I hate to be a wet blanket, but I would caution against generalizing from
one anecdotal observation. Perhaps if produced in nature, the cohort would
remain together. But we have no way of knowing that from the fragmentary
information available to us.
The young could have remained a group because no other juveniles of the same
size and schooling behavior were available, because of the dimensions of the
tank, because of the absence of, or over-abundance of cover, because of the
lack/presence of predators, and on and on.
Please, don't make too much of this kind of casual observation. If you
really want to talk about this, and since hybrids are apparently easy to
produce, do some planned experiments with appropriate controls.
George W. Barlow Ph 510/642-2947
Department of Integrative Biology FAX 510/643-6264
University of California barlowgw at garnet.berkeley.edu Berkeley, CA
94720-3140 USA
"We have to believe in free will.
We've got no choice"
Isaac Bashevis Singer