Myomere

A myomere (Greek: 'mys' meaning muscle, and 'meros' meaning part) is a serially repeated muscle segment found in chordates, particularly in fish, amphibians, and some other vertebrates. These muscle blocks are typically W-shaped or chevron-shaped and are separated by myosepta, connective tissue that provides attachment points for the muscle fibers. Myomeres are essential for locomotion, allowing for the lateral undulation or swimming motion characteristic of many aquatic species. Their arrangement and structure vary depending on the animal's body plan and lifestyle.

Myomere meaning with examples

• The streamlined body of the trout allows for efficient swimming, thanks to the coordinated contraction of its myomeres. Each myomere pulls against its adjacent segment, generating the lateral flexions necessary for propulsion. Observing the precise arrangement of the myomeres aids in understanding the biomechanics of fish movement and their adaptations to aquatic environments.
• During embryonic development, the myomeres of a frog tadpole are clearly visible through the translucent skin. These distinct muscle segments facilitate the early swimming behavior, allowing the tadpole to navigate its aquatic environment. Researchers often study the development of these myomeres to understand muscle differentiation and segmentation.
• Paleontologists study the fossilized myomeres of extinct fish to reconstruct their swimming styles. The shape and arrangement of the myomeres in the fossil record provide crucial clues about the animal's size, speed, and the environment it inhabited. This offers insights into the evolution of movement in vertebrates.
• In lampreys, the myomeres form simple, segmented blocks that contribute to their eel-like locomotion. The simple arrangement of their myomeres is a result of their primitive body plan, making them a vital animal in studying the evolution of these muscles in other vertebrates. This myomere structure is different from that of more derived fish.
• The study of myomere function in different fish species reveals variations related to their lifestyle. Fast-swimming predators have myomeres adapted for quick bursts of speed, while more sluggish bottom-dwellers have myomeres designed for prolonged, low-energy movements. This reveals the plasticity of myomeres in response to natural selection.