Histological Analysis of Embryonic Development and Generation of Reproductive Structures in Lumbriculus

A histological approach was used to examine the process of embryonic development and generation of reproductive structures in Lumbriculus. As the Tweeten laboratory has collected Lumbriculus from sloughs and lakes in Minnesota, Iowa, Wisconsin, and Montana over the past four years, we have found an abundance of specimens that were sexually reproducing. With access to sexually reproducing forms of Lumbriculus, we have initiated a series of experiments related to studies on embryonic development and sexual reproduction. We analyzed tissue sections of Lumbriculus embryos at different stages of development and described the morphology of the embryos. Patterns of cleavage and cell arrangement during gastrulation, neurulation, and organogenesis were examined. The embryonic stage at which reproductive structures including ovaries and testes develop was also determined.