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A Contribution to the Biology of the Spotted Weakfish, C̲y̲ṉo̲s̲c̲i̲o̲ṉ Ṉe̲ḇu̲ḻo̲s̲u̲s̲, (Cuvier) from Northwest Florida

其他書名	With a Description of the Fishery
出版	Marine Laboratory, University of Miami, 1959
URL	http://books.google.com.hk/books?id=dhAnMgEACAAJ&hl=&source=gbs_api

註釋The three counties located in the study area, Taylor, Wakulla, and Franklin, produce approximately seven per cent of the annual Florida west coast production of spotted weakfish. The commercial production of spotted weakfish is largely incidental to the catch of other fish. The commercial gears which produce this species include gill nets, trammel nets, seines and hook and lines. These gear types are selective as to size of fish caught. Gill net caught spotted weakfish ranged in standard length from 23.5 to 47.5 cm while fish caught by hook and line ranged in length from 17.5 to 43.6 cm. Three-, four-, and five-year-old fish are the principal year classes in this fishery. Angler catches may be sold to commercial outlets. The major portion of angler catches is taken in the winter. The marks on spotted weakfish scales are true annuli, thus allowing age and growth calculations. The maximum age of spotted weakfish observed was seven years while the average age was between three and four years. Male fish may attain sexual maturity by the end of their first year of life; sexual maturity apparently occurs for the first time among females at the end of the second year of life. Spawning begins in the latter part of April and continues through September. There is a changing sex ratio with size. Male fish dominated the catches up to a standard length of 29.4 cm while above this length catches contained a greater percentage of females. Spotted weakfish were found to feed mainly on fish and shrimp. There are differences between the spotted weakfish from the east and northwest coast of Florida in the rate of growth, average size of fish, length at first maturity and length of spawning season. Some possible reasons for these differences are discussed.