Population biology of an endangered species: the common guitarfish Rhinobatos rhinobatos in Lebanese marine waters of the eastern Mediterranean Sea

This study focuses on the population biology of the common guitarfish Rhinobatos rhinobatos, a cartilaginous fish listed as Endangered in the International Union for the Conservation of Nature (IUCN) Red List. Between December 2012 and January 2014, 67 individuals were collected by bottom longlining...

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Bibliographic Details
Published in:Journal of fish biology 2016-04, Vol.88 (4), p.1441-1459
Main Authors: Lteif, M., Mouawad, R., Khalaf, G., Lenfant, P., Verdoit-Jarraya, M.
Format: Article
Language:English
Subjects:
Animals
Body Size
chondrichthyan
Ecology, environment
Endangered Species
Female
Fisheries
Gastrointestinal Contents
IUCN
Lebanon
life history
Life Sciences
Male
Mediterranean Sea
overfishing
Population Dynamics
reproductive biology
Seasons
Sex Ratio
Sexual Maturation
Skates (Fish)
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Summary:This study focuses on the population biology of the common guitarfish Rhinobatos rhinobatos, a cartilaginous fish listed as Endangered in the International Union for the Conservation of Nature (IUCN) Red List. Between December 2012 and January 2014, 67 individuals were collected by bottom longlining in coastal Lebanese marine waters at different ports at depths ranging from 10 to 110 m. The total length (LT) of the specimens ranged from 50 to 143 cm, and the mean ± s.d. was 76·2 ± 19·7 cm. The most common LT classes were between 60 and 70 cm. The total mass of the specimens ranged from 410 to 10 000 g, and the mean ± s.d. was 1841 ± 1987 g. A total of 34 males and 33 females were collected, and the sex ratio was not significantly different from 1:1. The mass and LT relationship showed positive allometric growth (b = 3·096 and r2 = 0·99), and the mean ± s.d. LT at which 50% of the individuals were sexually mature was 84·73 ± 5·81 cm for females and 78·57 ± 4·88 cm for males. The gonado‐somatic and hepato‐somatic indices were determined along with a condition factor, and parturition appeared to occur in winter. The primary prey items found in the fish stomachs during the autumn and winter seasons were Penaeidae. The results of this study will help to parameterize models of the population dynamics for this exploited fish stock to ensure the long‐term sustainability of its fishery.
ISSN:0022-1112
1095-8649
DOI:10.1111/jfb.12921