Biochemical composition and digestive enzyme activities during the embryonic development of the redclaw crayfish, Cherax quadricarinatus

Abstract

The biochemical composition and the activity of five digestive enzymes of embryos were studied during embryonic development in the redclaw crayfish, Cherax quadricarinatus (Von Martens, 1868), in order to investigate the relationship between embryonic development and the utilization of yolk. Carbohydrates remained a minor constituent of the yolk as a whole. The contents of total proteins and total amino acids (TAA) were all observed to decrease. Among the essential amino acids (EAA), the contents of leucine and arginine were relatively high, while of the non-essential amino acids (NEAA), the most important components were glutamine and aspartic acid. The contents of total lipids (TL) decreased during embryonic development, and the predominant fatty acids of both neutral lipids (NL) and polar lipids (PL) were C16:0, C18:0, C18:1ω9, and C18:3ω3. The five digestive enzymes tested all showed changes in their activities. The specific activities of pepsin and trypsin gradually increased in the earlier stages of embryonic development, pepsin decreased rapidly in later stages, while trypsin still kept a high level of activity. The specific activity of amylase changed in a "V" shape and reached high values again in later stages. The specific activities of cellulase and lipase showed relatively low values. It is shown that carbohydrates may play an important role in synthesizing many specific compounds to participate in signal transmission and in forming the carapace. Proteins and lipids were the dominating construction and energy substances; proteins were primarily consumed in the early stages, as against lipids in later stages. Saturated fatty acids (SFA) (16:0 and 18:0) and monounsaturated fatty acids (MUFA) (16:1ω7 and 18:1ω9) were always used for energetic purposes and polyunsaturated fatty acids (PUFA) (20:5ω3 and 22:6ω3) were important as structural components of cell membranes and in the development of the central nervous system. The activities of the digestive enzymes were controlled by their genes and expressed sequentially during embryonic development. They hydrolyse the yolk and provide construction substances and energy sources for the formation of tissues, organs, and various systems in general. 3 ) RÉSUMÉ La composition biochimique et l'activité de cinq enzymes digestives d'embryons ont été étudiées au cours du développement embryonnaire de l'écrevisse à patte rouge, Cherax quadricarinatus (Von Martens, 1868), dans le but d'investiguer les inter-relations entre le développement embryonnaire et l'utilisation du vitellus. Les glucides représentent un constituant mineur du vitellus. Les contenus en protéines totales et en acides aminés totaux (TAA) diminuent. Parmi les AA essentiels (EAA), les contenus en leucine et arginine ont été relativement élevés, tandis que parmi les acides aminés non-essentiels (NEAA), les composés les plus importants ont été la glutamine et l'acide aspartique. Les contenus en lipides totaux (TL) diminuent au cours du développement embryonnaire, et les acides gras prédominants parmi, à...

Biochemical changes during vitellogenesis in the red claw crayfish,Cherax quadricarinatus(von Martens)

“…The small scale and the cost of spawning and feeding are the main limitations in redclaw production in China. In addition, the conditions in hatcheries producing the juveniles limit the industrialization of redclaw production (Luo, Zhao & Yao 2008). As these crayfish grow, their feeding habits change to a dietary preference for plant material (Figueiredo & Anderson 2003).…”

“…For example, evaluation of amino acid and fatty acid composition during vitellogenesis provides information about gonadal performance, nutrient flow and use of nutritional reserves during vitellogenesis (Cheng, Du & Lai 1998; Cavalli, Lavens & Sorgeloos 1999; Wen et al 2001). As the physiological and nutritional status of the female determines the biochemical composition of eggs and the success of embryonic development (García‐Guerrero et al 2003; Luo et al 2008), evaluation of this biochemical composition will be helpful in understanding the nutritional requirements of the female redclaw during vitellogenesis, as well as in improving the spawning rate and reducing feeding costs.…”

Biofloc contribution to antioxidant defence status, lipid nutrition and reproductive performance of broodstock of the shrimp Litopenaeus stylirostris: Consequences for the quality of eggs and larvae

“…The prime factors that could cause differences in reproductive performance and the success of embryonic development are the physiological and nutritional status of the female Luo et al, 2008). Moreover, the relationship between broodstock and offspring quality is often suspected insofar as the vitellus of penaeid shrimp eggs must entirely support the development of the embryo and the first larval stages (nauplius) until molting into a "first-feeding" larvae (Zoe1) (Harrison, 1990).…”

Treatise on Zoology - Anatomy, Taxonomy, Biology. The Crustacea, Volume 9 Part A

“…Despite this luminal connection, the main digestive tract is apparently not involved in yolk digestion of late embryos and the first postembryonic life stages. Its breakdown is rather accomplished by the yolk sac epithelium that seems to secrete the necessary enzymes, first of all trypsin (Luo et al, 2008). Thus, digestion of yolk in the yolk sac and digestion of food in the digestive tract can occur concomitantly, which facilitates transition from endogenous to exogenous feeding in crayfish.…”