Are Hypancistrus Really Carnivores?

[racoll]

Accepted wisdom is that this genus is mainly carnivorous in their feeding habits.

Is there any papers that prove this by way of stomach contents analysis?

You can say they are by citing their reduced dentition. however, this is intuitive guesswork, and not proof.

I mention this because my Hypancistrus seem to enjoy tucking into veg just as much as my other more vegetarian plecs. it just got me thinking.

[bronzefry]

Racoll,
I'm glad you brought this up because I was thinking the same thought, but of the Peckoltia species. I've noticed a tendency more toward veggie than carnivore. Quite curious.

[Jools]

OK, first thing here is that Peckoltia are omnivores, so they shouldn't be counted the same as Hypancistrus.

Secondly, why would the fish have reduced dentition if it needed to rasp at algae etc?

Thirdly, I don't remeber any analysis of H. zebra, but the description of H. inspector mentions gut analysis including seeds and nothing "meaty".

My severum eats cucumber, that doesn't make him or indeed anything else a vegetarian - it just makes me a good fishkeeper as I offer a varied diet.

So, why do we go on about meaty foods for Hypancistrus? Well, simple really, they are considerably more prolific when fed as such. There are no breeders out there feeding their Hypancistrus anything more than a passing veggie. Perhaps the meaty stuff should really be seeds, but I doubt it.

Jools

[racoll]

Secondly, why would the fish have reduced dentition if it needed to rasp at algae etc?

i agree it does make a lot of sense, but is it true?

maybe a fish with rasping pads for algae is in fact a specialised fish feeder that uses these pads to rasp away at dead fish (probably a considerable source of food in the deep water channels).

i know that just because a fish eats something it doesn't mean that's it's natural diet.

however my Panaque L002's probably eat far too much high protein food, and as a result started as the smallest plecs in the tank and are now the largest by far.

this i would would consider to be prolific, but is that good for a fish that is shown to mainly eat wood?

i do agree though that most Loricariids are not specialised feeders and are more opportunistic, and a varied diet is better.

if we knew however, that would help a lot.

[Jools]

maybe a fish with rasping pads for algae is in fact a specialised fish feeder that uses these pads to rasp away at dead fish (probably a considerable source of food in the deep water channels).

And that's what Pseudacanthicus do; look at their teeth.

this i would would consider to be prolific, but is that good for a fish that is shown to mainly eat wood?

I mean prolific in the true sense of the word. I.E. Breeds with larger broods and or more often.

Jools

[Yann]

Just to add my 2 cents!

How would you explain then if they were indeed vegetarian, that the lower jaw only have a few teeth, certainly not the most effective way to rasp algaes, it would be like trying to take the leaves out of the garden with a fork...(evolution is logic and effective at least most of the time)

Also it has been said that young specimens of the genus Hypancistrus (sensu lato) seems to need a vegetarian apport in the beginning of their life...

Stricly carnivorus I have my doubt but certainly omnivorus

cheers
Yann

[Jools]

I'd go for "more carnivorous than herbivorous". Bear in mind we're talking about species that, in the main, are undescribed by science, their wider behaviour therefore doesn't have any studies on it beyond what aquarists observe.

Jools

[bronzefry]

Thanks for the information.

[racoll]

The breeding output does seem like good evidence.

i'm not saying that i think they are vegetations, as pointed out it doesn't make sense, but i wondered whether there was any science to back up the assumption.