Muscles of Lower Animals

The muscles of all animals, from flatworms to humans, are similar in that they are all composed of long cylindrical or spindle-shaped fibers that are capable of contraction due to their protein chains. Even coelenterates, which lack true muscle fibers, have cells that can contract. But there are, however, some differences.

For example, most invertebrates have only smooth muscles, whereas arthropods have only striated muscles. All types of muscle contraction involve electrical phenomena, but some animals, such as the electric eel, have developed specialized muscle cells in which contraction is minimized and electrical generation is maximized. The “electric organ” of such an eel can create a potential of 400 V or higher, sufficient to stun or kill the fish on which the eel feeds, or inflict a very sensitive blow on a person.

Related links:

1. Article "Structure and physiology of muscle tissue" - https://studme.org/133512/biologiya/stroenie_fiziologiya_myshechnoy_tkani

2. Article "Muscular system of invertebrate animals" - https://studfiles.net/preview/2489799/

3. Article "Electric organs of fish" - https://biomolecula.ru/articles/elektricheskie-organy-ryb