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

Abstract

This study aimed to evaluate muscle organization in tambaqui in order to describe the muscle growth process. We analyzed the morphometric pattern of fibers from white muscle of young-adults (300 days) by smaller diameter. The organization of white muscle exhibited a typical morphological pattern found in other fish species. Heavier animals showed higher frequency of larger diameter fibers (>50 μm) and smaller animals had higher frequency of smaller diameter fibers (<20 μm) (P=0.005). However, both animals showed the same frequency of intermediate diameter fibers (20-50 μm). Body weight showed a positive correlation with muscle diameter fiber (r=0.45), being 20-50 μm the diameters that contributed the most to animal weight (P <0.0001). A weak correlation between fiber diameter and animal sex was observed (r=0.2). Females showed higher frequency of large fiber diameters (>50 μm) than males. However, there was no difference between body weight and sex (P=0.8). Our results suggest that muscle growth is by hypertrophy and hyperplasia due to a mosaic appearance from different diameters fibers, which is characteristic of large size fish species.O objetivo deste trabalho foi avaliar a organização muscular em tambaqui, a fim de descrever o processo de crescimento muscular. Foi analisado o padrão morfométrico das fibras do músculo branco de animais com 300 dias de idade usando o método de diâmetro menor. O músculo branco apresentou uma organização morfológica padrão encontrado em peixes. Animais de maior peso apresentaram maior frequência de fibras de maior diâmetro (> 50 μm) e os animais de menor peso apresentaram maior frequência de fibras de menor diâmetro (<20 μm) (P = 0,005). Entretanto, ambos os animais, com maior e menor peso, apresentaram frequências semelhantes de fibras de diâmetro intermediário (20-50 μm). O parâmetro peso corporal mostrou correlação positiva com o diâmetro da fibra muscular (r = 0,45), sendo as fibras de diâmetro intermediários (20-50 μm) que mais contribuíram para o peso do animal (P <0,0001). Fêmeas apresentaram maior frequência de fibras de maior diâmetro (>50 μm) que machos. Observou-se uma fraca correlação entre o diâmetro da fibra e o sexo dos animais (r = 0,2). Apesar de fraca, a correlação estimada é corroborada pela fibras de grandes diâmetros (> 50 μm) serem mais frequente nas fêmeas que nos machos. No entanto, não houve diferença entre o peso corporal dos animais aos 300 dias de idade e sexo (P = 0,8). Os resultados encontrados sugerem que o crescimento muscular ocorre por hipertrofia e hiperplasia, caracterizado pela aparência em mosaico de fibras de diferentes diâmetros, característico de peixes de grande tamanho.

Carcass Weight and Skeletal Muscle Microscopic Structure of Red Nile Tilapia (Oreochromis niloticus) in The Different Aeration and Filtration

“…As long as the fish is still in the larval stage then hyperplastic dominates for growth and if the fish has reached the juvenile to adult stage then hypertrophy changes which will dominate the growth of the fish. Research conducted by De Mello et al (2016) showed that there is a positive relationship between muscle fiber diameter and body weight. The increase in the size of the diameter of the muscle fibers is related to the increasing number of muscle fibers.…”

Estimation of the gill respiratory surface area and some features of the red muscle fibers in two teleost species

“…Muscle growth is associated with the recruitments of new fibers (hyperplasia) and/or the increase in the volume of muscle fibers (hypertrophy), such that the muscle may contain fibers with a wide range of diameters, the red muscle fibers usually are small in diameter (25-45 µm) (Kiessling et al, 2006;De Mello et al, 2016).…”