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Instantaneous Growth Rate (IGR) experiments on krill during the BROKE-West voyage of the Aurora Australis, 2006

Created 23/06/2025

Updated 23/06/2025

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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. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

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Field Value
Title Instantaneous Growth Rate (IGR) experiments on krill during the BROKE-West voyage of the Aurora Australis, 2006
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/f376fe8b-ecba-4892-947c-a73c7f4eea5a
Contact Point
Australian Ocean Data Network
metadata@aad.gov.au
Reference Period 20/01/2006 - 05/03/2006
Geospatial Coverage
Map data © OpenStreetMap contributors
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      ],
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Data Portal Australian Oceans Data Network

Data Source

This dataset was originally found on Australian Oceans Data Network "Instantaneous Growth Rate (IGR) experiments on krill during the BROKE-West voyage of the Aurora Australis, 2006". Please visit the source to access the original metadata of the dataset:
https://catalogue.aodn.org.au/geonetwork/srv/eng/csw/dataset/instantaneous-growth-rate-igr-experiments-on-krill-during-the-broke-west-voyage-of-the-aur-2006