Spatial patterns in the biology of the chokka squid, Loligo reynaudii on the Agulhas Bank, South Africa

Olyott, L J H; Sauer, Warwick H H; Booth, Anthony J

Title: Spatial patterns in the biology of the chokka squid, Loligo reynaudii on the Agulhas Bank, South Africa
Creator: Olyott, L J H
Creator: Sauer, Warwick H H
Creator: Booth, Anthony J
Date Issued: 2007
Date: 2007
Type: text
Type: article
Identifier: http://hdl.handle.net/10962/127053
Identifier: vital:35947
Identifier: https://doi.10.1007/s11160-006-9027-5
Description: Although migration patterns for various life history stages of the chokka squid (Loligo reynaudii) have been previously presented, there has been limited comparison of spatial variation in biological parameters. Based on data from research surveys; size ranges of juveniles, subadults and adults on the Agulhas Bank were estimated and presented spatially. The bulk of the results appear to largely support the current acceptance of the life cycle with an annual pattern of squid hatching in the east, migrating westwards to offshore feeding grounds on the Central and Western Agulhas Bank and the west coast and subsequent return migration to the eastern inshore areas to spawn. The number of adult animals in deeper water, particularly in autumn in the central study area probably represents squid spawning in deeper waters and over a greater area than is currently targeted by the fishery. The distribution of life history stages and different feeding areas does not rule out the possibility that discrete populations of L. reynaudii with different biological characteristics inhabit the western and eastern regions of the Agulhas Bank. In this hypothesis, some mixing of the populations does occur but generally squid from the western Agulhas Bank may occur in smaller numbers, grow more slowly and mature at a larger size. Spawning occurs on the western portion of the Agulhas Bank, and juveniles grow and mature on the west coast and the central Agulhas Bank. Future research requirements include the elucidation of the age structure of chokka squid both spatially and temporally, and a comparison of the statolith chemistry and genetic characterization between adults from different spawning areas across the Agulhas Bank.
Format: 14 pages
Format: pdf
Language: English
Relation: Reviews in fish biology and fisheries
Relation: Olyott, L.J.H., Sauer, W.H.H. and Booth, A.J., 2007. Spatial patterns in the biology of the chokka squid, Loligo reynaudii on the Agulhas Bank, South Africa. Reviews in fish biology and fisheries, 17(2-3), pp.159-172
Relation: Reviews in fish biology and fisheries volume 17 number 2-3 159 172 2007 0960-3166
Rights: Reviews in fish biology and fisheries
Rights: Use of this resource is governed by the terms and conditions of the SpringerLink Terms of Use Statement ( https://link.springer.com/termsandconditions)

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Booth, Anthony John (Prof)

Sauer, Warwick H H (Prof)

RU Department of Ichthyology and Fisheries Science

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