My Research

Title: The evolution of parasitic castration using cymothoid isopods as a model system

Cymothoid isopods are common parasites of fishes. Despite being ubiquitous, large, and likely impacting host populations, very little is known about the scope of interactions between these parasitic isopods and their host organisms. From relatively few published studies, we know that there can be a range of pathologies; from moderately minor attachment wounds to complete castration, to death. Because cymothoids produce such a diversity of affects on their hosts, this suggests that within the family Cymothoidae, different trophic strategies (typical parasitism, micropredation, partial castration and full castration) are utilized. This is novel and can be used as a model for the evolution of castration, as all other known higher level taxa utilize only one trophic strategy.

Ph.D. Research

Master’s Research

Title: Effect of the parasitic isopod, Anilocra apogonae (Cymothoidae) on the growth, condition, reproduction and survival of cardinal fish, Cheilodipterus quinquelineatus (Apogonidae)

My Master’s examined the effect of the ectoparasitic cymothoid isopod, Anilocra apogonae, on the growth, condition, reproduction and survival of its host, the five-lined cardinal fish. The effects of juvenile isopods (mancae) on the growth and survival of two other species of late-stage larval apogonids (Apogon trimaculatus and Apogon nigrofasciatus) were also examined. The first aim was to investigate whether A. apogonae parasitically castrates its host. Parasitic castration represents a distinctive trophic strategy as characterized in the trophic adaptive syndrome paradigm, in which host reproduction is blocked or reduced by the presence of an intensity-independent, or single, parasite. The second aim was to describe the life-history of A. apogonae and examine the affect of mancae on late-stage larval and juvenile fish by identifying whether mancae showed host preference when presented with two late-stage larval apogonids (Apogon trimaculatus and Apogon nigrofasciatus) which were not the definitive host, and one late-stage larval apogonid (A. trimaculatus) and a late-stage larval non-apogonid (Pomacentrus amboinensis), neither of which were the definitive host.