Title: Instantaneous Growth Rate (IGR) experiments on krill during BROKE-West
Crustaceans grow or shrink in size as they moult. Length of discarded moults represent length of animals before their moulting
events. Therefore, by measuring length of discarded moult and length of animal after moult, growth increments at the time
of moult can be obtained. IGR is defined as the growth increment expressed as a proportion of pre-moult total length (TL).
IGR can be converted into daily growth rate for a given value of TL by calculating absolute growth increment and dividing
by an estimate of inter-moult period (IMP).
The IGR technique depends on the collection of live krill in good condition. Krill were caught with an RMT-8 net and individual
freshly caught animals were randomly selected from the catch and immediately transferred to individual jars. They were then
maintained onboard and checked regularly for moults for up to 5 days following capture. The experiments were run a flowthrough
seawater system which used 250 ml jars with small holes to allow water exchange in a large flow-through tank of seawater maintained
at ambient ocean temperature. No additional food was provided. The system allowed experiments with over 4000 krill. Each krill
was checked daily after capture to ascertain whether it had moulted. If an animal had moulted, then the animal and its moult
were collected and frozen in liquid nitrogen or at -85 degrees C to be measured back ashore. The growth rate will be estimated
from the difference in length of the uropod of the moult and that of the whole post-moult krill.
A document providing detailed information on the collection of krill aboard the Aurora Australis is available for download
from the URL given below.
This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > SPECIES LIFE HISTORY
Theme_Keyword: R/V AA > R/V AURORA AUSTRALIS
Theme_Keyword: Instantaneous Growth Rate
Theme_Keyword: Intermoult Period
Theme_Keyword: Growth Model
Place_Keyword: OCEAN > SOUTHERN OCEAN
Place_Keyword: CONTINENT > ANTARCTICA
Place_Keyword: GEOGRAPHIC REGION > POLAR
These data are publicly available from the provided URL. Additionally, a document providing detailed information on the collection
of krill aboard the Aurora Australis is available for download from the URL given below.
This data set conforms to the PICCCBY Attribution License
The chief investigator must be contacted before using these data.
Please follow instructions listed in the citation reference at the provided URL when using these data.