Growth And Moulting Of Captive Panulirus Homarus Homarus In Kenya, Western Indian Ocean.
Panulirus homarus homarus is the most widely distributed among the three P. homarus subspecies and is the second most important spiny lobster in the Kenyan lobster fishery after P. ornatus. Growth and moulting of lobsters, held in concrete tanks with a flow-through seawater supply and at ambient temperatures, were monitored for 18 months (October, 2001 - March, 2003). Both moult increment and moulting frequency were inversely correlated with size. Mean moult increment ranged from 4mm in the 36-45 mm CL size class to 0.6 mm in the 86-95 mm CL size class. Mean intermoult period increased from 49 days in the 46-55 mm CL size class to 81 days in the 86-95 mm CL size class. Growth rates were 19% and 46% higher for males and females, respectively during the southeast monsoon (low temperature) period than during the northeast monsoon (high temperature) season. A shift in energy use from growth to reproduction rather than the influence of temperature was responsible for the variation in the growth rates between the two seasons. Marking induced injuries caused a significant 65% growth reduction in the affected individuals. Mean moult increments calculated for most size classes of uninjured lobsters were comparable to those observed in lab reared subtropical P. homarus rubellus in South Africa but smaller than those reported in the Indian P. homarus under similar conditions. This indicates that growth in our experiment was slightly depressed probably in response to sub-optimal holding conditions.
Main Authors: | , |
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Format: | Conference Material biblioteca |
Language: | English |
Published: |
Royal Society of New Zealand
2004-02
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Subjects: | Panuliris homarus homarus, Injury, Growth, Moulting, Kenya, Lobster fisheries, |
Online Access: | http://hdl.handle.net/1834/723 |
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Summary: | Panulirus homarus homarus is the most widely distributed among the three P. homarus subspecies and is the second most important spiny lobster in the Kenyan lobster fishery after P. ornatus. Growth and moulting of lobsters, held in concrete tanks with a flow-through seawater supply and at ambient temperatures, were monitored for 18 months (October, 2001 - March, 2003). Both moult increment and moulting frequency were inversely correlated with size. Mean moult increment ranged from 4mm in the 36-45 mm CL size class to 0.6 mm in the 86-95 mm CL size class. Mean intermoult period increased from 49 days in the 46-55 mm CL size class to 81 days in the 86-95 mm CL size class. Growth rates were 19% and 46% higher for males and females, respectively during the southeast monsoon (low temperature) period than during the northeast monsoon (high temperature) season. A shift in energy use from growth to reproduction rather than the influence of temperature was responsible for the variation in the growth rates between the two seasons. Marking induced injuries caused a significant 65% growth reduction in the affected individuals. Mean moult increments calculated for most size classes of uninjured lobsters were comparable to those observed in lab reared subtropical P. homarus rubellus in South Africa but smaller than those reported in the Indian P. homarus under similar conditions. This indicates that growth in our experiment was slightly depressed probably in response to sub-optimal holding conditions. |
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