A preliminary study of age and growth of the monkfish Lophius upsicephalus (Pisces: Lophiidae) on the Agulhas Bank,South Africa |
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| Abstract: | The sagittal otoliths of Lophius upsicephalus, although extremely variable in shape, were found to be the only structures suitable for age estimation. The annuli are multi-ringed zones separated by "wider than normal" opaque zones. They are difficult to interpret, especially those of fish older than nine years. Periodicity of annulus formation could not be determined by standard methods. By inference, annulus formation could be related to feeding habits and reproductive seasonality. The growth in length (sexes combined) is best described by Length-at-age = 733,7 (1 – e?0,1054 (t + 1,879))mm. There is a significant difference in growth by mass between the sexes. The respective equations describing growth by mass (in g) for males and females are: Weight-at-age = 8616 (1 – e?0,1054 (t + 1,879))2,805 and Weight-at-age = 9499 (1 – e?0,1054 (t + 1,879))2,890. |
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| Keywords: | ALLOMETRY KENYA PANULIRUS HOMARUS SEXUAL MATURITY |
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