What determines growth potential and juvenile quality of farmed fish species?

Abstract

Enhanced production of high quality and healthy fry is a key target for a successful and competitive expansion of the aquaculture industry. Although large quantities of fish larvae are produced, survival rates are often low or highly variable and growth potential is in most cases not fully exploited, indicating significant gaps in our knowledge concerning optimal nutritional and culture conditions. Understanding the mechanisms that control early development and muscle growth are critical for the identification of time windows in development that introduce growth variation, and improve the viability and quality of juveniles. This literature review of the current state of knowledge aims to provide a framework for a better understanding of fish skeletal muscle ontogeny, and its impact on larval and juvenile quality as broadly defined. It focuses on fundamental biological knowledge relevant to larval phenotype and quality and, in particular, on the factors affecting the development of skeletal muscle. It also discusses the available methodologies to assess growth and larvae/juvenile quality, identifies gaps in knowledge and suggests future research directions. The focus is primarily on the major farmed non-salmonid fish species in Europe that include gilthead sea bream, European sea bass, turbot, Atlantic cod, Senegalese sole and Atlantic halibut.

Effects of sea horse (Hippocampus abdominalis)-derived protein hydrolysate on skeletal muscle development

“…Physical exercise increases protein synthesis and energy efficiency in the body, therefore analysis of the primary MRFs such as Myf5 and MyoD involved in cell proliferation and secondary MRFs such as Myogenin (Myo G) and Mrf4, responsible for myotube formation can be used to evaluate the effect of exercise on muscle growth (Valente et al 2013). In addition, analysis of AMPK-expression is one of the primary indicators of ATP production due to energy expenditure by a process termed mitochondrial biogenesis (Richter and Ruderman 2009).…”

Alteration in expression of atrogenes and IGF-1 induced by fasting in Nile tilapia Oreochromis niloticus juveniles

“…Hyperplasia was evident within the first week of the experiment by the observation of several small fibers with central nuclei. This morphological feature characterizes skeletal muscle development in mosaic hyperplasia, with small fibers containing central nuclei surrounding big fibers throughout the myotome (Johnston et al 2003;Johnston and Hall 2004;Johnston et al 2008;Steinbacher et al 2007;Valente et al 2013). However, after 10 weeks of refeeding the growth pattern changed, with increasing the frequencies of muscle fibers in the [ 50 lm diameter classes and decreasing the frequencies in the 10 and 30 diameter classes.…”

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“…In myogenesis two types of hyperplasia can be distinguished: stratified hyperplasia (SH), and mosaic hyperplasia (MH) (Johnston et al, 2011). SH, the step of myogenesis occurring after myoblast fusion is observed during embryogenesis, and shortly after hatching (Steinbacher, Haslett, Sänger & Stoiber, 2006;Valente et al, 2013). MH, a step following SH, is characterized by presence of muscle fibers of various sizes (Rescan, 2005;Johnston et al, 2011).…”

“…Growth is a quantitative trait, under polygenic control, with the most important influence on the somatotropic axis and myogenic transforming growth factor superfamily (Valente et al, 2013;Yue, 2013). Identification of the major quantitative trait loci (QTLs) or genes affecting growth is performed usually by linkage map construction and QTL mapping or in association studies and candidate gene approaches (De-Santis & Jerry, 2007;Yue, 2013).…”

“…Therefore, it is essential to recognize the most important causes of this phenomenon, to minimalize the differences in growth rate. Main factors affecting fish growth described so far are: environmental conditions (Szczepkowski, Szczepkowska & Piotrowska, 2011), exercise training (Martin & Johnston, 2006), diet, including quality and availability of food (Ostaszewska, Dąbrowski, Wegner & Krawiec, 2008;Kamaszewski, Prasek, Ostaszewska & Dąbrowski, 2014) and genetic background (Valente et al, 2013).…”