Tuesday, May 14, 2013
Egg capsule and larva of the intertidal snail Littorina scutulata
L. scutulata females typically lay transparent egg capsules shaped like a stack of two unequally sized disks. The egg capsules of L. plena females look similar, except that the upper and lower disk are equal in diameter (Hohenlohe 2002). The upper picture shows a side view of the L. scutulata egg capsule, in which the distinctive shape is evident. The lower picture focuses on the embryos, each of which develops in its own membrane (Buckland-Nicks et al. 1972).
Reid, D. 2007. Littorina. In: Intertidal Invertebrates from Central California to Oregon. Carlton, James T. ed. University of California Press. Berkeley and Los Angeles, California. 2007.
Kozloff, E. N. and Price, L. H. 1996. Phylum Mollusca: Class Gastropoda. In: Marine Invertebrates of the Pacific Northwest. Kozloff, E.N. ed. University of Washington Press. Seattle and London.
Buckland-Nicks, J., Chia, F-S, and Behrens, S. 1972. Oviposition and development of two intertidal snails, Littorina sitkana and Littorina scutulata. Canadian Journal of Zoology. 51: 359-365
Hohenlohe, P. A. 2002. Life history of Littorina scutulata and Littorina plena, sibling gastropod species with planktonic larvae. Invertebrate Biology. 12 (1): 25-37.