Leiodon Cutcutia Pufferfish Care Sheet
- Macauley Sykes
- Sep 30
- 21 min read
Updated: Oct 2
This care sheet is written with the aim of providing the optimal care for this species of fish.
Pufferfish Enthusiasts Worldwide endeavours to inspire and promote the highest standards of care - not basic or minimum care - using the best evidence available at the time.
Introduction
The Leiodon cutcutia is one of the most remarkable yet underappreciated puffers in the aquarium world.
Endemic to South and Southeast Asia, it ranges across India, Bangladesh, Sri Lanka, Myanmar, and the Mekong basin, where it thrives in a diverse array of habitats, from shaded rivers and floodplains to canals, ponds, and estuarine waters.
First described in 1822 by Francis Buchanan-Hamilton, L. cutcutia was long regarded as the sole representative of its genus following its separation from Tetraodon in 2013. However, subsequent catalogues and databases now also recognise L. dapsilis as a valid congener, making Leiodon a two-species genus. Its appearance is striking: bold vertical barring, a metallic golden-green sheen, and eyes that capture the attention of every observer. Positioned neatly on either side of the head, these eyes move independently with a curious precision, giving the fish an almost hypnotic expressiveness. Watching them track their surroundings is part of the endless fascination this species offers.
Reaching 10–15 cm (4–6″), the L. cutcutia occupies a perfect middle ground: substantial enough to be a commanding presence, yet still very manageable compared with the true giants of the puffer world. Owners quickly discover its hallmark trait, a bold, intelligent personality that makes it one of the most interactive puffers available. Once settled, it readily engages with its keeper, displaying curiosity and recognition that feel almost uncanny.
What truly sets L. cutcutia apart is its combination of beauty, adaptability, and character. Unlike many puffers whose appeal lies in rarity or sheer size, this species brings together elegance, resilience, and charisma in a way few others can match.
It may not yet enjoy the widespread recognition of more “fashionable” species, but for those who keep it, the Cutcutia often becomes a lifelong favourite: a fish that rewards its keeper with a decade or more of fascination and companionship.
Common names include Ocellated Pufferfish, Emerald Puffer, Red-eye Puffer, Common Puffer, and the regional name Potka.
In the wild
Cutcutia is a fish of the floodplains. Its natural range spans much of South and Southeast Asia, with confirmed populations in India, Bangladesh, Sri Lanka, Myanmar, and the Mekong basin, and records extending into parts of the Malay Peninsula and Archipelago.
Within this vast distribution, it inhabits calm, lowland waters: ponds, canals, beels (floodplain lakes), quiet river margins, and even creeks that swell and shrink with the monsoon.
These habitats are shaped by seasonal flooding. During the rains, rivers spill into wetlands and rice fields, transforming the landscape into a broad mosaic of shallow pools and slow channels. As the waters retreat, L. cutcutia follows the receding margins, moving between ponds and river edges in search of shelter and food. This makes it a potamodromous species, shifting within freshwater systems rather than migrating to the sea.
In the field, L. cutcutia is most often encountered under the shade of submerged vegetation or tangled roots in areas of little to no flow. Here it hunts invertebrates among grasses and leaf litter, or rests in cover while its independently moving eyes scan the surroundings.
Stomach studies confirm it as a generalist feeder, taking aquatic snails, insect larvae, worms, and occasional fish tissue. Opportunistic cannibalism has also been recorded, a reflection of the species’ bold, adaptive feeding style.
Environmental snapshots from its range suggest typical tropical floodplain conditions: warm waters between 24–28 °C, soft to moderately hard mineral content, and pH values hovering around neutral.
While the species is overwhelmingly recorded in fresh water, it is also found in estuarine systems and even large coastal lagoons such as India’s Chilika Lake, showing an ability to tolerate low-end brackish conditions. This flexibility has led to some confusion in the aquarium trade, but in the wild, it is best regarded as a freshwater fish with euryhaline tolerance, rather than a brackish obligate.
Conservation & Trade
L. cutcutia is harvested locally for the ornamental fish trade and is occasionally offered in international markets. However, its wide distribution and ability to thrive in varied habitats mean it is not currently considered at risk. The IUCN Red List (2009) classifies the species as Least Concern, with no evidence that collection poses a threat to wild populations. As with all floodplain fish, long-term pressures are more likely to come from habitat loss, pollution, and river modification than from the aquarium hobby itself.
