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Mesospermalege
The spermalege (also known as the organ of Berlese or organ of Ribaga) is a special-purpose organ found in female bed bugs that appears to have evolved to mitigate the effects of traumatic insemination. The spermalege has two embryologically distinct parts, known as the ectospermalege and mesospermalege. The evolution of the spermalege as a female counter-adaptation for traumatic insemination was proposed by the French entomologist Jacques Carayon in 1966. Structure The spermalege has two embryologically distinct parts, known as the ectospermalege and mesospermalege. The ectospermalege is derived from the ectoderm. It consists of a groove in the right-handed posterior margin of the fifth sclerite, overlying a pleural membrane. In order to access the female's haemocoel during traumatic insemination, male bed bugs insert their needle-like aedeagus into the groove, and pierce the pleural membrane. This piercing produces wounds that leave melanised scars. The mesospermalege is der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traumatic Insemination
Traumatic insemination, also known as hypodermic insemination, is the mating practice in some species of invertebrates in which the male pierces the female's abdomen with his aedeagus and injects his sperm through the wound into her abdominal cavity (hemocoel). The sperm diffuses through the female's hemolymph, reaching the ovaries and resulting in fertilization. The process is detrimental to the female's health. It creates an open wound which impairs the female until it heals, and is susceptible to infection. The injection of sperm and ejaculatory fluids into the hemocoel can also trigger an immune reaction in the female. Bed bugs, which reproduce solely by traumatic insemination, have evolved a pair of sperm-receptacles, known as the spermalege. It has been suggested that the spermalege reduces the direct damage to the female bed bug during traumatic insemination. However experiments found no conclusive evidence for that hypothesis; as of 2003, the preferred explanation f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cimex
''Cimex'' is a genus of insects in the family Cimicidae. ''Cimex'' species are ectoparasites which typically feed on the blood of birds and mammals. Two species, ''Cimex lectularius'' and ''Cimex hemipterus'', are known as bed bugs and frequently feed on humans, although other species may parasitize humans opportunistically. Species primarily parasitizing bats are known as bat bugs. The insects are long and have flattened reddish-brown bodies with small nonfunctional wings. Description Adult ''Cimex'' are light brown to reddish-brown, flat and oval. The mouthparts are beak-like, and adapted for piercing and sucking. Following a blood meal the abdomen is plump and darker in colour. The front wings are Vestigiality, vestigial and reduced to pad-like structures. ''Cimex'' lacks hind wings. They have segmented abdomens with microscopic hairs that give them a banded appearance. Adults grow to long. The different species are very similar in Morphology (biology), morphology and ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermis (zoology)
In zoology, the epidermis is an epithelium (sheet of cells) that covers the body of a eumetazoan (animal more complex than a sponge). Eumetazoa have a cavity lined with a similar epithelium, the gastrodermis, which forms a boundary with the epidermis at the mouth. Sponges have no epithelium, and therefore no epidermis or gastrodermis. The epidermis of a more complex invertebrate is just one layer deep, and may be protected by a non-cellular cuticle. The epidermis of a higher vertebrate has many layers, and the outer layers are reinforced with keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ... and then die. References Animal anatomy Epithelium {{animal-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exocuticle
Arthropods are covered with a tough, resilient integument, cuticle or exoskeleton of chitin. Generally the exoskeleton will have thickened areas in which the chitin is reinforced or stiffened by materials such as minerals or hardened proteins. This happens in parts of the body where there is a need for rigidity or elasticity. Typically the mineral crystals, mainly calcium carbonate, are deposited among the chitin and protein molecules in a process called biomineralization. The crystals and fibres interpenetrate and reinforce each other, the minerals supplying the hardness and resistance to compression, while the chitin supplies the tensile strength. Biomineralization occurs mainly in crustaceans. In insects and arachnids, the main reinforcing materials are various proteins hardened by linking the fibres in processes called sclerotin, sclerotisation and the hardened proteins are called sclerotin. The dorsal tergum, ventral sternum (arthropod anatomy), sternum, and the lateral pleur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fecundity
Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the capability to produce offspring, measured by the number of gametes (eggs), seed set, or asexual propagules. Human demography Human demography considers only human fecundity, at its culturally differing rates, while population biology studies all organisms. The term ''fecundity'' in population biology is often used to describe the rate of offspring production after one time step (often annual). In this sense, fecundity may include both birth rates and survival of young to that time step. While levels of fecundity vary geographically, it is generally a consistent feature of each culture. ''Fecundation'' is another term for fertilization. In obstetrics and gynecology, fecund-ability is the probability of being pregnant in a single menstrual cycle, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatozoa
