Digestive enzymes and in-vitro digestibility of different species of phytoplankton for culture of the freshwater pearl mussel, Hyriopsis (Hyriopsis) bialatus

Abstract

Hyriopsis (Hyriopsis) bialatus has been cultured during the mussel life cycle from glochidia to the adult stage with a low total survival of 6% up to 130-day-old juveniles. The main digestive enzymes (amylase and proteinases) were not detectable in one-day-old juveniles, and increased during development. The stomach, including digestive glands, was the major digestive organ for both carbohydrate and protein. The optimum conditions for amylase activity were 40°C and pH 7; for acidic proteinases they were 60°C and pH 5. Two main alkaline proteinases were found in the intestine, with optimum conditions of 30°C and pH 8 and 60°C and pH 8. To improve mussel survival by finding suitable phytoplankton species and age as food for juveniles and adults, an in-vitro digestibility test was performed on ten algal species three and seven days old using amylase and proteinases in crude enzyme extracts from different mussel life stages. Among the phytoplankton selected, the three most efficiently digested by juveniles were sevenday-old Chlorella sp.2, seven-day-old Chlorococcum sp. and seven-day-old Kirchneriella incurvata, in the ratio 1:1:3 for 30-day-old juveniles and 3:1:1 for 130-day-old juveniles. For the adult mussel, three-day-old Chlorella sp.2, seven-day-old Coccomyxa sp., and seven-day-old Monoraphidium sp., in the ratio 3:1:1, were the most digestible phytoplankton. Levels of in-vitro digestibility were related to the quality (not the concentrations) of carbohydrate and protein in the phytoplankton mixtures, and protein digestibility seemed to be the key factor determining food quality for the mussel.

Different Dietary Levels of Protein to Lipid Ratio Affected Digestive Efficiency, Skeletal Growth, and Muscle Protein in Rainbow Trout Families

“…Our results suggest the association between the diet dependent in vitro protein digestibility value and protein growth in fish, whereas the T/C ratio is associated with fish growth regardless of protein or lipid growth. In vitro digestibility by protein digestion is the key factor for diet quality, not only in carnivores but also in herbivores where carbohydrate digestion (the second important digestion factor in herbivores after protein digestion) is also related to dietary protein levels [19,20] while lipid digestion is not related to any diet quality [19]. A high protein diet may limit feed efficiency, weight, and growth rate of the fish, as they become mature.…”

“…[20,[28][29][30]. The protein concentration of the standards was determined using TRIzol reagent (Life Technologies, NY, USA) to obtain complete solubilisation of protein, as described in RungruangsakTorrissen [11] modified from Sunde et al [10,18].…”

“…The P/L ratio is important as both protein and lipid levels in the diets affect the levels of both protein and lipid in fish where the variations may not be observed if either protein or lipid level is studied alone. Although both protein and lipid deposition are important but the in vitro lipid digestibility was not determined because it has never been shown to associate with feed efficiency and the quality of the lipid itself [19], and in vitro protein digestibility is the key factor for feed quality even in the herbivore like mussel [19,20]. This work was designed to illustrate the effects of dietary P/L ratio levels on fish digestive ability and the quality of fish growth performance (condition factor and composition of P/L ratio in the body and white muscle) in families of rainbow trout with different growth capacities throughout the life history.…”

In Vitro Culture of Freshwater Pearl Mussel from Glochidia to Adult

“…The main differences concerned the composition of the commercial media M199. While the protein source was exclusively horse serum in Keller & Zam (1990) and common carp, Cyprinus carprio fish plasma was used as an alternative support to the medium for cultured glochidia of H. (L.) myersiana (Uthaiwan et al, 2002;Kovitvadhi et al, 2006Kovitvadhi et al, , 2007Kovitvadhi et al, , 2008Kovitvadhi et al, , 2009, Hyriopsis (Hyriopsis) bialatus (Areekijeree et al, 2006;Supannapong et al, 2008;Srakaew et al, 2010;Chumnanpuen et al, 2011;Kovitvadhi & Kovitvadhi., preparation), Chamberlainia hainesiana (Kovitvadhi et al, submitted) and Anodonta cygnea (Lima et al, 2006). Glochidia could transform into juvenile in the media containing common carp fish plasma as protein source.…”

“…Juvenile has been successfully cultured in the laboratory by attaching glochidia to fish until they could transform into the early juvenile stage (Fukuhara et al, 1990;Panha, 1992;Buddensiek, 1995;Uthaiwan et al, 2003;Hanlon & Neves, 2006). Furthermore, sterilized artificial media could be utilized for the culture of glochidia (to bypass the parasitic stage); the progress of this technique can be followed in a succession of reports by Isom & Hudson (1982, 1984a, Keller & Zam (1990), Uthaiwan et al (2001Uthaiwan et al ( , 2002, Kovitvadhi et al (2006Kovitvadhi et al ( , 2007Kovitvadhi et al ( , 2008Kovitvadhi et al ( , 2009, Areekijeree et al (2006), Lima et al (2006), Supannapong et al (2008), Srakaew et al (2010) and Chumnanpuen et al (2011). Moreover, some species of freshwater mussel glochidia cultured in artificial media could develop to adulthood as well as inducing gonadal development to sexual maturity and the marsupia could develop, namely Hyriopsis (Limnoscapha) myersiana , Chamberlainia hainesiana (Kovitvadhi et al, submitted) and Hyriopsis (Hyriopsis) bialatus (Kovitvadhi & Kovitvadhi., in preparation).…”