Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/807523
- Title
- The reproductive biology and spawning behaviour of Chromis hypsilepis (Pisces: Pomacentridae)
- Author/Creator
-
Thewes, Samantha Athena
- Institution
- University of Newcastle. Faculty of Science and Information Technology, School of Environmental and Life Sciences
- Description
- Masters Research - Master of Philosophy (MPhil)
- Description
- Fishes of the family Pomacentridae utilize a great range of reproductive strategies, although most research has focussed on tropical species. Chromis hypsilepis is a schooling planktivore that occurs on temperate rocky reefs from northern New South Wales to northern Tasmania. During the summer breeding season, large numbers of C. hypsilepis migrate to spawning aggregation sites. This spawning strategy is unusual in the family Pomacentridae and demersal spawning is very uncommon among fishes that form spawning aggregations. This study was undertaken to fill the gap in understanding of the reproductive biology of C. hypsilepis and to provide detailed descriptions of the reproductive behaviour as part of improving the understanding of this unusual reproductive strategy. Age, growth, sexual maturity and reproductive behaviour of C. hypsilepis were described from a population at Terrigal, New South Wales. The length and age at sexual maturity were also compared to a population at Jervis Bay, 200 km south of Terrigal. C. hypsilepis is gonochoristic and occurred in a 1:1 sex ratio. The use of bands in the sagittal otoliths of C. hypsilepis as a measure of age was validated with marginal increment analysis. A maximum age of 22.5 years was recorded. Males and females, respectively, attained sexual maturity at 75.2 and 89.2 mm SL at Terrigal, corresponding to ages of 1.9 and 2.0 years. Von Bertalanffy growth models showed that males and females attained 50% of their asymptotic length within 1-2 years. There was minimal variation between the Terrigal and Jervis Bay populations. Spawning behaviour was described using mounted underwater video cameras, recording up to 11 hours per day. Spawning was acyclic. Spawning occurred throughout the day, building up during the morning hours to a peak at midday and dramatically dropping in frequency throughout the rest of daylight hours. The results of this study are a necessary component of understanding the unique reproductive strategy of C. hypsilepis.
- Relation
- University of Newcastle Research Higher Degree Thesis
- Date
- 2010
- Keyword(s)
-
Chromis hypsilepis;
damselfish;
reproduction;
spawning
- Resource Type
- thesis
- Rights
- Copyright 2010 Samantha Athena Thewes
- Identifier
- http://hdl.handle.net/1959.13/807523
- Language
- eng
- Full Text
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