Green Phantom Pleco (L200) Breeding Guide

What is known about breeding the green phantom pleco (Hemiancistrus subviridis, L200): a rare cave-spawner with male egg-guarding and demanding water needs.

Overview

The green phantom pleco (Hemiancistrus subviridis, L200) is a loricariid catfish reaching about 15 cm, native to the Orinoco and Casiquiare drainages of Venezuela, where it lives in flowing water among granitic rocks. It is one of two species sharing the L-200 label, the other being Baryancistrus demantoides. Confirmed aquarium breeding is rarely reported, so breeding should be approached as challenging and not guaranteed.

Sexing

Detailed sexing characters are not well documented in the sources reviewed. In a documented spawning, the female was identified by being visibly ripe with eggs and becoming noticeably slimmer after spawning.

Breeding Setup

The species is found in flowing water among granitic rocks in the Orinoco and Casiquiare drainages, so a breeding attempt should reproduce strong flow and high oxygenation. Provide several enclosed cave-like spawning sites so a male can claim and defend one against rivals. Soft, warm water in line with the species' general range is appropriate, kept under very stable, clean conditions; this is a territorial bottom-dweller, so spacing the caves apart reduces conflict.

Spawning Behavior & Trigger

In a documented account from imported fish around 8-10 cm, the male selected one of the available caves and chased other fish away from it, behaviour consistent with a male cave-spawner that guards the eggs. The pair spawned several times, judged from the female repeatedly becoming slim afterwards, although the spawning act itself was not directly observed. In comparable cave-spawning loricariids the male typically remains in the cave to fan and guard the developing eggs.

Common Challenges

Because reliable breeding protocols are not well established for this species, success is uncertain. The main practical hurdles are recreating the strong-current, highly oxygenated conditions of its native rivers and providing defensible caves; without these, spawning is unlikely.