Teruhisa Katayama

Growth response of Tilapia zillii fingerlings fed isocaloric diets with variable protein levels

Abstract Six purified casein diets within a range of 21–53% crude protein were fed for 3 weeks to young tilapia (Tilapia zillii) to determine the optimum protein requirement and protein: energy ratio for growth. Growth rate increased proportionally to protein level of the diet to an incorporation rate of about 35%. Beyond this a gradual retardation in growth rate was observed. The diet containing about 30% crude protein with a protein: energy ( P E ) ratio of 81, however, appeared to be more efficiently utilized by the fish in terms of protein deposition and energy retention than diets with higher levels of crude protein. These results indicate that Tilapia zillii requires about 35% protein in the diet for optimum growth while 30% for the maximum bodily protein deposition when casein is used as the sole source of protein. All six diets, however, showed an excellent feed conversion. Protein efficiency ratio (PER) decreased with the increase in protein in the diet.

The biosynthesis of astaxanthin- XVI. The carotenoids in Crustacea.

Abstract 1. 1. The carotenoids were isolated from seven species of Crustacea. 2. 2. Astaxanthin was the most prominent pigments in both carapaces and internal organs. 3. 3. Other pigments isolated include β-carotene, echinenone, canthaxanthin, lutein, zeaxanthin, 3-hydroxy-canthaxanthin and 3,3′-dihydroxy-ϵ-carotene.

The biosynthesis of astaxanthin—XIV. The conversion of labelled β-carotene-15,15′-3H2 into astaxanthin in the crab, Portunus trituberculatus

Abstract The crab, Portunus trituberculatus , was cultured in a laboratory for 2 weeks by feeding a special diet containing β-carotene-15,15′- 3 H 2 dissolved in plant oil. β-Carotene-15,15′- 3 H 2 was converted to labelled astaxanthin through the steps of isocryptoxanthin, echinenone, canthaxanthin and 3-hydroxy-canthaxanthin. A classification of aquatic animals, based on their biosynthesis of astaxanthin, is discussed.

The biosynthesis of astaxanthin—VII. The carotenoids in sea bream, Chrysophrys major Temminck and Schlegel

Abstract 1. 1. Astaxanthin was the major pigment in the integuments of sea bream. 2. 2. Besides 3,3′-dihydroxy-e-carotene, lutein, α-doradexanthin ester and astaxanthin, the existence of zeaxanthin and α-carotene was confirmed. 3. 3. In the internal organs, echinenone and 3,3′-dihydroxy-e-carotene were the dominant pigments and also the existence of β-carotene, zeaxanthin, lutein and astaxanthin was confirmed.

The incorporation of dietary astacene into Artemia.

Australian Artemia (Shark Bay) were fed rice bran for 10 days, then fed purified astacene 6 days, then returned to rice bran for 6 days. Artemia were shown to be able to bioaccumulate astacene to the same extent as astaxanthin. While the occurrence of astacene may be the result of oxidation during the analysis, these results show that its occurrence may also be the result of bio-accumulation. No other pigments than astacene, echinenone and canthaxanthin were isolated from Artemia fed astacene.