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Sexual Selection In Spiders
Sexual selection in spiders shows how sexual selection explains the evolution of phenotypic traits in spiders. Male spiders have many complex courtship rituals and have to avoid being eaten by the females, with the males of most species survive a few matings, and having short life spans. Pre-copulatory mate choice processes have been observed in a wide range of spider species, including ''Stegodyphus lineatus, Argiope aurantia, Schizocosa floridana, Hygrolycosa rubrofasciata, and Schizocosa stridulans''.Maklakov, A. a., Bilde, T. & Lubin, Y. Sexual selection for increased male body size and protandry in a spider. Animal Behaviour 68, 1041–1048 (2004).Foellmer, M. W. & Fairbairn, D. JCompeting dwarf males: sexual selection in an orb-weaving spider.Journal of Evolutionary Biology 18, 629–41 (2005).Rosenthal, M. F. & Hebets, E. a. Resource heterogeneity interacts with courtship rate to influence mating success in the wolf spider Schizocosa floridana. Animal Behaviour 84, 1341–13 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneidae
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. The family has a cosmopolitan distribution, including many well-known large or brightly colored garden spiders. With 3,108 species in 186 genera worldwide, the Araneidae comprise the third-largest family of spiders (behind the Salticidae and Linyphiidae). Araneid webs are constructed in a stereotypical fashion, where a framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb webs are also produced by members of other spider families. The long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Aran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mate Choice
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choice, Cambridge University Press, 1985 In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular Phenotypic trait, trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort. These mechanisms are a part of evolutionary change because they operate in a way that causes the qualities that are desired in a mate to be more frequently passed on to each generation over time. For example, if female peacocks desire mates who have a colourful plumage, then this trait will increase in frequency over time as male peacocks with a colourful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phidippus Putnami Male
''Phidippus'' is a genus in the family Salticidae ( jumping spiders). Some of the largest jumping spiders inhabit this genus, and many species are characterized by their brilliant, iridescent green chelicerae. ''Phidippus'' is distributed almost exclusively in North America, with the exception of two exported species ('' Phidippus audax'' and '' Phidippus regius'').Edwards, G. B. (2004). pp. vii, 4–6. , there were about 80 described species in the genus. Species previously described in ''Phidippus'' which are found in India and Bangladesh do not belong in this genus. Name The genus name is likely derived from Cicero's speech ''Pro Rege Deiotaro'' (Speech in Behalf of King Deiotarus): Phidippus was a slave who was physician to King Deiotaros. Literally, the word means "one who spares horses" in Ancient Greek.Ubick ''et al.'' 2005 The name for the jumping spider family, Salticidae, also comes from the verb "to jump" in Latin. Species , the World Spider Catalog accepted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephila Pilipes
''Nephila pilipes'' (northern golden orb weaver or giant golden orb weaver''Nephila pilipes'' Arachne.org.au) is a species of golden orb-web spider. It resides all over countries in and as well as . It is commonly found in |
Unicorn Catleyi
''Unicorn catleyi'' is a species of spider in the family Oonopidae, found in Chile and Argentina. References Oonopidae Spiders of South America Fauna of the Andes Arthropods of Argentina Arthropods of Chile Spiders described in 1995 {{oonopidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm Competition
Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. However, multiple mates for a female means each individual male has decreased chances of producing offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase males' chance of reproductive success. Sperm competition results in a sexual conflict of interest between males and females. Males have evolved several defensive tactics including: mate-guarding, mating plugs, and releasing toxic seminal substances to reduce female re-mating tendencies to cope with sperm competition. Offensive tactics of sperm competition involve direct interference by one male on the reproductive success of another male, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corn Spider
''Argiope aurantia'' is a species of spider, commonly known as the yellow garden spider, black and yellow garden spider, golden garden spider, writing spider, zigzag spider, zipper spider, black and yellow argiope, corn spider, Steeler spider, or McKinley spider. The species was first described by Hippolyte Lucas in 1833. It is common to the contiguous United States, Hawaii, southern Canada, Mexico, and Central America. It has distinctive yellow and black markings on the abdomen and a mostly white cephalothorax. Its scientific Latin name translates to "gilded silver-face" (the genus name '' Argiope'' meaning "silver-face", while the specific epithet ''aurantia'' means "gilded"). The body length of males range from ; females range from . These spiders may bite if disturbed or harassed, but the venom is harmless to non-allergic humans, roughly equivalent to a bumblebee sting in intensity. Habitat Yellow garden spiders often build webs in areas adjacent to open sunny fields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectus Hasselti
The redback spider (''Latrodectus hasselti''), also known as the Australian black widow, is a species of highly venomous spider believed to originate in South Australia or adjacent Western Australian deserts, but now found throughout Australia, Southeast Asia and New Zealand, with colonies elsewhere outside Australia. It is a member of the cosmopolitan genus ''Latrodectus'', the widow spiders. The adult female is easily recognised by her spherical black body with a prominent red stripe on the upper side of her abdomen and an hourglass-shaped red/orange streak on the underside. Females usually have a body length of about , while the male is much smaller, being only long. Mainly nocturnal, the female redback lives in an untidy web in a warm sheltered location, commonly near or inside human residences. It preys on insects, spiders and small vertebrates that become ensnared in its web. It kills its prey by injecting a complex venom through its two fangs when it bites, before wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Dar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelicerae
The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as " jaws", chelicerae may be shaped as either articulated fangs, or similarly to pincers. Some chelicerae, such as those found on nearly all spiders, are hollow and contain (or are connected to) venom glands, and are used to inject venom into prey or a perceived threat. In '' Pisaurina mira'', also known as the nursery web spider, the chelicerae are utilized to snatch the prey once it becomes within reach, facilitating the "sit-and-wait ambush predator" behavior. Both pseudoscorpions and harvestmen have structures on their chelicerae that are used for grooming (papillae in pseudoscorpions, cheliceral teeth in Opiliones). Types Chelicerae can be divided into three kinds: jackknife chelicerae, scissor chelicerae, and 3-segmented chelate chelicerae. Jackknife chelicerae The jackknife chelicera is subchelate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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