Re: NANFA-- Freshwater inverts

Bohlen (
Fri, 17 Dec 1999 19:14:05 +0100

> Re freshwater sponges - These have proven almost impossible to keep in
> captivity for more than a few weeks.

This depends on how often you try it. My first ten trials with freshwater
sponges failed also. The animals were just decomposing during their weeks in
aquarium. Later some established a growing spot of coin size until end of
season. In autum they produced gemmulae and died off.
Maybe the mistake was to take the animals too late in season or from running
water or the wrong species (I mostly wanted the threedimensionally
sculptured ones - these always failed until today). Anyway, one day a sponge
apeared in one tank in early spring, started to grow during the season to
size of my whole hand. It did not completely disappear during winter, but in
the next year starting several small colonies on the filter, the stones and
on Javamoss. Some of these colonies I transferred to other tanks and since
that time I somewhere have a sponge (about five years). It never grew to a
similar size like in its first year but I like them as they are.
This little happy-end story certainly based on the gemmulae which were
released by the first samples. One of these gemmulae was able to handle the
conditions in that tank and started to take its chance. This is similar in
many tiny freshwater invertebrates: to install them in a tank or pond you
have to use patiently the system of trial and error.


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