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Dystenoid
A dystenoid nervous system is an arrangement of ganglia in the anterior region of some molluscs in which the cerebral and pleural ganglia are situated closer to each other than they are in those molluscs with the more archaic hypoathroid nervous system but still farther apart than those animals with an evolutionarily more recent epiathroid nervous system. Examples of animals having dystenoid systems include '' Macleaniella moskalevi'', '' Teuthirustria cancellata'', and '' Fedikofella caymanensis'' (weakly dystenoid in all three). These are deep sea limpets belonging to the superfamily Cocculinoidea The Cocculinoidea is a superfamily of deepwater limpets (marine gastropods), the only superfamily in the order Cocculinida , one of the main orders of gastropods according to the taxonomy as set up by ( Bouchet & Rocroi, 2005). The clade Coccil .... References {{reflist Mollusc anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglion
A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Structure Ganglia are primarily made up of somata and dendritic structures which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems. Among vertebrates there are three major groups of ganglia: *Dorsal root ganglia (also known as the spinal ganglia) contain the cell bodies of se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoathroid
The term hypoathroid (Ancient Greek ''hypo-'', "under" + ''-athroid'', "gathered together") is used to describe the arrangement of ganglia in the nervous system of molluscs. In the hypoathroid state, the pleural ganglia of the "chest" and the pedal ganglia of the "feet" lie close to each other more or less underneath the gut, and they communicate with the cerebral ganglia via long connectives. It is a condition that is characteristic of the Archaeogastropoda clade, and represents one end of a three-part spectrum of such arrangements, the other two being the dystenoid system in which the pleural and cerebral ganglia are closer together but still distinctly separate, and the epiathroid condition in which the pleural, pedal, and cerebral ganglia all lie close together (characteristic, for example, of the Mesogastropoda and Neogastropoda Neogastropoda is an order of sea snails, both freshwater and marine gastropod molluscs. Description The available fossil record of Neogas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiathroid
The term epiathroid (Ancient Greek ''epi-'', "above" + ''-athroid'', "gathered together") is used to describe the arrangement of ganglia in the nervous system of molluscs. In the epiathroid state, the pleural ganglia of the "chest" and the pedal ganglia of the "feet" lie close to the cerebral ganglia of the "head" forming a neural cluster which begins to approximate a brain. It is a condition characteristic of the Mesogastropoda and Neogastropoda, and is the obverse of the more-primitive hypoathroid condition in which the pleural and pedal ganglia lie close together under the animal's gut and communicate with the cerebral ganglia via long connectives. The Archaeogastropoda clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ... is described as "hypoathroid", and is the clade close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macleaniella Moskalevi
''Macleaniella'' is a genus of deep-sea limpets in the family Cocculinidae. Species Species within the genus ''Macleaniella'' include: * ''Macleaniella moskalevi'' Leal & Harasewych, 1999 Distribution ''Macleaniella moskalevi'' is endemic to Puerto Rico Trench. Description The shell of ''Macleaniella moskalevi'' is small and cap-shaped.Strong E. E. & Harasewych M. G. (1999). "Anatomy of the Hadal Limpet ''Macleaniella moskalevi'' (Gastropoda, Cocculinoidea)". ''Invertebrate Biology'' 118(2): 137-148abstract/ref> The maximum recorded shell length is 5.17 mm.Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". '' PLoS ONE'' 5(1): e8776. . Habitat Minimum recorded depth is 5184 m. Maximum recorded depth is 8595 m. Life cycle Simultaneous hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limpet
Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended independently from different ancestral gastropods. This general category of conical shell is known as "patelliform" (dish-shaped). All members of the large and ancient marine clade Patellogastropoda are limpets. Within that clade, the members of the Patellidae family in particular are often referred to as "true limpets". Other groups, not in the same family, are also called limpets of one type or another, due to the similarity of their shells' shape. Examples include the Fissurellidae ("keyhole limpet") family, which is part of the Vetigastropoda clade (many other members of the Vetigastropoda do not have the morphology of limpets) and the Siphonariidae ("false limpets"), which use a siphon to pump water over their gills. Behaviour and ecolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocculinoidea
The Cocculinoidea is a superfamily of deepwater limpets (marine gastropods), the only superfamily in the order Cocculinida , one of the main orders of gastropods according to the taxonomy as set up by ( Bouchet & Rocroi, 2005). The clade Cocciliniformia used to be designated as a superorder. Taxonomy According to Bouchet & Rocroi, 2005, the superfamily Cocculinoidea contains the families Bathysciadiidae and Cocculinidae. The Cocculinoidea (Cocculinacea Dall, 1882) are combined with the Lepetelliodea (Lepetellacea Dall, 1882) in Cocculinoformia Haszprunar, 1987, referred to as a clade in Bouchet & Rocroi, 2005 although it used to be designated a superorder by Ponder & Lindberg, 1997. Bouchet & Rocroi (2005) leave the Cocculiniformia to consist only of the Cocculinoidea, having moved the Lepetelloidea to the Vetigastropoda. (Note that before the stipulation by the ICZN, the majority of invertebrate superfamilies ended in -acea, or -aceae, not -oidea.) Overview of species Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
