Every few minutes, the surface of the lake erupts. Not with the splashing scatter of small fish fleeing a predator, not with the slow roll of a big carp coming up to sip air, but with something altogether more dramatic: an armoured, prehistoric-looking animal the size of a man, launching itself broadside into the air, rolling as it clears the surface, and coming back down with a concussive slap that sends ripples to the bank. This is Arapaima gigas breathing. Not a feeding rise, not a display, not an escape response — just the routine business of a fish that is obliged to breathe atmospheric air every ten to twenty minutes to survive. Watching it happen at Gillhams Fishing Resort in Krabi, or at IT Lake Monsters on the eastern edge of Bangkok, is one of the genuinely extraordinary experiences available to any angler visiting Thailand, regardless of whether they ever hook one.
That they are not native — that A. gigas is a South American fish introduced to Thai waters decades ago — does nothing to diminish the spectacle.
Identification and Biology
Arapaima gigas is the largest scaled freshwater fish in the world and one of the largest freshwater fish of any kind. Wild specimens in the Amazon basin have been recorded at weights approaching 200 kilograms and lengths exceeding four metres, though fish of this size are now extremely rare in their native range due to overfishing pressure. In Thai stocked venues, fish in the 60–120 kg class are not uncommon; exceptional specimens at well-established venues like Gillhams have exceeded 150 kg.
The fish is unmistakable. It has a long, torpedo-shaped body covered in large, hard scales that grade from a dark olive-green or grey-green along the back to a brilliant crimson-orange banded pattern along the flanks and tail — the origin of the local Thai name pla chomphu (ปลาชมพู), sometimes translated loosely as "pink fish." The head is bony and angular, with a distinctly upturned jaw and small, embedded scales. The dorsal and anal fins are set far back, giving the fish an almost eel-like silhouette from certain angles.
The obligate air-breathing habit — the arapaima's lung-like swim bladder supplements its gill respiration — is the defining characteristic of the species and the key to locating and targeting it. Fish must surface to breathe, and this behaviour makes them visible in ways that most freshwater fish are not. It also means they can survive in low-oxygen environments that would suffocate other large fish, and it is one reason they have thrived in the warm, sometimes oxygen-poor waters of Thai fishing lakes.
In the Amazon, arapaima are apex predators, feeding on fish, crustaceans, and animals at the water's surface. This predatory disposition is retained in stocked environments, and it is what makes the fish a legitimate target for lure and fly anglers — a distinction shared with very few of Thailand's other large freshwater targets.
Where to Catch It in Thailand
The arapaima's distribution in Thai fishing venues is more geographically diverse than that of the large native catfish and carp, with significant fisheries in both the south and around Bangkok.
Gillhams Fishing Resort in Krabi is the venue most strongly associated with arapaima fishing in Thailand, and by many measures the finest freshwater fishing resort in Southeast Asia. Its large, clear lake holds a population of arapaima that has been established and carefully managed for many years, producing some of the largest fish available to visiting anglers anywhere in the region. The combination of beautiful surroundings, excellent infrastructure, and consistently large fish makes it the destination of choice for dedicated arapaima hunters travelling specifically for the species.
IT Lake Monsters in the Bangkok area carries arapaima as part of its diverse stocking programme, alongside the Giant Mekong Catfish and numerous other species. The lake's arapaima are reliably present and catchable, and the Bangkok location makes it the most accessible arapaima venue for anglers on a short visit or connecting through the capital.
Exotic Fishing Thailand in Phang Nga is a specialist venue in the south with a dedicated arapaima fishery, positioned conveniently for anglers combining their freshwater fishing with saltwater adventures in the Andaman Sea — the Andaman Sea fishing guide and the GT popping Andaman page cover the offshore options in the area.
Best Season and Conditions
The arapaima's air-breathing behaviour removes one of the main constraints that governs other freshwater fish — the need for well-oxygenated water — and this makes the species catchable in conditions that would suppress other targets. In practical terms, arapaima at Thai venues can be caught year-round.
