Carinotetraodon irrubesco · Red-tailed Redeye Puffer

Overview

Red dorsal and tail fins in males and conspicuously raised eyes help recognize Carinotetraodon irrubesco. This small freshwater puffer may be more tolerant than some relatives, but still needs cover and carefully chosen companions.

Distribution & habitat

Known Indonesian localities are the lower Banjuasin basin of southern Sumatra and the Sambas drainage in West Kalimantan. Fish were collected among inundated bankside terrestrial vegetation, including a site with murky brown water.

Aquarium setup

Arrange dense plant growth around roots and branches, using floating vegetation for shade. Dried leaves add shelter and microbial surfaces. Gentle flow and regular small changes are preferable to allowing water quality to decline.

Diet & feeding

Regular portions of manageable shelled invertebrates help wear the continuously growing mouthparts. Snails, shellfish, and small crab legs can be supplemented with chopped mollusk flesh, small earthworms, bloodworms, and Artemia. Avoid making ordinary dry foods the staple. Retain biofilm on decor, since attached organisms may contribute to natural feeding.

Behaviour & compatibility

Keep alone or cautiously with peaceful schooling cyprinids sized to avoid both predation and intimidation. Social grouping is loose, and males tend to defend space. Several can be maintained with ample room and dense cover, but breeding interactions can single out an individual for attack.

Sexual dimorphism

Males show a distinct boundary between the gray mottled flank and white underside, a broad pale side stripe, and a red belly line. Their dorsal and tail fins are red, without a dark spot at the dorsal base. Females have paler, irregularly reticulated markings, broken dark lines beneath, and a yellowish barred tail. Eyes are generally red, though some males appear blue-green.

Breeding

At least one aquarium account documents spawning. Of two females with one male, one was removed after attacks, while the other received courtship displays involving darker male coloration and an extended ventral ridge. Several hundred eggs were deposited among plants and on decor. Adults were removed after the male began eating eggs.

The first larvae emerged after about 65 hours and swam while still carrying yolk. Infusoria were introduced around day three as the yolk was absorbed. At day ten, 30–40 fry remained and ate rotifers; subsequent rearing success was unclear.