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Gonopod
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 Opiliones penis, 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 decapoda, decapod crustaceans, gonopods are modified swimming appendages (pleopods). The anterior two pair of pleopods in males are modified for sperm transferring, with dif ... [...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] |
Gonopore
A gonopore, sometimes called a gonadopore, is a genital pore in many invertebrates. Hexapods, including insects have a single common gonopore, except mayflies, which have a pair of gonopores. More specifically, in the unmodified female it is the opening of the common oviduct, and in the male, it is the opening of the ejaculatory duct. The position of the gonopore varies considerably between groups, but is generally constant within groups, allowing its position to be used as a "segmental marker". In Malacostraca, it is on the sixth thoracic segment; in Symphyla it is on the fourth trunk segment; in arachnids, it is on the second segment of the opisthosoma. In insects and centipedes, the gonopores are close to the animal's tail, while in millipedes they are on the third body segment behind the head, near the second pair of legs. See also * Gonopod * Gonopodium Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They ar ... [...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] |
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] |
Aedeagus
An aedeagus (plural aedeagi) is a reproductive organ of male arthropods through which they secrete sperm from the testes during copulation with a female. It can be thought of as the insect equivalent of a mammal's penis, though the comparison is fairly loose given the greater complexity of insect reproduction. The term is derived from Ancient Greek αἰδοῖα (''aidoia'', "private parts") and ἀγός (''agos'', "leader"). It is pronounced or . The aedeagus is part of the male's abdomen, which is the hindmost of the three major body sections of an insect. The pair of testes of the insect are connected to the aedeagus through the genital ducts. The aedeagus is part of the male insect's phallus, a complex and often species-specific arrangement of more or less sclerotized (hardened) flaps and hooks which also includes in some species the valvae (clasper), which are paired organs which help the male hold on to the female during copulation. During copulation, the aedeagus co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomeridesmida
Glomeridesmida is an order of millipedes in the infraclass Pentazonia containing 2 families and at least 31 species. Glomeridesmida is the only living order of the superorder Limacomorpha. Glomeridesmidans are small (less than ) and somewhat flattened, and unlike other orders of Pentazonia, are unable to roll into a ball. Ocelli (eyes) are absent. Adult females in this order have 36 pairs of legs and 21 segments, counting 20 tergites plus the anal shield. Male specimens in this order are rare, unknown for all species in the family Termitodesmidae, and known for only a small number of species in the family Glomeridesmidae. Descriptions of mature males in at least three species (''Glomeridesmus spelaeus'', ''G. siamensis'', and ''G. marmoreus'') report 35 pairs of legs, including a pair of telopods, and 20 segments, one fewer than the 21 segments found in adult females. The description of an adult male of another species (''G. indus''), however, reports 37 pairs of legs, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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