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Maxwellia (gastropod)
''Maxwellia'' is a genus of sea snails, marine gastropod mollusks in the family Muricidae, the murex snails or rock snails. The genus was named after Maxwell Smith (1888-1961), an American malacologist. Description The species in this genus have small to moderate-sized, solid fusiform shells with a low, globose spire. The siphonal canal is rather short, curved to the left, fused at the top and almost sealed below. They have six to seven well-developed varices per whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ..., with deep hollows at the sutures. These varices extend from the shoulder margin to the tip of the siphonal canal and become twisted at the base of the shell. The deflection of the varices at the top of the shoulder of each whorl gives rise to a small pointed sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxwellia Gemma
''Maxwellia gemma'', commonly known as gem murex, is a species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails. Description The fusiform shell is of moderate size and its length varies between 16 mm and 40 mm. The color of the shell is somewhat white with spiral bands with a reddish-brown to bluish-black color on the leading edge of each varix. The shell has a rather short, subacute, conical spire. There are five convex whorls. The body whorl is broad and spindle-shaped. Each spire whorl contains six rounded varices that are broader at the body whorl, but thinner and curved back at the stubby, top whorls and around the siphonal canal. The sutures between the whorls are deep and crossed by the oblique varices. The porcelaneous white aperture has an oval shape and has a finely dentate outer lip. The siphonal canal is rather short, almost completely closed and curved to the left at the base. There is no apparent a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxwellia Angermeyerae
''Maxwellia angermeyerae'' is a species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails. Description The size of the subfusiform shell varies between 14 mm and 25 mm. The shell surface is chalky white, crossed by horizontal purple to black streaks on the seven rounded axial ribs, that are twisted and swollen at the base of the body whorl. There are also eight or nine spiral riblets. The low spire is globose and consists of two and a half whorls, sitting op top of four body whorls. As each subsequent whorls rises above the shoulder margin of the previous whorl, the sutures are not visible. The body whorl is large and almost spindle-shaped. The ovate aperture has a small anal canal that point slightly backwards. The outer lip is crenulate, but has a smooth inner surface. The columellar lip is callused. The siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including ''Nautilus'', ''Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book ''On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siphonal Canal
The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is drawn into the mantle cavity and over the gill and which serves as a chemoreceptor to locate food. Siphonal canals allow for active transport of water to sensory organs inside the shell. Organisms without siphonal canals in their shells rely on passive or diffuse transport or water into their shell. Those with siphonal canals have a direct inhalant stream of water that interacts with sensory organs to detect concentration and direction of a stimulus, such as food or mates. In certain groups of carnivorous snails, where the siphon is particularly long, the structure of the shell has been modified in order to house and protect the soft structure of the siphon. Thus the siphonal canal is a semi-tubular extension of the aperture of the shell th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spire (mollusc)
A spire is a part of the coiled shell of molluscs. The spire consists of all of the whorls except for the body whorl. Each spire whorl represents a rotation of 360°. A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods. In textbook illustrations of gastropod shells, the tradition (with a few exceptions) is to show most shells with the spire uppermost on the page. The spire, when it is not damaged or eroded, includes the protoconch (also called the nuclear whorls or the larval shell), and most of the subsequent teleoconch whorls (also called the postnuclear whorls), which gradually increase in area as they are formed. Thus the spire in most gastropods is pointed, the tip being known as the "apex". The word "spire" is used, in an analogy to a church spire or rock spire, a high, thin, pinnacle. The "spire angle" is the angle, as seen from the apex, at which a spire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusiform
Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a blood vessel. Examples * Fusiform, a body shape common to many aquatic animals, characterized by being tapered at both the head and the tail * Fusiform, a classification of aneurysm * Fusiform bacteria (spindled rods, that is, fusiform bacilli), such as the Fusobacteriota * Fusiform cell (biology) * Fusiform face area, a part of the human visual system which seems to specialize in facial recognition * Fusiform gyrus, part of the temporal lobe of the brain * Fusiform muscle, where the fibres run parallel along the length of the muscle * Fusiform neuron, a spindle-shaped neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malacologist
Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, and cephalopods, along with numerous other kinds, many of which have shells. One division of malacology, conchology, is devoted to the study of mollusk shells. Malacology derives . Fields within malacological research include taxonomy, ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ... and evolution. Applied malacology studies medical, veterinary, and agricultural applications; for example, mollusks as vectors of disease, as in schistosomiasis. Archaeology employs malacology to understand the evolution of the climate, the biota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
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 gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine (ocean)
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the world ocean is conventionally divided."Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, |
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