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Gonopods
Gonopods are specialized appendages of various arthropods used in reproduction or egg-laying. In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and millipedes, gonopods are modified walking or swimming legs. Gonopods may be highly decorated with elaborate structures which may play roles in sperm competition, and can be used to differentiate and identify closely related species. Gonopods generally occur in one or more pairs, as opposed to the single (un-paired) reproductive organs such as the aedeagus of insects or the penis of harvestmen. Insects In insects, gonopods are appendages of the genital segment that may be used in insemination, or that comprise the egg-laying apparatus. Crustaceans In male decapod crustaceans, gonopods are modified swimming appendages ( pleopods). The anterior two pair of pleopods in males are modified for sperm transferring, with differing degree of morph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millipedes
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. Although the name "millipede" derives from the Latin for "thousand feet", no species was known to have 1,000 or more until the discovery of '' Eumillipes persephone'', which can have over 1,300 legs. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures. Most millipedes are slow-moving detritivores, eating decaying leaves and other dead plant matter. Some eat fungi o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millipede
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. Although the name "millipede" derives from the Latin for "thousand feet", no species was known to have 1,000 or more until the discovery of ''Eumillipes persephone'', which can have over 1,300 legs. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures. Most millipedes are slow-moving detritivores, eating decaying leaves and other dead plant matter. Some eat fungi or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callipodida
Callipodida is an order of millipedes containing around 130 species, many characterized by crests or ridges. Description Callipodida are long and narrow millipedes, up to in length with 40-60 body segments. A dorsal groove is present running down the mid-line of the body, and many species are ornamented with longitudinal crests or ridges. Sexually mature males possess a single pair of gonopods, consisting of the modified anterior leg pair of the 7th body segment, and carried concealed within a pouch. Distribution Callipodida occurs in North America, Europe, west Asia, southern China and Southeast Asia. Classification The living (extant) Callipodida are classified into three suborders, seven families, and approximately 130 species. The genus '' Sinocallipus'', which constitutes the suborder Sinocallipodidea, is thought to be the most primitive, and a sister group to all other callipodans. A fourth, extinct, suborder was described in 2019 to accommodate '' Burmanopetalum inex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craspedosomatidea
Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as "sausage millipedes," they possess around 30 body segments behind the head (including the telson) as adults and reach about in length. Description Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from . A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment ( collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterochordeumatidea
Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as "sausage millipedes," they possess around 30 body segments behind the head (including the telson) as adults and reach about in length. Description Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from . A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment ( collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordeumatidea
Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as "sausage millipedes," they possess around 30 body segments behind the head (including the telson) as adults and reach about in length. Description Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from . A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment ( collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordeumatida
Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as "sausage millipedes," they possess around 30 body segments behind the head (including the telson) as adults and reach about in length. Description Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from . A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment ( collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeumat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Striariidea
Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as "sausage millipedes," they possess around 30 body segments behind the head (including the telson) as adults and reach about in length. Description Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from . A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment ( collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleopod
The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various groups these may be reduced or missing. They are, from head to tail: Cephalothorax Head # antennules # antennae #mandibles # first maxillae # second maxillae The head also bears the (usually stalked) compound eyes. The distal portion of a mandible or maxilla which has a sensory function is known as a palp. Thorax / pereon #first maxillipeds #second maxillipeds #third maxillipeds #first pereiopods #second pereiopods #third pereiopods #fourth pereiopods #fifth pereiopods Maxillipeds are appendages modified to function as mouthparts. Particularly in the less advanced decapods, these can be very similar to the pereiopods. Pereiopods are primarily walking legs and are also used for gathering food. They are also the ten legs from which decapo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intromittent Organ
An intromittent organ is any external organ of a male organism that is specialized to deliver sperm during copulation. Intromittent organs are found most often in terrestrial species, as most non-mammalian aquatic species fertilize their eggs externally, although there are exceptions. For many species in the animal kingdom, the male intromittent organ is a hallmark characteristic of internal fertilization. Species with intromittent organs Invertebrates Molluscs Male cephalopods have a specialized arm, the hectocotylus, which is inserted into the female's mantle cavity to deliver a spermatophore during copulation. In some species, the hectocotylus breaks off inside the female's mantle cavity; in others, it can be used repeatedly to copulate with different females. Arachnids In spiders the intromittent organs are the male pedipalps, even though these are not primarily sexual organs, but serve as indirect mating organs; in the male the pedipalps have hollow, clubbed tips, oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinocallipus Steineri Gonopods
''Sinocallipus '' is a genus of predominantly cave-dwelling millipedes in the order Callipodida. Five of the six known species are found in limestone caves on the Indochinese Peninsula from Vietnam to southern China, and it is the only callipodidan genus entirely confined to the tropics. Individuals range from long and possess 55 to 70 segments. ''Sinocallipus'' is the sole taxon of the callipodidan suborder Sinocallipodidea, and thought to be the most primitive and sister group to all other callipodidans. In contrast to many other millipede groups, the gonopods (reproductive legs) of ''Sinocallipus'' show little variation between species, while other characters such as color, size, and other body parts differ more noticeably between species. Species All species except ''S. thai'' have been collected solely from caves, and show troglomorphic (cave-adapted) traits such as pale coloration, long antennae, and long legs. ''S. jaegeri'' and ''S. simplipodicus'' show reduced eyes, cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, plural ''coxae''), ''trochanter'', ''femur'' (plural ''femora''), ''tibia'' (plural ''tibiae''), ''tarsus'' (plural ''tarsi''), ''ischium'' (plural ''ischia''), ''metatarsus'', ''carpus'', ''dactylus'' (meaning finger), ''patella'' (plural ''patellae''). Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a ''Hox''-gene, could result in parallel gains of leg segments. In arthropods, each of the leg segments ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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