Aquascope

Facts


Common shrimp

Spring migration and larvdrift

Soon after the ice has disappeared from shallow waters, the shrimp migrates from its winter habitat into deeper water. Most of the individuals are about one year old and about 5-15 mm in size.
   The common shrimp becames sexually mature at about one year. Some are hermaphrodites, that start as males and later transform into females. It normally reproduces 3-5 times each season, producing thousands of eggs each time. After the female has sloughed her skin she lays on her side to enable copulation. When egg laying takes place, she attaches the eggs to the base of her swim legs and as far up as her last legs. After 4-8 weeks the eggs hatch while she is in deeper water, thereafter the larvae swim up towards the surface. The common shrimp has five larvae stages, with intermittant sloughing of its skin. From June-July, after 4-5 weeks as a larva, the shrimp drifts into shallow sandy bottomed areas where it falls to the bottom. The last group of larvae fall to the bottom in October.
   Up until October, large quantities of young shrimps grow up in these shallow sandy bottomed areas. The species is very common, with up to 6-100 individuals per m2. Shrimps are preyed upon by fish, for example cod when it visits shallow sand bottoms, because of this, shrimps are seldom older than four years.

Seasonal migration
The shrimps life cycle and seasonal migration.


Previous page

Page 3 of 4

Next page

Hunt at night

Hidden during the day

Autumn migration

Spring migration and drifting larvae

Sloughing

Food


Common shrimp     More facts     Other names
Home    Contents    Inspiration    Facts    Collaboration   
© Aquascope 2000   Tjärnö Marine Biological Laboratory, Strömstad, Sweden
Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson