Growth and Spawning The Resources

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2.3 Growth and Spawning

Growth of the tongue sole is described as rapid Chauvet, 1972. Females grow at slightly higher rates than males Ajayi, no date. Fishermen state that young of the year recruit to their gear 6 months after spawning. The juveniles stay within the rocky and sandy areas for approximately 6 months. When mature, which may occur within the first year, they move to deeper waters. New information relative to agelength is included in the Appendix. Recent information obtained by the processing plant in The Gambia, indicate that the lengthweight relationship for the red and black sole are only slightly different. There is a great deal of scatter in the weight data for each length of fish, which may be a function of their maturity and spawning stage. The condition factor K=100WL 3 varies as a function of month ranging from 1.63 and 0.54 Figure 3. Abowei 2009 found the lowest condition factors during the spawning season for red sole in Nigeria. However, given the data collected to date in The Gambia, it appears that condition factors for red sole increase during the season that fishermen believe is the spawning period Appendix 4. Information about black sole is missing during this period. Figure 3. Condition factor of black and red sole. 8 As the sole move to shallow waters starting in January, the females carry eggs that are not well developed Figure 4. Fishermen observed that in June to July, the eggs are fully mature and are released in sandy areas known locally as “pass”. Contrary to the commonly described spawning behavior of flatfish which produces planktonic eggs that float freely in the water column, it is believed that the eggs of red sole are laid in the bottom sediment when the fish burrow. Larval stages may vary from a few days to a couple of months influenced by water temperature. Fishermen report eggs to be encased in a thin film which hatch after 3 days. More information on spawning condition is being collected to verify these findings. Figure 4. Eggs are clearly visible in the processed product. 9

Chapter 3: The Fishery