxygenation: Good
• ☠️ Ammonia: 0 ppm
• ☠️ Nitrite: 0 ppm
• 🔄 Nitrate: Keep as low as reasonably practical

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💩 Large Cichlid = Significant Bioload

An adult Severum is a substantial fish.

It produces:

• Feces
• Uneaten food
• Dissolved organic waste

and therefore needs dependable filtration.

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💨 Filtration

Suitable filtration may include:

• Large canister filters
• Sump filtration
• Large hang-on-back filtration systems
• Supplemental biological filtration

Use enough mechanical filtration to capture:

• Food debris
• Plant fragments
• Waste

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🔄 Water Changes

Regular partial water changes are important.

Frequency depends on:

• Aquarium size
• Fish size
• Number of fish
• Feeding
• Filtration
• Nitrate production

Maintain:

AMMONIA = 0

and:

NITRITE = 0

at all times.

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😌 Temperament – Peaceful for a Large Cichlid

Green Severums are commonly described as:

RELATIVELY PEACEFUL

That description is fair when compared with aggressive Central and South American cichlids.

However:

RELATIVELY PEACEFUL DOES NOT MEAN COMPLETELY NON-AGGRESSIVE

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⚠️ Still a Cichlid

Green Severums can:

• Defend territories
• Chase tankmates
• Fight with other Severums
• Become aggressive when paired
• Guard spawning sites
• Eat small fish

Temperament also varies between individuals.

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🥚 Breeding Aggression

A normally peaceful pair can become much more territorial after:

• Pairing
• Cleaning a spawning surface
• Laying eggs
• Protecting fry

A breeding pair may claim a substantial portion of the aquarium.

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🐟 Small Fish May Be Eaten

Do not assume that because Severums are relatively calm they are safe with:

• Neon tetras
• Tiny rasboras
• Small guppies
• Very small juvenile fish
• Dwarf shrimp

A large Severum may simply:

EAT THEM

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🐠 Tankmates

Potential tankmates can include appropriately sized:

• Larger tetras
• Silver dollars
• Geophagus
• Larger peaceful catfish
• Plecos
• Other moderate South American cichlids

Compatibility always depends on:

• Aquarium size
• Individual temperament
• Territory
• Breeding status

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⚠️ Avoid Highly Aggressive Cichlids

Green Severums can be bullied by extremely aggressive species.

Use caution with large aggressive:

• Amphilophus
• Parachromis
• Highly territorial Vieja
• Other very aggressive cichlids

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⚠️ Avoid Tiny Tankmates

Also avoid fish that are:

SMALL ENOUGH TO SWALLOW

even if they are technically peaceful community species.

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👥 Keeping Multiple Severums

Multiple Green Severums can be kept together in sufficiently large aquariums.

However:

• Dominance hierarchies develop
• Pairs may form
• Territorial aggression can increase
• Subordinate fish may be harassed

Large aquariums with:

• Visual barriers
• Multiple territories
• Open swimming space

are essential.

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🧠 Intelligent & Interactive

Severums are well known for becoming:

INTERACTIVE WITH THEIR KEEPERS

They may learn to:

• Recognize feeding routines
• Approach the front glass
• Follow people around the room
• Beg for food
• Establish recognizable personalities

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♂️ Male vs. Female

Sexing Green Severums is not always easy.

Mature Males May Show:

• More extensive facial vermiculation
• More pointed dorsal fin
• More pointed anal fin
• Longer fin extensions
• Larger body size
• Stronger head profile

Mature Females May Show:

• Less facial vermiculation
• Rounder fins
• Fuller abdomen
• More persistent body bars

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⚠️ Facial Markings Are Not a Guarantee

Facial vermiculation is useful, but:

DO NOT GUARANTEE SEX BASED ONLY ON FACE PATTERN

Individual variation exists.

The most reliable confirmation comes from:

• Mature breeding behavior
• Genital papilla examination
• Proven spawning history

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🥚 Breeding – Open Substrate Spawner

Green Severums are:

OPEN-SUBSTRATE SPAWNERS

They typically select and clean a surface such as:

• Flat stone
• Slate
• Root
• Driftwood
• Large leaf
• Aquarium surface

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🚫 Green Severums Are Not Mouthbrooders

This deserves repeating because of widespread older aquarium information:

HEROS EFASCIATUS IS NOT THE MOUTHBROODING SEVERUM

It deposits eggs openly and protects them at the spawning site.

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💕 Pair Formation

Severums generally form:

PAIR BONDS

Finding a compatible pair is often more difficult than inducing an established pair to spawn.

Aquarists frequently obtain several juveniles and allow a natural pair to form.

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🧹 Preparing the Spawning Site

Before spawning, both adults may:

• Clean a rock
• Clean a piece of wood
• Dig around the area
• Chase tankmates away
• Intensify coloration

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🥚 Egg Production

Scientific references report:

UP TO APPROXIMATELY 1,000 EGGS

being deposited on:

• Flat stones
• Roots

Actual clutch size varies according to:

• Female size
• Age
• Conditioning
• Pair experience

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👨‍👩‍👧 Biparental Care

One of the most impressive Green Severum behaviors is:

BOTH PARENTS CARE FOR THE BROOD

The parents participate in:

• Guarding eggs
• Fanning eggs
• Defending the territory
• Protecting larvae
• Guarding fry

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🐣 Hatching

Eggs normally hatch within several days depending on:

• Temperature
• Water chemistry
• Oxygenation

The parents may move newly hatched larvae to prepared depressions or other protected locations.

