Spotted Blue-eye

Geographical Origin and Variants:

They inhabit the marginal zones (often in very few centimeters of water) and the stagnant swamps of billabongs (lagoons) in Northern Australia and southern Papua New Guinea. There are many strains (locality morphs) such as the 'Aru II' strain, each with chromatic variations in the number of black polka dots and in the yellow or bluish tint of the fins.

Courtship Morphology:

The male's transformation during courtship is lightning fast. From an almost invisible resting position, it literally shoots upwards and expands the first and second dorsal fin, as well as the anal fin, which being covered in dark reticulated black spots resemble the spotted wings of a butterfly. They will execute a dancing circle in short, almost robotic jerks, a hypnotic spectacle to watch in the aquarium.

Tank Setup:

The ideal home for *P. gertrudae* is a dedicated 40-60 liter (10-15 gallon) aquarium (species-tank) or shared only with shrimp (it is one of the most "shrimp-safe" fish absolutely). This species lives literally suspended among the floating weeds. Without a dense and suffocating cover of surface plants (*Ceratophyllum*, *Pistia* roots, floating moss), the fish will remain stressed on the bottom hiding. Filters must not generate currents, otherwise the fish will be blown away; the use of a sponge air filter is the master choice for these delicate jewels.

Feeding (The Micro Challenge):

It shares with *Iriatherina werneri* the morphology of the oral cavity. They are not able to swallow standard feed. They commonly die of starvation in the tanks of well-intentioned beginners. You must flood the tank with live brine shrimp nauplii, microworms, and possibly supplement with ultra-fine micronized freeze-dried powders specifically designed for fry.

Water Quality:

Less demanding than Forktails regarding hardness, they appreciate much more the addition of botanical leaves (Oak, Indian Almond - Catappa, alder cones) which will lightly amber the water and lower the pH to ideal levels (6.0-6.8), reducing the bacterial load to which they are sensitive.