Juvenile reef fishes often have a color pattern different from that of adults. It has been theorized that this reduces the aggression received by juveniles from adult conspecifics. This was tested using two species of Labroides cleaning wrasses in which certain-sized individuals can quickly shift back and forth between the adult and juvenile color patterns. Adult Labroides phthirophagus has the same single-male grouping social structure as previously described for L. dimidiatus. Small L. phthirophagus and L. dimidiatus in juvenile coloration shifted to adult coloration when isolated and then quickly shifted back to juvenile coloration when chased by an adult conspecific female. In L. phthirophagus the adult females attacked small cleaners more frequently when they displayed the adult color pattern, indicating that juvenile coloration gives some protection from conspecific aggression. Two other species oflabrids, Thalassoma duperrey and Coris gaimard, showed the ability to shift back to juvenile coloration when aggression was received from con specific adults, although the shift was not nearly as rapid as seen in Labroides species. Dascyllus albisella and Zebrasomajlavescens, common reef fishes, preferred to solicit cleaning (by posing) from the adult-colored L. phthirophagus, indicating that some hosts prefer the adult color pattern. Small L. phthirophagus shifted to adult coloration more quickly when starved than when provided with host fish on which to feed, indicating that the coloration shift is motivated by hunger. Even though juvenile coloration in some fishes may reduce the aggression received from adults, in cleaner wrasses it also reduces food availability, making it advantageous for them to shift to adult-coloration as soon as possible. Cleaner wrasses have developed a quick, reversible coloration shift that allows changing to adult coloration at a small size but allows reversing coloration if too much aggression is received. / x, 59 leaves, bound : ill., maps ; 29 cm.

No description available.

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

No description available.

This thesis investigates the possibility of using aposematic insects as guides to plants that contain pharmacologically-active compounds. Plants were monitored within national parks in the Republic of Panama over a period of six months and all insects feeding on them were collected and raised in captivity. The insects were then extracted and analyzed to determine how they were treating toxic chemical compounds in their host plant. Two principal plants were investigated with their associated insects: (1) Vismia baccifera and (2) Mikania guaco. One generalist and one specialist Lepidopteran species were found to sequester vismione B from their host plant Vismia baccifera, a cytotoxic compound active against three cancer cell lines. Two specialist Coleopterans were found to sequester the novel compound Guacanone, isolated by the primary author from the vine Mikania guaco and active against Trypanosoma cruzi, the causative agent of Chagas' disease. A generalist Coleopteran was found to not sequester this compound. (Abstract shortened by UMI.)

No description available.