What is osphradium and its significance?
Definition of osphradium : a single or paired sense organ connected with one of the visceral ganglia and situated near the gill of most aquatic mollusks that is supposed to be olfactory or to test the purity of the water passing to the gills.
What is the mantle used for?
The mantle is highly muscular. In cephalopods the contraction of the mantle is used to force water through a tubular siphon, the hyponome, and this propels the animal very rapidly through the water. In gastropods it is used as a kind of “foot” for locomotion over the surface.
What is the function of the Ospharidium in Buccinum Undatum?
Carnivorous snails, such as the common whelk (Buccinum undatum), use their osphradium to find prey.
In which animal osphradium is found?
mollusks
mollusks. …a chemoreceptive sense organ (the osphradium) monitors the water currents entering the mantle cavity. This organ has regressed in scaphopods, some cephalopods, and some gastropods.
What is Statocyst in zoology?
The statocyst is a balance sensory receptor present in some aquatic invertebrates, including bivalves, cnidarians, ctenophorans, echinoderms, cephalopods, and crustaceans. The statocyst consists of a sac-like structure containing a mineralised mass (statolith) and numerous innervated sensory hairs (setae).
Where is the location of osphradium?
The osphradium is located in the mantle cavity, usually where the water passes to the branchial organs. It is well developed in some gastropod mollusks, in which it apparently serves as an olfactory organ.
What happens in mantle?
The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant), whereas in areas that are cooler it sink down. This convection takes place in mantle rock (a mixture of silicate minerals) that at any given time would appear solid to us.
What is mantle in geography?
The mantle is the mostly-solid bulk of Earth’s interior. The mantle lies between Earth’s dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up a whopping 84% of Earth’s total volume.
How does the snail sense its environment?
Land snails, such as Helix, sense the environment using two pairs of tentacles. A simple eye is located at the end of each of the longer tentacles. These eyes are able to detect shadows and movement. The shorter pair of tentacles is used for smell and touch.
What organ does the snail use to detect if something to eat is nearby?
In terrestrial gastropods the most important sensory organs are the olfactory organs which are located on the tips of the 4 tentacles. Some terrestrial gastropods can track the odor of food using their tentacles (tropotaxis) and the wind (anemotaxis).
What is statocyst function?
The statocyst is responsible for balance and such reactions as rising to the surface of the water or sinking.
Is statocyst present in Arthropoda?
Complete answer: Statocysts are found in organisms belonging to the phylum Arthropoda and Mollusca. These are also known as lithocysts and are related to equilibrium and balance.
What is the main function of the osphradium?
The main function of this organ is disputed but it is believed to be used to test incoming water for silt and possible food particles or, in some species, for sensing the presence of light. It is a popular idea among malacologists that the presence of an osphradium should be a molluscan synapomorphy.
Where is the osphradium located in a mollusc?
The osphradium is a pigmented chemosensory epithelium patch in the mantle cavity present in six of the eight extant classes of molluscs (it is absent in the scaphopoda and monoplacophora; among cephalopoda, only the nautilus has what appears to be a set of osphradia), on or adjacent to the ctenidia (gills).
What is the function of the osphradium in a cone snail?
Osphradium. The main function of this organ is thought to be to test incoming water for silt and possible food particles. The organ is present in all members of the genus Conus, the cone snails, a group of predatory sea snails . It is a popular idea among malacologists that the presence of an osphradium should be a molluscan synapomorphy.
Is the osphradium absent in monoplacophorans and scaphopods?
However, an osphradium is absent in monoplacophorans and scaphopods. Moreover, the differences in enervation of these patches suggest that the osphradium (as a patch enervated from the ctenidial nerve) may be different from another organ sometimes called the posterior sensory organ (PSO) with separate enervation from the lateral nerve cords.