mating behaviour of neriene radiata
the tiny male of golden orb weaver (nephila clavipes) (near top of leaf) protected female producing right vibrations in web, , may small worth eating.
spiders reproduce sexually , fertilization internal indirect, in other words sperm not inserted female s body male s genitals intermediate stage. unlike many land-living arthropods, male spiders not produce ready-made spermatophores (packages of sperm), spin small sperm webs on ejaculate , transfer sperm special syringe-like structures, palpal bulbs or palpal organs, borne on tips of pedipalps of mature males. when male detects signs of female nearby checks whether of same species , whether ready mate; example in species produce webs or safety ropes , male can identify species , sex of these objects smell .
spiders use elaborate courtship rituals prevent large females eating small males before fertilization, except male smaller not worth eating. in web-weaving species, precise patterns of vibrations in web major part of rituals, while patterns of touches on female s body important in many spiders hunt actively, , may hypnotize female. gestures , dances male important jumping spiders, have excellent eyesight. if courtship successful, male injects sperm palpal bulbs female s genital opening, known epigyne, on underside of abdomen. female s reproductive tracts vary simple tubes systems include seminal receptacles in females store sperm , release when ready. because sperm stored in epigyne, eggs not fertilized while inside female, during oviposition when stored sperm released chamber. 1 exception spider israel, harpactea sadistica, has evolved traumatic insemination. in species male penetrate pedipalps through female s body wall , inject sperm directly ovaries, embryos inside fertilized eggs start develop before being laid.
males of genus tidarren amputate 1 of palps before maturation , enter adult life 1 palp only. palps 20% of male s body mass in species, , detaching 1 of 2 improves mobility. in yemeni species tidarren argo, remaining palp torn off female. separated palp remains attached female s epigynum 4 hours , apparently continues function independently. in meantime, female feeds on palpless male. in on 60% of cases, female of australian redback spider kills , eats male after inserts second palp female s genital opening; in fact, males co-operate trying impale on females fangs. observation shows male redbacks never opportunity mate, , lucky ones increase number of offspring ensuring females well-fed. however, males of species survive few matings, limited short life spans. live while in mates webs.
females lay 3,000 eggs in 1 or more silk egg sacs, maintain constant humidity level. in species, females die afterwards, females of other species protect sacs attaching them webs, hiding them in nests, carrying them in chelicerae or attaching them spinnerets , dragging them along.
baby spiders pass larval stages inside egg , hatch spiderlings, small , sexually immature similar in shape adults. spiders care young, example wolf spider s brood cling rough bristles on mother s back, , females of species respond begging behaviour of young giving them prey, provided no longer struggling, or regurgitate food.
like other arthropods, spiders have molt grow cuticle ( skin ) cannot stretch. in species males mate newly molted females, weak dangerous males. spiders live 1 2 years, although tarantulas can live in captivity on 20 years.
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