(full paper is archived in the Miller Library)
Title: Studies on the jaw, digestive system, and coelomic derivatives in representatives of the genus Acmaea (Mollusca: Gastropoda: Prosobranchia)
Student Author(s): Walker, Catherine Gene
Faculty Advisor(s): Abbott, Donald P
Location: Final Papers Biology 175H
Date: June 1966
Abstract: Placement and extent of the radula sac, the form of the jaw, the arrangement of the salivary glands, the looping of the gut, and the interconnections of coelomic derivatives are described and illustrated for Acmaea asmi, A. digitalis, A. limatula, A. pelta, A. scutum, A. scabra. The ratio of radula length/shell length is nearly 2 in A. scutum and 1-1.5 in other Acmaea species. Jaws vary in shape; the hard anterior band in A. pelta, A. incessa, and Lottia gigantea bears an anterior median tooth. Salivary glands vary between species in length of ducts, size and position of glands. The pattern of gut loops shows minor but consistent differences between Acmaea species. Development of the adult pattern of loops is essentially completed before animals reach a shell length of 4mm. The gut tends to be thicker and heavier in species feeding on larger erect or encrusting algae (A. pelta, A. limatula, A. scutum) than in species feeding on films of microscopic algae (A. digitalis, A. scabra, A. asmi). Limpets from the high intertidal zone (A. digitalis and A. scabra) have relatively larger right and left kidneys than do Acmaea species from lower levels.
Notes: Published 1968, Veliger 11(Suppl): 89-97