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👶 Free-Swimming Fry

Once free swimming, fry can receive foods such as:

• Baby brine shrimp
• Microworms
• Fine powdered cichlid food
• High-quality fry food

Feed small portions frequently while maintaining excellent water quality.

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⚠️ New Parents May Fail

Young or inexperienced pairs sometimes:

• Eat eggs
• Eat larvae
• Abandon the spawn
• Fight with each other

This does not necessarily mean the pair will never reproduce successfully.

Many cichlid pairs improve after repeated spawning attempts.

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🌎 Conservation Status

Heros efasciatus is currently classified as:

LEAST CONCERN

on the IUCN Red List.

The species is widespread within the Amazon system.

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⚠️ Least Concern Does Not Mean Release Is Acceptable

Even common aquarium fish must never be released outside their native environment.

Released cichlids can:

• Compete with native fish
• Introduce parasites
• Introduce disease
• Disrupt local ecosystems

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⭐ Why Keep a Green Severum?

The Green Severum combines:

• 🟢 Attractive natural green coloration
• 🐟 Large disc-shaped body
• 🧠 Intelligent interactive behavior
• 😌 Relatively calm cichlid temperament
• 🌿 Fascinating plant- and fruit-oriented feeding ecology
• 🌎 Amazon Basin origin
• 🥚 Impressive spawning behavior
• 👨‍👩‍👧 Strong biparental care
• 📏 Impressive 8–10 inch adult presence

into one of the most popular larger South American cichlids in the aquarium hobby.

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⚠️ Important Considerations

Before purchasing a Green Severum:

• The correct scientific name is Heros efasciatus.
• Heros efasciatus remains a valid species.
• Do not automatically call all Severums Heros severus.
• Green Severums are Amazon Basin fish.
• Remove the Orinoco Basin from the normal H. efasciatus range.
• Remove the Essequibo Basin from the normal product range.
• The Orinoco contains other Heros species.
• Green Severums are open-substrate spawners.
• Do not describe H. efasciatus as a mouthbrooder.
• Both parents guard the eggs and fry.
• Up to approximately 1,000 eggs have been reported scientifically.
• Wild H. efasciatus are omnivorous but mainly frugivorous.
• Plant foods should be an important part of the aquarium diet.
• Animal and insect protein should provide variety rather than dominate the diet.
• Do not maintain Green Severums on an all-protein diet.
• Do not rely on beef heart.
• Green Severums may eat aquarium plants.
• Scientific maximum is approximately 17 cm / 6.7 inches standard length.
• Standard length excludes the full tail.
• Plan for approximately 8–10 inches total adult length.
• Provide approximately 75 gallons or larger for one adult.
• Use approximately 90–125+ gallons for a pair or substantial community.
• Maintain approximately 76–84°F.
• Maintain approximately pH 5.5–7.5.
• Low to moderate current is sufficient.
• Maintain good oxygenation and filtration.
• Keep ammonia and nitrite at zero.
• Green Severums are relatively peaceful for large cichlids.
• They can still become territorial.
• Breeding pairs can become significantly more aggressive.
• Very small fish may be eaten.
• Sexing by coloration alone is not guaranteed.
• The species is currently Least Concern.
• Never release aquarium fish into natural waterways.

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🧬 Taxonomy

The currently accepted scientific name is:

Heros efasciatus Heckel, 1840

Classification:

• Order: Cichliformes
• Family: Cichlidae
• Subfamily: Cichlinae
• Genus: Heros
• Species: efasciatus

Current recognized native distribution:

AMAZON RIVER BASIN – SOUTH AMERICA

including records from:

• Brazil
• Peru
• Ecuador
• Colombia
• Bolivia

For this product, use:

Green Severum – (Heros efasciatus)

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🧬 Severum Identification Disclaimer

The genus Heros has a complicated taxonomic and aquarium history.

Several different:

• Species
• Locality forms
• Color strains

have historically been marketed simply as:

SEVERUM

For accurate breeding and sales records, preserve:

• Scientific identification
• Locality when known
• Breeder information
• Color-strain information

Do not deliberately mix different Heros forms and later represent the offspring as a documented pure locality fish.

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🚚 Live Fish Shipping

Live fish are professionally packed for safe transport.

Shipping availability depends on:

• Fish size
• Destination
• Weather conditions
• Carrier availability
• Applicable state and local regulations

The current Green Severum listing is approximately:

7–8 INCHES

and requires:

SPECIAL BAG PACKING

Large Severums may require:

• Larger insulated shipping boxes
• Additional water
• Heavy-duty shipping bags
• Multiple protective bag layers
• Specialized packing
• Airline cargo depending on size and destination

Please review our Shipping & Payment Information and Live Arrival Guarantee / DOA Policy before ordering.

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⚠️ Buyer Responsibility

Customers are responsible for confirming that Heros efasciatus may legally be purchased, possessed, transported, and received in their state or local jurisdiction before ordering.

Never release aquarium fish into natural waterways.