Editing Dendrobranchiata (section)

==Life cycle==
[[File:Shrimp nauplius.jpg|thumb|[[Nauplius (larva)|Nauplius]] of an unidentified prawn from the family [[Penaeidae]]]]
[[File:Penaeus vannamei 01.jpg|thumb|A juvenile ''[[Litopenaeus vannamei]]'' (whiteleg prawn)]]
Prawns may be divided into two groups: those with an open thelycum (female genitalia) and those with a closed thelycum.<ref name="TM125">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 125</ref> In the open-thelycum species, mating takes place towards the end of the moulting cycle, and usually at sunset.<ref name="TM125-6">[[#TavaresMartin2010|Tavares & Martin, 2010]], pp. 125–126</ref> In closed-thelycum species, mating takes place shortly after moulting, when the [[exoskeleton]] is still soft, and usually occurs in the night.<ref name="TM126">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 126</ref> [[courtship display|Courtship]] and mating may take up to 3 hours in ''[[Penaeus monodon]]'', while in ''[[Farfantepenaeus paulensis]]'', mating lasts just 4–5 seconds.<ref name="TM126"/> Spawning may occur several times during the moulting cycle, and usually occurs at night.<ref name="TM127">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 127</ref>

With the exception of [[Luciferidae]], the [[egg (biology)|eggs]] of prawns are shed directly into the water, rather than being brooded.<ref name="TM130">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 130</ref> The eggs hatch into [[nauplius (larva)|nauplius]] [[crustacean larvae|larvae]], which are followed by [[zoea]] larvae (initially protozoea, and later mysis) and then a postlarva, before reaching adulthood.<ref name="TM130"/> The changes between [[ecdysis|moults]] are gradual, and so the development is [[Anamorphosis (biology)|anamorphic]] rather than [[metamorphosis|metamorphic]].<ref name="TM130"/>

Uniquely among the Decapoda, the nauplii of Dendrobranchiata are free-swimming.<ref name="TM130"/> There are five to eight naupliar stages.<ref name="TM131">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 131</ref> The earlier stages have three pairs of appendages that are used for locomotion – two pairs of [[antenna (biology)|antennae]] and the [[Mandible (arthropod mouthpart)|mandibles]]. Later stages also have rudiments of other [[arthropod mouthparts|mouthparts]], but the nauplius is unable to feed, and only lasts 24 to 68 hours.<ref name="TM130"/> The body ends at a two-lobed [[telson]], and the beginnings of a [[carapace]] emerge at this stage.<ref name="TM131"/>

There are typically five or six zoea stages in Dendrobranchiata, divided into protozoea and mysis.<ref name="TM130"/> In the protozoea larvae, the antennae are still used for locomotion, but the mandibles become specialised for [[mastication]].<ref name="TM131"/> All the thoracic somites (body segments) have formed, and a [[carapace]] is present, covering part of the thorax.<ref name="TM131"/> It is smooth in the family [[Penaeidae]], but bears many spines in the family [[Solenoceridae]].<ref name="TM131"/> The [[pleon]] (abdomen) is unsegmented in the first protozoea, and ends in a bilobed telson, which may be used for cleaning other appendages, or for steering.<ref name="TM131"/> By the second protozoea, segmentation appears on the pleon,<ref name="TM131"/> and by the third protozoea, which may also be called the metazoea, the [[uropod]]s have appeared.<ref name="TM133"/>

By the mysis stages, the [[pereiopod]]s (thoracic appendages) start to be used instead of the antennae for locomotion.<ref name="TM133">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 133</ref> The larva swims backwards, with its tail upwards, spinning slowly as it goes.<ref name="TM133"/> The carapace covers most of the segments of the thorax, and claws appear on the first three pereiopods.<ref name="TM133"/> By the last mysis stage, the beginnings of [[pleopod]]s have appeared on the first five segments of the abdomen.<ref name="TM133"/>

The post-larva or [[juvenile (animal)|juvenile]] stage is characterised by the use of the pleopods for locomotion.<ref name="TM134">[[#TavaresMartin2010|Tavares & Martin, 2010]], p. 134</ref> The claws become functional, but the [[gill]]s are still rudimentary.<ref name="TM134"/> The telson is narrower and only retains traces of its two-lobed development.<ref name="TM134"/> Through a series of gradual changes over following moults, the animal takes on its adult form.<ref name="TM134"/>