Biological and medical sciences Fundamental and applied biological sciences. Psychology Invertebrates Mollusca Morphology. Histology. Cytology
The protoconch length of Epitonium echinaticosta ranges from 330 to 790 mum in the northern Bahamas. The length increases along depth gradients from near 0 m to 40-52 m. Intermediates are from intermediate depths. One planktotrophic species is involved. A possible explanation is given. Systematists should be aware that the phenomenon may occur in other planktotrophic epitoniids or other marine prosobranchs.