{"id":18808,"date":"2021-09-01T20:18:32","date_gmt":"2021-09-02T00:18:32","guid":{"rendered":"https:\/\/wordpress.world.dan.org\/?post_type=dan_alert_diver&p=18808"},"modified":"2023-06-28T11:51:37","modified_gmt":"2023-06-28T15:51:37","slug":"undercover-crabs","status":"publish","type":"dan_alert_diver","link":"https:\/\/world.dan.org\/fr\/alert-diver\/article\/undercover-crabs\/","title":{"rendered":"Crabes sous couverture"},"content":{"rendered":"

Il y a une dizaine d'ann\u00e9es, Anna et moi avons pass\u00e9 la majeure partie de trois ans \u00e0 photographier des pieuvres, des crabes, des crevettes et une multitude d'autres cr\u00e9atures sans queue ni t\u00eate pour un guide de la vie marine. Notre plus grand d\u00e9fi \u00e9tait de trouver des formes de vie qui ont \u00e9volu\u00e9 pour rester cach\u00e9es. De nombreux illusionnistes sont nocturnes et ne sortent de leur cachette qu'apr\u00e8s le coucher du soleil pour se nourrir, ce qui a n\u00e9cessit\u00e9 de nombreuses plong\u00e9es de nuit.<\/p>\n\n\n\n

Much of our adventure unfolded in Indonesia\u2019s Lembeh Strait \u2014 a hot spot of marine biodiversity in the western Pacific. The famed 10-mile strait provided just what we needed: easy access to a variety of underwater habitats and veteran dive guides with the wherewithal to track down an assortment of unconventional animals.<\/p>\n\n\n

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\"Crabe
Un crabe d\u00e9corateur de 4 pouces se cache \u00e0 la vue de tous.<\/figcaption><\/figure>\n<\/div>\n\n\n

Each evening Anna and I joined Liberty Tukunang, Ben Sarinda, or both aboard a wooden water taxi retrofitted for diving. Consistent and persistent, our little team invariably set out at 6 p.m. for a pair of two-hour dives night after night for weeks on end. The hunting was so good that no one dared to skip an evening for fear of what they might miss. During this extraordinary time, Anna and I discovered decorator crabs and their amazing ability to hide in plain sight. I can still remember the first crab I couldn\u2019t see.<\/p>\n\n\n\n

I didn\u2019t have my aha moment for almost a minute after Ben began repeatedly pointing his muck stick at what seemed to be nothing \u2014 at least nothing my citified eyes could see. I just stared stupidly, squinting and blinking at a reef ledge quilted with life. Then, ever so subtly, a claw moved, a whisker twitched, eyes appeared, and a 4-inch crab cloaked in algae and crowned with a branch of soft coral popped into focus. With that single eye-opening encounter, decorator crabs soared to the top of our already lengthy most-wanted list.<\/p>\n\n\n\n

As we learned, most decorator crabs belong to one of eight families in the superfamily Majoidea, commonly referred to as spider crabs. About 75 percent of the group\u2019s more than 1,100 global species mask their presence by wearing disguises made from living organisms scissored from the landscape. They commonly hijack seaweeds, sponges, tunicates, bryozoans and hydroids. Most detainees survive the ordeal and continue to grow, and a few even reproduce.<\/p>\n\n\n\n

 Les crabes manipulent les v\u00eatements vol\u00e9s avec leur bouche avant de les attacher \u00e0 l'une des nombreuses soies en forme d'hame\u00e7on dispos\u00e9es en rang\u00e9es sur la carapace, le rostre, les pattes et les bras griffus, selon l'esp\u00e8ce. Le processus ne se fait pas \u00e0 la h\u00e2te ; dans les aquariums, il faut environ huit heures \u00e0 un crabe d\u00e9corateur pour accomplir sa t\u00e2che. Les crabes d\u00e9corateurs se red\u00e9corent \u00e9galement apr\u00e8s la mue, en rattachant g\u00e9n\u00e9ralement des mat\u00e9riaux provenant des carapaces \u00e9pluch\u00e9es \u00e0 leur nouvel exosquelette \u00e9largi pendant les heures n\u00e9cessaires au durcissement de leur armure.<\/p>\n\n\n\n

Les araign\u00e9es de mer sont des cibles de choix pour une longue liste de carnivores, dont les poissons, les homards, les pieuvres, les tortues, les loutres de mer, les go\u00e9lands et d'autres crabes. D'apr\u00e8s les quelques observations de pr\u00e9dation faites sur le terrain et dans les aquariums, la d\u00e9coration semble \u00eatre une strat\u00e9gie efficace pour minimiser le carnage. Bien que tr\u00e8s efficace la nuit, le camouflage semble \u00eatre encore plus avantageux pendant la journ\u00e9e, lorsque les crabes se cachent apr\u00e8s une soir\u00e9e de recherche de nourriture.<\/p>\n\n\n\n

\"Un
Un crabe ourson ressemblant \u00e0 un jouet est envelopp\u00e9 d'algues.<\/figcaption><\/figure>\n\n\n\n

These motionless daytime decorators are the dickens to find, but they can be found. Liberty proved the point one morning by tickling out an exquisite specimen cloaked in hydroids. The discovery wasn\u2019t a fluke. As he explained later, the hydroid colony seemed out of place, so on a hunch he nudged it, causing the concealed crab to move. In our effort to explore alternate habitats, we searched the seaward flumes of dry river beds, where the tedium of turning over stones in the end proved quite productive. Everybody\u2019s favorite find was a toylike teddy bear crab shrouded in algae as soft as a whisper.<\/p>\n\n\n\n

We took great pride in figuring out how to detect decorators. Each sighting became an event. It quickly became apparent that the crabs were more plentiful, diverse and outrageous than we had imagined. Soon we began noticing variations on the decorators\u2019 successful strategy. Carry crabs tote urchins, sea stars and jellyfish across the sand, sponge decorators hide beneath clipped sponge wedges, and boxer crabs attach miniature anemones to their claws.<\/p>\n\n\n\n

\"un
D\u00e9couvert sur le sable, un crabe d\u00e9corateur recouvert d'algues fait de son mieux pour para\u00eetre grand, m\u00e9chant et effrayant.<\/figcaption><\/figure>\n\n\n\n

M\u00eame si les crabes d\u00e9corateurs sont difficiles \u00e0 trouver, une fois que vous avez perc\u00e9 leur d\u00e9guisement, votre travail est termin\u00e9. N'ayant aucun autre moyen de d\u00e9fense efficace, les crabes se figent, ce qui vous permet de les admirer \u00e0 loisir. Mais dans la nature, il y a toujours des anomalies, comme le crabe aux algues lavande de la baie de Beangabang. Lorsqu'il a \u00e9t\u00e9 d\u00e9couvert, ce petit d\u00e9corateur de 3 pouces s'est d\u00e9cha\u00een\u00e9, se transformant en une image burlesque d'un fant\u00f4me tentant d'\u00eatre grand et m\u00e9chant, ce qui en fait une parfaite carte d'Halloween.<\/p>\n\n\n\n

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En savoir plus<\/strong><\/h2>\n\n\n\n

D\u00e9couvrez les crabes d\u00e9corateurs en action dans cette vid\u00e9o.<\/p>\n\n\n\n

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