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dc.contributor.advisor Forward, Jr., Richard B. en_US
dc.contributor.author Ziegler, Tracy Ann en_US
dc.date.accessioned 2008-01-02T16:33:42Z
dc.date.available 2008-01-02T16:33:42Z
dc.date.issued 2007-11-28 en_US
dc.identifier.uri http://hdl.handle.net/10161/456
dc.description Dissertation en_US
dc.description.abstract This dissertation investigated larval release and larval behavior of the Caribbean spiny lobster Panulirus argus and the spotted spiny lobster P. guttatus. These species were examined under laboratory conditions to determine the phase relationship between larval release and natural environmental cycles. P. argus displayed a nocturnal tidal rhythm, while P. guttatus displayed a circadian rhythm in larval release. P. argus releases larvae near the time of nocturnal high slack water, while P. guttatus released larvae near the time of sunrise. The role of 'pumping pheromones' in controlling larval release behaviors was tested by measuring the pumping response of ovigerous P. argus to (1) hatch water, (2) homogenized-embryo water, (3) embryo-conditioned water, and (4) water containing homogenized-egg cases. Lobsters with late-stage embryos displayed increased pleopod pumping with increased concentration of hatch water. Water individually conditioned with homogenized late-stage embryos, intact late-stage embryos, and homogenized egg-cases induced pumping activity in females with late-stage embryos, indicating the presence of a chemical cue. I quantified pumping responses upon exposure to synthetic peptides to determine if they mimicked pheromones that induce larval release behaviors. Pumping behavior was evoked by oligopeptides with a basic amino acid at the carboxy-terminus, preceded by several neutral amino acids. Carboxyl-terminal arginine peptides serve as pheromone mimics. I investigated whether these peptides originate from the action of trypsin-like enzymes by conducting a bioassay measuring pumping activity of ovigerous P. argus subjected to increasing concentrations of trypsin, trypsin inhibitor, and a combination of the two. Pumping activity increased with increasing concentrations of trypsin and trypsin inhibitor, while behaviors ceased when ovigerous females were subjected to a complex of the two. Pheromones are generated by trypsin-like enzymes assisting in the degradation of the egg membranes at the time of hatching. Vertical swimming behaviors of stage-I phyllosoma larvae of P. argus and P. guttatus were observed under laboratory conditions. P. argus larvae displayed a pattern of twilight vertical migration, while P. guttatus larvae displayed nocturnal diel vertical migration (DVM). Rhythms persisted for 5-6 cycles under constant conditions, indicating that an endogenous rhythm in activity plays a proximate role in DVM for both species. en_US
dc.format.extent 3370845 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject Biology, Ecology en_US
dc.subject Biology, Animal Physiology en_US
dc.subject larval release rhythms en_US
dc.subject circadian en_US
dc.subject circatidal en_US
dc.subject pumping pheromones en_US
dc.subject vertical migration en_US
dc.subject spiny lobster en_US
dc.title Larval Release Rhythms and Larval Behavior of Palinurid Lobsters: a Comparative Study en_US
dc.type Dissertation en_US
dc.department Environment en_US

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