Breeding the Saddled Bichir (Polypterus endlicheri)

Polypterus endlicheri spawns during the rains; the male cups his anal fin to fertilise eggs. Home breeding is not practical and is rarely achieved.

Overview

The Saddled Bichir (Polypterus endlicheri) is a large African polypterid that reaches around 61-76 cm, with females growing larger than males. It is a piscivore of central and western Africa, recorded across the White Nile, Niger River and Chad Basin (FishBase; Wikipedia). Polypterids have rarely been bred in captivity: the first documented success in the family was Polypterus senegalus by Arnoult in 1964, and P. endlicheri was reported reared from 1995 (Wikipedia). Home reproduction is not a realistic goal.

Sexing

Within the genus the most reliable external sex cue is the anal fin, which is broader and thicker in mature males because it forms a cup used during fertilisation. In P. endlicheri females also grow larger than males (Wikipedia).

Conditioning

Spawning in P. endlicheri occurs during the rainy season in response to changes in water temperature and chemistry (Wikipedia). Conditioning therefore centres on heavy feeding of meaty foods on mature adults, followed by simulated seasonal change. Because of the fish's large adult size, this is feasible only in very large systems.

Spawning Behavior & Trigger

A receptive male displays by cupping his enlarged anal fin, then follows and nudges the female. According to species accounts, when the female is ready the male places his cupped anal fin beneath her genital papilla, catching and fertilising the eggs as they are released (Wikipedia). Across the genus, spawning is triggered by imitating the rains - large, generous changes with cooler, softer water that lower conductivity, followed by a temperature rise.

Egg & Fry Care

Eggs are slightly adhesive and stick to vegetation. In P. endlicheri they hatch after about three days into fry roughly 5 mm long (Wikipedia). Polypterid larvae carry branched external gills resembling those of newt and salamander larvae, which are lost as the fish grows (genus account, Wikipedia). Bichirs generally provide no parental care, so eggs and fry must be protected from the adults.

Common Challenges

The principal obstacle is the species' size and the very large volumes needed to house breeding adults and trigger a seasonal flood cycle. Reliable pair formation, predation of eggs and fry by the parents, and the rarity of any documented home success make this an advanced, largely commercial undertaking.