African tigerfish

African tigerfish are pursuit predators of large open freshwater systems, and their habitat requirements follow from needing both speed and oxygen.

THEY NEED WELL-OXYGENATED WATER and are intolerant of the stagnant, deoxygenated conditions that snakeheads and catfish handle easily. That confines them to flowing rivers, large lakes with wind mixing, and the main channels rather than the backwaters.

THEY HUNT IN OPEN WATER AND AMBUSH FROM EDGES. Tigerfish work channel margins, drop-offs, confluences, rocky reaches and the boundaries between fast and slack water, holding out of the main flow and striking into it. Structure matters as a break rather than as cover.

WARM WATER IS THE OTHER REQUIREMENT — the species is tropical and subtropical, and at the cooler edges of the range it becomes seasonal and sluggish.

JUVENILES USE MARGINAL AND FLOODPLAIN HABITAT, in shallower vegetated water, before moving into the main channel as they grow.

TURBIDITY IS TOLERATED but the fish is a visual predator with excellent eyesight, so clearer reaches concentrate feeding activity.

AND THE LARGE-LAKE POPULATIONS BEHAVE DIFFERENTLY FROM THE RIVER ONES, occupying open pelagic water and hunting shoaling prey — the same species using a completely different habitat, which is worth knowing before generalising about where to expect them.

Tigerfish reproduction is tied to the seasonal rise of tropical rivers, and the timing is entirely hydrological.

RISING WATER IS THE TRIGGER. Spawning follows the onset of the rains and the resulting flood, with adults moving out of the main channel into inundated marginal habitat — flooded grass, backwaters and floodplain — to spawn.

EGGS ARE SCATTERED OVER VEGETATION rather than deposited in a nest, and there is no parental care. The flooded vegetation provides both substrate and cover for the resulting fry.

THE FLOODPLAIN IS THE NURSERY. Juveniles grow in the warm, food-rich, predator-sheltered flood before dropping back to the channel as water recedes. Recruitment therefore depends on how much ground flooded, for how long, and how early — the same flood-pulse logic that governs the Mekong and the Amazon.

SO A POOR FLOOD IS A POOR YEAR CLASS, regardless of how many adults spawned. Where rivers are regulated and the flood is suppressed, tigerfish recruitment suffers in a way that no fishing rule addresses.

MATURITY COMES AT A FEW YEARS and the fish grows quickly in warm productive water.

AND THE MIGRATION MATTERS. Populations in river systems undertake spawning movements of substantial distance, so barriers on the mainstem affect reproduction directly.

Tigerfish dentition is unusual enough to change how the fish must be held. The teeth are large, conical, and set so that upper and lower rows interlock outside the closed mouth — they are visible with the jaws shut. They are shearing teeth, designed to remove a section from a fish larger than the mouth, and they are set in a bony jaw with an extremely fast closing action.

THE INJURY IS NOT A BITE. It is almost always a head shake. The fish is held, it convulses, and the exposed teeth are dragged across whatever is in contact with them — a forearm, the inside of a hand, a thigh. The wound is a clean deep laceration rather than a puncture, and it bleeds accordingly. This happens on the boat, after the fight, at the moment everybody has relaxed.

SO THE HEAD MUST BE IMMOBILISED FIRST. A wet cloth over the eyes reduces movement markedly. A firm grip across the back of the head, from above, with the body supported, keeps the jaws from travelling. Hands never approach the mouth: long pliers or a hook-out tool, every time, and cut the trace if the hook is deep.

AND THE HOOKS ARE PART OF THE HAZARD. Tigerfish are usually taken on lures with multiple trebles, from a fish that shakes violently, at close range. A fish thrashing with a treble in its jaw and another swinging free is the commonest way people are hooked in this fishery, and it is a worse outcome than the teeth.

HANDLE THEM QUICKLY. These are warm-water fish, often taken in high air temperatures after a hard fight. The fish's tolerance for handling time is lower than the angler's enthusiasm for photographs.

