Studies of yellowfin eggs, larvae, and juveniles

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The larvae hatched from eggs spawned in captivity have been used in a variety of laboratory experiments.  The main objective of the research is to determine the biological and physical processes that influence survival during the larval and early-juvenile life stages.  The results can also be applied to rearing studies of other species of tunas.  Experiments have been carried out to examine the effects of larval stocking density, microturbulence, light intensity, and prey density on feeding incidence, survival, and growth of yellowfin larvae.

Juveniles are routinely reared for 5-6 weeks after hatching, and have survived up to 100 days.  Growth in length and weight of larvae and early juveniles is rapid and non-linear.

During 2001 Drs. William McFarland, of the University of Washington, and Ellis Loew, of Cornell University, in collaboration with an IATTC scientist, initiated a study of the development of vision in yellowfin tuna.  The objective is to identify the types of photoreceptor cells and color vision present in larval and juvenile yellowfin.  The data on spectral sensitivity is being analyzed to determine if the photosensitivity of certain life stages can be related to stage-specific life histories.