In September 2006 I launched a small experiment when I found tiny plancton-like larvae in my 12 Litre aquarium. I quickly discovered that it was shrimp larvae and subsequently spent most of a whole night trying to figure out what to do with them. I quickly located several webpages mostly about failed breeding attempt or simply warnings that Caridina multidendata(previously Caridina japonica) was almost impossible to raise successfully to adulthood.
Finally I came upon a webpage by a Swedish aquarist, Mike Noren, who had indeed bred Caridina multidendata successfully.
This was all the encouragement I needed to start my own project.
The following day I started aquiring the necessary items. Aquarium salt, hydrometer (salinity measurer) from the local aquariumshop, but phytoplancton, which I read was the ideal food, took me a few days to find but finally I ordered it online.
2 12 Litre aquariums
1 3 Litre plasticcontainer with a lid
10 3 centilitre plasticglasses or similar
1 airpump with airstone
Aquarium salinity meter
One of the 12 Litre aquariums was already established as a nice little planted aquarium with gravel, driftwood and plants. It was without filter or any other piece of equipment, apart from light. In the aquarium 3 female shrimp and 6 male shrimp had lived for a few months, being fed regular flakefood and on rare occasions some red mosquito larvae.
When, one day, very small, extremely small!, larvae appeared in the aquarium I moved the female into the 3 litre container. This would serve as the birthplace until all the new larvae were swimming freely. The container was only used for hatching the larvae and for 4 days it was the larvae's home. Because of this I didn't find it necessary to find a larger home for this stage.
In the 3 Litre container I had aquariumwater from the first 12 litre aquarium. Apart from that I only had a small lamp which was on all day and night. The sides and bottom of the aquarium was covered with black plastic, both to help the shrimp orienting themselves, and to avoid stressing the female.
Instead of moving the female, I could have left her in her aquarium and 4 days later removed the larvae with a
piece of airtubing. The Larvae swims towards any lightsource, so with a small flashlight, at night, I could have moved most of them. I found this rather laborous so I decided to move the female. 'Mom' would only stay in her container for 2 days until all the larvae was swimming freely, then she'd return home to her usual surroundings.
I guesstimated approximately 150 larvae. Not as many as you can find in a batch but still a good amount of larvae.
I didn't feed the larvae in this aquarium, and as far as I could tell, all larvae survived, so all I think you will get from feeding at this stage is contaminated water.
The 2nd aquarium was without any form of equipment or decorations. It would function only as a tank for
raising the little shrimplets.
Like the first 12 litre aquarium I had covered the sides and bottom with black plastic and used a small lamp with a low-energy bulb which was on 24/7. The tank was filled with saltwater with a salinity of 35 ppm, and a small airpump with an airstone kept the water moving.
Because the larvae aren't really strong enough to swim if there's too strong a current, you cannot have much movement in the water. Therefore I only had the airpump deliver enough air for 2 tiny coloums of airbubbles from the airstone.
Now the water should have matured for a few weeks, with the phytoplancton added, before the larvae was introduced into the tank, but since I wasn't prepared for my experiment, the larvae was added 2 dys after the saltwater had been mixed og wasn't fed any phytoplancton until the 4th day in saltwater. This didn't appear to have bothered them terribly because I didn't see any dead larvae on the bottom of the aquarium.
On the 7th day I changed 3 litres of water and added a few millilitre's of phytoplancton. I don't know if it was necessary to change water at all, because this was the only time I changed any water during the experiment.
I fed them a small amount of freshly hatched dried brineshrimp just to vary their diet, and I saw a distinct change in their colour when I fed them the brineshrimp, so they did indeed eat them. Apart from that I didn't do much else for the little creatures. 3 or 4 times a day I, carefully, stirred the tankwater so whatever was on the bottom of the aquarium was introduced back into the water. I don't know what it was, it looked like fine white sand, but all the larvae grabbed a piece and started eating it.
On the 10th day the largest larvae had grown to about 3mm in size, whereas the smallest still retained a size of about 1mm.
