A small , up to 1 cm shrimp. Mysis Relicta is a freshwater species,
imported from the USA. In the Netherlands its found in brakkish water.
Mysis mixta can be found in the Baltic Golf.
Although called a shrimp it's in fact a more primitive relative of the
nowaday shrimp found in the sea's and oceans, like the common shrimp.
Mysis feed mostly on algae, like diaptoms, and in May this is the
most important source of food. But they also feed on bloodworms
and other creatures that live on the bottom of the ditch.
At night they can be found near the surface. at daytime they
live near the bottom.
Mysis relicta
Some mysis relicta together, these photo are made by
Jaap Cost Budde, have a look at:
Flickr
Mysis, with even more details.
Mysis as a living food
Mysis can be used as a living food source for saltwaterfish
(especially seahorse and Pipefish
and lower saltwater animals, like anaemonen, shrimp, fishes
and insects that live in brakkish water. In freshwater they
are also hunted by salamander and fish. .
In aquaria, mysis is mostly used as frozen food. Seahorses
typicaly eat 6 of them a day
Mysis is very good food for saltwaterfish as:
- its high in fat, and contains different kinds of fat
- its low in phosfate (or has a high N:P ratio), so can be
used to reduce the phosfate level, important if youre
aquarium is suffering from blue algae.
This can occur when the N:P ratio in the aquarium is lower
then the Redfield Ratio.
-its low in salt, so fish don't have to uses much energy to pour salt out
of theire body.
Mysis in brakkish water
Mysis form groups in the brakkish water aquarium . They have unique
feeding habits that differs between day and night:
At day time they stay near the bottum eating mostly
detrusis and algae. At night they get to the surface
hunting on plancton, rotifers, daphnia, so largely
as a filter-feeder.
One can feed them with koikarper fish-pallets, but almost
everything will do the job: Artemia , bloodworms, daphnia can be given.
Mysis, a dime-size crustacean,
here seen in live seize
Distribution
Originally they used to live in the northern parts of Europe and
America. But are introduced in the Usa and middle Europe.
In holland they now live in the brakkish water between the harbour of
Amsterdam and the sea (het Noordzee kanaal).
Mysis contains the highest amount of protein in living found
and also a large amount of fat.
Vertical migrations of mysis
Mysis Relicta, Mysis Mixta and Neomysis Integer are all living in the Baltic Golf
They all do have an vertical migrations: at daytime they feed on the bottom
feeding on detrusis and nematodes and avoiding fish, at night they transfer to upper
layers, hunting for zooplancton. Mysis is different of this zooplancton: it lives longer,
about two year, zooplancton lives for some months. And its bigger ,1cm normally.
(as described by Ilmar and Jonne Kotta, 2001).
breeding
Breeding mysis is not very difficult, and I have a large amount of
these lovely creatures swimming around. Some rule-of-thumbs are:
- salanity or amount of salt , keep this between 1003-1010 =light brakkish
and use (of course} seasalt.
Use oxygenbubble blocks wich produces large bubbles, as mysis, as all the
shrimp can stick on small bubbles. Keep the water moving!
microscopy
Mysis is fun to look at under a microscope
mysis ,head and antennae, 60x, alive
Vestibulair organ
Mysis has a little organ under its telson (tail) called a statocyst
,a little stone in a space filled with fluid.
In this way the mysis knows what's up and down.
