Culaeatrema inconstans gen.n., sp.n. (Digenea: Alloereadiidae) from the brook stickleback (Culaea inconstans) in Wisconsin and observations on parthenogenetic populations

Abstract

Culaeatrema inconstans gen.n., sp.n. is described from the intestine of Culaea inconstans (Kirtland) collected in Wisconsin. Culaeatrema is a small, fusiform, nonspinous trematode resembling both allocreadiins and bunoderins. Culaeatrema is placed in the subfamily Bunoderinae because testes are oblique in position, uterus extends into the posterior region, and vitellaria do not extend beyond the anterior testis. Reproduction in two populations of the new species from Shell and Little Waumandee creeks appears to be parthenogenetic. Parthenogenetic worms exhibited larger phenotypic size, one or both testes lacking in 84% of the examined specimens, lack of spermatozoa, and reduced development of male reproductive structures. A discussion of parthenogenesis in parasitic helminths is included.