What is the function of Ostia in sponges?
All sponges have ostia, channels leading to the interior through the mesohyl, and in most sponges these are controlled by tube-like porocytes that form closable inlet valves.
What is the function of Ostia and osculum?
Ostia are tiny pores present all over the body of sponges. its function is to let the water, along with desire nutrient flows interior of the sponges.Osculum is a excretory structure opening to the outside through which current of water exist after passing through the spongocoel. [ - ]
What is the structure of sponges in Porifera?
Sponges: Description and Structure | Phylum Porifera. 1 1. Spongocoel: At the free end of a branch, a fairly large aperture known as osculum is present. Osculum leads internally into a canal, the ... 2 2. Incurrent Canal: 3 3. Radial Canal: 4 4. Ex-Current Canal:
What are the histological elements of sponges?
Histological Elements Constituting the Wall of Sponges: The different microscopic elements constituting the body wall of Scypha are known as histological elements. The elements may be divided into three groups—cell elements, skeletal elements and mesenchymal substance (Figs. 19.3-19.6). 1.
What are Ostia of a sponge and its function?
Scattered among the pinacoderm are the ostia that allow entry of water into the body of the sponge. These pores have given the sponges their phylum name Porifera—pore-bearers. In some sponges, ostia are formed by porocytes, single tube-shaped cells that act as valves to regulate the flow of water into the spongocoel.
What is the function of the Ostia?
Ostia are small, slit-like, paired openings in the dorsal vessel that allow hemolymph to enter or leave the vessel. Incurrent ostia allow hemolymph to enter during diastole and excurrent ones permit hemolymph to exit.
What is an Ostia in biology?
ostium. / (ˈɒstɪəm) / noun plural -tia (-tɪə) biology. any of the pores in sponges through which water enters the body. any of the openings in the heart of an arthropod through which blood enters.
What called Ostia?
Ostia are the inhalant pores in the body of sponges. Water enters the body of sponges through ostia and reaches the spongocoel. It then flows out of the body through osculum. Ostia is present only in sponges i.e. phylum Porifera as sponges have a porous body. So, the correct answer is 'Porifera'.
What are Pinacocytes in sponges?
Pinacocytes. These cells are the "skin cells" of sponges. They line the exterior of the sponge body wall. They are thin, leathery and tightly packed together.
What animals have Ostia?
Ostia are minute pores present in the body wall of Sponges (Phylum – Porifera), through which water enters into a central cavity, spongocoel, from where it goes out through the osculum. This pathway of water transport is helpful in food gathering, respiratory exchange and removal of waste.Aug 9, 2011
Where do we find Ostia?
Ostia, modern Ostia Antica, seaport of ancient Rome, originally on the Mediterranean coast at the mouth of the Tiber River but now, because of the natural growth of the river delta, about 4 miles (6 km) upstream, southwest of the modern city of Rome, Italy.
What is the function of Ostia and osculum?
Answer: Ostia are tiny pores present all over the body of sponges. its function is to let the water, along with desire nutrient flows interior of the sponges. Osculum is a excretory structure opening to the outside through which current of water exist after passing through the spongocoel.Aug 6, 2015
What are pinacocytes and choanocytes?
Choanocytes are body cells of sponges and pinacocytes are flat shaped cells that make up the pinacoderm of sponges. The key difference between choanocytes and pinacocytes is that choanocytes contain flagella while pinacocytes do not contain flagella.May 7, 2018
What is Porocyte function?
In the Calcarea, the outer surface of the body also contains flattened granular cells called porocytes because they contain the pores needed to allow water into the sponge. The porocytes can contract, thus closing the pores during unfavourable environmental conditions.
What is the function of the osculum in a sponge?
The osculum (plural "oscula") is an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel. Wastes diffuse into the water and the water is pumped through the osculum carrying away with it the sponge's wastes.
What is a sponge?
A sponge is a tool or cleaning aid made of soft, porous material. Typically used for cleaning impervious surfaces, sponges are especially good at absorbing water and water-based solutions.
What are the structural elements found in sponges?
