Browsing by Subject "Copepoda reproduction"

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Mesozooplankton population dynamics : factors affecting reproduction and predation
(2000) Collumb, Christopher J., 1969-; Buskey, Edward Joseph, 1952-
Two important factors controlling population abundance of mesozooplankton are reproductive success and predation. This research analyzed the physiological affects of bloom events, particularly the Texas brown tide alga Aureoumbra lagunensis and the red tide alga Gymnodinium breve on survival, feeding and reproduction of the copepod Acartia tonsa. From fieldwork, it appears bloom events could dominate other controlling factors such as temperature, salinity and chlorophyll abundance in determining A. tonsa fecundity. Laboratory experiments demonstrated that A. lagunensis and G. breve are not utilized effectively as food items, as indicated by low egg production values, however neither alga appeared directly toxic to A. tonsa. Behavioral and predation effects of natural and artificial increases in mesozooplankton pigmentation were measured. The egg bearing copepod Dioithona oculata was used to measure the effects of the presence of heavily pigmented egg sacs on predation. The resulting increase in image size led to a higher rate of predation on egg bearing D. oculata by the juvenile grunt (Haemulon aurolineatum). Neutral red was used to stain several species of mesozooplankton to see if the artificial increase in pigmentation would increase predation rates by visual predators. Of the four species examined only A. tonsa had a higher rate of predation of stained individuals