Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman
Age, growth, and monthly reproductive characteristics were determined for the orange-spotted grouper (Epinephelus coioides) from northern Oman. This species is characterized by a prevalence of females (1-11 years old), and males make up 6.5% of the total sample. Growth parameters indicate a typical...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
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U.S. National Marine Fisheries Service
2016
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| Online Access: | http://hdl.handle.net/20.500.11937/22802 |
| _version_ | 1848750973398286336 |
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| author | McIlwain, Jennifer Ambu-Ali, A. Al Jardani, N. Halford, A. Al-Oufi, H. Feary, D. |
| author_facet | McIlwain, Jennifer Ambu-Ali, A. Al Jardani, N. Halford, A. Al-Oufi, H. Feary, D. |
| author_sort | McIlwain, Jennifer |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Age, growth, and monthly reproductive characteristics were determined for the orange-spotted grouper (Epinephelus coioides) from northern Oman. This species is characterized by a prevalence of females (1-11 years old), and males make up 6.5% of the total sample. Growth parameters indicate a typical pattern for groupers with a low growth coefficient (K=0.135). The trajectory of the von Bertalanffy growth function was almost linear with no evidence of asymptotic growth. Estimates of mortality revealed a low natural mortality of 0.14/year but a high fishing mortality of 0.59/year. More alarming was the high rate of exploitation (0.81/year), considered unsustainable for a slow-growing grouper. The population off southern Oman is diandric protogynous, and sex change takes place between 449 and 748 mm in total length (TL) or over a period of 4–8 years. The gonadosomatic index for females showed a short spawning season from March through May, although ~30% of females were ripe for 7 months of the year. Size and age at 50% maturity for females was estimated to be 580 mm TL and 4 years, respectively. We suggest that substantial changes in the management of this species will be vital in sustaining viable populations of orange-spotted grouper and other species of Epinephelidae within Oman. |
| first_indexed | 2025-11-14T07:45:20Z |
| format | Journal Article |
| id | curtin-20.500.11937-22802 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:45:20Z |
| publishDate | 2016 |
| publisher | U.S. National Marine Fisheries Service |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-228022017-09-13T13:55:44Z Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman McIlwain, Jennifer Ambu-Ali, A. Al Jardani, N. Halford, A. Al-Oufi, H. Feary, D. Age, growth, and monthly reproductive characteristics were determined for the orange-spotted grouper (Epinephelus coioides) from northern Oman. This species is characterized by a prevalence of females (1-11 years old), and males make up 6.5% of the total sample. Growth parameters indicate a typical pattern for groupers with a low growth coefficient (K=0.135). The trajectory of the von Bertalanffy growth function was almost linear with no evidence of asymptotic growth. Estimates of mortality revealed a low natural mortality of 0.14/year but a high fishing mortality of 0.59/year. More alarming was the high rate of exploitation (0.81/year), considered unsustainable for a slow-growing grouper. The population off southern Oman is diandric protogynous, and sex change takes place between 449 and 748 mm in total length (TL) or over a period of 4–8 years. The gonadosomatic index for females showed a short spawning season from March through May, although ~30% of females were ripe for 7 months of the year. Size and age at 50% maturity for females was estimated to be 580 mm TL and 4 years, respectively. We suggest that substantial changes in the management of this species will be vital in sustaining viable populations of orange-spotted grouper and other species of Epinephelidae within Oman. 2016 Journal Article http://hdl.handle.net/20.500.11937/22802 10.7755/FB.114.4.10 https://creativecommons.org/publicdomain/zero/1.0/ U.S. National Marine Fisheries Service fulltext |
| spellingShingle | McIlwain, Jennifer Ambu-Ali, A. Al Jardani, N. Halford, A. Al-Oufi, H. Feary, D. Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title | Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title_full | Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title_fullStr | Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title_full_unstemmed | Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title_short | Demographic profile of an overexploited serranid, the orange-spotted grouper (Epinephelus coioides), from Northern Oman |
| title_sort | demographic profile of an overexploited serranid, the orange-spotted grouper (epinephelus coioides), from northern oman |
| url | http://hdl.handle.net/20.500.11937/22802 |