Breeding report Atya gabonensis

Text and photos: Peter Verburg

About a year ago I thought about challenging myself to breed Atya gabonensis. So I started an aquarium specially for these shrimps. After seven times carefully catching a pregnant gabonensis and watching the larvae slowly die in a matter of days or weeks I finally succeeded. This is my breeding report with which I hope a lot of other people can start breeding these beautiful creatures.

The Atya home tank

I have 10 Atya gabonensis (4-10 cm) in an 80 cm tank. It has been scaped with a bottom of sand, a lot of stacked pebbles, a lot of epiphytes like anubias and java fern and a nice piece of spiderwood. Because of a lot of plants there is a lot of shade in the aquarium, which I found out they like very much.

For water flow I installed a 3000 liters per hour stream pump and for filtering I used a aquaflow200 filter that produces about 400 liters of water flow an hour. They are positioned in a way they enhance each other’s water flow. I wash out the filters sponge three times a week and the shrimp seem to like it very much. Water perimeters are:

• pH: 7,8
• GH: 11
• KH: 8
• NO3: 20-30
• Temperature: 26 °C
• Conductivity: 300 ppm

This is one of the three moms I have in the tank.

The hatching tank 

The tank in which the pregnant lady’s are put is a simple 15 liter tank without any soil. A piece of pondweed is put in to have some green in there. I also put an air tube in there without an airstone to make some bubbles to keep the water flowing. This tank was filled with water straight from the big tank so water perimeters are exactly the same. During pregnancy I kept feeding and refreshed half of the water twice a week because there is no filter in there. The larvae hatched all at the same time all eight times I have seen it. It is important to get the mother out as quickly as you can, because she can eat about 80% of her offspring in one night, catching them with her fans.

Freshly hatched larvae

The breeding tank:

This tank also is a simple 15 liter tank without any soil. It is heated up to a temperature of 27-28 degrees Celsius. In here was also an air tube without air stone, slowly releasing bubbles. The water is salt, 30 grams per liter (1.020-1.021). It had been mixed 10 days before the hatching of the larvae. The water is 75%  straight from the big tank (just to get some NO3 in) and 25% tap water (do not try this at home if you don’t have very clean tap water like I have in the Netherlands). After dissolving the salt I put in 10 drops of phytoplus opti ocean live marine phytoplankton. After a few days it started to become slightly green and after 10 days it was a nice dark green. This water I never changed. I counted on the algae to get rid of every NO3 or NO2 and I think they did.

The fresh water growing up tank

This tank is a 25 liter tank, filled with water straight out of the big tank. This tank also doesn’t have a soil but has a aquaflow100 filter of which I glued some openings shut to prevent the young shrimps to get inside and be crushed. A sponge filter would be easier and more safe but I didn’t have one at the time. I also have three air stones in to make the water flow heavily. There is a little lava stone put on the bottom to have something to hold on to and to hide underneath.

The young shrimps

During the process of growth it has been nearly impossible to get a nice shot of the larvae because of the dark green algae infested water. I can tell you though that the larvae grow in a similar way compared to caridina multidentata, a shrimp of which you can find numerous breeding reports with pictures of the larvae. They start really small, about 2mm. At that time they hang upside down and drift around in the current. Slowly they grow, at 4 mm they get a curve in their body. They grow, turn red instead of transparent. All this time they hang upside down and only drift around in the current.

Left: 30-day-old post larva in fresh water

Right:  the same post larva after two minutes in fresh water (dead)

At about 7mm they evolve and start swimming quickly forward instead of slowly upside down. At that moment I tried to put one in fresh water like I did with Caridina multidentata. It died after two minutes. They can’t handle fresh water at that time. They have to moult once more. Then they also have very small fans, but they are difficult to see. When they start to swim, you can put them in a bowl and slowly increase the amount of fresh water until it is totally fresh. I did it in 14 days. I thought, when they start to swim in nature, they are in salt water but at a certain moment they need to go back to fresh water. It worked, the decreasing salinity helped them to mould and to turn into young shrimp. They also moult in salt water, but when I tried this most of them died after a few days in salt water. Once they have their fans, they can’t survive in salt water I think.

