Krewetki w akwarium słodkowodnym

Macrobrachium assamense

Apperance:	Brown-beige with transparent carapax. Big tongs are typical for these shrimp, males' tongs are really big, usually red or rust with black stripes.
Origin:	East Himalaya, also Chota Nagpur and Satpura in India as well mountain part of Burma.
Size:	Males 8cm, female 6 cm.
Water conditions:	Temp round 20 - 30 C, 3 GH, 1,5 KH. Water must be very rich in oxygen.
Tank layout:	Sand substrate, roots, rock, oak, bleech and alder leafs on the bottom. Plants might be eaten, even ones with hard leafs.
Food:	Live or frozen food, snails, pieces of fish, dead animals, artificial aliments and own made ones with egg yolk. They can be feed with new born guppies.
Breeding:	No larvae stadium. Female carries about 20-60 eggs for couple of weeks, depends from temperature and oxygen. Young ones become adult in age of 3 month.

Aggressive and territorial shrimp. Kept in too small tank M. assamensis fight against each other losing legs very often (they grow back during next moultations). Males are more aggressive than females. They attack with elevated front part of body and spread tongs. But they runaway backwards very nimble. They swim in open water very rarely, but they like to climb over decorations and tank equipment.
For one couple 50 liter tank will be ok, for bigger number you will need min. 100 liter tank. Rule given by Andreas Karge (Aquarist Aktuall sonderheft 2004) says that you can keep 3 adult males in 100 liter tank. Tank should be so decorated that shrimps could make their territories. Best solution is to make it so that they wouldn't be able to see their "neighbors" as well as putting lots of hiding places. When there's too many M. assamensis in one tank you can observe the fact that dominating male usually after moultation losses tongs and his place is taken by other male. During day M. assamensis stay hidden (especially when tank is well lit) but usually they come out in time of feeding - just to grab food and go back to hideout. During night they like to make walks around tank, and unfortunately sometimes they get out of tank (climbing is their specialty) so you should make sure that you have a good coverage.
M. assamensis are raptures, so if they are accompanied by small shrimps, fish or snails they will soon eat them. Seeing hunting M. assamensis is something unforgettable. It's worth to make small tank in which you will breed small snails which are one of M. assamensis favorite food. Generally M. assamensis doesn't make problems with feeding them and they are really gluttonous.
Courtship is very spectacular - couple touches each other all the time and male tries to "hug" female using tongs. She runs away, he chases her - just a soap opera :) Females are carrying eggs all the time. Unfortunately act of copulation takes place at night, so aquarist doesn't have chance to see it. But it is possible to see parturition, of course not the whole process because it might take even 2 days. Female bends in a bow and using legs she helps little one to get out of egg. Small one falls down on the bottom, it's transparent and hard to see. It has about 7mm and it's convoluted but after few minutes it stretches and sits next to the female, like if it was waiting for its brothers and sisters. Female becomes very aggressive and chases male away. He shows understanding and goes away. Female shouldn't be taken away from tank because in stress she might eat her offspring. If you want to get maximum number of offspring in separate tank you should put female there earlier. Uwe Werner in his book "Garnelen, Krebse und Krabben im Susswasseraquarium" says that females of Macrobachium, which have higher form of breeding look after their babies at least during their first hours in this world. But there are still discussions about it.
Growing up young M. assamensis is only possible in general tank when there are enough hideouts. Some of them might be eaten by grown ones but since this species breeds often and easy so there will be always too much offspring:) When they reach about 2 cm they are safe and they start to even steal food from adults:) They become aggressive then as well. They don't make their own territories yet but they already chase each other away. They also start to pigmentation at this time. They don't grow equally. Kept in small tanks they grow slower and probably they don't reach maximum size.
M. assamensis are very nosy and not afraid of owner. They even try to attack him through the glass. There are 2 subspecies: Macrobachium assamensis assamensis (origin: east Nepal, Bangladesh and Assam) and Macrobrachium assamensis peninsulanis (origin: Satpura and Vindhy in Madhya Pradesh mountains).

Jackie Sawicka

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