Nick Baker takes a look Daphnia pulex and how its reproduction strategy helps future generations survive <\/p>
Water fleas are crustaceans \u2013 it is their proportions (no more than 5mm long) and jerky movements that give them their common name. Of the UK\u2019s 80 or so species, Daphnia pulex<\/i> is the most common and widespread.<\/span><\/p>\n <\/p><\/div> <\/section> Have a close look at one under a microscope or under hand lens, and you\u2019ll see a beautiful, delicate, glassy animal. A single compound eye stares back at you, long feathery antennae (used for swimming) flick out on either side of the head. The whole body is encased in a transparent hinged \u2018clamshell\u2019 arrangement, which enables you to see everything: guts, a beating heart, even eggs or a brood pouch full of developing babies.<\/span><\/p>\n Modified feeding legs protrude through the gap in the species\u2019 shell. The legs draw microscopic algae and bacteria towards Daphnia\u2019s<\/i> mouth. So efficient is this feeding current, it can filter more than 4ml an hour. Multiplied by thousands, you can see why these superabundant organisms have a significant impact on water quality.<\/span><\/p>\n Daphnia<\/i> are also a major food source for many other creatures, including the larvae of phantom midges, dragonfly and damselfly<\/a><\/strong> nymphs, bugs such as water boatmen<\/a><\/strong>, newt larvae and fish fry. However, they\u2019re not merely nature\u2019s cannon fodder. They fight back, albeit in a surprising way: when conditions are right, Daphnia<\/i> multiply phenomenally fast.<\/span><\/p>\n Part of the trick is a strategy called parthenogenesis<\/a><\/strong>, meaning they reproduce without males. The females give birth to clones of themselves; males are formed only when temperatures drop, or the water they\u2019re in is drying up. Entire populations may also undergo a process known as cyclomorphosis, which modifies the appearance and shape of the next generation to make it less palatable.<\/span><\/p>\n What triggers these changes in Daphnia<\/i>? Chemicals released into the water by the very animals attacking them! The warning chemicals are by-products of digestion, as the predators enjoy their meal. In response, the development of the next generation of Daphnia<\/i> embryos is altered. Specific genes are turned on, leading to the formation of a variety of extensions to their bodies, making them difficult to swallow.<\/span><\/p>\n Each type of predatory animal induces a slightly different shape-shifting response in the water fleas. The development of long tail spines, neck teeth and huge hooded helmets are just some of the options available to them. These adaptations may be more energetically expensive, but it\u2019s worth it. By rendering the owner impossible to swallow, they can ensure a higher number survive to breed.<\/span><\/p>\n Size is a defence, too. In response to predation, Daphnia <\/i>are able to change how they invest in growth. For example, by speeding up development <\/p><\/div> <\/section> Main image: \u00a9 Paul Hebert), CC BY 2.5 <https:\/\/creativecommons.org\/licenses\/by\/2.5>, via Wikimedia Commons<\/p> <\/body><\/html>\n Nick Baker takes a look Daphnia pulex and how its reproduction strategy helps future generations survive <\/p>\n","protected":false},"author":24,"featured_media":25921,"template":"","categories":[1],"acf":{"readingTimeMinutes":"3"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy.png",2154,1336,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-150x150.png",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-300x186.png",300,186,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-768x476.png",768,476,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-1024x635.png",800,496,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-1536x953.png",1536,953,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/44\/2023\/03\/meet-the-water-flea-daphnia-pulex-which-has-a-remarkable-reproduction-survival-strategy-2048x1270.png",2048,1270,true]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcwildlife\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"Nick Baker takes a look Daphnia pulex and how its reproduction strategy helps future generations survive","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/rss_feed\/25920"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/media\/25921"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/media?parent=25920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcwildlife\/wp-json\/wp\/v2\/categories?post=25920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
What does Daphnia pulex<\/em> look like?<\/h2>\n
What does Daphnia pulex <\/em>eat?<\/h2>\n
What eats Daphnia pulex?<\/em><\/h2>\n
How does Daphnia pulex\u00a0<\/em>reproduce quickly when needed?<\/h2>\n
How cyclomorphosis helps future generations survive<\/span><\/h2>\n
\n
","protected":false},"excerpt":{"rendered":"