Tigerfish seasonality is governed by the flood pulse of a tropical river system, which is a fundamentally different clock from the temperature-driven year of a temperate fish and is worth setting out on its own terms.

THE RIVER HAS A WET SEASON AND A DRY SEASON AND THEY ARE NOT SUMMER AND WINTER. In the wet season the river rises, spills onto floodplains, floods grassland and backwaters, becomes turbid and pushes a huge pulse of nutrients and organic material into the system. In the dry season it falls, clears, and contracts into the main channel and residual pools. Every fish in the system organises its life around that cycle.

TIGERFISH SPAWN ON THE RISING WATER. Spawning is cued by rising levels and flooding, with fish moving into inundated marginal areas and floodplain habitat where eggs and larvae have warm shallow productive water and cover. The flood is the reproductive trigger, and a poor flood year produces a poor year class regardless of how many adults are present.

THE PREY BASE FOLLOWS THE SAME PULSE. Small fish spawn and recruit on the flood, and the floodplain becomes a nursery producing enormous numbers of them. As the water falls, those fish are forced off the floodplain and back into the channel — and that draining period is a concentrated feeding opportunity for every predator in the river. Tigerfish exploit it heavily.

WHICH MAKES THE FALLING AND LOW-WATER PERIOD THE PRODUCTIVE ONE FOR AN ANGLER, and for two reasons at once. The water clears, which suits a visual predator and suits anybody trying to present a lure to one; and the prey is concentrated in a smaller volume with the predators on it. High flood water is turbid, spread over an enormous area, and difficult in every respect.

TEMPERATURE STILL MATTERS AT THE EDGES. Tigerfish are warm-water fish and become notably less active in the cooler part of the year in the southern parts of the range, which layers a temperature effect onto the flood cycle in systems like the Zambezi.

SO THE ANSWER TO 'WHEN' IS A HYDROGRAPH RATHER THAN A MONTH. The dates shift between years with the rains, and a season described by calendar in one catchment does not describe another. Where fishing is permitted, in what form and at what time is separately a matter for the competent authority in each country.

Tigerfish tackle is designed around one fact that most anglers meet for the first time on the water: an enormous proportion of takes do not result in a hooked fish, and the reason is anatomical rather than a matter of timing.

THE MOUTH IS BONE AND THE TEETH INTERLOCK. A tigerfish's jaws carry large conical teeth that close into sockets in the opposing jaw, so a closed mouth is effectively a solid box with very little soft tissue anywhere in it. A hook arriving into that gets almost no penetration, and a fish that clamps down and shakes ejects it. Hook-up rates in this fishery are low by any standard and it is not the angler's fault.

SO EVERYTHING FOLLOWS FROM GETTING A POINT IN. Chemically sharpened, strong, short-shanked hooks kept genuinely sharp — checked and touched up during a session rather than assumed — are the single highest-return tackle decision. A blunt hook here does not merely reduce the odds; it removes them.

AND THE STRIKE HAS TO BE HARD, WHICH SETS THE ROD AND LINE. Driving a point into bone requires the strike to reach the hook, so low-stretch braided line and a rod with the stiffness to transmit it are the standard combination. A soft rod and stretchy line absorb exactly the energy that was needed. This is one of the few fisheries where a stiff rod is a hooking tool rather than a fighting one.

A WIRE TRACE IS NOT OPTIONAL AND IT IS FOR THE SAME REASON AS PIKE. Those teeth part monofilament and braid alike on contact, and a bitten-off fish swims away carrying a lure. The trace is a welfare requirement as much as a tackle one.

THE FISH JUMPS, AND THAT IS WHERE THEY ARE LOST. A tigerfish leaves the water repeatedly and violently, and a hook in bone has nothing holding it once tension drops. Keeping a bend in the rod through a jump — rather than bowing to it as one would for a tarpon — is the practice most experienced anglers settle on, and it is one of the genuine differences from other jumping fish.

AND THE HANDLING KIT IS PART OF THE OUTFIT: long pliers and a controlled grip, because the same teeth that defeat a hook are entirely capable of an injury the record's handling section describes.