Jasna
I think your point is completely valid.  Judging from some of the other related
postings, many of us agree.
And as Ross and some others clarified, 'rare' in collections and 'rare' in nature are
two separate and in many cases unrelated ideas.  After all, some might call a Penny
Black stamp rare, but this has nothing to do with it's ability or inability to be
populous in nature.
A thought - I suspect Mytlus edulis is 'rare' in most of our collections.
 
Nora
Calgary, Alberta
CANADA (on a hot and lovely holiday Monday...back to the garden, enough computers)
 
Jasna Peternel wrote:
 
> Into my humble opinion, the true rarities should live in environments where the
> biomass is low.
> The main source of food in deep sea trenches is probably organic debris which has
> its origin on land.Trenches are usualy proximal to land or islands and high
> quantities of plant material is carried down to the bottom.That should be the
> truth especially for trenches in tropic or sub-tropic.
> But what about trenches at higher latitudes, like South-Sundvich trench.I don't
> believe there is enough organic debris carried down from the islands to support
> high biomass..Therefore the biomass
> in such environment should be low,as a consequence of lack of food.
> As the predators usualy represent just a small part of biomass,  rarities should
> belong to predators living in such trenches.
> So the predators living in such high latitude trenches should be the true
> rarities.
>
> Perhaps I'm completely wrong and biomass is high even in such trenches (because
> there is enough food available in form of snow of organic particles-dead
> foraminifera,fish carcasses...)
> Any opinion?
>
> Milan