Breeding Ivantsoff's Blue-eye (Pseudomugil ivantsoffi)
Breeding Pseudomugil ivantsoffi, an endangered Western Papua blue-eye: sexing, plant or mop spawning with daily eggs and rearing the tiny fry.
Overview
Pseudomugil ivantsoffi is a blue-eye endemic to Western Papua in Indonesia, described in 1999 by Gerald R. Allen and Samuel J. Renyaan from types collected in southern Irian Jaya near the Kopi River during 1995 expeditions. According to Wikipedia it was named in honour of the ichthyologist Walter Ivantsoff of Macquarie University in Sydney. FishBase gives a maximum standard length of 2.8 cm and classifies it as Endangered, so maintaining captive stocks has conservation value. As a member of the blue-eye genus Pseudomugil it is a continuous plant-spawner.
Sexing
In line with the genus, males are the more colourful sex with more extended fins and stronger yellow-orange fin tips, while females are plainer with a rounder body and shorter fins. Displaying males show their fullest colour during courtship.
Conditioning
Condition a small group on varied small live and frozen foods until the females are full of eggs and the males display steadily, as is typical for the small, short-lived blue-eyes.
Breeding Setup
- Provide fine-leaved plants such as java moss or nylon spawning mops as egg sites.
- FishBase places the species in freshwater, tropical habitats.
- A small group with one male to two or three females encourages steady spawning.
Spawning Behavior & Trigger
As a continuous spawner of the blue-eye group, the males court females that deposit small numbers of adhesive eggs into the plants or mop each day over an extended period rather than in a single batch.
Egg & Fry Care
Eggs attach to the medium by fine threads. Following the pattern of the genus, the very small fry begin on infusoria-type foods before taking free-swimming foods such as brine shrimp nauplii and microworm as they grow.
Common Challenges
Adults may eat eggs and fry, so removing the spawning medium for separate hatching improves yields. For an Endangered species, keeping pure, well-recorded lines is also valuable, and the very small first fry need infusoria-sized foods and clean water.