Spawning seasons of Rasbora tawarensis (Pisces: Cyprinidae) in Lake Laut Tawar, Aceh Province, Indonesia
Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia.Unfortunately, its status is regarded a critical endangered with populations decreasing in recent years. To date noinformation on the spawning activities of the fish are available. Therefore, this study provides a contribution to the. knowledge on reproductive biology of R. tawarensis especially on spawning seasons as well as basic information for conservation of the species.Monthly sampling was conducted from April 2008 to March 2009 by using selective gillnets. The gonadosomatic index, size composition and sex ratio were assessed. The gonadal development was evaluated based on macroscopic and microscopic examinations of the gonads.The gonadosomatic index (GSI) varied between 6.65 to 18.16 in female and 4.94 to 8.56 for male. GSI of thefemale R. tawarensis was higher in March, September and December indicating the onset of reproductive seasons, theGSI and oocyte size being directly correlated with gonadal development stages. Although, a greater proportion ofmature male than female was detected during the study, the sex ratio showed that the overall number of female washigher than male. The ovaries had multiple oocyte size classes at every stage of gonadal development, thus R.tawarensis can be classified as a group synchronous spawner or a fractional multiple spawner. The spawning seasons of R. tawarensis were three times a year and September being the peak of the reproductive season and the female was the predominant sex. This species is classified as a group synchronous spawner. (PDF contains 8 pages)
| Main Authors: | , , |
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| Format: | article biblioteca |
| Language: | English |
| Published: |
2010
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| Subjects: | Conservation, Fisheries, Aquaculture, Biology, Limnology, |
| Online Access: | http://hdl.handle.net/1834/21320 |
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