The Eel-tailed Catfish (Tandanus tandanus)

Last week, I wrote about the great builders of the animal world, the beavers. But of course all sorts of other creatures build things.  The Eel tailed catfish (Tandanus tandanus) lives in the Murray-Darling river basin of Eastern Australia where the creatures’ nest-building habits are costing them dearly.

The eel-tailed catfish is from the family Plotosidae (in fact it is a close relative of the striped eel catfish) and like other family members its most distinctive feature is a continuous fin margin surrounding the posterior half of their bodies—aka an eel tail!  These catfish prefer to live on the gravel or sand at the bottom of lakes or slow-moving rivers.  They eat crayfish, yabbies’, worms, mollusks, insect larva, and other smaller fish.

An eel-tailed catfish nest (the parent is in the middle)

A week or two before spawning, pairs of eel-tailed catfish build nests for their eggs. The fish construct these torus-shaped structures out of sand and pebbles and, once the female lays the eggs, one or both parents stay with the nest to guard it and to aerate the eggs until they hatch.  Unfortunately, because of drought and agriculture, the Murray basin is rapidly drying out and silting up.  As the pebbles and coarse sands which the fish use for nests are smothered with slimy silt, the species has been declining.  Additionally, eel-tailed catfish are being out-competed by invasive carp which were introduced in a hare-brained aquiculture scheme.

Advertisement