In the aquarium
L. cutcutia has a special place in aquarium history. It was one of the very first freshwater puffers to be imported, arriving from India as early as 1903, and it also became the first pufferfish to spawn successfully in captivity. These early breakthroughs gave aquarists an early glimpse into the potential of pufferfish in aquaria, though widespread breeding never followed. More than a century later, most specimens available to hobbyists are still wild-caught, but its long record in captivity proves just how well this species can adapt when given the right conditions.
Creating those conditions begins with understanding its natural haunts. In the wild, L. cutcutia thrives in the shaded edges of rivers, beels, and canals, where aquatic weeds, roots, and fallen branches break up the flow.
To reflect this, the aquarium should be heavily structured and visually complex, so that the fish feels secure, has constant opportunities to explore, and can display its natural confidence. In an enriched layout filled with cover, L. cutcutia becomes bold, curious, and interactive. In bare or overly open tanks, it often appears restless or withdrawn.
Planting is central to this sense of security. Stem plants such as Limnophila sessiliflora, Hygrophila polysperma, and Rotala rotundifolia can be massed into soft thickets that replicate the margins of their native waterways.
Hardy broad-leaved species like Anubias and Echinodorus withstand exploratory nips and offer shaded resting spots. Floating plants such as Salvinia, water lettuce, or Limnobium are particularly valuable, dimming the light and creating the dappled conditions in which this fish feels most at ease. Under such cover, colours deepen and behaviours become more natural.
Hardscape should be chosen not only for structure but for enrichment value. Redmoor branches and driftwood form overhangs and tangles that invite investigation.
Ceramic caves, a time-tested favourite for this species, provide secure bolt-holes and a sense of territory. Leaf litter and botanicals can be scattered across the substrate, mimicking the detritus of floodplain pools while encouraging foraging and microfauna growth. Even subtle changes, such as rotating decor or adding new pieces, stimulate curiosity and keep the fish mentally engaged.
Heavily scaping the back of the tank is especially effective. When L. cutcutia knows it has secure retreats behind it, the fish feels confident enough to patrol the open foreground. This design actively encourages it to come to the front and interact with its keeper, secure in the knowledge that it can dash back to its favourite hiding place at any moment.
When these conditions are met, L. cutcutia often emerges from its harbourage to greet the aquarist as they enter the room, a behaviour that quickly makes it feel like a true companion.
Keeper’s Insight
A well-designed L. cutcutia tank feels alive. Plants sway gently, floating leaves cast shifting shade, and roots and caves offer countless paths to explore. In such an environment, this puffer shows its best side: inquisitive, confident, and interactive. More than a pet, L. cutcutia becomes a true character in the home aquarium, a living reminder of why pufferfish have fascinated aquarists for over a century.
Water Movement & Conditions
Water flow should be gentle to moderate. In the wild, L. cutcutia avoids main channels and strong currents, favouring calmer margins and backwaters. In aquaria, a canister filter fitted with a spray bar or lily pipe is ideal for creating broad, diffuse circulation. Avoid jet-like outputs that buffet the fish; instead, aim for steady turnover that maintains water quality and oxygenation.
Like all puffers, L. cutcutia is sensitive to poor water quality. Their protein-rich diet and messy feeding habits demand excellent filtration and a mature biological system. Frequent, substantial water changes should be standard practice, as consistently clean water is the foundation of long-term success.
Substrate
A soft, sandy substrate is the best choice for L. cutcutia. In its native range, this species inhabits floodplains, ponds, canals, and quiet river margins where the bottom is usually muddy or silty, often carpeted with organic debris and fallen leaves. Fine aquarium sand provides the closest equivalent. It creates a natural aesthetic, allows the fish to forage safely, and reduces the risk of injury during sudden movements.
L. cutcutia frequently explores the substrate with its mouth, sifting through sand and litter in search of edible fragments. A smooth, fine-grade sand supports this instinctive behaviour, while coarse gravel should be avoided. Gravel not only looks unnatural in a floodplain biotope, but can also damage the lips and dental plates if the fish collides with it.
Adding leaf litter over the sand greatly enhances the environment. Indian almond, oak, or beech leaves replicate the detritus of shaded margins, gradually breaking down to attract microfauna. This creates foraging opportunities and keeps the fish mentally engaged.
Like many puffers, L. cutcutia may react to sudden disturbances by darting headfirst towards the bottom. A forgiving sand base cushions these impacts, preventing injury to the snout and mouthparts.
