Search results
Results from the WOW.Com Content Network
The sensory organs of bivalves are largely located on the posterior mantle margins. The organs are usually mechanoreceptors or chemoreceptors, in some cases located on short tentacles. The osphradium is a patch of sensory cells located below the posterior adductor muscle that may serve to taste the water or measure its turbidity.
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. Both types of sensory organs are found in the nautilus. [2]
Those bivalves that have siphons, have two of them. Not all bivalves have siphons however: those that live on or above the substrate, as is the case in scallops, oysters, etc., do not need them. Only those bivalves that burrow in sediment, and live buried in the sediment, need to use these tube-like structures. The function of these siphons is ...
Semper's organ; suprapedal gland; snail slime; sensory organs of gastropods. caryophyllidia; Hancock's organ; osphradium; rhinophore; nervous system of gastropods. euthyneury; streptoneury; torsion (gastropod) digestive system of gastropods. proboscis#Gastropods; radula; odontophore; hepatopancreas = digestive gland diverticulum (mollusc) style ...
Drawing of the statocyst system Statocysts (ss) and statolith (sl) inside the head of sea snail Gigantopelta chessoia. The statocyst is a balance sensory receptor present in some aquatic invertebrates, including bivalves, [1] cnidarians, [2] ctenophorans, [3] echinoderms, [4] cephalopods, [5] [6] crustaceans, [7] and gastropods, [8] A similar structure is also found in Xenoturbella. [9]
In some mollusks the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a locomotory organ. 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.
Fish can sense sound through their lateral lines and their otoliths (ears). Some fishes, such as some species of carp and herring, hear through their swim bladders. [9] Hearing is well-developed in carp, which have the Weberian organ, three specialized vertebral processes that transfer vibrations in the swim bladder to the inner ear.
The heads of vertebrates are complex structures, with distinct sense organs for sight, olfaction, and hearing, and a large, multi-lobed brain protected by a skull of bone or cartilage. [ citation needed ] Cephalochordates like the lancelet , a small fishlike animal with very little cephalization, are closely related to vertebrates but do not ...