bethnic goby genus Morgunda is endemic to Australasia. Here they inhabit freshwater
rivers; sinkholes and jungle pools were they make the most of whatever form of
natural cover is available. In the aquarium hobby the species most commonly seen
is Mogurnda mogurnda (the Purple Spotted Gudgeon).
receiving a pair of M. mogurnda, from Kevin Webb, I set about a breeding programme
but the fish beat me to the post and spawned in a community tank. Here are my
notes on what occurred: -
On Tuesday 1/7/03
I noticed, to my surprise, that my mature pair of Mogurnda mogurnda were checking
out an area of glass in the front left-hand corner of their tank (in the wild
they spawn in small crevices). Suddenly the female lowered her ovipositor and
began to paste eggs, in several small batches, upon the glass (very similar to
the spawning of Jewel Cichlids). The male was quick to follow her moves and spread
milt over these eggs, which would eventually total around 140.
Kevin had explained to me the eggs are attached to the glass on tiny shreds and
move about like those of marine Clownfish. As soon as they realised that spawning
activity was over the rest of the tanks residents, spearheading their advances
through a Bulldog Plec. moved in for their share of fresh caviar. Something very
strange happened at this point as any fish getting close to the two mature Mogurnda
usually pay for their audacity with a quick 'nip to the flanks' but on this occasion
(probably through breeding shock) they simply stood aside as their eggs were assaulted.
acted quickly removing around 40 eggs and placing these into a water filled shallow
plastic container, which was then floated in a spare tank. I didn't add a trickling
airstone or any Protozin and this might have been a big mistake?
the morning of 3/7/03 some eggs had fungused (quickly removed), some were clear
in colour while a few were showing a small black streak over a yellow centre.
The shape of the eggs was clearer to see now and their resemblance to the shape
of the egg cases of a Port Jackson Shark was astonishing (of course, though, they
were much smaller).
By evening some of the
egg cases have broken open and the tiny black streaks are fish skeletons minus
a face. 3 viable eggs, attached by their shreds to the sides of the container,
remain. Their skeletons are curved over the yellow centre and have eyespots now.
the afternoon of 4/7/03 the 3 eggs had all increased in size and, as a result,
you could see the growth of the 3 fry inside also taking place.
the morning of 5/7/03 a fry had tried to break clear of its case but must have
been very weak as it had died in the effort. By afternoon the remaining two cases
were empty and their fry were sat on the base of the container. It had never dawned
on me that the large yellow centre of the eggs was a huge, in comparison to the
fry atop them, yolk sac.
Sadly I would find
both fry dead the following morning. At least I had witnessed a spawning of this
particular fish and made some interesting notes on the eggs that add to our knowledge
of these very peculiar creatures.
able to take things a stage further were able to raise fry by first feeding the
micro-organisms found in green water, followed by live brine shrimp and, finally,
crushed flake. Cannibalism amongst the fry is high.