Hyperplastic and hypertrophic growth of lateral muscle in blackspot seabream Pagellus bogaraveo from hatching to juvenile

Abstract

To understand better the growth mechanisms in the economically important fish Pagellus bogaraveo, in terms of muscle fibre hyperplasia v. hypertrophy, the lateral muscle of this fish was studied morphometrically from hatching to juvenile comparing rostral and caudal locations. Fish were sampled at 0, 5, 23, 40, 70, 100, 140 and 180 days. Fibre types were first identified by succinate dehydrogenase (SDH) and immunostaining with a polyclonal antibody against fish slow myosin (4-96). Morphometric variables were then measured in transverse body sections, at both post-opercular and post-anal locations, to estimate the following variables: total muscle area [A (muscle)], total fibre number [N (fibres)], fibre number per unit area of muscle [N(A)(fibres, muscle)] and cross-sectional fibre area [a (fibres)] of the two main muscle fibre types (white and red). Overall, growth throughout the various stages resulted from increases both in the number and in the size of muscle fibres, paralleled by an expansion of the [A (muscle)]. Nonetheless, that increase was not significant between 0-5 days on one hand and 100-140 days, on the other hand. On the contrary, the [N(A)(fibres, muscle)] declined as the body length increased. Analysis of the muscle growth kinetics suggested that, within the important time frame studied, hyperplasia gave the main relative contribution to the increase of white muscle [A (white muscle)], whereas red muscle [A (red muscle)] mainly grew by hypertrophy, with both phenomena occurring at a faster pace posteriorly in the body. Finally, when comparing rostral and caudal locations, a greater [N (fibres)] and [A (muscle)] of the posterior white and red fibres were the consistent features. It was also observed that the proportion of the cross-sectional area of the myotomal muscle comprised of white muscle was greater in the anterior part of the fish.

Morphological and morphometric analysis of skeletal muscle between male and female young adult Colossoma macropomum (Characiformes: Serrasalmidae)

“…For example, in adult rabbits muscle growth is due the hypertrophy process on white fibers (Dal Pai & Curi, 1992); in contrast, muscle growth in fish at juvenile and young-adult stages is by hyperplastic process (Stickland, 1983;Rowlerson & Veggetti, 2001). The contribution of hyperplasia to muscle growth in tambaqui described here is in accordance with results of morphometric studies carried out in the same and related species (Dal Pai et al, 2000;Silva et al, 2009;Alves-Costa et al, 2013). Appearance of "mosaic fibers" observed in the tambaqui muscle resulted from the growth by hyperplasia, increase of fiber numbers, which occurs mainly during the juvenile phase in species that reach large final size.…”

Different dietary protein levels affect meagre ( Argyrosomus regius ) larval survival and muscle cellularity

“…Similarly to other fish species, meagre shows a mosaic distribution of fibres of different areas (Alami-Durante et al, 1997;Galloway et al, 1999;López-Albors et al, 2003;Aguiar et al, 2005;Silva et al, 2009b). This is commonly observed when studying white muscle of fish species (Johnston et al, 1998(Johnston et al, , 2002Aguiar et al, 2005;Valente et al, 2013).…”

“…The second fibre class might represent a fibre boom which had occurred in an earlier larval stage, especially because most fibres are smaller than 150 μm 2 . After an initial high rate of hyperplasia a decrease is often observed as fish size increases (Alami-Durante et al, 1997;Silva et al, 2009b) and that could explain why the frequency of fibres in the first class was approximately 13% in both groups. The mean fibre area obtained for meagre is consistent to the area reported for P. bogaraveo (Silva et al, 2009b) and carp (Alami-Durante et al, 1997) for larvae of similar sizes.…”

Morphological analysis and muscle-associated gene expression during different muscle growth phases of Megalobrama amblycephala

“…Compared to red muscle, white muscle tissue had significantly larger areas with fibers suggesting that white muscle growth was the principal contributor to overall muscle growth. In Pagellus bogaraveo, hyperplasia is mainly responsible for the increase in white muscle areas at 70 to 100 dph (Silva et al, 2009);by contrast, in M. amblycephala, hypertrophy was the main contributor during the analogous growth phases, while red muscle also increased as a result of hypertrophy (Silva et al, 2009;Chang et al, 2012).…”