Hemiancistrus has become a very messy genus. Scientists have had, and continue to have, a hard time sorting it out, but one thing is certain: The first described species of the genus; H.medians, is currently the only true Hemiancistrus. It was unknown in our hobby until 2011, when some specimens arrived in Germany. In later years, it has been exported from Suriname fairly regularly, but because of the high price most individuals end up in the Far East. We still haven’t learned too much on their requirements in captivity, but we are dealing with a rather quarrelsome, somewhat sensitive species. They are not unlike Baryancistrus, and their numerous teeth tell we are dealing with a grazing omnivore. H.medians reach 30 cm in length, so they should be provided some space. It may turn out that H.medians is not a very hardy species during its initial period of settling in, and combined with the high price this is likely to prevent it from become anything but a rare oddity for a few, especially interested keepers.
Facts:
Name: Hemiancistrus medians (Kner, 1854)
Trade names: Big-Eyed Pleco
Origin: Rio Maroni, Suriname
Maximum TL: 30 cm / 12”
Although not much is known about keeping H.medians in aquariums yet, it’s likely that they will be rewarding fishes to keep once settled in larger tanks. Breeding is likely to occur in typical Hypostominae fashion, with the male caring for the brood in a narrow cave.
More info:
https://www.scotcat.com/loricariidae/hemiancistrus_medians.htm
http://www.l-welse.com/reviewpost/showproduct.php/product/765/cat/46
https://www.planetcatfish.com/common/species.php?species_id=1171