For L. cutcutia, substrate choice is therefore more than decorative. A fine sand bed, enriched with scattered leaves and botanicals, provides both safety and stimulation, enabling this intelligent species to behave naturally and confidently, just as it would along the silty floodplain margins of its wild habitat.
Tank size
L. cutcutia does not demand the vast aquaria required by some of its larger relatives.
A minimum footprint of 40 × 40 × 40 cm, which equates to around 64 litres (17 US gallons), is sufficient to house a single specimen.
That said, aquarists who can provide 100–130 litres or more will see clear benefits. A larger volume not only stabilises water quality but also allows for more elaborate aquascaping, with multiple retreats and sight breaks. In such tanks, L. cutcutia tends to be more confident, interactive, and active at the glass, rewarding the keeper with its full range of behaviours.
While not a “giant tank” species, L. cutcutia is a fish that thrives when given space to explore. The more room and structure it is offered, the more it will reveal its bold, inquisitive nature.
Water values
Maintain the following water parameters:
pH: 6.5–7.5
Temperature: 24–28 °C
Ammonia (NH₃/NH₄⁺): 0 ppm
Nitrite (NO₂⁻): 0 ppm
Nitrate (NO₃⁻): Below 15 ppm (ideal)
General Hardness (GH): 3–10 dGH typical, tolerant up to ~15 dGH
Why these Numbers?
These recommendations reflect both ecological surveys from South and Southeast Asian floodplains and the ranges consistently reported in long-term successful husbandry.
Field measurements across habitats such as beels, ponds, and quiet river margins record warm tropical water (20.5–31 °C depending on season), with pH generally close to neutral and soft to moderately hard mineral content. Some populations also occur in estuarine systems and coastal lagoons such as India’s Chilika Lake, showing a capacity to tolerate low-end brackish water, though the majority of wild Cutcutia are strictly freshwater.
The captive ranges of 24–28 °C and pH 6.5–7.5 sit comfortably within these field values while giving aquarists a safe buffer for day-to-day variation. This is warm enough to reflect the tropical floodplain climate, yet not so high that it reduces dissolved oxygen or accelerates metabolism unnecessarily.
Although many wild sites test very soft, the guideline of 3–10 dGH is typical, up to ~15 is a deliberate adjustment. A modest degree of hardness provides essential calcium and magnesium for osmoregulation and dental health, while also adding stability to pH and preventing the fluctuations often seen in ultra-soft, closed systems. In practice, this balance mirrors the softer end of the species’ natural waters while still safeguarding against instability in the aquarium.
Expectations of 0 ppm ammonia and nitrite are absolute. Puffers are particularly sensitive to nitrogenous waste, and even trace levels can cause stress, appetite loss, or disease.
The nitrate benchmark of <15 ppm is not a hard toxicity line but a marker of best practice. Research across freshwater taxa shows that long-term exposure to elevated nitrate can suppress immune function, slow growth, and shorten lifespan. For puffers, which are messy feeders with high protein diets, keeping nitrate very low is both a measure of water cleanliness and a safeguard for long-term health.
Together, these numbers capture the essence of L. cutcutia's native environment: warm, calm, soft-edged waters, while adding the stability and safety margins required for reliable success in the home aquarium.
Tankmates
L. cutcutia should be regarded as a solitary species in the aquarium. While not the largest pufferfish, it is among the most aggressive, and its natural feeding habits make it a direct threat to almost any potential tank mate. In the wild, it is an opportunistic predator, taking insects, small fish, and even parts of conspecifics when the chance arises. In captivity, this translates into a tendency to harass, injure, or outright consume other fish, even those much larger than itself.
For this reason, the safest and most responsible approach is to house L. cutcutia alone. A solitary setup allows the fish to express its bold and inquisitive behaviour without the stress or danger of conflict. It also gives the aquarist complete control over feeding and enrichment, ensuring the fish’s needs are fully met.
Experienced keepers may experiment with housing pairs or small groups, particularly with the goal of breeding, but such attempts come with significant risk. Behaviour between conspecifics is highly unpredictable: periods of tolerance can be punctuated by sudden aggression, and serious injury can result very quickly. If attempted at all, it should only be done in very large, heavily structured aquaria where visual barriers and escape routes are plentiful. Even then, constant observation is required.
