Red-hook Silver Dollar (Myloplus rubripinnis) Breeding Guide

Myloplus rubripinnis is a large herbivorous silver dollar whose aquarium breeding has not been achieved; this guide explains sexing and the obstacles.

Overview

Myloplus rubripinnis, the red-hook silver dollar, is a tall, peaceful, herbivorous South American characin reaching about 25 cm. According to Seriously Fish it inhabits slower-moving river sections where marginal or overhanging vegetation is dense. Seriously Fish states plainly that breeding has not been achieved in the hobby.

Sexing

Seriously Fish lists sexing as not known, suggesting only that the male may have a longer anal fin. Reported community observations describe a wavy male anal fin that is thicker in the middle with a convex curved edge, versus a straighter, uniform anal fin in females, but this is not a confirmed method.

Conditioning

As a herbivore the species takes courgette, cucumber, peas and spring greens plus algae wafers, spirulina and vegetable flake. A varied vegetable-rich diet maintains condition, though no spawning trigger is documented.

Breeding Setup

No documented breeding setup exists. Seriously Fish lists keeping parameters of 23-27 C, pH 6.0-7.0 and hardness up to about 10 dH, with a group of adults needing a tank of at least 265 litres, so any attempt would begin from soft, slightly acidic water in a very large aquarium.

Spawning Behavior & Trigger

Seriously Fish records no spawning type, egg information or successful fry-rearing data for Myloplus rubripinnis, so no reliable spawning sequence or trigger can be stated.

Common Challenges

The large adult size and the absence of any documented spawning make home breeding effectively unestablished. As a herbivore, conditioning stock will also consume live plants intended for cover.