Chordata and Abstraction
What is Chordata and how does their locomotion and defense work?
- Chordates are a classification or Phylum of organisms that include organisms that are both vertebrates and invertebrates, but most commonly vertebrates. Chordates are classified by a flexible rod that supports the organism’s back, called a notochord. Chordates can also be invertebrates. There are two subcategories, or subphyla of chordates that include invertebrates. A type of invertebrate chordates is a tunicate, which are, in simplicity, marine chordates with tunics or coats. The other type is called a lancelet which are essentially marine, elongated, filter feeders. Now that that’s out of the way, let’s discuss movement and defense in the phylum of chordates. In the subphylum of lancelets, lancelets move by swimming as both larvae and adults are free swimming. Their notochord provides structural support in the lancelet, and likewise helps the lancelet swim rapidly without shortening or compressing itself. In addition, lancelets have body muscle cells that build up body muscle tissues which surround the lancelet’s organs, keeping everything in place. Hence, lancelets are known to defend themselves by swimming away, but adults can also bury themselves in the sand. In the subphylum of tunicates, tunicates move by swimming and using their notochord as tadpoles to move around. However, once tunicates attach to an object such as rocks, they remain sessile for the most part. Though they are sessile, they can still move by detaching from the object and reattaching. Tunicates are able to defend themselves because of their tunic, which acts as an extra exoskeleton. Last but not least are vertebrates. Vertebrates are classified as any chordate that is also equipped with a backbone. Types of vertebrate chordates include mammals, birds, reptiles, and amphibians. We as humans can be classified as vertebrate chordates. There are a variety of ways vertebrates can move. In mammals and amphibians, the use of legs or limbs to walk, and swimming for amphibians. In fish, swimming is the method of movement, and birds use their wings for flight, as well as legs to move. Along with the various ways to move, there are also multiple ways vertebrates are able to defend themselves. The first is the ability to flee, using the aforementioned method of movement. Vertebrates are able to sense danger by the sensory organs of eyes. Many vertebrates are also able to use their nasal systems to smell any danger. Furthermore, the central nervous system, which is prevalent in a majority of vertebrates, helps organisms to sense danger and quickly act upon danger in order to protect themselves.
