FN Archimer Export Format PT C TI Structural and biochemical characteristics in adult scallop shells BT AF DEVAUCHELLE, Nicole CUIF, Jean Pierre Larvor, H AS 1:;2:;3:;4:; FF 1:PDG-DS;2:;3:;4:; SI BREST SE PDG-DS UR https://archimer.ifremer.fr/doc/00044/15548/12935.pdf LA English DT Proceedings paper AB This paper presents results of studies carried out on the microstructure, composition of organic matter and amino acids in abnormal shells of adult Pecten maximus. Results indicate that abnormal P. maximus shells can have two types of brown material on the inner layer of the valves. Brown calcified areas can be present and they have abnormal crystals on the internal foliated layer of the shell. An index (MIBC) was developed to describe this type of abnormality that depended on the extent of the brown areas. The other type abnormality had brown material consisting of uncalcified membranes that were embedded in mud tubes made by Polydora sp. worms. The amino acid composition of these two materials was completely different. When compared to white (normal) calcified shell, the brown calcified areas were characterized by decreases in aspartic acid and the proportion of serine, and the presence of a brown pigment that was resistant to decalcification and hydrolysis in 6N HC1. Biochemical analysis showed the brown uncalcified areas caused by Polydora contained chlorophyll, carotene and fUcoxanthin pigments. The crystal abnormalities were considered to result from natural ecological disturbances. Crystal abnormalities have been noticed when scallop broodstock have been submitted to unfavourable rearing conditions in the laboratory. PY 1994 ID 15548 ER EF