If you are looking for a long-lived, extremely robust, pretty and peaceful fish, Agamyxis is the right fish for you. Although these virtually indestructible spiny catfish grow relatively large at up to 15 cm in total length, they are absolutely peaceful and require so little movement due to their well-kept phlegm that they can live happily in “normal-sized” aquariums for a lifetime – which can easily be 20 years or more.
There are two species in this genus that supposedly cannot be distinguished by external characteristics: A. albomaculatus and A. pectinifrons. Both species actually look very similar. The scientifically accepted distinguishing feature is the number of swim bladder appendages. To see these, you have to dissect the fish. However, a (syn-)type specimen (ZMB 10043) of A. albomaculatus has a white underside, while the (syn-)type of A. pectinifrons (ANSP 8346) has the typical black, white-spotted underside. The specimens in the trade are mostly captive bred and are referred to as A. pectinifrons, which also matches the belly coloration.
In the wild, A. pectinifrons is widespread, the species is known from Bolivia, Brazil, Ecuador, Colombia and Peru, i.e. practically the entire Amazon catchment area, while A. albomaculatus is considered to inhabit the Orinoco (Colombia and Venezuela). Sexual differences are only slightly pronounced in Agamyxis, the males are smaller and slimmer. The animals probably do not practise brood care, but the spawn is scattered freely in roots and plants.
In the case of the black, white-spotted loricariid catfish we have asked about the purpose of the coloration; in the case of the spiny catfish there is at least one idea: it has been observed that a close relative of A. pectinifrons, the white-striped Platydoras armatulus (see https://www.aquariumglaser.de/en/10-catfishes/platydoras-armatulus-2/), acted as a cleaner fish for large predatory tetras (Hoplias). It is assumed that the other striking black and white spiny catfishes (there are several of these, but only Agamyxis is spotted) also do this.
For our customers: Agamyxis have code 202811 on our stocklist. Please note that we only supply the wholesale trade.
Text: Frank Schäfer, Photos: Frank Schäfer & Erwin Schraml
