Surubí in Paraguay: where it is caught, when, and how to tell the spotted from the striped

The surubí is the biggest fish caught in the rivers of Paraguay. The spotted surubí (Pseudoplatystoma spp.) reaches 182 centimetres and 100 kilos according to the scientific records, and fish of over two metres and 80 kilos have been documented on the Paraná. What comes out of the water on a normal day runs between 10 and 25 kilos, and that is already a fish you need to know how to fight.

It is listed in all 12 areas of the guide. It is the fish that turns up everywhere: from the Pantanal at Bahía Negra to the Paraná at Ayolas and Encarnación, and on the Tebicuary at Villa Florida.

Spotted and striped: two species, not two varieties

Two surubíes share the basin, and it pays to tell them apart, because their minimum sizes differ. The spotted one has a metallic grey to olive back with spaced pale vertical bars and a body sprinkled with dots. The striped one carries 13 or 14 dark transverse bands running down to the belly, like a tiger. The striped is scarcer and smaller: it reaches 1.10 metres.

A naming detail that confuses even the regulations: the striped surubí of the Paraná and Paraguay rivers is Pseudoplatystoma reticulatum. Until 2007 it was treated as a subspecies of P. fasciatum, which actually lives in the Amazon and the Guianas; the revision of the genus split them. The Unified Fishing Regulation and the Yacyretá entity still write fasciatum, and it is the same fish. In Brazil, pintado and cachara.

There is a third one that should not be in the river: the hybrid of pintado and cachara, farmed in Brazil because it grows faster and is more docile. It is fertile, it has escaped from fish farms, and its genes have already been detected in wild populations. If the fish you land has dots and dashes mixed together and a strongly curved snout, it may be one of those.

Where the surubí is by day and by night

It is a bottom fish. By day it keeps to the deep holes, above all those with strong current, and at dusk and at night it comes in to the bank, even into very shallow water. That is why the classic technique in the guide is live bait in deep pools, night drifting: live bait for a fish that eats fish, with sábalo as the main course, and night drifting to find it where it is at night.

Between June and September, with the river low and the water cold, it concentrates in the deep holes, where it is easier to locate. That is the figure the Paso de la Patria guides give as their best months, and the one the species page carries: year round (outside the closed season); from june to september it holds in the deep pools.

When it is caught in Paraguay

All year outside the closed season. The surubí matures between October and November and spawns from October to December, running upriver with the rising water, which is exactly the period the closed season protects: it starts in the first days of November, until December 20 on waters shared with Argentina and until January 31 of the following year on waters shared with Brazil. The month-by-month picture, with the closure marked, is at the month-by-month calendar.

The minimum size, and why it matters more here than for other fish

Spotted 85 cm and striped 80 cm, total length, snout to tail tip. They are the sizes of the Argentina-Paraguay Unified Fishing Regulation, in force on the shared stretches, and the full table is at licence, closed season and sizes. An 85 centimetre surubí has several years of river behind it: it is a slow-growing fish that the dams have already punished. Upstream of Yacyretá, the spotted surubí fell from 68th to 94th in abundance after the dam closed.

That is why the IUCN Red List has it as Near Threatened since 2020, and why the Yacyretá binational entity has bred it at its San Cosme y Damián station, both species, since 2012. And that is why the record most worth telling is the 80 kilo, two-metre-plus surubí caught by anglers from Asunción at the confluence of the Paraná and the Paraguay, which went back into the river.

Who to go with

The lodges, guides and hotel boats that fish for it are on the species page, area by area: Surubí catfish. In the north, the hotel boats of Concepción and Bahía Negra are the way to reach the deep holes of the Paraguay river; in the south, the guides of Ayolas, Paso de Patria and Pilar head out onto the Paraná from the shore.

Frequently asked questions