In short, L. cutcutia is best enjoyed as a single-specimen fish, a true centrepiece species that more than justifies its own dedicated aquarium.
Sexual dimorphism
Sexual dimorphism in L. cutcutia is subtle and not well documented. Unlike some smaller puffers, such as the pea puffer (Carinotetraodon travancoricus), males and females of this species do not show dramatic differences in colouration or patterning. Both sexes display the same bold vertical barring and characteristic golden-green sheen.
There are, however, a few tentative indicators noted by experienced keepers and in scattered literature:
Body shape: Mature females are often more rounded in the abdomen, especially when carrying eggs, while males tend to appear slightly slimmer and more streamlined.
Size: Some reports suggest females may reach a marginally larger size than males, though this is not consistent across all observations.
Behaviour: During breeding attempts, males may become more territorial and persistent in their interactions with females, but this is behavioural rather than visual dimorphism.
Because these differences are not consistent or easily observed, sexing L. cutcutia with certainty is extremely difficult outside of breeding conditions. Most specimens in the trade are sold unsexed, and aquarists should assume that external features alone are not reliable indicators.
Notable behaviour
L. cutcutia is a fish of character, and much of its appeal lies in the way it interacts with its environment and with its keeper.
One of the most important practical notes is that this species is an accomplished jumper. In the wild, it inhabits shallow floodplains and river margins, where darting upwards is a natural escape response. In captivity, the same instinct can send a startled fish out of the water entirely. For this reason, a tight-fitting lid is essential on any aquarium that houses L. cutcutia. Even small gaps should be sealed, as determined puffers have been known to find their way through.
In terms of day-to-day activity, L. cutcutia is not a hyperactive swimmer. It spends much of its time cruising slowly along the mid and lower levels of the tank, pausing frequently to investigate crevices, sift through sand, or watch movement outside the glass. This steady, deliberate style should not be mistaken for dullness. On the contrary, it is a highly intelligent fish that constantly scans its surroundings with those independently moving eyes, giving the impression of thoughtfulness and intent.
Perhaps the most endearing behaviour is the way L. cutcutia forms a bond with its keeper. Once settled, individuals often learn to recognise the person who feeds them and will emerge from cover to meet them at the glass. Many aquarists describe the fish as “begging”, swimming in anticipation of food, or even following their keeper’s movements across the room. In a well-scape tank where the fish feels secure, this greeting behaviour can become a daily highlight, transforming the aquarium into a truly interactive experience.
L. cutcutia also thrives on exploration and novelty. It will investigate new decor, sift through leaf litter, and test its beak against hard surfaces. These investigative behaviours underline just how important enrichment is for this species. A varied, complex environment does more than provide shelter: it gives the fish reasons to engage, explore, and reveal its personality.
In short, while L. cutcutia may not race around the tank, but it has an unmistakable presence. It is thoughtful, observant, and responsive, a fish that rewards patience and careful design with a unique level of interaction. For many aquarists, it is this engaging behaviour, more than its striking pattern or historic significance, that cements L. cutcutia as a favourite species.
Feeding
Feeding L. cutcutia is always an event. This is a fish that rarely snatches food without thought. Instead, it circles, angles itself, and makes deliberate strikes, testing and crunching in ways that reveal both instinct and intelligence. Each meal becomes a small display of the fish’s resourcefulness and curiosity.
In the wild, L. cutcutia is a versatile omnivore. Studies of gut contents show a diet dominated by aquatic invertebrates - worms, snails, insect larvae, and small crustaceans - supplemented by scraps of fish, carrion, and even plant material. Its survival across ponds, canals, and estuaries depends on this adaptability, taking advantage of whatever the floodplain provides.
In captivity, this same versatility allows keepers to offer a wide variety of foods. The goal is not just to nourish, but to engage. At Pufferfish Enthusiasts Worldwide, we encourage aquarists to think of feeding as enrichment as much as nutrition. A varied diet delivers the proteins, minerals, and vitamins needed for long-term health, but just as importantly, it stimulates the fish mentally, keeping it alert and behaviourally active.
Watching a L. cutcutia prise a worm from the sand, snap down on an insect, or crunch a snail shell is to see the floodplain come alive in your own aquarium.
Recommended Foods
Worms and insects: Earthworms, cockroaches, crickets, locusts, and woodlice provide the bulk of nutrition. Gut-loading insects with vegetables improves their value.
