The reproductive development of the large wrasses

Liew, Pik Ngan (2005) The reproductive development of the large wrasses. Universiti Malaysia Sabah. (Unpublished)


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Biological information for large, hermaphroditic wrasses (Labridae) are very limited although populations of these species are exploited sustenance for the market. Large wrasses, such as Choerodon anchorago, Cheilinus trilobatus, Choerodon schoenleinii and Hemigymnus melanopterus, although not highly important commercially as Napoleon wrasse, Cheilinus undulatus, were found in the market of Kudat District. Samples of these large species were collected from Kudat fish market from middle of August 2004 to end of November 2004 to gather information on some aspects of growth and reproduction of these species. Measurements of length and weight of otolith, gonad, and body were made and gonadal examination was made for sex and stage of maturation of C. anchorago. These were gathered to get information on the growth of these species and to attempt in testing the hypotheses that maturation of fishes is 50 % of the maximum length and that sex reversal occurs at 80 % of the maximum length. The linear correlation is found for the length-weight relationship between the otolith length and standard length for C. anchorago (R2 = 0.668) and C. trilobatus (R2 = 0.273). The large wrasses are found to be protogynous hermaphrodites, where individuals change sex from female to male like other labrids. For expected (i.e., < 50 % of maximum length and 80% of maximum length); maturation of C. anchorago was found at size 14.5 cm, C. trilobatus in size 13.9 cm and H. melanopterus matured at size more than 24 cm. The maturity of C. schoenleinii cannot be detennined because limitation of samples and resources. These findings on maturation and sex reversal on C. anchorago, C. trilobatus and H. melanopterus indicate that fishing pressure is causing an adaptive change in these populations. For further studies, more sampJes, are needed to confirm these initial findings.

Item Type: Academic Exercise
Uncontrolled Keywords: maturation, sex reversal, fishing pressure, protogynous hermaphrodites
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: SCHOOL > School of Science and Technology
Date Deposited: 27 Jan 2014 05:30
Last Modified: 10 Oct 2017 09:02

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