African Starry Night Eel - (Mastacembelus frenatus)

Fish Details, Description and Information Below:

🌌 African Starry Night Eel – (Mastacembelus frenatus) – African Longtail Spiny Eel

The African Starry Night Eel (Mastacembelus frenatus), also known as the Longtail Spiny Eel or East African Spiny Eel, is a fascinating African freshwater fish known for its long eel-like body, pointed snout, secretive personality, and highly variable dark pattern.

Depending on the individual, its coloration can include combinations of:

Brown
Tan
Olive
Dark chocolate
Black
Cream
Yellow-brown

with:

Spots
Blotches
Reticulated markings
Broken lines
Irregular star-like patterns

running along the body.

Despite the common name:

THIS IS NOT A TRUE EEL

It belongs to the freshwater spiny eel family Mastacembelidae, rather than the true eel order Anguilliformes.

🔎 Quick Facts – African Starry Night Eel

📛 Common Name: African Starry Night Eel
📛 Other Names: Longtail Spiny Eel, East African Spiny Eel
🔬 Scientific Name: Mastacembelus frenatus
📅 Described: 1901
🐟 Family: Mastacembelidae
🧬 Order: Synbranchiformes
📏 Current Offered Size: Approximately 4–5 inches
🌍 Origin: Africa
🌊 Native Range: East, Central and Southern African freshwater systems
🏞️ Major Systems: Lake Victoria, Lake Tanganyika, upper Congo, upper Zambezi and Okavango
💧 Water Type: Freshwater
📏 Scientific Maximum: 40 cm / approximately 15.7 inches standard length
📏 Adult Planning Size: Approximately 16–18 inches total length
🏠 Minimum Permanent Aquarium: Approximately 75 gallons
🏠 Preferred Adult Aquarium: 90+ gallons
📐 Aquarium Shape: Long aquarium strongly preferred
🌡️ Temperature: Approximately 73–81°F
💧 pH: Approximately 7.4–8.4
💦 Hardness: Approximately 7–30 dH
💨 Oxygenation: Good to High
🌊 Water Movement: Gentle to Moderate with good circulation
🏖️ Substrate: Fine, soft sand strongly recommended
🪨 Shelter: Caves, rocks, roots and driftwood
🔒 Secure Lid: Absolutely Essential
🍽️ Diet: Predatory Carnivore / Invertebrate Feeder
🪱 Primary Foods: Worms, insect larvae, shrimp and other aquatic invertebrates
🐟 Small Fish: May be eaten
🌙 Activity: Primarily Nocturnal
😌 Temperament: Generally peaceful toward fish too large to swallow
⚠️ Spines: Dorsal spines can snag nets and injure careless handlers
🥚 Breeding: Flood-season spawner in nature
🧪 Captive Breeding: Rare / poorly documented
⭐ Care Level: Intermediate
🌎 Conservation Status: Least Concern

🧬 Valid Scientific Species

The currently accepted scientific name is:

Mastacembelus frenatus

The species was described by:

George Albert Boulenger in 1901

Modern taxonomic references continue to recognize:

Mastacembelus frenatus

as the valid species name.

Some aquarium sources may use:

Afromastacembelus frenatus

but modern taxonomic work does not support maintaining Afromastacembelus as a separate genus.

For this product, use:

**African Starry Night Eel – (Mastacembelus frenatus)**

⚠️ Not a True Eel

Although it has an eel-like body, Mastacembelus frenatus is:

NOT A TRUE EEL

True eels belong to:

ORDER ANGUILLIFORMES

The African Starry Night Eel belongs to:

ORDER SYNBRANCHIFORMES

and:

FAMILY MASTACEMBELIDAE

These fish are commonly known as:

SPINY EELS

🦔 Why Is It Called a Spiny Eel?

Along the back of the fish are numerous individual:

DORSAL SPINES

before the soft dorsal fin.

Mastacembelus frenatus can have approximately:

18–35 DORSAL SPINES

These spines are part of the reason members of this family are called:

SPINY EELS

⚠️ Spines Are Not Venomous

The dorsal spines should be respected because they can:

Prick skin
Catch in aquarium nets
Become tangled during handling

However:

THE SPECIES IS NOT CONSIDERED VENOMOUS

Care is still required whenever handling or transferring the fish.

👃 Specialized Snout

The African Starry Night Eel has an unusual:

ELONGATED, FLESHY SNOUT

The anterior nostrils form short tubular structures.

The fish uses its sensitive snout while searching through:

Sand
Crevices
Vegetation
Rocks

for prey.

