Origin
Echinoderms, also known as starfish, were first discovered in the Cambrian period. The Somasteroidea were the first asterozoans discovered, and they share characteristics with both classes (Blowes et al. 327). Starfish fossils are uncommon, presumably because the animal’s complex skeletal elements differentiate as it decays. Since they are in the form of a star and live in the ocean with fish, they are called starfish. Due to being echinoderms rather than fish, their common name was changed to ‘sea star.’
Classification
The starfish has been known since ancient times, and the Greeks gave it the name ‘Aster,’ which means ‘a star.’ They are related to sand dollars, marine urchins, and sea cucumber, and belong to Echinodermata Phylum. Echinoderms can be present in almost any marine ecosystem and make up a significant portion of the biomass (Blowes et al. 340). Asteroidea is a genus of starfish named after Greek words ‘aster’ (star) and ‘eidos’ (shape).
Characteristics
Body Type
Most organisms’ body walls are often thought of as inert packing material serving as a framework for the more complex organ systems that it houses. However, recent biomechanics research has confirmed that an organism’s body wall is the main factor of its niche. It decides which motions, feeding strategies, and environments are accessible to the organism. The body walls’ collagen fibers are arranged in an orthogonal network. Ossicles and papulae can be found in the web’s voids. The orthogonal web provides dimensional stability while allowing for the shear needed for raytorsion (Blowes et al. 336). The ossicles and fibres work together to load the fibres in strain and expand the ossicles.
Organ Structures
A microscopic eye, known as an ocellus, is located at the end of each forearm and aids the animal in distinguishing between light and dark and tracking movement. Starfish organs are made up of calcium carbonate ossicles and fibres (Blowes et al. 338). The endoskeleton is composed of these components, which are externally represented as spines and granules. The mouth is found on the body’s underneath of the Echinodermata. The mouth leads into a cardiac stomach, which then progresses into a second, pyloric, stomach through a short esophagus. Each Echinoderms arm has two-pyloric caeca, large tubes that branch off the pyloric abdomen. A small intestine extends from the pyloric stomach’s outer portion to the anus in the upper body’s middle, where it opens. The anus on the aboral or abactinal side of the body excretes waste.
Form and Function
Starfish travel around the seafloor in pursuit of immobile or slow-moving prey, including clams and mussels. Starfish can squeeze into small spaces, making them effective at cracking mollusk shells. Many starfish have an odd way of digesting food in their system (Blowes et al. 325). The outer body includes a non-stick substance used to treat human inflammatory diseases, including arthritis and hay fever. The anti-bacterial and anti-viral properties of the non-stick material are achieved by deterring bacteria and viruses that trigger humans’ diseases.
Nutrition
The starfish has a rather unusual method of consuming nutrients. They eat mussels, clams, and small fish with their mouths on the underside of their bodies. Starfish tie their stomach around their prey and split the mussel or clamshells moderately. The bivalve’s stomach is then forced into the bivalve’s shell through its mouth. It digests the animal inside the shell there and then pulls its abdomen back into its own body (Blowes et al. 338). The starfish’s unusual feeding mechanism allows it to eat larger species than can fit into its tiny head.
Locomotion
Echinodermata need to move around, but they do not have a skeleton to do so. A starfish’s tube feet are the components that allow it to travel about on the ocean floor. Starfish have tube feet on the ventral side of their bodies. An ampulla, or tiny bulblike appendage, is located on the tube foot (Blowes et al. 341). This ampulla aims to force water into the tube foot, which extends as a result. The tube feet muscles compress them, allowing the starfish to step forward. As the tube feet travel, compounds are released to assist in their attachment to the concrete. It is as if they are gluing and ungluing themselves over a ground. Hence, starfish are quite incredible invertebrate species of the seafloor.
Reproduction
Starfish can reproduce both sexually and asexually, depending on whether they are male or female. Echinodermata cannot be both male and female at the same time, although they can sometimes change their gender. The gonopore allows fertilization to take place outside of the starfish in their natural habitat (Blowes et al. 330). Gametes are released into the water by both males and females. The embryos are incubated in the water and develop there until they can break free from the zooplankton. Some species can reproduce asexually by fragmentation, which usually involves a portion of the starfish’s arm being disconnected and evolving into an individual starfish. A starfish will only recover if a part of its central nerve ring is connected to the missing arm.
The Decision on Starfish
Sea stars are essential aquatic ecosystems leaders and are known for their unique regenerating features. These creatures have both an interesting appearance and a rather exciting body structure and characteristics. Besides, starfish are rather significant members of the marine world, and their removal from the environment could lead to disastrous effects for the ecosystem. Thus, it is important to protect this species and increase the public’s awareness of them.
Work Cited
Blowes, Liisa M., et al. “Body Wall Structure in the Starfish Asterias Rubens.” Journal of Anatomy, vol. 231, no. 3, 2017, pp. 325-341.