Yolŋu classifications of local shellfish types throw into stark relief the differences between indigenous knowledge systems and those of the western sciences. Systems of knowledge are embedded in distinctive worldviews that are often incommensurable with others, but within themselves, they are wholly coherent. Knowledge and practices maintained by peoples with extended histories of intimate coexistence with their environments typically emphasize symbiotic and spiritual connectedness to place. Such thinking tends to link people, animals, plants and other elements of the cosmos through social relations and engender systems that look and feel very different from the formal conventions of modern western style sciences. What may appear ambiguous from a purely scientific perspective may reveal a magnificent pattern of intimate and holistic connection where colour, shared habitat or mythological origin inform the logic of classification.