🎨 Appearance

Mastacembelus frenatus is naturally:

EXTREMELY VARIABLE IN COLOR

The base coloration is usually some shade of:

Brown
Tan
Olive-brown
Chocolate
Gray-brown

with variable:

Spots
Blotches
Reticulations
Broken stripes
Dark bands

🌌 Why “Starry Night”?

The aquarium name:

STARRY NIGHT EEL

refers to individuals whose body pattern contains numerous contrasting:

Pale spots
Small markings
Broken patterns

that can resemble stars scattered across a dark background.

However:

**NOT EVERY M. frenatus WILL HAVE AN IDENTICAL STARRY PATTERN**

The species is naturally variable.

⚠️ Pattern Disclaimer

Exact coloration and pattern cannot be guaranteed.

Individual specimens may differ substantially in:

Spot size
Number of spots
Body darkness
Reticulated pattern
Stripe development
Contrast

Appearance can also change with:

Stress
Shipping
Lighting
Substrate color
Age
Acclimation
Water conditions

🌍 Native Distribution

The African Starry Night Eel has an unusually broad African distribution.

It occurs from:

EAST AFRICA

through:

CENTRAL AFRICA

and into portions of:

SOUTHERN AFRICA

🌊 Lake Victoria Basin

The species occurs throughout portions of the:

LAKE VICTORIA BASIN

and associated river systems.

Records include waters associated with:

Uganda
Kenya
Tanzania

🌊 Lake Tanganyika Region

Mastacembelus frenatus also occurs in:

LAKE TANGANYIKA

and its associated drainage systems.

This does not mean the species is exclusively a Lake Tanganyika eel.

Its distribution is much broader.

🌊 Upper Congo Basin

The species is also documented in the:

UPPER CONGO RIVER BASIN

including records from:

Democratic Republic of the Congo
Zambia

🌊 Upper Zambezi

The range extends southward into the:

UPPER ZAMBEZI SYSTEM

with records from portions of:

Zambia
Zimbabwe
Angola
Namibia

🌊 Okavango

The species is also found within the:

OKAVANGO RIVER SYSTEM

making this one of the more geographically widespread African spiny eels.

🇹🇿 East-Flowing Tanzanian Rivers

Populations are additionally documented from:

EASTWARD-FLOWING RIVERS OF TANZANIA

For the product page, the most accurate concise origin is:

EAST, CENTRAL & SOUTHERN AFRICA

rather than simply:

African Rivers

🌊 Natural Habitat

The African Starry Night Eel occupies a surprisingly broad range of freshwater habitats.

It is primarily a:

RIVERINE SPECIES

but is also found in:

Lakes near river mouths
Vegetated lake margins
Swamps
Flooded areas
Rocky streams
Rapids

🪨 Rapids & Rocks

The species has been documented in:

RAPIDS

where individuals shelter among:

Rocks
Crevices
Submerged structure

This shows that the species can tolerate and occupy flowing water.

🌿 Vegetated Margins

It can also inhabit quieter:

Vegetated margins
Swamps
Flooded habitats

Therefore, the aquarium does:

NOT

need to reproduce an extreme high-current river throughout the entire tank.

🏠 Aquarium Setup

A suitable African Starry Night Eel aquarium should contain:

Fine sand
Smooth rocks
Caves
Driftwood
Root structures
Shaded areas
Plants when desired
Open feeding areas
Good filtration
Good oxygenation

🏖️ Soft Sand Is Strongly Recommended

One of the most important aquarium requirements is:

SOFT, FINE SAND

Spiny eels naturally:

Dig
Burrow
Push beneath the substrate
Search the bottom for food

A soft sand substrate allows these behaviors without damaging the skin.

🚫 Avoid Sharp Gravel

Avoid substrates containing:

Sharp gravel
Jagged stones
Crushed coral with sharp edges
Rough decorative rock fragments

Repeated contact with abrasive material can damage the eel's:

Skin
Snout
Belly

and potentially create sites for infection.

🕳️ Burrowing Behavior

Do not be surprised if your Starry Night Eel:

DISAPPEARS INTO THE SAND

Sometimes only the:

Head
Snout
Eyes

remain visible.

This is normal spiny eel behavior.

🪨 Hiding Places

Provide multiple secure hiding places such as:

Smooth caves
PVC-style shelters hidden by décor
Driftwood tunnels
Rock overhangs
Root structures

The fish should always have somewhere dark and secure to retreat.

🌑 Dim Lighting

Because this species is naturally:

NOCTURNAL

subdued lighting can help it feel more secure.

