Slender Woodcat

Trachelyichthys exilis is a small, slender member of the Auchenipteridae found across a broad range of the Amazon basin in Peru, Colombia, and Brazil. Its elongated body, short head, and translucent fins give it an almost ghost-like appearance when swimming among dense plantings or submerged roots in low light. Like all auchenipterids it practises internal fertilisation, making females capable of storing sperm and producing fertile eggs independently.

In the aquarium, Trachelyichthys exilis is a thoroughly nocturnal species that tucks itself into tight shelters during the day. It is somewhat less robust than Tatia or Centromochlus and benefits from stable, high-quality water conditions. In the evening it becomes active and will investigate the entire tank, particularly the mid-water and lower zones, searching for invertebrate prey.

This species is gentle and compatible with a wide range of small, peaceful community fish. Feed in the evening with frozen bloodworm, daphnia, brine shrimp, and micro-pellets. Its graceful build and secretive lifestyle provide an interesting behavioural subject for the patient aquarist who enjoys observing catfish nocturnal activities.

Water: 22–28°C, pH 5.8–7.5, soft to moderately hard (GH 2–12). Tank: 80 L minimum; driftwood and bark hides; dense planting; low lighting or blue moonlight supplement. Feeding: Frozen bloodworm, daphnia, brine shrimp, micro-pellets; feed after lights-out. Breeding: Internal fertilisation; not reliably reported in captivity. Compatibility: Peaceful; compatible with small tetras, pencilfish, and nano community species.