A link between macroinvertebrate functional diversity and fish parasite diversity in the New Jersey Pine Barrens

Host diversity has been shown to play a major role in shaping parasite diversity. However, it is less clear if this relationship holds across various hosts in complex life cycles, and what aspects of host diversity are regulating parasite diversity. This study tests whether host diversity at lower trophic levels (i.e., invertebrate hosts) is linked to parasite diversity at higher trophic levels (i.e., vertebrate hosts). This study then compares whether invertebrate host taxonomic vs. functional diversities have a greater influence on this relationship. To test this, fish parasites and macroinvertebrates were sampled from multiple sites along rivers in the New Jersey Pine Barrens. Upon examining diversity, macroinvertebrate taxonomic diversity was not significantly correlated with parasite diversity in vertebrate hosts. On the contrary, there was a significant positive correlation between macroinvertebrate functional feeding group diversity and parasite diversity in vertebrate hosts. These results suggest that intermediate host feeding strategies may serve as a means of structuring parasite communities in subsequent fish hosts. However, a better understanding of parasite life cycles in the N.J. Pine Barrens is necessary to support this hypothesis.