What is the purpose of Otocinclus' dark lateral line?

harsmann · Post by **harsmann** » 06 Aug 2006, 11:44

Hi,

I have been wondering at the purpose of Otocinclus' coloration, especialy the dark lateral line.

A similar line is found on unrelated species like the siamese algae eater (Crossocheilus siamensis) and pencil fish (Nannostomus sp). Since the fish have similar patterns, the purpose might be similar. I suppose it is related to camouflage, just like the oto's brown top colororation makes it difficult to see against wood or substrate. But what is the advantage of looking like a black line?

Does anyone know what the purpose of the dark lateral line?

- Allan

apistomaster · Post by **apistomaster** » 07 Aug 2006, 07:32

My thoughts are that they school in huge numbers in the wild and help them stay in touch with signals from "sentinels" at scool perimeters and help maintain cohesion of the school.
Larry

bronzefry · Post by **bronzefry** » 09 Aug 2006, 14:00

I also agree with the shoaling in numbers. I'm no expert, but I do like to watch them a lot. I do notice that they are agile, no matter where they are: on the glass, on a tiny leaf, on a large leaf, on a rock or even skimming a piece of food off the surface of the water. It reminds me of that song "Over Under Sideways Down." They're motion is so purposeful. I wonder if their color helps them blend in. I'm probably saying the same thing as Larry.

Amanda

apistomaster · Post by **apistomaster** » 09 Aug 2006, 14:43

Sharon,
I beleive the line is also a camoflage design feature. Unless trapped in a drying out pool they live in streams with swaying leaves in the current. Most of the Otocinclus love the grass like plant where they blend in by the thousands. They really don't seem to do well unless you can keep them in groups and the more the merrier.
I have been slowly collecting some Paraotocinclus species. They are a little bit different than common Oto. So far I have P. jumbo and P. spilosoma that I hope to raise some. They are all fun to keep. I have always enjoyed small or nano fish and invertebrates. Back to catfish these 2 are not suposed to be too hard to breed and would be easy to sell.
Larry

harsmann · Post by **harsmann** » 09 Aug 2006, 18:39

Thanks for the input.

Allan

Mike_Noren · Post by **Mike_Noren** » 14 Aug 2006, 16:02

A personal reflection... I've noticed that for whatever reason, it is very common for schooling _algae eating_ fish to have a dark lateral line. Some examples from different groups:
http://www.fishbase.se/Photos/PicturesS ... 1&ID=50435
http://www.fishbase.se/Photos/PicturesS ... m?ID=26587
http://www.fishbase.se/Photos/PicturesS ... 1&ID=23432
http://www.fishbase.se/Photos/PicturesS ... 1&ID=26386
http://www.fishbase.se/Photos/PicturesS ... m?ID=12298

I'm not saying that all small schooling algae eaters are light-colored with a dark longitudinal streak, or that only they have that pigmentation, but I have frequently been struck by how common that pigmentation is among them.

What is the purpose of Otocinclus' dark lateral line?

What is the purpose of Otocinclus' dark lateral line?

Purpose of lateral stripe on common Oto's

Otocinclus' stripes