Easy to intermediate
Chocolate Cherry Shrimp (Neocaridina davidi)
18–26°C · pH 6.5–8 · 30L
£13.99
A smaller banded spiny eel for mature, tightly covered aquariums with soft sand, shaded hiding places and peaceful tank mates too large to swallow.
Macrognathus circumcinctus
A smaller banded spiny eel for mature, tightly covered aquariums with soft sand, shaded hiding places and peaceful tank mates too large to swallow.
Maintain these water conditions for optimal health and vibrant colors
Half-Banded Spiny Eel (Macrognathus circumcinctus) is a smaller spiny eel for mature, well-covered tropical aquariums. It may also be labelled Belted Spiny Eel, Zig-Zag Eel or by the older trade/supplier name Mastacembelus circumcinctus. This listing is for the same banded, nocturnal oddball, corrected to the accepted Macrognathus name and written around care decisions rather than repeated buyer keywords.
This is a secretive fish at first, but it becomes a fascinating dusk and night-time aquarium resident when it has soft sand, secure shelter and calm tank mates too large to be swallowed. It is not a true eel; it is a mastacembelid spiny eel with a pointed snout, delicate skin and a strong instinct to burrow and explore after lights dim.
| Accepted name | Macrognathus circumcinctus |
|---|---|
| Also seen as | Half-Banded Spiny Eel, Belted Spiny Eel, Zig-Zag Eel, Mastacembelus circumcinctus |
| Adult size | Plan for 20-28 cm, with FishBase listing 28.6 cm total length as the published maximum |
| Current size options | 6-8 cm and 12-15 cm variants when in stock |
| Care level | Moderate; best for keepers who can provide sand, cover and stable water |
| Temperament | Peaceful with robust fish, predatory toward very small fish and shrimp |
| Temperature | 24-27 C |
| Best aquarium | Mature, tightly covered softwater or neutral tropical aquarium with a broad footprint |
The supplier text used the older Mastacembelus circumcinctus wording, but the current product page now leads with Macrognathus circumcinctus. Keeping the old name as a synonym is useful because many hobbyists still search for it, but using it as the main scientific name would be misleading.
| What changed | The accepted genus is shown first, while the older supplier/trade name is kept as a natural search bridge. |
|---|---|
| Why it matters | Half-banded spiny eels stay smaller than the giant spiny eels, but they still need specialist planning, not a tiny novelty tank. |
| Visual ID | Look for an eel-like body with regular dark oblique bars on a tan to brown background. |
FishBase places Macrognathus circumcinctus in tropical freshwater across the Mekong and Chao Phraya basins, south-eastern Thailand, the Malay Peninsula and Sumatra. It is recorded from medium to large rivers, flooded fields and peat-influenced waters, and it feeds at night on invertebrates and small fish.
That habitat explains the aquarium priorities: soft substrate, dimmer areas, leaf litter or wood cover, and reliable filtration. This fish is built to push through cover with its snout, so sharp gravel and unstable rockwork are poor choices.
| Substrate | Soft sand is strongly preferred so the eel can bury without damaging its skin or snout. |
|---|---|
| Cover | Use wood, smooth caves, pipes, plant thickets and shaded retreats. Make sure heavy decor cannot fall if the eel burrows. |
| Lid | A tight lid is essential. Cover gaps around cables, pipework and filter outlets. |
| Lighting | Low to moderate lighting with floating plants or shaded zones helps confidence. |
| Tank footprint | Length and floor space matter more than height. Use 200 litres as a sensible starting point, with 250 litres or more preferred for a group or mixed oddball display. |
Do not build this aquarium like a bright, open community tank. The best displays give the eel multiple dark exits and let it choose between sand, leaf cover and tubes. Once settled, it often becomes more visible during evening feeding.
| Temperature | 24-27 C |
|---|---|
| pH | 6.0-7.5 is a practical aquarium range; avoid sudden swings |
| Hardness | Soft to moderately hard water; keep it stable and clean |
| Filtration | Mature biological filtration with gentle to moderate flow |
| Maintenance | Regular partial water changes and careful removal of uneaten meaty foods |
Clean water is especially important because spiny eels spend so much time in contact with the substrate. If the tank is new, unsettled or still showing ammonia or nitrite, wait before adding this species.
Half-banded spiny eels are carnivorous dusk feeders. Offer frozen bloodworm, mosquito larvae, mysis, chopped prawn, chopped earthworm, blackworm, brineshrimp and suitable sinking carnivore foods. Some individuals learn prepared foods quickly, while others need patient target-feeding after the main lights go down.
| Best feeding time | After lights dim, or just before the room gets dark |
|---|---|
| Staple foods | Frozen and live meaty foods, then sinking carnivore pellets if accepted |
| Watch point | Fast mid-water fish can steal food before the eel finds it |
| Water quality | Remove leftovers; meaty foods spoil quickly in warm water |
This species is not usually aggressive, but it is still a predator. Choose peaceful, robust fish that are too large to fit in its mouth. Avoid neon-sized tetras, tiny rasboras, small shrimp, fry and any very delicate bottom-dweller that will lose out at feeding time.
| Good choices | Larger rasboras, peaceful gouramis, robust loaches, suitable L-number plecos and calm cichlids that do not bully bottom fish |
|---|---|
| Avoid | Very small fish, shrimp, fry, fin-nippers, aggressive cichlids and sharp-spined competitors in cramped tanks |
| Same species | Can work in groups when the aquarium is large enough and has multiple shelters |
| Handling | Use soft nets or containers and avoid rough handling; spiny eels have sensitive skin and spines |
The 6-8 cm and 12-15 cm variants share the same long-term care, but the larger size usually settles faster and is less vulnerable to being outcompeted. The smaller size needs especially careful feeding and peaceful tank mates. Both sizes need a covered aquarium from day one.
If you are planning a spiny-eel or oddball aquarium, compare this fish with Barred Spiny Eel, Tire Track / Zig-Zag Eel, Zebra Spiny Eel and Frecklefin Eel. The key difference is adult size: Macrognathus circumcinctus is a more compact choice than the biggest mastacembelids, but it is still a specialist bottom fish.
Order only when the aquarium is mature, covered and ready for a burrowing oddball. Livestock is packed for dispatch across the UK and sent by a licensed live-animal courier where live-animal shipping applies. Livestock orders are covered by our Live Arrival Guarantee.
| Can it live in a community aquarium? | Yes, if the community is peaceful, mature and made of fish too large to be swallowed. Tiny fish and shrimp are unsafe. |
|---|---|
| Does it need sand? | Yes, soft sand is strongly recommended because this species naturally burrows and has delicate skin. |
| Is it brackish? | No. Treat this listing as a freshwater tropical species; stable clean water is more important than adding salt. |
| Why does the old name appear? | Mastacembelus circumcinctus is kept as a synonym/trade bridge, but the accepted listing name is Macrognathus circumcinctus. |
Care and identity were checked against FishBase for accepted name, range, size, habitat and diet, and against the Maidenhead Aquatics/Fishkeeper species profile for aquarium husbandry details such as soft sand, tight lids, compatibility and feeding.
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