Life Sciences Commons^™

Asexual Reproduction In Planaria Characteristics Of The Inhibitor(S), Linda Gail Sheffield

Theses and Dissertations

A study was made of the postulated fission-inhibiting substance located in the cephalic region of Dugesia dorotocephala. Rearing decapitated planaria in four different concentrations (25, 50, 75 or 100 ug/ml) of head or whole body extract resulted in a positive correlation between the inhibition of fission rate and the concentration of extract. The difference in inhibitory activity between the two types of extracts was three percent at maximum. The inhibitory substance was partially inactivated at 60° C. There was a direct correlation between the length of time that the extract was heated and the inactivation of inhibitor. The active substance …

Asexual Reproduction In Planaria Studies On Inhibition, Hal R. Fitzgerald

Theses and Dissertations

The invertebrates display several methods of asexual reproduction, such as fission and gemnule formation and budding (Hay, 1966). Planaria reproduce asexually only by fission.

Reproductive Biology Of Thais Emarginata (Deshayes, 1839) And Thais Canaliculata (Dulcos, 1832), Roy Seamands Houston

University of the Pacific Theses and Dissertations

Thais emarginata (Deshayes, 1839) and Thais canaliculata (Dulcos, 1832), are two common Pacific coast gastropods (Family: Muricidae). T. emarginata is found in semi-protected rocky areas from Alaska to Baja California, while T. canaliaulata occurs in quiet bays from Alaska to Monterey Bay, California (Ricketts and Calvin, 1966). Both species occur on rocks and jetties where they can be seen feeding upon barnacles and young mussels. Despite the abundance of these species their reproductive biology has not been examined.

In the present study, the following aspects of the reproductive biology of T. emarginata and T. canalieulata are presented: Relationship of gonadal …