The clam Mulinia edulis is occasionally infected by the parasite Edotea magellanica. In this paper the normalized optical transmittance of the clam and its parasite have been disclosed for the first time using a hyperspectral imaging system. It has been identified that, in the spectral band of 600-950 nm, the normalized optical transmittance of clam's mantle cavity changes in the presence or absence of the parasite. This relative change in the normalized optical transmittance has been used as an effective spectral feature for designing parasite detectors. As a proof of concept two detectors have been designed. The first detector, which relies on all the hyperspectral information, achieved a perfect detection accuracy in identifying parasite-infected clams. The second detector, which is based on a reduced number of hyperspectral bands, achieved an 85% detection accuracy. These results provide insights on the fundamental trade-off between detection accuracy and the amount of hyperspectral information for parasite detection in clams. (C) 2013 Published by Elsevier Ltd.