Useful options include:

Floating plants
Shaded caves
Dark backgrounds
Gradual sunrise/sunset lighting

🔒 EXTREME ESCAPE ARTIST

One of the most important warnings for any spiny eel is:

THE AQUARIUM MUST BE COMPLETELY SECURE

Mastacembelus can escape through surprisingly small openings.

🚨 Cover Every Opening

Check carefully around:

Filter hoses
Heater cords
Airline tubing
Overflow boxes
Plumbing
Lid gaps
Feeding openings

If the head fits through:

THE REST OF THE FISH MAY FOLLOW

⚠️ Do Not Rely on a Loose Glass Lid

A proper setup should have:

A TIGHT-FITTING, ESCAPE-RESISTANT COVER

This is not optional.

Escaped spiny eels can quickly become:

Dehydrated
Injured
Lost behind furniture or aquarium stands

📏 Adult Size

FishBase documents Mastacembelus frenatus at:

40 CM STANDARD LENGTH

or approximately:

15.7 INCHES

📏 What Is Standard Length?

Standard length measures from the front of the fish to the end of the vertebral body and:

DOES NOT INCLUDE THE FULL TAIL FIN

Therefore, a 40 cm standard-length fish can have a somewhat greater:

TOTAL LENGTH

📏 Responsible Adult Planning

For permanent housing, customers should plan for approximately:

16–18 INCHES TOTAL LENGTH

with unusually large individuals potentially approaching:

20 INCHES

This is more useful than promising that every specimen will stop at exactly 15 inches.

🏠 Aquarium Size

The older recommendation of:

55 GALLONS

is possible for a smaller individual but is tight for a fully mature 16–18 inch fish.

For permanent adult housing:

75 GALLONS SHOULD BE CONSIDERED A GOOD MINIMUM

with:

90+ GALLONS PREFERRED

📐 Length Matters More Than Height

The African Starry Night Eel spends most of its time:

Along the bottom
Under structure
Searching substrate
Moving horizontally

Therefore:

AQUARIUM LENGTH + BOTTOM AREA

are more useful than a tall aquarium.

4-FOOT OR LONGER AQUARIUM

is strongly preferred for an adult.

👥 Keeping More Than One

More than one African Starry Night Eel may be possible in a sufficiently large aquarium.

However, mature spiny eels can become:

TERRITORIAL WITH ONE ANOTHER

For multiple adults:

A MUCH LARGER AQUARIUM IS RECOMMENDED

with:

Multiple shelters
Large bottom area
Visual barriers
Several feeding locations

💧 Important Water-Chemistry Correction

The older product page listed:

pH 6.5–7.5

Current FishBase information gives a natural range of approximately:

pH 7.4–8.4

Therefore, I would not describe this primarily as an acidic-water fish.

💧 Water Parameters

A practical long-term range is:

🌡️ Temperature: Approximately 73–81°F
💧 pH: Approximately 7.4–8.4
💦 Hardness: Approximately 7–30 dH
💨 Oxygenation: Good to High
🌊 Water Movement: Gentle to Moderate
☠️ Ammonia: 0 ppm
☠️ Nitrite: 0 ppm
🔄 Nitrate: Keep reasonably low

⚠️ Stability Matters

Avoid sudden changes in:

Temperature
pH
Hardness
Salinity

A stable, mature aquarium is much safer than constantly attempting to chase exact numbers.

🧂 Freshwater Species

The African Starry Night Eel is a:

FRESHWATER FISH

Routine addition of aquarium salt is:

NOT REQUIRED

Do not assume that an eel-like fish needs brackish water.

🌊 Water Movement

The species naturally occurs in habitats ranging from:

Rapids

to:

Quieter vegetated areas

Therefore, a good aquarium provides:

GOOD CIRCULATION WITHOUT FORCING EXTREME CURRENT THROUGHOUT THE ENTIRE TANK

💨 Oxygenation

Maintain:

GOOD TO HIGH DISSOLVED OXYGEN

through:

Surface agitation
Air stones when useful
Filter returns
Proper circulation

💩 Filtration

Use reliable:

Mechanical filtration
Biological filtration

Predatory fish fed frozen and meaty foods can create substantial organic waste.

Remove uneaten food promptly.

🔄 Water Changes

Regular partial water changes are important.

Maintain:

AMMONIA = 0

and:

NITRITE = 0

at all times.

Do not allow uneaten:

Worms
Shrimp
Fish pieces

to decay beneath décor.

🍽️ Diet – Predatory Carnivore

Wild Mastacembelus frenatus feed primarily on animal prey.

