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Flexible reproductive strategies in tropical and temperate Sepioteuthis squids

Citation

Pecl, GT, Flexible reproductive strategies in tropical and temperate Sepioteuthis squids, Marine Biology, 138, (1) pp. 93-101. ISSN 0025-3162 (2001) [Refereed Article]

DOI: doi:10.1007/s002270000452

Abstract

A major difficulty confronting the determination of cephalopod reproductive life history is assessing over what portion of the life span an individual is reproductively mature and actively depositing eggs. This paper assesses the potential of the tropical Sepioteuthis lessoniana and two genetic types of the temperate Sepioteuthis australis, to spawn multiple batches of eggs at discrete times throughout the adult life span. This is achieved by histological examination of the ovarian gametogenic cycle and detailed morphological assessments of the reproductive system, in conjunction with other biological information. The genetic type of S. australis found at the northern limits of its Australian distribution showed evidence of a high correlation between body size and quantity of mature eggs, suggesting that eggs may be accumulating to be laid in a single batch. Although maturation was also a size-related process in S. lessoniana and Tasmanian S. australis, oviduct size was not correlated with body weight in mature females, which is indicative of multiple spawning. Further supporting evidence includes relatively low gonadosomatic indices, the heavier weight of the ovary relative to the oviduct, and the feeding activity of mature animals. Mature S. lessoniana and S. australis individuals were present at each location over very wide age and size ranges. In Tasmanian waters, there were distinct seasonal differences in the reproductive biology of S. australis. Summer-caught individuals had much higher gonadosomatic indices and may have been laying larger batches of eggs compared with winter-caught individuals. Summer-caught females also showed a negative correlation between egg size and egg number within the oviduct, suggesting that some individuals were producing fewer, larger eggs and others many smaller eggs. Evidence suggests that considerable flexibility is inherent in the reproductive strategy of both S. lessoniana and S. australis.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Invertebrate Biology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Pecl, GT (Associate Professor Gretta Pecl)
ID Code:35282
Year Published:2001
Web of Science® Times Cited:50
Deposited By:TAFI - Marine Research Laboratory
Deposited On:2007-08-01
Last Modified:2011-11-21
Downloads:0

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