INHIBITORY LEARNING AND MEMORY IN THE TOPSHELL (MONODONTA-LINEATA)

One hundred eighty topshells (Monodonta lineata) were exposed to inhib itory learning procedures. Results indicate that (1) topshells are cap able of inhibitory learning, (2) long-term memory for this type of lea rning persists for at least 32 days, and (3) topshells housed in group s of 10 learned more efficiently than did those housed in groups of 5. The latter groups, however, learned more efficiently than did animals housed singly. These results were interpreted in terms of the evoluti onary significance of such behavior.