Documented natural foods include:

Aquatic insect larvae
Insects associated with rocks
Shrimp
Oligochaete worms
Small fish

Only occasional vegetable matter has been recorded.

The best aquarium description is:

PREDATORY CARNIVORE / INVERTEBRATE FEEDER

🪱 Worms Are Excellent Foods

Spiny eels often respond exceptionally well to:

Earthworms
Nightcrawler pieces
Blackworms
Bloodworms

appropriately sized for the individual fish.

🦐 Crustacean Foods

Good foods also include:

Mysis shrimp
Krill
Chopped shrimp
Prawn
Brine shrimp for smaller specimens

🐟 Fish Foods

Wild Starry Night Eels will consume small fish.

In captivity, appropriate alternatives include:

Quality frozen fish
Fish flesh
Carnivore pellets once accepted

🚫 Avoid Routine Feeder Fish

There is no need to regularly feed live feeder fish.

Feeder fish can introduce:

Parasites
Bacteria
Disease
Poor nutritional balance

Frozen, fresh and prepared foods are generally safer.

🥩 Prepared Foods

Some established individuals learn to accept:

Sinking carnivore pellets
Soft sinking sticks
Gel foods
Other prepared predatory-fish foods

However, newly imported or newly acquired fish may initially prefer:

FROZEN OR LIVE INVERTEBRATE FOODS

🍽️ Can Be a Slow Feeder

African spiny eels can be:

DELIBERATE FEEDERS

Fast or aggressive tankmates may consume everything before the eel has an opportunity to eat.

🌙 Feed Near Dusk

Useful feeding times include:

Shortly before lights out
During dim evening lighting
After aquarium lights turn off

Food can also be placed close to the eel's shelter.

🎯 Target Feeding

A feeding:

Pipette
Tongs
Turkey baster

can be useful for delivering food near a shy eel.

Avoid striking or startling the fish with feeding equipment.

😌 Temperament

Toward fish too large to swallow, the African Starry Night Eel is generally:

PEACEFUL

It is not normally an aggressive community predator that attacks large tankmates.

⚠️ Small Fish Are Food

The important exception is:

ANY FISH SMALL ENOUGH TO SWALLOW

Potential prey can include:

Tiny tetras
Small rasboras
Small livebearers
Very small catfish
Small fry

🐠 Tankmates

Good tankmates should be:

Too large to swallow
Not excessively aggressive
Not fin-nipping
Not extremely competitive at feeding time

Potential compatible fish depend on aquarium size and water requirements.

🚫 Avoid Aggressive Cichlids That Harass It

The eel's elongated body and relatively slow feeding style make it vulnerable to persistent harassment.

Avoid fish that repeatedly:

Bite the eel
Nip fins
Attack its snout
Prevent it from feeding

🌙 Nocturnal Hunter

Mastacembelus frenatus is naturally:

NOCTURNAL

In the wild it often remains relatively sedentary inside cover and waits for prey to:

Swim nearby
Drift within range
Move past its shelter

The eel then darts forward to capture it.

☀️ May Learn Daytime Feeding

Established aquarium specimens can become accustomed to:

Their keeper
Feeding schedules
Daytime activity

Some eventually emerge readily when food is offered.

🥚 Natural Reproduction

Unlike many aquarium species where reproduction is poorly understood, some natural reproductive information is available for Mastacembelus frenatus.

The species breeds during:

THE FLOOD SEASON

🌧️ Flooded Habitat Spawning

Wild breeding occurs in:

INUNDATED / FLOODED AREAS

Seasonal rising water likely provides:

Expanded habitat
Vegetation
Food
Protected nursery areas

for eggs and young fish.

🥚 Eggs

The eggs have been described as:

LARGE AND YELLOW

and are believed to be deposited among:

AQUATIC VEGETATION

⚠️ Captive Breeding Is Rare

Despite what is known from the wild:

ROUTINE HOME-AQUARIUM BREEDING IS NOT WELL ESTABLISHED

I would not advertise this as an easily bred aquarium species.

🚫 Do Not Invent a Captive Breeding Formula

Avoid promising that breeding can be achieved simply by:

Raising temperature
Adding caves
Performing one large water change
Keeping a male and female together

Reliable species-specific captive breeding information remains limited.

♂️ Male vs. Female

African Starry Night Eels are:

DIFFICULT TO SEX VISUALLY

External sexual differences are not dependable enough for normal retail sexing.

Unless sex is confidently known:

SELL AS UNSEXED

🛡️ Handling

Spiny eels should be handled carefully.

