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Summary

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).

Geographic Coverage Spatial coordinates   

N: -61.67

S: -69.21

E: 80.04

W: 29.92

Temporal Coverage

Start Date: 2006-01-20 Stop Date: 2006-03-05

Location Keywords

CONTINENT > ANTARCTICA OCEAN > SOUTHERN OCEAN GEOGRAPHIC REGION > POLAR

Science Keywords

BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > ARTHROPODS > CRUSTACEANS BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > SPECIES LIFE HISTORY BIOSPHERE > AQUATIC ECOSYSTEMS > PELAGIC HABITAT

ISO Topic Category

OCEANS BIOTA

Platform

LABORATORY SHIPS

Instrument

TRAWL

Quality

The IGR experiments were set up whenever large number of live krill in good conditions were caught by RMT haul.

Access Constraints

These data are not yet publicly available. A document providing detailed information on the collection of krill aboard the Aurora Australis is available for download from the URL given below.

Use Constraints

The chief investigator must be contacted before using these data.

Ancillary Keywords

Instantaneous Growth Rate IGR Intermoult Period IMP Growth Model

Data Set Progress

IN WORK

Data Center

Australian Antarctic Data Centre, Australia Data Center URL: http://data.aad.gov.au Data Center Personnel Name: DATA OFFICER AADC Phone: +61 3 6232 3244 Fax: +61 3 6232 3351 Email: metadata at aad.gov.au Contact Address: Australian Antarctic Division 203 Channel Highway City: Kingston Province or State: Tasmania Postal Code: 7050 Country: Australia

Distribution

Distribution Media: HTTP Distribution Size: 4306 kb Distribution Format: Word Fees: free

Personnel

SO KAWAGUCHI Role: INVESTIGATOR Role: TECHNICAL CONTACT Role: DIF AUTHOR Phone: +61 3 6232 3216 Email: So.Kawaguchi at aad.gov.au Contact Address: Australian Antarctic Division, Channel Highway City: Kingston Province or State: Tasmania Postal Code: 7050 Country: Australia

Related URL

Link: GET DATA Description: Download point for the data - documentation on collecting krill aboard the Aurora Australis Link: VIEW PROJECT HOME PAGE Description: Public information for ASAC project 2655 Link: VIEW PROJECT HOME PAGE Description: Public information for ASAC project 2679 Link: VIEW RELATED INFORMATION Description: Citation reference for this metadata record and dataset

Creation and Review Dates

DIF Creation Date: 2006-03-11 Last DIF Revision Date: 2008-04-10

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