Spicules are structural elements found in most sponges. They provide structural support and deter predators. Large spiculesthat are visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres.
Do sponges have organs?
Sponges don't have internal organs. They don't have muscles, a nervous system, or a circulatory system. Their walls are lined with many small pores called ostia that allow water flow into the sponge. Sponges are able to get microorganisms such as algae and bacteria for food through openings.
What is a calcareous sponge?
a. Calcareous sponges; skeleton solely of calcareous spicules which may be one, three or four-rayed and not distinguishable into mega-and microscleres.
What are the cells of the dermal layer covering the outer surface of the sponge called?
The cells of the dermal layer covering the outer surface of the sponge are known as pinacocytes.
Why is the Monaxon bristly?
Due to protrusion of numerous monaxon spicules from the surface, it appears bristly.
Why are sponges beneficial?
Sponges are mostly beneficial to man. Skeleton of some sponges are used to manufacture commercial sponge, which is of great economic importance. The sponging skeleton is treated with hydrochloric acid and the spicules dissolve.
How deep do Sponges live?
They grow mainly in shallow waters but their habitat may extend up to a depth of 5,600 metres. Sponges are of varying shapes, sizes and colours. They are distinct from the Protozoa in having a cellular construction but the cellular grade is at the lowest.
What is a sponge used for?
Sponges are extensively used in bath rooms, laboratories and in surgical operations.
What is the canal system in a sponge called?
All the canals are collectively called canal system. The canal system in Scypjia (Sycon) is known as syconoid type. It establishes a continuous passage for the inflow and outflow of water within the body of a sponge (Fig. 19.2).
What is the body of a sponge?
A sponge's body is hollow and is held in shape by the mesohyl, a jelly-like substance made mainly of collagen and reinforced by a dense network of fibers also made of collagen. The inner surface is covered with choanocytes, cells with cylindrical or conical collars surrounding one flagellum per choanocyte. The wave-like motion of the whip-like flagella drives water through the sponge's body. All sponges have ostia, channels leading to the interior through the mesohyl, and in most sponges these are controlled by tube-like porocytes that form closable inlet valves. Pinacocytes, plate-like cells, form a single-layered external skin over all other parts of the mesohyl that are not covered by choanocytes, and the pinacocytes also digest food particles that are too large to enter the ostia, while those at the base of the animal are responsible for anchoring it.
What is the skeleton of a sponge?
Skeleton. In zoology a skeleton is any fairly rigid structure of an animal, irrespective of whether it has joints and irrespective of whether it is biomineralized. The mesohyl functions as an endoskeleton in most sponges, and is the only skeleton in soft sponges that encrust hard surfaces such as rocks.
What are the functions of sponges?
They filter food particles out of the water flowing through them. Particles larger than 50 micrometers cannot enter the ostia and pinacocytes consume them by phagocytosis (engulfing and intracellular digestion). Particles from 0.5 μm to 50 μm are trapped in the ostia, which taper from the outer to inner ends. These particles are consumed by pinacocytes or by archaeocytes which partially extrude themselves through the walls of the ostia. Bacteria-sized particles, below 0.5 micrometers, pass through the ostia and are caught and consumed by choanocytes. Since the smallest particles are by far the most common, choanocytes typically capture 80% of a sponge's food supply. Archaeocytes transport food packaged in vesicles from cells that directly digest food to those that do not. At least one species of sponge has internal fibers that function as tracks for use by nutrient-carrying archaeocytes, and these tracks also move inert objects.
How do sponges produce sperm?
Sperm are produced by choanocytes or entire choanocyte chambers that sink into the mesohyl and form spermatic cysts while eggs are formed by transformation of archeocytes, or of choanocytes in some species. Each egg generally acquires a yolk by consuming "nurse cells". During spawning, sperm burst out of their cysts and are expelled via the osculum. If they contact another sponge of the same species, the water flow carries them to choanocytes that engulf them but, instead of digesting them, metamorphose to an ameboid form and carry the sperm through the mesohyl to eggs, which in most cases engulf the carrier and its cargo.
How do sponges reproduce?
