Blue hook silver dollar

Myloplus aylan

Also known as Aylan's silver dollar, Blue hook myloplus

FreshwaterFish

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 5.0–7.0
Adult size: 13.8 in (35 cm)
Minimum tank: 170 gal (645 L)
Temperament: Mostly peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Western Amazon basin, Peru and Brazil
Family: Serrasalmidae

Overview

The blue hook silver dollar is a large, disk-shaped schooling fish that should be kept in a group of at least five, since lone or paired fish tend to be skittish and stressed. It swims mainly in the middle of the water and is peaceful toward tankmates, but it grows big and eats plants, so it works best with other calm, similarly sized fish in a very large tank of around 645 liters or more. Live plants will usually be grazed down, so use tough species or artificial ones. Feed it a mostly vegetable diet of blanched greens, spirulina, and quality pellets, with occasional frozen foods. Give it open swimming space and keep tankmates too large to look like a snack.

In the wild

This silver dollar comes from the western Amazon basin in Peru and Brazil, living in warm river channels and flooded forest where soft, acidic water flows over sand and submerged wood. Match that with warm water from 24 to 28 C and a soft, slightly acidic to neutral pH between about 5.0 and 7.0. A big tank with open water, a sandy floor, and some large driftwood suits a school, and steady filtration keeps oxygen high. It is a strong swimmer, so current is welcome and fine plants are best left out, since they become food.

Good to know

Myloplus aylan is a pacu in the family Serrasalmidae, the same group that holds piranhas, though like other silver dollars it is mainly a plant eater with flat, crushing teeth. It reaches around 35 centimeters and carries a broad dark bar across a tall, silvery body, with a reddish, hooked anal fin in mature males that gives the trade name blue hook. Described only in 2024, it was previously lumped with the widespread Myloplus schomburgkii. Aquarium breeding has not been recorded.

Did you know

The species was named in 2024 after Aylan Moraes Andrade, the infant son of one of the researchers, who was born in late 2022 and died the following year.

Tank mates

Blue hook silver dollar is a mostly peaceful, schooling species that keeps to the middle. These picks match on water type, temperature, pH, size and temperament.