Blotched snakehead

Its range

Japan, southern China, Viet Nam, Taiwan and the Philippines.

Part of that distribution has passed through human hands. The fish has long been raised in flooded plots, and the sources record it as a rice-field animal as readily as a wild one. An island record therefore does not say by itself whether the population is old or descended from stock, and for many points on the map that distinction can no longer be recovered. Anyone reasoning from the range of this species needs to know which of the two a given locality represents.

Breeding

The record stops at pairing. Male and female pair off distinctly through the breeding season, then move into shallow fresh water among plants, and the species is oviparous.

In a genus described mostly through its constructions and its guarding adults, that is where the documentation for this fish ends. No nest, no clutch size, no duration of care has been recorded for it, and the gap is worth stating rather than filling with what its relatives do.

The choice of site is at least consistent with the rest of its biology: a few tens of centimetres of sun-warmed water, dense plant cover, no depth whatever.

The water it needs

Adults hold over silty, weedy bottoms in slow rivers, in ponds and in lakes. Soft mud and plant beds go together here, and this is not a fish of moving water.

Those are habitats that agriculture has multiplied rather than destroyed. Irrigation channels, field-edge ditches, farm ponds and flooded plots reproduce exactly the conditions the species needs, which is close to the reverse of the relationship most freshwater fish have with cultivated land.

What it eats

The prey list is out of all proportion to the fish. It takes crustaceans, large insects, frogs and fishes — the diet of a general predator, in an animal whose recorded common length is 11 cm.

An adult frog and a fish of that length are not in the same order of magnitude. The wide gape and toothed jaws that run through the whole group are what make the difference, allowing prey that approaches a substantial fraction of the predator's own length.

Of the four items, the large insects are the operational half of the list, because they are the part that can be imitated.

How to catch it

Everything is in miniature. This is the smallest snakehead that anybody fishes for with a rod, and the first decision is to drop the tackle a size or two: micro soft baits, fine hooks, a short rod. A rig meant for the metre-long members of the genus passes over its head without being noticed.

The diet opens a route its relatives close off. A surface insect — a grasshopper, a large beetle — works on a fish that eats them regularly, so it can be fished on sight, on the fly or under a float, in the top 20 cm along the edge of a weed bed.

The ground is farmland. Ditches, channels, farm ponds and flooded plots are better than large open water, and the fish holds against the vegetation, in water that is usually coloured and always shallow.

The species moves widely outside its native range, and several territories consequently regulate the transport and the keeping of captured fish. Those provisions are set locally, and the fisheries administration for the area is the only source for them.

Other names

Blotched snakehead in English, after the dark brown marks that stand out on an olive flank, and maculata says the same thing in Latin.

Regional names across East Asia mostly fail to separate it from the other snakeheads that share its water and its uses. That imprecision has a practical consequence: a local mention of a snakehead in Japan or in southern China does not identify a species, and neither does a market name, so a published record without a binomial cannot be attributed to this fish.