Sponges have three asexual methods of reproduction: after fragmentation; by budding; and by producing gemmules. Fragments of sponges may be detached by currents or waves. They use the mobility of their pinacocytes and choanocytes and reshaping of the mesohyl to re-attach themselves to a suitable surface and then rebuild themselves as small but functional sponges over the course of several days. The same capabilities enable sponges that have been squeezed through a fine cloth to regenerate. A sponge fragment can only regenerate if it contains both collencytes to produce mesohyl and archeocytes to produce all the other cell types. A very few species reproduce by budding.
How fast can a sponge move?
Although adult sponges are fundamentally sessile animals, some marine and freshwater species can move across the sea bed at speeds of 1–4 mm (0.039–0.157 in) per day , as a result of amoeba -like movements of pinacocytes and other cells.
What are the different types of sponges?
Included are the yellow tube sponge, Aplysina fistularis, the purple vase sponge, Niphates digitalis, the red encrusting sponge, Spirastrella coccinea [ nl], and the gray rope sponge, Callyspongia sp. Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells.
Which category of body organization is the largest and most complex sponge?
The third category of body organization is leuconoid. These are the largest and most complex sponges. These sponges are made up of masses of tissue penetrated by numerous canals. Canals lead to numerous small chambers lined with flagellated cells.
What class are sponges in?
Sponges in the class Calcarea, considered to be the most primative group, and have asconoid, synconoid and leuconoid members. The Hexactinellida and Demospongiae groups have only leuconoid forms. Sponges are found in virtually all aquatic habitats, although they are most common and diverse in the marine environment.
What are the different types of sponges?
Sponges have three different types of body plans, although these morphologies do not define taxonomic groups. Asconoid sponges are shaped like a simple tube perforated by pores. The open internal part of the tube is called the spongocoel; it contains the collar cells. There is a single opening to the outside, the osculum. Syconoid sponges tend to be larger than asconoids and have a tubular body with a single osculum. The synconoid body wall is thicker and the pores that penetrate it are longer, forming a system of simple canals. These canals are lined by collar cells, the flagellae of which move water from the outside, into the spongocoel and out the osculum. The third category of body organization is leuconoid. These are the largest and most complex sponges. These sponges are made up of masses of tissue penetrated by numerous canals. Canals lead to numerous small chambers lined with flagellated cells. Water moves through the canals, into these chambers, and out via a central canal and osculum. Sponges in the class Calcarea, considered to be the most primative group, and have asconoid, synconoid and leuconoid members. The Hexactinellida and Demospongiae groups have only leuconoid forms.
How do sponges reproduce?
Reproduction by sponges is by both sexual and asexual means. Asexual reproduction is by means of external buds. Some species also form internal buds, called gemmules, which can survive extremely unfavorable conditions that cause the rest of the sponge to die. Sexual reproduction takes place in the mesohyl. Male gametes are released into the water by a sponge and taken into the pore systems of its neighbors in the same way as food items. Spermatozoa are "captured" by collar cells, which then lose their collars and transform into specialized, amoeba-like cells that carry the spermatozoa to the eggs. Some sponges are monoecious; others are dioecious. In most sponges for which developmental patterns are known, the fertilized egg develops into a blastula, which is released into the water (in some species, release takes place right after fertilization; in others, it is delayed and some development takes place within the parent). The larvae may settle directly and transform into adult sponges, or they may be planktonic for a time. Adult sponges are generally assumed to be completely sessile, but a few studies have shown that adult sponges in a variety of species can crawl slowly (Bond and Harris 1988).
How many species of sponges are there?
Sponges are a diverse group of sometimes common types, with about 5000 species known across the world. Sponges are primarily marine, but around 150 species live in fresh water. Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, ...
What are the characteristics of a sponge?
Sponges are either radially symmetrical or asymmetrical.
Do sponges eat coral?
The corals or molluscs are not eaten; rather, the sponge is probably seeking protection for itself by sinking into the hard structures it erodes. Even this process has some beneficial effects, however, in that it is an important part of the process by which calcium is recycled. Sources: Brusca, R. C., and G. J. Brusca.