Surface activity — the explosive rolls and breathing behaviour that betray the fish's location — is most visible during the hotter months, March through May, when water temperatures are high and surface activity among large fish is pronounced. This makes location easier and can concentrate fishing effort effectively. Hot, overcast days with relatively still water often produce excellent surface presentations.
The cool season (November through February) brings more stable, comfortable conditions and remains highly productive. Arapaima that are slightly less active at the surface still need to breathe, and their locations can often be inferred from the visual evidence of their periodic rolls. Water clarity tends to be higher in the cool season at many southern venues, which can affect presentation choice.
The rainy season (June through October) is productive but comes with logistical considerations. Heavy rainfall can temporarily colour the water, and extreme storms occasionally interrupt sessions. That said, the cloud cover of the wet season moderates the otherwise brutal heat, and arapaima fishing remains entirely viable. See the monsoon season fishing strategy guide for venue-specific advice.
Techniques
The arapaima is uniquely versatile among Thailand's large freshwater targets in that it can be legitimately targeted with bait, lure, and fly. Each approach has its adherents and its conditions, and the best anglers at venues like Gillhams are fluent in all three.
Bait Fishing
Surface bait presentations — floating a deadbait or large chunk of fresh fish on the water above the fish's location — are highly effective when arapaima are actively rolling and visible. A large piece of mackerel, mullet, or local freshwater fish, floating or slow-sinking, presented on a 6/0 to 9/0 circle hook with minimal weight, can produce explosive takes as the fish rises to breathe and intercepts the bait.
Bottom fishing with large deadbaits is also practised, particularly for fish that are less active at the surface. Running leger or paternoster rigs with 4–6 ounce weights, a 100 lb fluorocarbon hooklength, and large circle or J hooks are typical. The venue's house bait is usually the reliable starting choice; guides at Gillhams and IT Lake Monsters can advise on what has been producing.
Lure Fishing
Arapaima are credible lure targets, and hooking one on a lure is considered by many visiting anglers to be the premium experience. The fish responds to large surface lures — pencil poppers, stickbaits, and large prop baits worked slowly across areas where fish have been seen rolling — with aggressive, bone-jarring strikes that leave little doubt about the take.
Large soft plastic swimbaits and paddle tails, worked on heavy jig heads at slow to medium retrieve speed through the mid-water column, are effective when surface presentations are refused. The arapaima's large mouth means lure size should be scaled up — small lures get ignored. Lures in the 15–25 cm range are appropriate. Strong, forged trebles or single hooks in 2/0 to 5/0 are needed to handle the impact of the strike and the subsequent battle.
The arapaima tackle guide has detailed recommendations on lure selection and rigging.
Fly Fishing
Fly fishing for arapaima is a specialist pursuit but an entirely achievable one, and Gillhams in particular has infrastructure for fly anglers and guides experienced in directing the presentation. Large, heavily weighted streamers — articulated flies up to 20 cm in length, tied on strong saltwater hooks in sizes 3/0 to 5/0 — fished on a 10- or 12-weight rod with a full-sinking or intermediate line are the standard approach. The tropical fly fishing setup guide on this site covers the wider context.
Takes on fly are explosive and immediate; the challenge is not inducing the strike but surviving it. A direct-drive reel with an absolutely smooth drag, pre-loaded with at least 200 metres of backing, is essential. Line management and stripping hand discipline matter enormously — a loose coil at the wrong moment ends the encounter very quickly.
Surface breathing = location finder
The arapaima's need to breathe every 10–20 minutes is your most reliable location tool. Watch the water from a high vantage point before fishing. Mark the areas where fish roll repeatedly — they often have preferred breathing spots — and present there.
Tackle Setup
The tackle demands of the arapaima vary by technique but share a common requirement for absolute structural integrity at every connection point.
For bait and lure fishing: a heavy-duty baitcasting or spinning outfit is typical. A medium-heavy to heavy action baitcasting rod in the 7- to 8-foot range, rated for 50–100 lb braid, paired with a large baitcasting reel or a saltwater spinning reel in the 10000–14000 size class, 80–100 lb braid mainline, and a 100–150 lb fluorocarbon or heavy monofilament shock leader. The leader is important — arapaima have bony, abrasive mouths and their rolling fight can saw through lighter material quickly.
