"MangroveJack" wrote in message
oups.com...
Well according to your source, NetMax, at least as much as 50% of their
diet would be plant matter:

http://www.fishbase.org/TrophicEco/F...cies=ocellatus

Since the rest is comprised mostly of shellfish and insects, it is
fairly safe to assume that the natural diet of the Oscar is not mostly
comprised of other fish. I concede that they are not necessarily
herbivorous, though what they may eat in captivity and what they
generally eat in their natural habitat is most likely completely
different. When the complete studies are done on wild-living oscars,
we'll all know for sure.

As to my source, I must confess that I completely forget where I first
heard it, but at the time, it was good enough to convince me of what I
already strongly suspected.

And let's not forget, that virtually any animal (including humans) can
be trained to eat a perfectly unnatural diet. It may end our lives
prematurely in the long run, but for what it's worth in the short term,
it appears to be perfectly adequate and suitable for meeting all health
requirements. I think that the lack of albino specimens in the wild is
indicative that something we are doing isn't quite right.


My comment was based on your statement:
snip
The trick is to always overstock predatory fish (and remember, oscars
are not predatory fish ordinarily, and in the wild, are considered to
be herbivorous), and make sure to have plenty of hiding spaces for
smaller fish, and only add them to the tank immediately after giving
the existing fish a big feed.
snip end

I'm not commenting on the 'overstocking predatory fish' as that's a highly
subjective case-sensitive topic (but overstocking is a typical course of
action with mbuna, and not with South or Central American cichlids, so it
did raise my eyebrows).

I don't see that 50% interpretation in the link you provided. It appears to
list items they have eaten (perhaps from observation or dissection), but I
don't see any references to quantities. I don't see any basis to support
your statement that they are non-predatory or that they are considered
herbivorous. I don't want to appear argumentative. New information related
to my favourite hobby (fishies) is always a joy to reed. However I tend to
be sceptical about new different information and I'm prone to checking
sources. I'll apologise if that makes me appear mistrustful ;~).

I agree wholeheartedly that Oscars are highly food-motivated, mobile garbage
processors who will only show much of a preference in foods when fully
satiated (which is a rare event). Accordingly, they would certainly chomp
down a variety of vegetation between their meat courses. I also agree that
they should be fed a wide diet of foods to provide their full fibre, vitamin
and mineral requirements and the use of live feeders is a bad idea on many
levels.

Here now is where I would deviate from your suggestions, purely based on my
observations. Take their hunting methods as an example. They drift like a
chunk of wood (which they often resemble), towards their prey, and then
'inhale' their target through a rapid expulsion of water through their gills
to draw them deep down their throat to their grinding teeth, to hold them
while chewing. They may swim around with an oversized victim for a day or
two while they slowly grind them down to swallowing size. During this time,
they are not in distress, other than being wary of other fish stealing part
of their meal. This evolved behaviour is not characteristic of a herbivore
hunting his salad ;~), so I think this would categorize them as predatory.

They are omnivores, but if they were strongly herbivorous, I think the
Amazon river would be stripped of all vegetation by now ;~). I always
thought of Oscars as piscivorous carnivores (specialized hunters of fish and
appropriately sized invertebrates) and opportunistic herbivores (a side of
salad if the plant was right, and the hunger was there), but I'm always
interested in reading from credible research papers which might say
different.

cheers
--
www.NetMax.tk