Snails: Soft-shelled species such as ramshorns and bladder snails are excellent for calcium, enrichment and dental health.
Thiaminase-free fish meat (read below): Small chunks of tilapia, trout, or salmon add useful variety.
Prepared foods: Repashy Grub Pie is a widely accepted standby that many keepers use successfully.
Occasional treats: Bloodworms or similar should be reserved for occasional feeding due to their high fat content.
Avoid cockles, mussels, clams, and oysters. These bivalves are not natural foods for L. cutcutia and can unbalance the diet.
Suggested Feeding Breakdown
A practical ratio for long-term success is:
50% Worms and Insects
20% Snails
20% Thiaminase-free Fish Meat
10% Prepared and Supplemental Foods
This balance replicates the opportunistic variety of the wild while safeguarding nutrition and dental health in captivity.
Because L. cutcutia is not a high-energy swimmer, it should not be overfed. Three to four meals per week are usually sufficient for adults. Juveniles can be fed more frequently in smaller portions to support growth.
Feeding Fish
In the wild, L. cutcutia is a versatile predator that will readily take smaller fish whenever the opportunity arises. To reflect this, offering whole fish and prepared fillets in the aquarium is highly beneficial. Variety is important: alternating between different species ensures a broad nutritional profile while keeping the fish mentally engaged.
One of the most convenient and widely available options is Frozen Pond Smelt (Hypomesus olidus). These small fish are the perfect size for L. cutcutia to consume whole and can be found in many aquatic stores or bait suppliers.
Note on Thiaminase: Thiaminase is an enzyme found in many raw fish species that breaks down vitamin B1 (thiamine). Regular feeding of thiaminase-rich fish can lead to vitamin deficiency, neurological issues, and even death. Always choose thiaminase-free species when offering fish to puffers.
Pond smelt are thiaminase-free, making them a safe staple. However, aquarists must be careful with other smelt species: Rainbow Smelt (Osmerus mordax), for example, contains thiaminase and should be avoided.
Beyond smelt, aquarists can make use of larger freshwater fish commonly available at markets or fish counters. Species such as Lake Trout (Salvelinus namaycush) and various Tilapia species are excellent choices.
Since these fish are far too large for L. cutcutia to swallow whole, preparation is key:
Remove the head, fins, and internal organs.
Fillet the fish, leaving scales and skin intact.
Cut the fillets into chunks small enough for Cutcutia to consume within one minute.
Prepared pieces can be frozen and stored for up to three months.
Offering fish in this way provides more than just nutrition. The texture, oils, and scales stimulate natural feeding responses, while the act of tearing at flesh engages L. cutcutia's problem-solving instincts. As part of a varied diet balanced with worms, insects, and snails, whole-fish feeding helps unlock the species’ full vitality in captivity.
Feeding as Enrichment
L. cutcutia is an intelligent fish, and for such a species, feeding should never be reduced to a routine of dropping food into the tank. Every meal is an opportunity to provide stimulation and challenge. Enrichment through feeding does not just keep the fish nourished; it keeps it alert, curious, and behaviourally active.
There are many simple but effective ways to turn feeding into an engaging experience:
Bury worms in sand so the fish must nose through the substrate, mimicking its natural search for prey hidden in floodplain silt.
Scatter snails among leaf litter or between roots so that Cutcutia must investigate crevices and crunch through shells, just as it would in the wild.
Float insects at the surface to encourage upward strikes and stimulate the reflexes that serve as escape and hunting responses in nature.
Offer food from tongs to create a direct interaction. Over time, the fish will learn to associate the tongs with feeding, eagerly approaching the keeper and turning mealtimes into shared moments of trust.
Rotate feeding locations so the fish never knows exactly where food will appear, encouraging exploration of the whole aquarium.
These techniques engage multiple senses - sight, smell, and touch - and make feeding a puzzle to be solved rather than a chore. Aquarists who invest in enrichment often report more confident, colourful fish that interact readily at the glass.
In short, feeding L. cutcutia should be seen as a creative exercise. By varying presentation and texture, keepers can bring the fish’s natural instincts alive, transforming the act of eating into one of the most rewarding aspects of keeping this remarkable puffer.
Feeding snails
Snails are an important part of L. cutcutia's diet and should be offered regularly.
