AbstractA series of ceramides, called oceanapins A–F (2–7), which are unique for branching at both the sphingosine and fatty‐acid chains, have been isolated as pure compounds from the haplosclerid spongeOceanapiacf.tenuisof the Coral Sea. Following acid hydrolysis, both the fatty‐acid and the sphingosine portions were obtained separately, which allowed their unequivocal structural definition. The absolute configuration was securedviaprotection of C(1′)–OH andMosher'sesterification at C(3′)–OH of