Weight gain, moulting frequency, survival response, and analyses of fatty acid composition of tissues were used to investigate the nutritional value of polyunsaturated fatty acids (PUFA) to juvenile mud crab, Scylla serrata in a puri ed diet. Five isonitrogenous and isoenergetic diets contained pure triglycerides of 18:3n-3 (trilinolenin), 18:2n-6 (trilinolein), 20:4n-6 (triarachidonin), and 22:6n-3 (tridocosahexaenoin), either alone or in combination. All diets were formulated to contain a total of 2% lipid. A diet containing only saturated (14:0, 16:0, 18:0) and monounsaturated (16:1n-7, 18:1n-9) fatty acids as lipid sources, in proportions similar to that found in a 2 : 1 cod liver oil/corn oil mixture, served as a control diet. The survival of crabs ranged from 87 to 100% for all dietary treatments.Levels of n-3 and n-6 PUFAs decreased in the neutral lipid of the whole body tissue, when not provided in the diet. Levels of 20:4n-6, 20:5n-3, and 22:6n-3 were conserved in the polar lipid of the whole body tissue of mud crabs when these were not provided in the diets. After feeding trials of 70 days, weight gain of crabs fed diets containing 18:2n-6 or a control diet were not signi cantly different. A dietary source of 22:6n-3, 20:4n-6, and 18:3n-3 is required by juvenile crabs, as indicated by a signi cant increase in weight gain of these crabs. RÉSUMÉLe gain de poids, la fréquence des mues, la survie et les analyses d'acides gras des tissus ont été utilisés pour étudier la valeur nutritionnelle des acides gras polyinsaturés (PUFA) pour les juvéniles de Scylla serrata. Cinq régimes isoénergétiques et isoazotés contenaient des triglycérides purs de 18:3n-3 (trilinolenin), 18:2n-6 (trilinolein), 20:4n-6 (triarachidonin), et 22:6n-3 (tridocosahexaenoin), soit seuls, soit en mélange. Tous les régimes ont été formulés pour contenir un total de 2% de lipides. Un régime contenant seulement des acides gras saturés (14:0, 16:0, 18:0) et monoinsaturés (16:1n-7, 18:1n-9) comme sources de lipides, dans des proportions analogues à celles trouvées dans un mélange huile de foie de morue/huile de maïs 2 : 1, a servi de régime témoin. La survie des animaux a été observée entre 87 et 100% pour tous les essais de régime.Les niveaux de PUFAs n-3 et n-6 ont diminué dans les lipides neutres des tissus du corps, quand ils n'étaient pas présents dans la nourriture. Les niveaux de 20:4n-6, 20:5n-3, et 22:6n-3

A new species of spider crab, Acanthonyx formosa, is described from seaweed beds in Taiwan. The species is allied to A. euryseroche Griffin & Tranter, 1986, from western Australia, but differs markedly in the proportions of the adult male rostrum, and in the structure of the hepatic tooth, the third maxilliped, the adult male chela, and the male first pleopod. Acanthonyx formosa is only the second species of Acanthonyx known from the Pacific, the other being A. simplex Dana, 1852, from Hawaii. Une nouvelle espece de crabe, Acanthonyx formosa, est decrite de lits d'algues, a Taiwan. L'espece est apparentee a A. euryseroche Griffin & Tranter, 1986, d'Australie occidentale, mais en differe nettement dans les proportions du rostre du male adulte, la structure de la dent hepatique, le troisieme maxillipede, la pince du male adulte et le premier pleopode male. Acanthonyx formosa n'est que la seconde espece du genre connue du Pacifique, la premiere etant A. simplex Dana, 1852, des Hawa.

The king crab, Lithodes turritus Ortmann, 1892, is reported from relatively deep waters in Taiwan for the first time. It also represents the first record of the family Lithodidae from Taiwan. Comparisons with its closest congener, L. longispina Sakai, 1971, are provided. The present Taiwanese specimens are the largest reported for this species.