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Quantifying Shell Hardness in the Southern Rock Lobster (Jasus edwardsii)


Gardner, C and Musgrove, R, Quantifying Shell Hardness in the Southern Rock Lobster (Jasus edwardsii), Journal of Aquatic Food Product Technology, 15, (2) pp. 17-35. ISSN 1049-8850 (2006) [Refereed Article]

DOI: doi:10.1300/J030v15n02_03


Southern rock lobsters Jasus edwardsii that are about to moult or have recently moulted have reduced market value due to higher mortality in live transport, higher cannibalism and lower meat recovery. Limiting the landing of softer shelled lobsters is desirable to maintain product quality; however, attempts to set closed seasons or to introduce industry self-regulation have been hampered by subjectivity in measuring shell hardness. We evaluated the use of durometers as a tool for collecting objective measurements of shell hardness. Of the ten locations on the exoskeleton that were evaluated, two locations along the lateral suture line of the exoskeleton gave most consistent readings and underwent largest changes through the moult. The effects of several factors on durometer readings were evaluated: sex, temperature (ambient plus elevated 3°C), location (from around the coast), and size. No effect on durometer readings could be detected from any of these factors with the exception of lobster size. A cumulative logistic function fitted to grouped data provides a method for predicting time before or after moulting from durometer readings. Although durometers appear to be a valuable tool for research on closed seasons, there was not sufficient precision for grading of individual lobsters by industry. © 2006 by The Haworth Press, Inc. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture and fisheries stock assessment
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Fisheries - wild caught not elsewhere classified
UTAS Author:Gardner, C (Professor Caleb Gardner)
ID Code:42505
Year Published:2006
Deposited By:TAFI - Marine Research Laboratory
Deposited On:2006-08-01
Last Modified:2011-10-12

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