In the wild, this species consumes a wide range of invertebrates, and snails play a dual role in captivity: they provide valuable calcium and protein while also helping to keep the fish’s beak in check. Like all puffers, L. cutcutia has continuously growing dental plates that must be worn down through regular crunching on hard foods. Without this, the beak can overgrow, eventually preventing the fish from eating properly.
Not all snails are equally suitable. Soft-shelled species such as Physella acuta (bladder snails), ramshorns, and small cultured terrestrial snails (commonly sold for reptile or even human consumption) are ideal. These provide the right balance of shell and flesh, encouraging natural feeding behaviour without excessive difficulty.
By contrast, species like Melanoides tuberculata (Malaysian trumpet snails) should be avoided. Their shells are extremely hard and contain relatively little meat. Puffers that attempt them may injure their beaks or simply give up, potentially learning to associate snails with frustration or pain.
For long-term success, it is best to maintain a separate snail culture. Breeding ramshorns or bladder snails is straightforward, and culturing terrestrial snails in mineral-rich conditions ensures their shells develop to the perfect hardness for safe feeding. Having a home culture not only guarantees a constant supply but also allows you to gut-load the snails, boosting their nutritional value before they are offered.
Beyond their nutritional role, snails are also a form of enrichment. Dropping a handful into leaf litter or scattering them among roots provides a stimulating foraging challenge, encouraging the fish to hunt and crunch just as it would in its floodplain habitat. A L. cutcutia working through a pile of snails is more than just feeding; it is engaging in one of the most natural and satisfying behaviours it can display in captivity.
Feeder Fish
We do not recommend the use of live feeder fish for L. cutcutia. While it may seem natural to provide live prey, the risks far outweigh the benefits.
Feeder fish are often bred in crowded, unhygienic conditions. In such environments, bacteria like Flavobacterium columnare (columnaris) and Mycobacterium spp. spread rapidly, along with parasites such as Camallanus worms and Ichthyophthirius multifiliis (whitespot/ich). Introducing live feeders into your aquarium is one of the most direct ways to bring these pathogens to your puffer, often with devastating results. Treating such infections is stressful, expensive, and sometimes unsuccessful.
Beyond the health risks, feeder fish are typically nutritionally poor. Commonly used species such as goldfish and rosy reds are high in thiaminase and often carry excessive fat and poor protein balance. Far from being a “natural” diet, they provide little of the balanced nutrition Cutcutia requires.
There is also a behavioural concern. Puffers that are regularly given live feeders may become fixated on movement and start refusing frozen or prepared foods. This makes long-term feeding more difficult, and in some cases, leads to chronic malnutrition when live feeders are unavailable.
The good news is that L. cutcutia does not need live fish to thrive. This species usually adapts to frozen-thawed foods quickly once settled, and with a thoughtful variety of worms, insects, snails, and prepared diets, it can achieve excellent health and condition without ever touching a live feeder.
Beginning the weaning process immediately upon acquisition is strongly encouraged. Offer frozen foods early and consistently, and most individuals will learn to accept them without hesitation.
By avoiding feeder fish, you protect your puffer from disease, ensure a nutritionally sound diet, and promote long-term feeding success. Far from limiting your options, it opens the door to a more varied, safer, and ultimately more rewarding approach to feeding.
Tong Training
One of the most effective and enjoyable techniques you can develop with L. cutcutia is tong training; teaching it to take food directly from feeding tools.
This is not only convenient, it also creates a new layer of interaction between the aquarist and the fish.
L. cutcutia is quick to learn. Once it associates the tongs with feeding, it will often swim to the front of the aquarium to meet them, watching intently with those independent eyes before striking with precision. What begins as a way to deliver food soon becomes a ritual that deepens the relationship between fish and keeper.
The practical benefits are significant. Tong training allows you to:
Control portions and avoid overfeeding.
Introduce new foods more easily, as unfamiliar items can be wiggled or moved to trigger interest.
Place food precisely, preventing it from being lost in substrate or hidden among plants.
Create enrichment, as the fish learns to anticipate and engage with the process.
For a solitary species like L. cutcutia, tong training also ensures every meal is an interaction. Feeding becomes less of a transaction and more of a shared experience, building trust and making the fish more confident overall.
With patience and consistency, most individuals adapt quickly. Once trained, L. cutcutia rarely loses interest, and many keepers describe it as eagerly waiting at the glass whenever the feeding tools appear.
