This tank is home to Panda Corys, Bladder Snails, and at
the
time of writing exactly two Cherry Shrimp.
Click the headings below to read more about them.
Look at him go
This tank is home to at least nine Panda Corys. Panda Corys originate from the Ucayali
river system in Peru, and are unique among your typical pet-shop tropical fish in that they can
survive in slightly cooler water. They are peaceful and sociable, and often swim or rest on the sand
in
groups.
Five of the original Panda Corys striking a pose
The fish in this tank are largely impossible to tell apart. The best way of trying to tell
individuals
apart is by looking at their
dorsal fins - they always start off black at the base, and then radiate out to white, but the point
at which they change fully from black to white, and the strength and shape of the gradiant between,
varies between individuals. You'll
also find that some Panda Corys have opaque or transparent fins, and some have distict black "rays"
that
cast out from the base of the fin all
the way to the edge. This method of identification works for smaller groups, but generally falls
apart
once you're dealing with more than
five or six.
A baby Cory chillin' with adults
Panda Corys are, as it turns out, quite enthusiastic breeders. When certain environmental
conditions
are met, they will
lay eggs in areas of dense vegetation or algae - this is not an issue I faced in my previous tank,
but
the "at least nine"
headcount probably tells you all you need to know on that front.
A two-week old Panda Cory fry (not my picture)
Baby Panda Corys start out as tiny, transparent tadpole-like creatures.
They don't start off with their distinctive black markings, but they do develope them quite quickly
-
from my experience, they gain the
triangles over their eyes before the band around their tail, giving them a funny sort of
glam-rock makeup look. Corys, like a lot of fish, don't have any sort of recognisable "child" stage
between beinga fry and an adult -
once they leave the fry stage and develope a little more colour, even if they are still just a few
millimeters long, they will begin to look - and act -
exactly like the adults.
Big scary shrimp
Cherry Shrimp, or Neocaridina Davidi, are small freshwater shrimps
originally from eastern China and Taiwan. They are generally friendly and non-cannibalistic (which
can't
be
said for all shrimp :( ), and very hardy and easy to keep. The downside of this is that, due in part
to
this hardiness and in part to how
popular they are, they have been invasivally introduced to a number of ecosystems. They have been
confirmed to
exist in the wild in Japan and Hawaii, but have also been reported in warmer waters in Germany,
Poland,
Hungary and
British Columbia.
A typical example of a male Cherry Shrimp. The males are smaller and
skinnier than the females, and are generally less deeply coloured
In the run-up to the dismantling and moving of the original tank, the shrimp population suffered a
massive and
unexplained die-off. Only two individuals could be rescued for the move, but they died as well in
fairly
short order.
Once the new tank has been established, I bought some new Cherry Shrimps. But again, for reasons I
don't
understand, they all died within about a month. Or so I thought.
The two survivors, eating algae. Without a large population to keep it
down, the algae in this tank has become way too overgrown
About two months after I'd last seen a living Shrimp in the tank, I spotted a single, tiny Shrimp.
It
was far too young to be part of the original cohort, and so must have been hatched
just before the rest died off. And inexplicably, it had survived just fine. After a few weeks I
spotted
a second survivor. And again, against the odds, it survived. As of writing, these two siblings -
one male and one female - are the only two Cherry Shrimp in the tank, still going strong almost a
year
after they first appeared.
Unlike the last tank, this tank has a far slimmer array of small residences. Which is the say it
only
has snails.
An adult and baby Bladder Snail
While Snails were entierly unable to
establish a foothold before, this tank has seen an explosion of Bladder Snails - a very common pest
species. They look like micro-scale versions
of common garden snails, having a greenish-brown conical shell and two visible antenna. If you look
very
carefully, you'll notice that the shell is partially transparent.
If you look VERY carefully, you might also spot two small black eyes just below the antenna.
Some larger or more aggressive fish species will eat these snails,
but the Corys generally leave them alone. Personally I don't mind their presence - while they aren't
able to tackle the tougher algaes that grow on the leaves and
wood, they do generally keep the glass clean.
~~~~~~~~~~~~~~~~~~~~~~~~~
In mid-2024, I bought my current flat in Roslin and left Edinburgh. A consequence of this was that
I needed to dismantle the original fishtank, bag up the Panda Corys, and set them up again in their
new
home. Moving a fish tank is not easy.
The original tank
In the run-up to the move, for reasons known only to god, nearly all of the old Shrimp population
died
off. Its normal
to see rises and falls in the population, but I still don't know exactly what happened that caused
this
mass die-off. In any case,
it did make the move slightly easier - catching Shrimps out of muddy water is stupidly difficult.
The Corys in their holding cell
Once everything had been moved over to the new flat, I decided to retire the old tank altogether and
build a new one in a larger tank. While I
repaired the space and gathered all the new equipment I'd need, the Corys (and the two Shrimp that I
managed to save, which again died for some unknown reason)
spent some time in a temporary holding tank. I'm fairly sure six went in, but only five came out. I
also
discovered around this time that Corys are absolutely
full of poison that they themselves are not immune to. This means that, if one
dies and gets left in its tank, it'll release all that poison
and can end up killing all their tankmates as well. Luckily I managed to dodge that possibility.
The new tank today
Finally, once everything was in place, I set up the new tank. I managed to reuse a lot of the larger
plants and wood features from the old tank, but added some new plants, and some stone features
and caves for the fish to hide in - something that the previous setup was lacking. Shortly after
this I
purchased two new Corys to replace the one that... went missing.
Hiding in a cave. Ooo
This tank has, like all fish tanks,
seen
a mixture of successes and failures. A very recent success has been the Corys having babies, which
never
happened
in the previous tank. A failure on the other hand has been the difficulty of maintaining a Cherry
Shrimp
population.
One odd quirk that I've recently noticed is that, while the previous tank generally had quite clear
water, this tanks water
has consistently had a browish-green colour to it. I'm not sure whats causing this, but it doesn't
seem
to be upsetting any
of the residents.