Is Protonephridia present in Amphioxus?
In Amphioxus, one above each gill slit on either side, there are 90 to 100 pairs of protonephridia present segmentally on the dorso-lateral pharyngeal wall. Simply, as structures, they are ciliated, thin walled, closed ectodermal tubules.
What is Protonephridia?
A protonephridium (proto = “first”) is a network of dead-end tubules lacking internal openings, found in the phyla Platyhelminthes, Nemertea, Rotifera and Chordata (lancelets). Protonephridia are generally found in basal organisms such as flatworms.
Which is the excretory organ of Amphioxus?
nephridium
Now, the excretory organ of Amphioxus is nephridium that has the similar function as that of kidney in vertebrates. This cell is found in pared form and expels the wastes from the body cavity to the exterior. Hence, the correct answer is ‘B’. Protonephridia.
What are the excretory organs of Branchiostoma?
The excretory organs of Branchiostoma include the nephridia, brown funnels and cells of the atrial wall. The main excretory organs of the Branchiostoma are so- called nephridia.
Is amphioxus a flatworm?
Is amphioxus a flatworm? Explanation: Protonephridia or flame cells are the excretory structures in Platyhelminthes (Flatworms, e.g., Planaria), rotifers, some annelids and the cephalochordate Amphioxus. Protonephridia are primarily concerned with ionic and fluid volume regulation, i.e., osmoregulation.
Do amphioxus have flame cells?
(a) Amphioxus is an example of a chordate that has flame cells as excretory structures. Flame cell is a type of excretory and osmoregulatory system.
What is difference between Protonephridia and Metanephridia?
The main difference between protonephridia and metanephridia is that protonephridia are a network of dead-end tubules without internal openings, whereas metanephridia are a type of excretory glands with a ciliated funnel opening into the body cavity.
Are Protonephridia cells?
Bundles of flame cells are called protonephridia. The flame cell has a nucleated cell body, with a “cup-shaped” projection, with flagella covering the inner surface of the cup.
What is the structure of amphioxus?
The excretory organs of Amphioxus occur as segmentally arranged structures throughout the pharyngeal region and may be divided into three components: the solenocytes, the renal tubule, and the renal glomerulus. The solenocytes possess foot processes that rest upon the coelomic surface of the ligamentum denticulatum.
What do you mean by amphioxus?
amphioxus, plural amphioxi, or amphioxuses, also called lancelet, any of certain members of the invertebrate subphylum Cephalochordata of the phylum Chordata. Amphioxi are small marine animals found widely in the coastal waters of the warmer parts of the world and less commonly in temperate waters.
What is brown funnel?
Brown Funnels: The narrow anterior end of each funnel opens into the epibranchial or dorsal coelomic canal of its side, while the broad posterior end opens into the atrium. Most zoologists consider the funnels to be excretory, while some regard them to be receptor organs.
Why is amphioxus not a vertebrate?
From the given organisms, the Amphioxus is a chordate but not a vertebrate. Amphioxus, commonly known as lancelet, is a marine fish like chordate that possesses a dorsal nerve cord which is not protected by bone but by a simple notochord made up of a cylindrical cell pattern, closely packed to form a toughened rod.
Where are the protonephridia located in the amphioxus?
They are similar to protonephridia of flat worms or polychaete, annelids and they are ectodermal in origin. In Amphioxus there are 90 to 100 pairs of protonephridia present segmentally on dorso-lateral pharyngeal wall one above each gill slit on either side. Simply, they are ciliated, thin walled, closed ectodermal tubules like structures.
What does amphioxus mean in terms of SlideShare?
Amphioxus (Branchiostoma) – Structure, Digestive system, Circulatory system, Sense organs and Protonephridia Amphioxus (Branchiostoma) – Structure, Digestive system, Circulatory system, Sense organs and Protonephridia Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Where are protonephridia found in a flatworm?
Protonephridia are generally found in basal organisms such as flatworms. Protonephridia likely first arose as a way to cope with a hypotonic environment by removing excess water from the organism (osmoregulation). Their use as excretory and ionoregulatory structures likely arose secondarily.
How are protonephridia and metanephridia related to each other?
Within the Bilateria metanephridia are strictly correlated to the existence of a coelom. Protonephridia on the other hand are the only functioning nephridial organs in acoelo mately organized animals. Nevertheless, we also find these organs in representatives of the Bilateria which possess simpl e or endothelialized body cavities (Tab. I)!.