Young shrimp 16 days after becoming a real shrimp

Nourishment

The larvae were fed with three different sorts of food. I used Liquizell, premium aty xxs dust and Opti Ocean live phytoplankton, produced by phytoplus (got it off ebay). As I said earlier I inoculated the salt water tank with 10 drops of Opti Ocean to start some algae growth. During the process I fed the larvae two days two drops of Opti Ocean and one day two drops of Liquizell. The dust I fed every day, but only the leftovers I had on my fingers after feeding the big gabonensis. Both bottles need to be shaken, not stirred before use to prevent the food to sink to the bottom of the bottle. I stirred the saltwater tank as often as I came by, to swirl all the algae on the bottom around so the larvae could easily grab onto it.

The big A. gabonensis in my 80 cm tank get dust food  twice a day. Once a day they get the aty xxs and once a day they get a mix of shrimp pallets, grinded to dust. The young shrimp in the growing up fresh water tank get an awful lot of food, up to 4 times a day. This means I have to refresh often but it is needed to feed this much. The young shrimps started to die after one month in fresh water. It stopped when I started to feed ridiculously much for such a small tank.

Temperature: At first the temperature in the 80cm tank was 24 degrees Celsius. At that moment they didn’t get pregnant. After a great tip of my friend Ingrid, who noticed that her atya scabra’s got pregnant after he put in a bigger stream pump I upgraded my pump. At the same time my breeding room warmed up because of the sun and the big tank (close to the sealing) warmed up. When the temperature was about 26-27 degrees Celsius the gabonensis females got pregnant. Ever since my gabonensis thrive at a temperature of 26 degrees Celsius.

Light: I only used the standard lights of the tanks. The lights were on for 11,5 hours a day. On the salt water tank the light was burning 24-7. This because I had heard of the story the larvae need the light to swim towards or else they die. I know for a fact they do swim towards the light, I don’t know if they really would die because of lack of light. I just didn’t want to take any unnecessary risks.

Aeration: In the hatching tank  and the salt water tank I used only the air tube without an air stone so the bubbles released weren’t too small. Small bubbles, I heard, could trap the larvae which would kill them. I don’t know this for a fact but again, I didn’t want to take unnecessary risks. In the fresh water growing up tank the aeration is big, with three big air stones. These shrimps are big enough and the bubbles create a nice water flow in which the shrimps can easily find food.

Salt water:  I succeeded with Reef Crystals sea salt. I tried other brands of salt but it didn’t work out for me. Re-using the salt water didn’t work, the larvae died quickly. Using only tap water with salt or RO water with salt didn’t work either. Just putting salt in the hatching tank after the larvae were born seemed to work, but the larvae died after 2 weeks. Of course you must not think it is impossible to breed different from my tactics because I didn’t succeed one trying these methods.

Larvae surviving in fresh water: As some kind of a test I kept a few larvae in fresh water to see for how long they could survive. After 7 days I saw the amount of larvae decreasing and after 9 days they were all dead. It is nice to know that the larvae can survive at least a week in fresh water.

Acclimatizing to salt water and back: I filled the saltwater aquarium with 14 liters of salt water. Hen the larvae were hatched, I caught the mother to put back in the big tank and I tapped almost all the water from the hatching tank through an artemia filter screen so I wouldn’t suck up some larvae. Then when just one liter of water was remaining with all the larvae I used a knotted air tube to slowly drip all the salt water in the liter of fresh water. This did take me about 2 hours. Catching the larvae with an artemia filter screen and putting them straight into salt water did work too, but I had the feeling at least half of the larvae didn’t survive this method. Acclimatizing the young developed shrimp into fresh water worked best when done over a period of two weeks. I tried doing this in 4 days with some shrimps but half of them died.

Results: The start wasn’t really good because the mother ate most of the larvae in one night. The larvae developed from larvae to shrimp in about a month. The first young shrimp was spotted after 33 days and the last one tuned into a shrimp after 44 days. In total I put 35 young shrimps into fresh water. In the first weeks I saw some of them die. This stopped when I started feeding more. I now have 13 shrimps left, after two months. Not a single one has died for at least 1 month. Right now, some of them measure about 13-14 mm. They grow slowly, just as their parents do.