A fascinating, elongated bottom-dweller known for its pointed snout. It is primarily nocturnal and spends much of its time buried in the substrate. While peaceful with fish too large to eat, it is an opportunistic predator that will consume small fish, shrimp, and fry. A soft sand substrate is absolutely mandatory to prevent severe bacterial skin infections from burrowing.
Lesser Spiny Eel At a Glance
Lesser Spiny Eel Tank Requirements
Will Lesser Spiny Eel fit in your tank?
Care guides tell you what Lesser Spiny Eel needs, the next question is whether your tank can safely provide it. Test Lesser Spiny Eel against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
We may earn from qualifying purchases
Lesser Spiny Eel Water Parameters
Water care products
We may earn from qualifying purchases
Lesser Spiny Eel Temperament & Compatibility
Lesser Spiny Eel Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard Adult
The fully grown adult form. Needs significant horizontal swimming space and deep, soft sand to bury itself. Ensure a tight-fitting lid as they are notorious escape artists.
Same care requirements as the base species
Also known as: Adult, Full Grown
Juvenile (Grow-out)
Typical commercial sale size. Extremely slender and highly vulnerable to starvation if outcompeted for food. Requires a diet of live or frozen bloodworms/blackworms. Can be temporarily housed in smaller aquariums but will grow rapidly.
Differs in 6 traits from base species
Also known as: Baby, Small Eel
Lesser Spiny Eel Care Guide Summary
The Lesser Spiny Eel, scientifically known as Macrognathus aculeatus, belongs to the Oddballs family group. Adults reach a maximum size of approximately 38 cm and have a eel body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the bottom zone of the aquarium and produces a medium level of biological waste.
To thrive, the Lesser Spiny Eel requires a brackish tolerant aquarium with a minimum volume of 200 litres and a tank length of at least 120 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 6.5–8 and a general hardness of 5–15 dGH. A moderate water flow is preferred.
Due to its specialist needs, the Lesser Spiny Eel is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard Adult and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Lesser Spiny Eel Habitat Setup
When setting up an aquarium for the Lesser Spiny Eel, a moderate water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, and dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper and expect substrate disturbance, so lightweight décor should be secured.
Lesser Spiny Eel Compatibility Notes
Classified as mostly peaceful, the Lesser Spiny Eel is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten, ornamental shrimp are not safe companions, and boisterous or fast-moving tankmates may cause this species undue stress. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Lesser Spiny Eel Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Lesser Spiny Eel.
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
Lesser Spiny Eel Feeding & Diet Considerations
The Lesser Spiny Eel is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided, will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups, will eat fry, so breeding efforts in the same tank are unlikely to succeed, and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition.
Feeding products
We may earn from qualifying purchases
.webp?2026-04-25T14%3A35%3A38.022Z)
Frequently Asked Questions About Lesser Spiny Eel
How big does Lesser Spiny Eel get?
Lesser Spiny Eel (Macrognathus aculeatus) typically reaches a maximum adult size of approximately 38 cm. They have a eel body shape and a moderate growth rate.
What tank size does Lesser Spiny Eel need?
A minimum aquarium volume of 200 litres and a tank length of at least 120 cm are recommended for Lesser Spiny Eel. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Lesser Spiny Eel need?
Lesser Spiny Eel thrives in brackish tolerant conditions with a temperature range of 23–28°C, a pH between 6.5 and 8, and a general hardness of 5–15 dGH. A moderate water flow is preferred.
Is Lesser Spiny Eel peaceful or aggressive?
Lesser Spiny Eel is classified as mostly peaceful with an aggression score of 4 out of 10. They are generally well-suited to peaceful community tanks.
Can Lesser Spiny Eel live alone?
Yes, Lesser Spiny Eel can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Lesser Spiny Eel safe with shrimp?
No. Lesser Spiny Eel is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Lesser Spiny Eel have any special tank requirements?
Yes. Lesser Spiny Eel benefits from sand (sifters), smooth gravel (sensitive barbels), and plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Lesser Spiny Eel need a lid on the tank?
Yes. Lesser Spiny Eel is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Top Tank Mates for Lesser Spiny Eel
These fish are strong compatibility matches for Lesser Spiny Eel based on water preferences, temperament, adult size, and tank behavior.
False Glass Catfish
Kryptopterus macrocephalus
Ideal Tank MatesBetta Imbellis
Betta imbellis
Ideal Tank MatesBanded Gourami
Trichogaster fasciata
Ideal Tank MatesPeppermint Pleco
Parancistrus nudiventris
Ideal Tank MatesHalf Banded Spiny Eel
Macrognathus circumcinctus
Ideal Tank MatesFreshwater Sole
Brachirus selheimi
Ideal Tank MatesPlants That Suit Lesser Spiny Eel
These plants pair well with Lesser Spiny Eel based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Anubias Barteri
Anubias barteri
Christmas Moss
Vesicularia montagnei
Congo Anubias
Anubias heterophylla
Coral Pelia
Riccardia chamedryfolia
Dwarf Buce
Bucephalandra pygmaea
Fish Similar to Lesser Spiny Eel
Half Banded Spiny Eel
Macrognathus circumcinctus
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.
Peacock Eel
Macrognathus siamensis
A peaceful, nocturnal spiny eel native to Southeast Asia, easily identified by the false eyespots (ocelli) along its dorsal fin. They are notorious escape artists and avid burrowers. A soft sand substrate is absolutely mandatory to prevent severe bacterial skin infections from scratching, along with a tight-fitting lid. They are picky eaters that generally require live or frozen meaty foods like bloodworms.
Tire Track Eel
Mastacembelus armatus
A massive, predatory spiny eel known for its distinctive tire-track patterning. They are nocturnal bottom-dwellers that love to burrow. A soft sand substrate is absolutely mandatory; sharp gravel will severely damage their skin and lead to fatal bacterial infections. While peaceful to fish too large to swallow, they are highly efficient predators that will eat any tank mate that fits into their surprisingly large mouths. Excellent escape artists; a heavy, tight-fitting lid is required.
Zebra Spiny Eel
Mastacembelus zebrinus
The Zebra Spiny Eel is a fascinating, small eel-like fish native to the Inle Lake region of Myanmar. Known for its striking vertical stripes and elongated snout, it is a peaceful but shy bottom-dweller. It strictly requires a soft sand substrate to burrow into, as gravel can severely damage its skin and lead to fatal bacterial infections. A micropredator by nature, it will hunt small shrimp and fry but remains entirely peaceful toward appropriately sized tank mates. A tight-fitting lid is absolutely mandatory, as they are notorious escape artists.
Bumblebee Catfish (South American)
Microglanis iheringi
The South American Bumblebee Catfish is a small, nocturnal bottom-dweller known for its striking yellow and dark brown bands. Highly secretive during the day, it requires plenty of caves, crevices, and driftwood for hiding. While completely peaceful towards larger tank mates, it is a strictly opportunistic predator with a surprisingly large mouth—any fish, fry, or shrimp small enough to swallow will be eaten at night.
Fire Eel
Mastacembelus erythrotaenia
The Fire Eel is a stunning, large species of spiny eel native to Southeast Asia, known for its brilliant red lateral stripes and highly interactive, 'dog-like' personality with owners. As a true 'monster fish', it requires massive aquariums. A soft sand substrate is absolutely mandatory, as they will burrow and suffer lethal bacterial infections from scratching themselves on gravel. They are notorious escape artists and will eat any fish small enough to fit in their mouths.