Deformities in high-bred shrimp

02 Jul 2013

by Ulli Bauer

Text: Marie-Sophie Germain

Photos: authors are known to the editors

In 2011, people were surprised to see some winning shrimps at the Hannover Shrimp Championship carrying deformities. That was the case for the first prize, a Panda showing an abnormally large carapace, a condition called « balloon-head ». (Picture here )

And this is not a problem of the past – time and again, one sees pictures of somehow weird-looking shrimp.

The fact is high-bred shrimp tend to suffer from various deformities, encouraged by intensive breeding. The problem is the shrimps don’t only look deformed, they also have a decreased lifespan and some females don’t survive when berried. Often, Taiwan Bees are affected, however, the problem has also been spotted e.g. in Sakura shrimp (Neocaridina davidi). One can’t tell which proportion of the shrimp are affected, but we can say for sure that such crippled shrimps appear at an alarming frequency.

Here are the main deformities:

Ballon-head : the carapace is abnormally large, looking like a ballon. This deformity is typical for many Taiwan Bees.

Open skirt : the carapace seams to be very slim and «too short» for the shrimp’s body. In the worse cases you can see the onset of the gills on the shrimp’s legs.

Hunchback : the middle of the back is curved, the shrimp has a « M » shape.

Roll up antennae : the antennae are rolled up to the ground and shorter. Some specialists call these shrimps « treasure hunters » (picture here).

Breeders should be really careful with this issue and have a lot of work to do to prevent such genetic problems to spoil their strains. The should only mate healthy pairs, and exclude any affected shrimp from their breeding program.

It is said that crippled shrimps are only seen in small breedings having a limited number of individuals, and not so much in the big shrimp factories we can see for example in Asia. However, some breeders try to widen the gene pool by crossing Taiwan Bees with CRS/CBS.

The judges at championships should also be aware of the problem and maybe think about disqualifying any shrimp showing deformities, in order to preserve the hobby and the animals’ life quality.