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Diplostraca
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 species have been recognised so far, with many more undescribed. The oldest fossils of diplostracans date to the Jurassic, though their modern morphology suggests that they originated substantially earlier, during the Paleozoic. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, though several anostracans live in hypersaline lakes. Most are long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive harsh conditions and disperse to distant habitats. Description The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclestherida
Clam shrimp are a group of bivalved branchiopod crustaceans that resemble the unrelated bivalved molluscs. They are extant and also known from the fossil record, from at least the Devonian period and perhaps before. They were originally classified in the former order Conchostraca, which later proved to be paraphyletic, because water fleas are nested within clam shrimps. Clam shrimp are now divided into three orders, Cyclestherida, Laevicaudata, and Spinicaudata, in addition to the fossil family Leaiidae. Characteristics Both valves of the shell are held together by a strong closing muscle. The animals react to danger by contracting the muscle, so that the valves close tightly and the crustacean, as if dead, lies motionlessly at the bottom of the pool. In most species the head is dorsoventrally compressed. The sessile compound eyes are close together and located on the forehead; in the genus ''Cyclestheria'' they are truly fused. In front of them is a simple naupliar eye. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinicaudata
Clam shrimp are a group of bivalved branchiopod crustaceans that resemble the unrelated bivalved molluscs. They are extant and also known from the fossil record, from at least the Devonian period and perhaps before. They were originally classified in the former order Conchostraca, which later proved to be paraphyletic, because water fleas are nested within clam shrimps. Clam shrimp are now divided into three orders, Cyclestherida, Laevicaudata, and Spinicaudata, in addition to the fossil family Leaiidae. Characteristics Both valves of the shell are held together by a strong closing muscle. The animals react to danger by contracting the muscle, so that the valves close tightly and the crustacean, as if dead, lies motionlessly at the bottom of the pool. In most species the head is dorsoventrally compressed. The sessile compound eyes are close together and located on the forehead; in the genus ''Cyclestheria'' they are truly fused. In front of them is a simple naupliar eye. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenopoda
Ctenopoda, from Ancient Greek κτείς (''kteís''), meaning "comb", and πούς (''poús''), meaning "foot", are an order of the superorder Diplostraca, comprising the three families Holopediidae, Pseudopenilidae, and Sididae. Its members mostly live in fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ..., but '' Penilia'' is marine. Some Ctenopoda have accidentally been introduced by humans to areas outside of their native range. References External links * Arthropod suborders Cladocera {{Branchiopoda-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomopoda
Anomopoda is an order of the superorder Diplostraca. These crustaceans, a type of water flea, are members of the class Branchiopoda Branchiopoda, from Ancient Greek βράγχια (''bránkhia''), meaning "gill", and πούς (''poús''), meaning "foot", is a class (biology), class of crustaceans. It comprises Anostraca, fairy shrimp, clam shrimp, Diplostraca (or Cladocera), .... The Anomopoda typically have five pairs of thoracic limbs, but sometimes have six pairs. The head of the Anomopoda lacks a clear separation from the trunk and the posterior, while the abdomen area gradually merges with the anterior of the trunk. See also *'' Daphnia'' - water fleas References Cladocera Freshwater crustaceans Arthropod suborders {{Branchiopoda-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre André Latreille
Pierre André Latreille (; 29 November 1762 – 6 February 1833) was a French zoology, zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare beetle species he found in the prison, ''Necrobia ruficollis.'' He published his first important work, , in 1796, and was eventually employed by the . His foresighted work on arthropod systematics and Taxonomy (biology), taxonomy gained him respect and accolades, including being asked to write the volume on insects for George Cuvier's monumental work, , the only part not by Cuvier himself. Latreille was considered the foremost entomology, entomologist of his time, and was described by one of his pupils as "the prince of entomologists". Biography Early life Pierre André Latreille was born on 29 November 1762 in the town of Brive-la-Gaillarde, Brive, then in the Limousin (province), province of Limousi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptodora
''Leptodora'' is a genus containing two species of large, nearly transparency and translucency, transparent Predation, predatory water fleas. They grow up to long, with two large antenna (biology), antennae used for swimming and a single compound eye. The legs are used to catch copepods that it comes into contact with by chance. ''Leptodora kindtii'' is found in temperate lakes across the Northern Hemisphere and is probably the only water flea species ever species description, described in a newspaper; ''L. richardi'' is only known from eastern Russia. For most of the year, ''Leptodora'' reproduces parthenogenesis, parthenogenetically, with males only appearing late in the season, to produce winter eggs which hatch the following spring. ''Leptodora'' is the only genus in its family, the Leptodoridae, and suborder, Haplopoda. Description Adults of ''Leptodora'' are the largest planktonic cladocerans native to North America; reports vary concerning the largest size, but adult femal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis
Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertilized Gametophyte, egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg. Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea, and parasitic wasps), and a few vertebrates, such as some fish, amphibians, and reptiles. This type of reproduction has been induced artificially in animal species that naturally reproduce through sex, including fish, amphibians, and mice. Normal egg cells form in the process of meiosis and are haploid, with half as many chromosomes as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In Vertebrate, vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Some Monitor lizard, monitor lizards, including Komodo dragons, can reproduce asexually. While all prokaryotes reproduce without the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. In placental mammals, sperm cells exit the penis through the male urethra and enter the vagina during copulation, while egg cells enter the uterus through the oviduct. Other vertebrates of both sexes possess a cloaca for the release of sperm or egg cells. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (biology)
An antenna (plural: antennae) is one of a pair of appendages used for Sensory system, sensing in arthropods. Antennae are sometimes referred to as ''feelers''. Antennae are connected to the first one or two Segmentation (biology), segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments. While they are typically sensory organs, the exact nature of what they sense and how they sense it is not the same in all groups. Functions may variously include sensing tactition, touch, air motion, heat, vibration (sound), and especially insect olfaction, smell or gustation, taste. Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring the arthropod to a substrate (biology), substrate. Larval arthropods have antennae that differ from those of the adult. Many crustaceans, for example, have free-swimming larvae that use their antennae for swimming. Antennae can also locate other group members i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abdomen
The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal cavity. In arthropods, it is the posterior (anatomy), posterior tagma (biology), tagma of the body; it follows the thorax or cephalothorax. In humans, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint (the intervertebral disc between Lumbar vertebrae, L5 and Vertebra#Sacrum, S1) to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear. In vertebrates, the abdomen is a large body cavity enclosed by the abdominal muscles, at the front an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