Filtration and Tank Maintenance
L. cutcutia generates a substantial bioload for its size. High-protein diets and messy feeding habits mean that filtration must be chosen with care. Robust, reliable systems are essential, with strong biological capacity to process nitrogenous waste and effective mechanical filtration to polish the water column.
For most aquarists, a canister filter is the best option. Positioning a spray bar or lily pipe ensures broad circulation and surface agitation, keeping oxygen levels high without creating stressful jets of current. In larger setups, a sump offers further advantages: high media volume, excellent gas exchange, and the ability to conceal heaters and equipment out of the display.
However, even the best filter cannot replace good husbandry.
Clean, stable water is non-negotiable:
Keep nitrates below 15 ppm, ideally as close to zero as possible.
Perform a minimum of 50% water changes weekly. Many keepers prefer more frequent or larger changes, especially when feeding heavily.
In heavily scaped aquaria with roots, caves, and leaf litter, siphon gently to prevent detritus from accumulating unseen.
Why Keep Nitrates Low?
L. cutcutia, like most puffers, is highly intolerant of long-term deterioration in water quality.
Chronic exposure to elevated nitrate levels has been shown in freshwater fishes to:
Suppresses immune function, increasing vulnerability to parasites and bacterial infections.
Reduce growth and feed efficiency, limiting long-term health and vigour.
Shorten lifespan and impair reproductive success.
For L. cutcutia, water quality is not just about survival, it is about enabling the fish to display its full personality. When maintained in clean, well-oxygenated, low-nitrate water, this puffer rewards its keeper with bright colouration, bold interactions, and a lifespan that can extend close to a decade.
Inflation
Like all members of the pufferfish family, L. cutcutia has the remarkable ability to inflate when it feels threatened or under extreme stress. By rapidly gulping water, or in emergencies, air, it can swell to several times its resting size. This transformation makes the fish far more difficult for predators to swallow, while presenting its beak in every direction as a deterrent.
In captivity, puffing should never be provoked. Forcing a puffer to inflate is highly stressful and can even be harmful. Inflation is a defence mechanism, not a party trick, and should only ever happen naturally.
L. cutcutia will sometimes display what aquarists describe as practice puffing. In these moments, a relaxed individual may casually inflate for a few seconds with no clear trigger before deflating again. It is thought that this helps exercise the muscles and stretch the skin associated with inflation.
These brief episodes are perfectly normal and not a cause for concern.
A prolonged or repeated inflation, on the other hand, is a warning sign.
It usually points to an environmental stressor such as:
Poor water quality (ammonia, nitrite, or elevated nitrates)
Sudden disturbances in the aquarium (sharp movement, loud vibration, sudden changes in lighting)
Overhandling or clumsy netting
In rare cases, territorial disputes during attempted breeding
If inflation persists, the priority should always be to identify and correct the cause so the fish can settle and deflate naturally.
Inflation is one of the most iconic behaviours of the pufferfish family, but in the aquarium it should be seen rarely, ideally only as the occasional practice puff of a healthy, secure Cutcutia.
Toxicity and Toxin Origin
Scientific studies on Leiodon cutcutia confirm that this species carries paralytic shellfish toxins (PSTs), most notably saxitoxin and related analogues. In Bangladeshi specimens, the skin was found to be the most toxic tissue, and researchers even identified a novel analogue known as carbamoyl-N-methylsaxitoxin. Tetrodotoxin (TTX) was not detected in these populations.
Toxin levels are not fixed. They vary by region, season, tissue type, and especially by diet.
The prevailing view is that puffers do not produce these toxins themselves but accumulate them indirectly through the food chain, most likely from toxin-producing microorganisms such as cyanobacteria that pass through their prey.
Compared to marine fugu species, L. cutcutia's toxin concentrations are generally lower, but they are still high enough to pose a risk if consumed. Outbreaks of freshwater puffer poisoning in Bangladesh highlight the danger of eating this species.
Implications for Aquarists
For aquarium keepers, this information is primarily of scientific interest rather than practical concern. L. cutcutia is not dangerous to handle, and routine care does not present any risk. The only caution is not to consume the fish or its organs, as ingestion is the only known pathway for poisoning.
In summary, L. cutcutia's toxin profile adds to its intrigue as a species but has no bearing on its care in captivity.
Disclaimer
Pufferfish health information given on this site is not intended to act as or replace the advice of a certified veterinary professional.
If your pufferfish is experiencing a medical emergency, contact an experienced aquatic veterinarian immediately.
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