Substrate questions

[WhistlingBadger]

No species sifts an inert substance of no nutritional value to find food.

Not true. Many cyprinids (most notably goldfish), many cichlids, and many catfish do indeed sift sand and soil with their mouths, looking for edible bits. They don't ingest the sand, true, but they do take it into their mouths, swish it around, and expel it through their mouths or gill slits.

 

[itiwhetu]

Not true. Many cyprinids (most notably goldfish), many cichlids, and many catfish do indeed sift sand and soil with their mouths, looking for edible bits. They don't ingest the sand, true, but they do take it into their mouths, swish it around, and expel it through their mouths or gill slits.

Cichlids move substrate as do Goldfish, that is different than what we are talking about Corydoras doing. The idea that a Corydoras can take a mouth full of sand and then find a crustacean in it and only swallow the crustacean, I'm sorry I just don't buy it. Corydoras have very sensitive barbs for detecting food, so why would they not just use those. Detect the food and swallow it.

 

[Byron]

Cichlids move substrate as do Goldfish, that is different than what we are talking about Corydoras doing. The idea that a Corydoras can take a mouth full of sand and then find a crustacean in it and only swallow the crustacean, I'm sorry I just don't buy it. Corydoras have very sensitive barbs for detecting food, so why would they not just use those. Detect the food and swallow it.

At the risk of pointlessly stating the obvious yet again...here is a video which clearly shows the cory using the barbels to dig into the substrate, then taking a mouthful of substrate, and expelling the sand out via the gill covers. We cannot see if the fish has found any food and swallowed it (with or without sand particles), but this is how cories feed. To try and suggest this is not occurring just because you cannot understand it is not a valid argument.

corydoras feeding ian fuller - Wyszukaj Filmy

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