Red fin thresher pleco

Aphanotorulus emarginatus

Also known as Squaliforma emarginata, L011, L035, L108

FreshwaterFish

Red fin thresher pleco (Aphanotorulus emarginatus) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 77–84°F (25–29°C)
pH: 6.0–7.4
Adult size: 13.4 in (34 cm)
Minimum tank: 119 gal (450 L)
Temperament: Peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Medium
Breeding: Hard
Rarity: Rare
Origin: Orinoco and Guiana Shield rivers
Family: Loricariidae

Overview

The red fin thresher pleco is a big, active, cruising pleco shaped like a request for a longer tank, so give it length and open swimming room. It is solitary and best kept one to a tank, since adults are territorial toward their own kind. It patrols the bottom and lower water and is peaceful toward other fish, suiting spacious communities of robust midwater species. Feed it as an omnivore that leans vegetable: blanched courgette, spinach, and algae wafers with modest protein from sinking pellets and occasional frozen foods. It needs strong current and high oxygen, so filter heavily and allow a large tank of around 450 liters.

In the wild

Aphanotorulus emarginatus ranges through big rivers of the Orinoco and Guiana Shield, living in flowing, highly oxygenated water over sand scattered with rock. Give it a long, open tank with a sand floor, some rounded stones and wood for cover, and clear lanes to cruise. Keep it warm at 25 to 29 C and around pH 6.0 to 7.4, clean and briskly moving. Space and current matter more than any single decor choice, since this is a roaming, riverine fish.

Good to know

Aphanotorulus emarginatus is a member of Loricariidae that reaches about 34 centimeters on a long, slender, streamlined frame. It was once placed in the genus Squaliforma, a name meaning shark-shaped, after exactly that silhouette. It reaches the trade under several codes, including L011, L035, and L108. Large and riverine, it is seldom bred in aquaria, so captive spawning is rated hard.

Did you know

Its old genus name Squaliforma means shark-shaped, and the thresher in its common name is a shark too. The fish is really a mild suckermouth grazer doing a convincing impression of a predator built for open water.

Tank mates

Red fin thresher pleco is a peaceful, solitary species that keeps to the bottom. These picks match on water type, temperature, pH, size and temperament.