Age and growth rates of the critically endangered fish Garra ghorensis can inform their conservation management

Authors: Hamidan, N. and Britton, J.R.

Journal: Aquatic Conservation: Marine and Freshwater Ecosystems

Volume: 25

Issue: 1

Pages: 61-70

Publisher: John Wiley and Sons Ltd

eISSN: 1099-0755

ISSN: 1052-7613

DOI: 10.1002/aqc.2449

Information on the life-history traits of threatened fishes can inform their conservation as they can indicate resilience to environmental change and vulnerability to extirpation and extinction. Garra ghorensis, a small (<140mm total length) riverine cyprinid fish, endemic to the southern Dead Sea area, is critically endangered through habitat loss and invasive species. There are, however, no data currently available on their life-history traits to inform their conservation management. The age structure and growth rate characteristics of three G. ghorensis populations in Jordan were assessed. Close to the sampling sites, minimum air temperatures approached 0°C in January but maxima exceeded 40°C in July and August. Samples collected monthly throughout 2011 contained fish with lengths between 23 and 137mm, with most less than 100mm. Monthly length distributions showed three distinct length modes in each population whose mean lengths increased throughout the warmer months. Growth check formation on scales was annual and their ageing revealed fish in each population present to at least 4years old, with a maximum of 6years. Comparison of these data with the length modes indicated that the modes corresponded to ages 0+, 1+ and >2years. Variability in length at age was apparent within sites, suggesting protracted spawning. Females were significantly larger than males. Growth rates and lifespans of G. ghorensis were highest at the most disturbed site (habitat loss and the presence of the invasive Oreochromis aureus). This growth plasticity in response to slower flows and deeper water suggests G. ghorensis has some resilience to environmental disturbances and suggests that their conservation management might not have to return their habitats to pristine conditions to avoid impacts on their lifespan and growth parameters. It also shows that further work is needed to identify the issues that are affecting the persistence of their populations.

This source preferred by Nashat Hamidan and Robert Britton

This data was imported from Scopus:

Authors: Hamidan, N. and Britton, J.R.

Journal: Aquatic Conservation: Marine and Freshwater Ecosystems

Volume: 25

Issue: 1

Pages: 61-70

eISSN: 1099-0755

ISSN: 1052-7613

DOI: 10.1002/aqc.2449

© 2014 John Wiley & Sons, Ltd. Information on the life-history traits of threatened fishes can inform their conservation as they can indicate resilience to environmental change and vulnerability to extirpation and extinction. Garra ghorensis, a small (<140mm total length) riverine cyprinid fish, endemic to the southern Dead Sea area, is critically endangered through habitat loss and invasive species. There are, however, no data currently available on their life-history traits to inform their conservation management. The age structure and growth rate characteristics of three G. ghorensis populations in Jordan were assessed. Close to the sampling sites, minimum air temperatures approached 0°C in January but maxima exceeded 40°C in July and August. Samples collected monthly throughout 2011 contained fish with lengths between 23 and 137mm, with most less than 100mm. Monthly length distributions showed three distinct length modes in each population whose mean lengths increased throughout the warmer months. Growth check formation on scales was annual and their ageing revealed fish in each population present to at least 4years old, with a maximum of 6years. Comparison of these data with the length modes indicated that the modes corresponded to ages 0+, 1+ and >2years. Variability in length at age was apparent within sites, suggesting protracted spawning. Females were significantly larger than males. Growth rates and lifespans of G. ghorensis were highest at the most disturbed site (habitat loss and the presence of the invasive Oreochromis aureus). This growth plasticity in response to slower flows and deeper water suggests G. ghorensis has some resilience to environmental disturbances and suggests that their conservation management might not have to return their habitats to pristine conditions to avoid impacts on their lifespan and growth parameters. It also shows that further work is needed to identify the issues that are affecting the persistence of their populations.

This source preferred by Nashat Hamidan and Robert Britton

This data was imported from Scopus:

Authors: Hamidan, N. and Britton, J.R.

Journal: Aquatic Conservation: Marine and Freshwater Ecosystems

eISSN: 1099-0755

ISSN: 1052-7613

DOI: 10.1002/aqc.2449

Information on the life-history traits of threatened fishes can inform their conservation as they can indicate resilience to environmental change and vulnerability to extirpation and extinction. Garra ghorensis, a small (<140mm total length) riverine cyprinid fish, endemic to the southern Dead Sea area, is critically endangered through habitat loss and invasive species. There are, however, no data currently available on their life-history traits to inform their conservation management. The age structure and growth rate characteristics of three G. ghorensis populations in Jordan were assessed. Close to the sampling sites, minimum air temperatures approached 0°C in January but maxima exceeded 40°C in July and August. Samples collected monthly throughout 2011 contained fish with lengths between 23 and 137mm, with most less than 100mm. Monthly length distributions showed three distinct length modes in each population whose mean lengths increased throughout the warmer months. Growth check formation on scales was annual and their ageing revealed fish in each population present to at least 4years old, with a maximum of 6years. Comparison of these data with the length modes indicated that the modes corresponded to ages 0+, 1+ and >2years. Variability in length at age was apparent within sites, suggesting protracted spawning. Females were significantly larger than males. Growth rates and lifespans of G. ghorensis were highest at the most disturbed site (habitat loss and the presence of the invasive Oreochromis aureus). This growth plasticity in response to slower flows and deeper water suggests G. ghorensis has some resilience to environmental disturbances and suggests that their conservation management might not have to return their habitats to pristine conditions to avoid impacts on their lifespan and growth parameters. It also shows that further work is needed to identify the issues that are affecting the persistence of their populations. © 2014 John Wiley & Sons, Ltd.

This data was imported from Web of Science (Lite):

Authors: Hamidan, N. and Britton, J.R.

Journal: AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS

Volume: 25

Issue: 1

Pages: 61-70

eISSN: 1099-0755

ISSN: 1052-7613

DOI: 10.1002/aqc.2449

The data on this page was last updated at 04:54 on April 18, 2019.