Potential problems include:

Dorsal spines snagging nets
Skin abrasion
Escape attempts
Powerful twisting

🚫 Avoid Fine Nets When Possible

The separate dorsal spines can become tangled in:

FINE NETTING

For larger specimens, a:

Smooth container
Appropriate fish bag
Large rigid transfer container

may be safer.

⚠️ Protect the Slime Coat

Do not handle the fish unnecessarily with dry hands.

Its skin and protective mucus layer can be damaged by:

Rough handling
Dry surfaces
Sharp substrate
Abrasive decorations

🩹 Skin Damage Matters

Because spiny eels spend substantial time:

Burrowing
Rubbing through substrate
Entering narrow spaces

small skin injuries can become problematic in poor water quality.

Use:

SMOOTH DÉCOR + CLEAN WATER + SOFT SUBSTRATE

🌎 Conservation Status

Mastacembelus frenatus is currently assessed as:

LEAST CONCERN

The current FishBase listing references a global assessment dated:

FEBRUARY 19, 2025

Its broad African distribution contributes to its current conservation classification.

⭐ Why Keep an African Starry Night Eel?

The African Starry Night Eel combines:

🌌 Beautiful variable star-like patterning
🐍 Fascinating eel-like body shape
👃 Specialized sensory snout
🏖️ Natural burrowing behavior
🌙 Nocturnal hunting behavior
🪱 Interesting invertebrate-based feeding
🌍 Broad African distribution
📏 Approximately 16–18 inch adult potential
😌 Generally peaceful behavior toward larger fish
🧬 True African spiny eel biology

into an extremely interesting centerpiece fish for a properly designed freshwater aquarium.

⚠️ Important Considerations

Before purchasing an African Starry Night Eel:

The correct scientific name is Mastacembelus frenatus.
Some older or aquarium references may use Afromastacembelus frenatus.
Modern taxonomy recognizes Mastacembelus frenatus.
This is a spiny eel, not a true eel.
The species was described in 1901.
Its body coloration is naturally extremely variable.
Do not guarantee one specific starry pattern.
The species has a broad African distribution.
It occurs in Lake Victoria and Lake Tanganyika drainage systems.
It also occurs in the upper Congo, upper Zambezi and Okavango systems.
It is primarily riverine but also occupies lakes, swamps, vegetated margins and rapids.
FishBase documents 40 cm / approximately 15.7 inches standard length.
Standard length excludes the full tail.
Plan for approximately 16–18 inches total length.
Some unusually large specimens may approach 20 inches.
Provide approximately 75 gallons minimum for permanent adult housing.
90+ gallons is preferred.
Prioritize aquarium length and bottom area.
Use fine, soft sand.
Avoid sharp gravel.
Provide multiple secure hiding places.
Expect natural burrowing behavior.
Use a completely secure aquarium lid.
Seal even small gaps around plumbing and equipment.
Maintain approximately 73–81°F.
Maintain approximately pH 7.4–8.4.
Do not describe this primarily as an acidic-water fish.
Routine salt addition is unnecessary.
Maintain good dissolved oxygen.
Feed a carnivorous, invertebrate-oriented diet.
Worms, insect larvae and shrimp are excellent foods.
The species may eat small fish.
Avoid routine feeder fish.
Ensure shy specimens receive enough food.
Feed near dusk when necessary.
Choose tankmates too large to swallow.
Avoid aggressive or persistent fin-nipping fish.
The dorsal spines can snag nets.
Captive breeding is uncommon.
Wild breeding occurs during the flood season.
Eggs are large and yellow and are believed to be deposited among vegetation.
The species is currently classified as Least Concern.
Never release aquarium fish into natural waterways.

🧬 Taxonomy

The currently accepted scientific name is:

Mastacembelus frenatus Boulenger, 1901

Classification:

Class: Actinopterygii
Order: Synbranchiformes
Family: Mastacembelidae
Genus: Mastacembelus
Species: frenatus

For this product, use:

**African Starry Night Eel – (Mastacembelus frenatus)**

🔬 Scientific Name Disclaimer

Some aquarium sources may still use:

Afromastacembelus frenatus

Modern taxonomic work does not support maintaining Afromastacembelus as a separate genus, and current major fish databases recognize:

Mastacembelus frenatus

as the valid name.

🚚 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

African Starry Night Eels require careful packing because of their:

Long flexible bodies
Escape ability
Dorsal spines
Sensitivity to abrasion

Larger specimens may require:

Larger insulated shipping boxes
Additional water
Heavy-duty shipping bags
Multiple protective bag layers
Specialized packing

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

⚠️ Buyer Responsibility

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

Never release aquarium fish into natural waterways.