Three weeks after the first sighting of a new baby shrimp we seem to have arrival of the next crop.  These guys are really tiny which does suggest the earlier one had been hiding out for a week or so before debuting.  There was a 50% water change today – the usual story with EI dosing – and I was a little concerned the new baby shrimp might get inadvertently changed out along with the water, but they seem to have hung on well and are none the worse for wear.  The successful shrimp breeding suggests we may shortly be inundated with shrimp in the Shrimphaus, but we’ll worry about that later.

Even newly hatched bloody mary shrimp are red

Even the tiniest of these new bloody mary shrimp have an easily distinguished red colouration.  So far the colour has bred really true, which is pretty typical for reports of bloody mary shrimp.  I saw an interesting video where a guy with a pretty normal looking bloody mary shrimp tank went and did an actual count during some rescaping that came in at 600 shrimp in a 5 gallon tank.  That’s about the same size as the shrimphaus!  Everything was looking happy and healthy there so maybe overpopulation isn’t such a concern after all.

Unintentional yet still welcome residents of the Shrimphaus, copepods are a form of zooplankton.  Like their much, much larger relatives the shrimp, copepods are also crustaceans, and also have ten (?) legs, an exoskeleton, the whole works.  Copepods tend to be sub-millimetre in length, whitish looking, and capable of very rapid jerky movement covering several centimetres at a time, making them the fastest animals on the planet (in terms of body lengths travelled per second).  Happily, copepods eat algae from the water column so are members of an aquarium clean-up crew.  They are a highly nutritious food source for fish, but I don’t think the shrimp eat them.

In the pictures above, both copepods are photographed at 10x optical zoom.  Both are “heading” to the upper right.  The female has two egg sacs to both the right and left of the bottom bit.  The male? copepod doesn’t have these, but that might simply be a female that doesn’t have eggs.  These two were resting on the surface of the glass; the ones swimming around in the water column don’t photograph very well…

Copepods are abundant in the Shrimphaus but I haven’t ever noticed them in the Fireplace Aquarium, either because they were never introduced in the first place, or because the fish do a super-efficient job of keeping the population down.  I might try a water transplant from the Shrimphaus to the Fireplace Aquarium at some point to cross-introduce these little guys.

There’s a new citizen in the Shrimphaus!  Recently a juvenile bloody mary shrimp has started openly exploring.  It seems strange that there is only one so far, but there was a mother shrimp that dropped most of her eggs and maybe this is one she held onto.  The new shrimp has already successfully moulted and has been touring the slate and plants in the Shrimphaus.  I take it as a good sign that the shrimp overall are happy and healthy.

The newcomer first showed up about a week ago, which would have been around 6 weeks since the shrimp first went into their home.  If I had to guess based on neocaridina lifecycle, this youngling has been hiding out for a couple weeks before debuting.  I do think there are some other females in there with eggs so there may be some younger siblings on the way as well.

Shrimp like to hang out upside down

The shrimp seem to enjoy hanging upside down from the under surface of the river run.  I don’t know if this is a practice that ordinarily goes unobserved, but it’s a pretty common sight in the Shrimphaus.  In the photo above there are three resting upside down (juvenile on the far right) and one more slightly out of focus right-side up sitting in the river itself on the top of the slate shelf.  Sitting in the flow of the river is something the shrimp also seem to enjoy.