| Phylogenetic, biogeographic and coevolutionary relationships were studied for ostraciin boxfishes and their gill parasitic Haliotrema species. Two monophyletic subgroups of ostraciins were recognized, each with two monophyletic genera: Atlantic Acanthostracion and Lactophrys and Indo-Pacific Ostracion and Lactoria. Two sister area relationships are evident: Caribbean/eastern Atlantic and Atlantic/Indo-Pacific. Six Atlantic and four Indo-Pacific Haliotrema species were recorded. Two new Haliotrema species are recorded from Ostracion species. The hypothesis that Haliotrema species from boxfishes form a monophyletic lineage was rejected. Their biogeographic history may have included two isolation events: one sister group relationship across the Panama Isthmus and another (possibly two) across the Indo-Australian archipelago. Three chronological phases in the history of coevolutionary studies are: (1) Recognition of predictable associations. (2) Search for patterns of association and their underlying causes. (3) Development of objective and repeatable methodologies for reconstructing and interpreting these patterns. Comparison of host and parasite phylogenies indicated a fairly high degree of coevolution (c.i.'s = 75%, 94% and 94%, respectively). These results were used to examine alternate views on three important issues in the history of coevolutionary research: (1) host specificity, (2) taxonomic scale and (3) biogeography. Distribution and area relationships based on parasite data indicated that host-parasite coevolutionary relationships involve parasite lineages on whole communities of hosts. |