A spermatozoon (; also spelled spermatozoön; : spermatozoa; ) is a motile sperm cell (biology), cell produced by male animals relying on internal fertilization. A spermatozoon is a moving form of the ploidy, haploid cell (biology), cell that is the male gamete that Fertilization, joins with an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, that normally develops into an embryo.) Sperm cells contribute approximately half of the nuclear gene, genetic information to the diploid offspring (excluding, in most cases, mitochondrial DNA). In mammals, the sex of the offspring is determined by the sperm cell: a spermatozoon bearing an X chromosome will lead to a female (XX) offspring, while one bearing a Y chromosome will lead to a male (XY) offspring. Sperm cells were first observed in Antonie van Leeuwenhoek's laboratory in 1677. Mammalian spermatozoa Humans The sperm cell of ''Homo sapiens'' is the small Gamete, reproductive cell produced by m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seminal Fluid
Semen, also known as seminal fluid, is a bodily fluid that contains spermatozoa which is secreted by the male gonads (sexual glands) and other sexual organs of male or hermaphroditic animals. In humans and placental mammals, seminal fluid is ejaculated through the penis and contains proteolytic and other enzymes as well as fructose, which promote the survival of spermatozoa and provide a medium through which they can move or "swim" from the vagina into the uterus to fertilize the female ovum and form a zygote. Semen is collected from animals for artificial insemination or cryoconservation of genetic material. Cryoconservation of animal genetic resources is a practice that calls for the collection of semen in efforts for conservation of a particular breed. Physiology Fertilization Depending on the species, spermatozoa can fertilize ova externally or internally. In external fertilization, the spermatozoa fertilize the ova directly, outside of the female's sexual organs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagocytic
Phagocytosis () is the process by which a cell (biology), cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a Multicellular organism, multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. The two main cells that do this are the Macrophages and the Neutrophils of the immune system. Where phagocytosis is used as a means of feeding and provides the organism part or all of its nourishment, it is called phagotrophy and is distinguished from osmotrophy, which is nutrition taking place by absorption. History The history of phag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemocyte (invertebrate Immune System Cell)
A hemocyte is a cell that plays a role in the immune system of invertebrates. It is found within the hemolymph. Hemocytes are phagocytes of invertebrates. Hemocytes in ''Drosophila melanogaster'' can be divided into two categories: embryonic and larval. Embryonic hemocytes are derived from head mesoderm and enter the hemolymph as circulating cells. Larval hemocytes, on the other hand, are responsible for tissue remodeling during development. Specifically, they are released during the pupa stage in order to prepare the fly for the transition into an adult and the massive associated tissue reorganization that must occur. There are four basic types of hemocytes found in fruit flies: secretory, plasmatocytes, crystal cells, and lamellocytes. Secretory cells are never released into the hemolymph and instead send out signalling molecules responsible for cell differentiation. Plasmatocytes are the hemocytes responsible for cell ingestion (phagocytosis) and represent about 95% of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoderm
The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical Embryology, 11th edition. 2010. The mesoderm forms mesenchyme, mesothelium and coelomocytes. Mesothelium lines coeloms. Mesoderm forms the muscles in a process known as myogenesis, septa (cross-wise partitions) and mesenteries (length-wise partitions); and forms part of the gonads (the rest being the gametes). Myogenesis is specifically a function of mesenchyme. The mesoderm differentiates from the rest of the embryo through intercellular signaling, after which the mesoderm is polarized by an organizing center. The position of the organizing center is in turn determined by the regions in which beta-catenin is protected from degradation by GSK-3. Beta-catenin acts as a co-factor that alters the activity of the transcription facto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primicimex Cavernis
''Primicimex'' is a monotypic genus of ectoparasitic bed bugs in the family Cimicidae, the only species being ''Primicimex cavernis'', which is both the largest cimicid, and the most primitive one. It feeds on bats and was described from Ney Cave in Medina County, Texas but has since been found in four other caves in Guatemala, Mexico, and southern United States. (39 MB) Description Like all cimicids, ''Primicimex cavernis'' is flat and oval-shaped, becoming plumper after feeding. It is unable to fly and has beak-like mouthparts with which it pierces the skin and sucks the blood of its host. It differs from other cimicids (except ''Bucimex chilensis'') in having claws and a row of erect, peg-like spines on the tarsus and has been observed using these structures to cling onto the bat's pelage. Ecology ''Primicimex cavernis'' and its nearest relative, '' Bucimex chilensis'', are the only members of the cimicid subfamily Primicimicinae. Their hosts are exclusively bats; in the ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aedeagus
An aedeagus ( or aedeagi) is a reproductive organ of male arthropods through which they secrete sperm from the testes during copulation (zoology), 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 . 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 Duct (anatomy), 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 connects with the ovipore of a female. The aedeagus can be quite pronounced or ''de minim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
