Which chordate structures are lost when a larval tunicate develops into the adult form?
https://www.britannica.com/animal/tunicate
To find the answer to your question, you can start by understanding the life cycle of a tunicate, also known as the sea squirt. Tunicates have both a larval and an adult form. In the larval stage, tunicates possess chordate characteristics similar to those found in most vertebrates. However, during metamorphosis into the adult form, some chordate structures are lost.
To identify the chordate structures lost during tunicate development, you can consult scientific literature or biology textbooks that discuss tunicate anatomy and development. By focusing on the transition from larvae to adults, you can gather relevant information about the changes in their anatomy throughout this process.
One of the primary chordate structures lost during tunicate development is the notochord. The notochord is a flexible rod-like structure running along the length of the body, found in the embryos of all chordates. In the adult tunicate, the notochord is absent or reduced to a vestigial remnant.
Additionally, tunicates lose other chordate features such as the dorsal nerve cord and pharyngeal gill slits. The dorsal nerve cord is a primitive nervous system structure that runs along the back of chordates, including humans. Tunicates retain a modified version of the dorsal nerve cord in their larval stage but lose it during metamorphosis into the adult form.
Pharyngeal gill slits, which are responsible for water filtration during feeding and respiration, are also lost in adult tunicates, except for the very early stages of development. These structures were vital for the larval tunicates, allowing them to feed and respire while swimming freely. However, as they transition into the adult sessile form, they become unnecessary and are eventually lost.
In conclusion, during the development of a larval tunicate into its adult form, it loses several chordate structures including the notochord, dorsal nerve cord, and pharyngeal gill slits.