title: Preliminary observations on the effects of vector-averaged gravity on the embryonic and larval development of the gastropod mollusk, Ilyanassa obsoleta Stimpson.
abstract: Fertilized eggs of Ilyanassa obsoleta Stimpson were collected immediately after their deposition in egg capsules.  Unopened egg capsules then were affixed to glass slides, and incubated either statically (controls) or on a clinostat (experimentals).  After incubation for 9-14 days, hatching occurred sooner and in a higher percentage of clinostated capsules than in controls.  Embryos that hatched while undergoing clinostat incubation were abnormal in morphology, whereas other embryos present in non-hatched capsules in the same tubes appeared normal, as did embryos in the control tubes.  Although the results are compatible with a conclusion that vector-averaged gravity in the experimental tubes caused the altered development, some other aspects of how the incubations were done may have contributed to the differences between the control and experimental results.
authors.affiliation: Mount Desert Island Biological Laboratory, Salsbury Cove, Maine 04672.
authors.forename: G W
authors.initials: GW
authors.lastname: Conrad
authors.forename: A P
authors.initials: AP
authors.lastname: Stephens
authors.forename: A H
authors.initials: AH
authors.lastname: Conrad
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000201:enzymology; D047108:Embryonic Development; D006112:Gravitation; D008974:Mollusca / Q000196:embryology* / Q000201:enzymology / Q000254:growth & development; D012399:Rotation