On the 14th day the first larvae had grown into actual 5mm small shrimplets. The were clearly more agile than the larvae and also looked like small copies of the adult shrimp. They were able to sit on the aquarium walls, and could swim around the tank very fast, as opposed to the small larvae which were only capable of swimming slowly and never against any current. This made it rather difficult to move the fully developed shrimplets out of the aquarium since they were able to swim away from the airtube I used to try and move them. I then used a pipette, it had a more powerful and faster 'suck'. I moved the shrimp into a small 30 centilitre plastic glass and changed 50% of the water with freshwater from a matured aquarium. Every day for 4 days, I changed 50% of the water with fresh water, and finally moved the shrimplets to a 100% freshwater aquarium.
In the freshwater aquarium I had Cryptocorynes and Anubias and a few pieces of driftwood. No filter, but an airpump, and quite opposite of the saltwater tank, this had a powerful airflow.
On the 19th day I saw a significant amount of fully developed shrimplets, but this time I chose to empty all of the inhabitants in the saltwater aquarium into the small plastic containers with 100% saltwater and those larvae that had molted into shrimplets began their journey towards freshwater(just like I did with the first shrimplets). The reason for this was that it was almost impossible to catch the fully developed shrimplets without catching a whole bunch of larvae as well. The shrimplets were extremely fast and were actually able to hold on to the aquarium window and avoid beeing sucked up by the pipette. It was easier in a small glas. Whenever I spotted a few shrimp I simply poured the larvae into a new glass, which only left the shrimplets in the glas.
This way I didn't have to deal with stubborn little shrimplets, since they were automatically left in the glass.
At this time about half of the original larvae had turned into shrimplets. The following days I found shrimplets every day and started adapting them to freshwater.
On the 24th day there were only about 50 larvae back. The shrimplets in the freshwater tank had grown to about 7 mm and had shed their exoskeleton for the first time.
On the 36th day all the shrimp had been accustomed to freshwater. They thrived and grew at lightning speed. The largest had already reached a size of 9mm. I had about 180 shrimplets to keep track of. I changed a few litres of water daily and fed the shrimplets flakefood 2 or 3 times a day and also had a small pea in the tank at all times, so they had something to nibble.
They were always VERY hungry and if no food was to be found in the aquarium they clearly became agressive towards eachother. There were absolutely no algae(for a change) since they always swam around looking for food. A pea with the outer layer removed seemed the optimum solution.
I may have lost a few larvae during the saltwater period, but I wouldn't consider this alarming when approximately 98% of the larvae survived and developed into shrimplets.
It might have been sheer luck that I was able to breed these little creatures but in my experience I would'nt say that Caridina multidendata is difficult to breed successfully. I kept it on a simple level and chose not to spend loads of time or money on it, in case it failed.
A lot of the things I did, I did based on the knowledge of how the shrimp live and breed in the wild
My theory on Breeding Caridina multidendata:
The adult shrimp live in nature in small rivers which run into the ocean. When the eggs hatch the larvae has so little ability to swim that they are flushed into the ocean, and this may take a few days. This is why I waited 4 days before I introduced them into the saltwater. When they are fully developed into shrimplets they are more than able to swim against the current, and that's how they swim up the river again. And because the rivers contain lots of O2 I chose to use strong airation in the freshwater aquarium, which also seemed to be to the shrimplets liking.
In 4 weeks it is time for another try. I have 2 pregnant shrimp and am ready to try breeding them again.
This can be followed here:
Unfortunately the site is only in Danish.
Translated & published by
Martin Rask Thomsen
Original article first published here: http://www.akvarieplanter.dk/breeding-caridina-multidendata.html
Link to my inspiration on breeding Caridina multidendata:
Mike Norens Caridina multidendata breeding
links of interest on Caridina multidentata breeding:
Breeding Amano/Yamato Shrimp
Breeding Red-Nosed Shrimp
Erste Zuchterfahrungen mit Amano-Garnelen