Biotope aquarium enthusiasts will particularly enjoy this in-situ look at a freshwater sole!
Biotope aquarium enthusiasts will particularly enjoy this in-situ look at a freshwater sole!

AMAZONAS contributor Dr. Leandro Sousa recently shared video of an exciting encounter in South America. The freshwater sole/flounder, Hypoclinemus mentalis, was encountered while diving in the Tocantins River, near the town of Itaguatins in the state of Tocantins, Brazil.

Hypoclinemus mentalis, image by Clinton & Charles Robertson, CC BY 2.0

Watch Sousa’s Wild Footage, then keep reading!

Known as “linguado” in Portuguese and sometimes encountered in the aquarium trade as the “Peruvian Freshwater Sole”, this species is actually widely distributed throughout the Amazon River Basin. It is definitely a rarity in the aquarium trade, with occasional offerings most notably seen in Europe.

Interested in Freshwater Flatfishes? The January/February 2022 AMAZONAS issue was dedicated to this fascinating group! Get it now!

H. mentalis reaches a length of 21 cm (approximately 8 inches), and as can be seen in the in-situ video, would probably be best suited for a tank with a significant open, sandy substrate and a fair amount of current. Little husbandry info exists, aside from a short entry at the website Mesonauta and more, which notes an initial requirement for frozen foods to entice a feeding response. Another hobbyist experience suggests this species is mainly active at night.

YouTuber ~Muh-Kuh~ shared a series of interesting videos in 2016 featuring the inclusion of Hypoclinemus mentalis in a South American biotope aquarium. Enthusiasts may want to check out all the videos uploaded to the channel, but the most interesting one shows the completed biotope aquarium with residents. Muh-Kuh ultimately selected a shoal of Colombian/Columbian Tetras (Hyphessobrycon columbianus), two Keyhole Cichlids (Cleithracara maronii), two Redbreast/Red-breasted Dwarf Acaras (Laetacara dorsigera), and three Peruvian Freshwater Soles (Hypoclinemus mentalis) to complete the community.

If you’re looking for something truly unique, or potentially a new breeding challenge, perhaps jump on the opportunity to acquire some freshwater flatfishes should you get the chance!

Watch Muh-Kuh’s Biotope Aquarium Now