Hooks must be strong. The fish's initial jump is an extraordinary event and the aerial stress on a hook and line is extreme. Forged, heavy-wire hooks in saltwater-grade steel are the minimum standard. Trebles on lures should be upgraded from factory fittings as a routine precaution.
For fly fishing: a 10- or 12-weight rod with a fast action and a fighting butt, a direct-drive reel with a sealed disc drag, and 30–40 lb tapered leader with a 60–80 lb tippet. Saltwater-grade fly gear throughout.
Records and Notable Catches
The arapaima's IGFA all-tackle record for the species stands at a weight well above 100 kg, with the record fish taken from South American waters. Thai stocked venues produce very large fish — Gillhams has documented numerous specimens above the 100 kg mark — but the IGFA record infrastructure for stocked lake fishing is complex, and the records most commonly cited are from native-range fish.
What can be said with certainty is that the arapaima available at Gillhams and IT Lake Monsters are genuine world-class fish by any measure — fish that would be considered extraordinary in any context, in any country.
Conservation and Ethics
Arapaima gigas occupies an unusual conservation position in Thailand: it is an introduced species rather than a native one, and its presence in Thai waters is entirely a product of deliberate stocking by commercial fishing venues. There is no wild Thai arapaima population in need of conservation. The species is, however, considered vulnerable or endangered across portions of its native Amazon range due to overfishing — a situation being addressed by Brazilian and Peruvian conservation programmes that have shown considerable success in community-managed fisheries.
The ethical dimensions of arapaima fishing in Thailand are therefore different from those of the native endangered species like the Giant Mekong Catfish and Giant Siamese Carp. Catch and release remains universal practice at reputable venues — not because the fish is nationally protected (it isn't, as a non-native species) but because the fish are the venue's primary asset and because anglers overwhelmingly prefer to release something this extraordinary. Practical handling: support the fish horizontally at all times, minimise air exposure, allow full recovery in water before release. A fish that has jumped five times and made three long runs will need significant recovery time.
An arapaima jumping five feet out of a Thai lake at dawn, scales catching the light like hammered copper, is the kind of image that doesn't leave you. It belongs to no category of normal experience.
What It's Like to Hook One
Arapaima do not fight like other fish. The take is violent and immediate — the surface detonates, or the rod loads in a single brutal movement — and what follows is a series of experiences that bear only a passing resemblance to fishing as most anglers understand it.
The jump comes first, usually within the first thirty seconds. A large arapaima becoming airborne is a confrontation with something the nervous system is not prepared to process: an animal of 80 or 100 kilograms, entirely out of the water, rolling in the air, its broad scaled flank catching the light as it turns. The impact when it re-enters the water is felt through the rod, through the line, through the reel. If the hook doesn't pull, the drag doesn't jam, and the leader doesn't part in that first second of re-entry, the real fight begins.
Runs are long and powerful, particularly the first one, which can strip a hundred metres of line before the fish begins to plane and turn. The mid-fight is a series of heavy, rolling surges as the fish tries to go deep and use its mass. Arapaima tire in stages — there are usually two or three secondary efforts that feel like a fresh fish — and the recovery period between stages is brief. The angler never quite relaxes.
Landing a large arapaima requires a net of serious dimensions or, at many venues, a wading guide who takes the leader, directs the fish, and controls it in the margins. The moment of landing — when the great copper-and-green body finally lies still, heaving with the effort of breathing — is both triumphant and humbling. You have caught something that has no business existing, and yet here it is.
Where to Go Next
Arapaima fishing sits at the intersection of Thailand's best freshwater venues and some of the country's most spectacular locations. Gillhams Fishing Resort in Krabi is the complete arapaima experience and a natural base for exploring the southern fishing scene. The arapaima tackle guide is essential reading before your trip. For anglers combining freshwater and saltwater, the Andaman Sea fishing guide covers the extraordinary offshore fishing accessible from the Krabi coast. If you want to add a second large predator to your session, the Giant Snakehead and Barramundi are both available at venues across Thailand and offer a completely different style of lure-fishing challenge.
