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In situ growth rate estimates of Southern Ocean krill, Thysanoessa macrura


Wallis, JR and Melvin, JE and King, R and Kawaguchi, S, In situ growth rate estimates of Southern Ocean krill, Thysanoessa macrura, Antarctic Science, 31, (3) pp. 116-122. ISSN 0954-1020 (2019) [Refereed Article]

Copyright Statement

Copyright 2019 Antarctic Science Ltd

DOI: doi:10.1017/S0954102019000063


Growth, which is intrinsically linked to environmental conditions including temperature and food availability are highly variable both temporally and spatially. Estimates of growth rates of the Southern Ocean euphausiid Thysanoessa macrura are currently restricted to limited studies which rely upon repeated sampling and length-frequency analysis to quantify growth rates. The instantaneous growth method (IGR) was used to measure the growth rate of T. macrura successfully in the southern Kerulen Plateau region during summer, providing the first IGR parameters for the Southern Ocean euphausiid species. Results of the four-day IGR incubation indicate a period of low somatic growth for adult T. macrura. Males had a longer intermoult period (IMP) (62 days) than females (42 days), but the sexes exhibited similar daily growth rates of 0.011 mm day−1 and 0.012 mm day−1 respectively. Juveniles exhibited the fastest growth, with an IMP of 13 days and daily growth rate of 0.055 mm day−1 indicating a prolonged growth season, similar to the Antarctic krill E. superba. Consequently, we highlight the usability of the IGR method and strongly encourage its use in developing a comprehensive understanding of spatial and seasonal growth patterns of T. macrura.

Item Details

Item Type:Refereed Article
Keywords:daily growth rate, krill, Southern Ocean, instantaneous growth rate, intermoult period
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Biodiversity in Antarctic and Southern Ocean environments
UTAS Author:Wallis, JR (Mr Jake Wallis)
UTAS Author:Melvin, JE (Miss Jessica Melvin)
UTAS Author:Kawaguchi, S (Dr So Kawaguchi)
ID Code:131611
Year Published:2019
Deposited By:Ecology and Biodiversity
Deposited On:2019-03-27
Last Modified:2020-08-21

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