Balroglanis macracanthus

Balroglanis: from the Balrog, the fire demon of J. R. R. Tolkien's The Lord of the Rings, and the Ancient Greek γλάνις (glánis), meaning 'catfish'. Grant (2015) chose it for the larger size of these species and the horn-like shape of the nuchal shield.

macracanthus: from the Ancient Greek μακρόν (makrós), meaning 'long', and ἄκανθα (ákantha), meaning 'thorn'.

Type locality is 'São Pedro, Rio Negro, Amazonas, Brazil', and this species is considered endemic to the upper rio Negro system.

In nature it takes refuge among submerged woody structures during the day, emerging to forage at night, and this habit gives rise to the common names of ‘wood’ or ‘driftwood’ catfishes for the family Auchenipteridae in general.

An aquarium with base dimensions of 80 ∗ 30 cm31 ∗ 12 in or equivalent should be the smallest considered for general care.

Not difficult to maintain under the correct conditions; we recommend keeping it in a tank designed to simulate a flowing stream with a substrate of variably-sized rocks, sand, fine gravel, and some water-worn boulders.

This can be further furnished with driftwood branches, terracotta pipes, plant pots, etc., arranged to form a network of nooks, crannies, and shaded spots.

Centromochlus species also enjoy sheltering among surface vegetation such as Ceratopteris spp.

Centromochlus species will accept most sinking dried foods, but particularly relish small live and frozen varieties such as bloodworm, Tubifex, etc.

Once acclimatised they readily leave their hiding places when food is introduced and unlike most catfishes tend to actively feed at the surface.

All members of the family Auchenipteridae are thought to practise internal insemination and females can carry mature, unfertilised eggs and sperm packets inside the body for unspecified periods of time.

When conditions are satisfactory fertilisation is triggered and the eggs deposited, and there is no subsequent parental care.

This species is poorly known but occasionally available in the aquarium hobby.

The genus Centromochlus is diagnosable by members having the proximal anal-fin radials enlarged and fused to each other at the base, forming a single ossified structure.

It's sometimes included in the putative subfamily Centromochlinae which also includes Gelanoglanis, Glanidium, and Tatia.

This grouping is told apart from other auchenipterids by having modified anal-fin rays and proximal pterygiophores orientated posteriorly, a male urogenital papilla emerging from a flap of skin at the anal-fin origin, and the proximal anal-fin radials at least partially joined to each other.

The family Auchenipteridae is endemic to the neotropics and members are told apart from other catfishes by the following combination of characters: absence of bony plates on body; predorsal area covered in sutured bony plates clearly visible beneath a thin epidermis; absence of nasal barbels; adipose-fin small, occasionally absent; eye without a distinct orbital rim and covered by adipose tissue.