The nudibranch mollusc Diaulula sandiegensis contained nine chlorinated acetylenes, 1-9, all of which were relatively unstable when purified. The nine metabolites were identified as (1Z, 3E, 9Z)-l-chlorohexadeca-5, 7-diyne-1, 3, 9-trien-15-one (l),(l2, 32, 9Z)-l- chlorohexadeca-5, 7-diyne-l, 3, 9-trien-l5-one (2),(12, 3E, SZ)-l-chlorohexadeca-5, 7-diyne- 1, 3, 9-trien-15-01 (3),(12, 32, 92)-l-chlorohexadeca-5, 7-diyne-l, 3, 9-trien-15-01 (4),
