#Infraorder: Anomura

[ketrinadrawsalot]

Decapocember Day 4: The infraorder Anomura is full of decapods called crabs that aren't actually crabs (brachyurans are true crabs). Carcinization led to many of them becoming crab-shaped. One feature common in anomurans is that two of their appendages are significantly smaller than the others, making them look like they have eight limbs.

#decapocember #decapod #crustacean #anomura #crab #carcinization #nature really likes crabs #art #educational

[n0rtist]

Could I suggest Pokemon based on the geological time periods of Earth's history, such as Paleozoic and Cenozoic?

Having a design represent a whole era might be hard to do, but my carcinization mon is taking a look at how one species evolved over time. I saw a comment or two saying how Anodukes is just a crab, but I was referencing the Anomura infraorder which are "fake crabs" including hermit crabs and squat lobsters (Anodukes more inspired by the latter).

[encyclopika]

Animal Crossing Fish - Expained #225

Brought to you by a marine biologist with our last crabby boy for now...

CLICK HERE FOR THE AC FISH EXPLAINED MASTERPOST!

Today's animal will be our last crustacean for the time being. Above I said "crabby" but, as we learned last time we spoke about crabs, carcinization, and the hermit crab, not every crustacean with a stout body and pinchers is a true crab, the InfraOrder Brachyura. That's right, marine biologists gatekeep crustaceans. Just one of those benefits. So, today's animal is, instead, the largest member of the InfraOrder Anomura, the hermit crabs. It's the infamous Coconut Crab!

I really wish this one was still in the games, especially ACNH. Would be cool as hell while you're scouring your island, you happen across this thing that would be larger than the tarantula, looks like it also, but way less agro. Unfortunately, it only appears in Animal Forest e+ late at night in coconut trees without fruit during the summer months. That is extremely on-brand for the coconut crab, and I appreciate it.

The coconut crab (Birgus latro) is the largest hermit crab in the world, and also the largest terrestrial arthropod as well. Crustaceans just beat every other arthropod in the size department no matter what, it seems. They are native to various Indo-Pacific island chains, including some archipelagoes belonging to Japan, Micronesia, Seychelles, etc etc. Hilariously, they have the densest population on Christmas Island, where they are outnumbered 50 to 1 by the Christmas Island red crab (which we suspected was Animal Forest e+'s other exclusive Crab). The distribution of coconut crabs also seems to follow the same pattern of the Coconut Palm and I just love how Animal Forest e+ brought these three species together, as they are in real life. They also come in various color morphs - looks like Animal Crossing decided to go with the blue variety.

By Brocken Inaglory - English wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3238751

Unlike most crustaceans we have covered who live out their lives on the ocean bottom, the coconut crab, and its terrestrial hermit brethren in Coenobitidae, lives a completely terrestrial life. In fact, if it spends too much time underwater, it will drown! That's because they have an important adaptation to living on land, and that is a lung-like gill-like organ called the branchiostegal lung. Plenty of other terrestrial crustaceans have this organ, allowing them to live on land. However, just like amphibians, the coconut crab needs to return to the sea to hatch their eggs. As larvae, they live amongst the plankton like any other crab does, molting and morphing into an adult that eventually lands on a new beach and begins its land-lubbing life.

Unlike other hermit crabs that famously make a home of discarded shells, the coconut crab, as a large adult, doesn't. Its back end hardens so that it's no longer vulnerable. And good thing, because as the largest invertebrate on land, it would have a hell of a time finding a big enough shell to put its behind in.

I think coconut crabs really got their fame from their immense size. Like I said above, this is THE largest arthropod living on land. It literally beats insects and spiders on their own turf. Some of the largest individuals' leg spans reach 3 ft (~1m). Below is probably one of the most popularized photos of a coconut crab, usually followed by some ignorant comment about "nightmare fuel". It does an excellent job showing how goddamn big they are.

At this size, it only has humans and other, bigger coconut crabs to worry about. Despite the size, there's no danger posed by the coconut crab to people. Though it's an omnivore, its diet is mostly made up of plant material, like fruits, nuts, and, on special occasions, coconuts. Those big claws help it get through its environment and get into the husks of coconuts, among other things, like trash cans.

And there you have it. Fascinating stuff, no?

#coconut crab #crab #hermit crab #marine biology #crustaceans #ocean #animals #arthropods #animal crossing #animal forest e+ #science in video games #animal crossing fish explained

[zevordofzeday]

Carcinisation

Carcinisation (or carcinization) is an example of convergent evolution in which a crustacean evolves into a crab-like form from a non-crab-like form. The term was introduced into evolutionary biology by L. A. Borradaile, who described it as "one of the many attempts of Nature to evolve a crab".[2] Most carcinised crustaceans belong to the infraorder Anomura.

[professionalunprofessional]

Shrimp and a Hermit Crab! What a pretty shell they’ve made into their home!

#idk what kind #Phylum: Arthropoda #Class: Malacostraca #Order: Decapoda #Suborder: Dendrobranchiata #Suborder: Pleocyemata #Infraorder: Anomura #Superfamily: Paguroidea #Superfamily: Penaeoidea #hermit crabs #shrimp #Crabs #crustaceans

[doodledex-project]

Doodledex - #740 Crabominable

In a bit of a weird twist, Crabrawler will only evolve if you level it up on Mount Lanakila, turning into the yeti-like Crabominable. This is probably really strange to most people who don’t know their crustaceans... but for those who do, it’s a play on a real deep-sea crustacean called a yeti crab! (And yep, they’re white and look really hairy as the name implies!)

According to the Rotom Dex this change occurred because a Crabrawler attempted to “aim for the top”... but took that so literally it climbed to the top of a mountain and got so lost it was forced to evolve hair to survive. Whatever the real reason is, evolution has certainly made its punches a lot stronger, enabling it to smash thick walls of ice! But if its wild punches aren’t enough, Crabominable can even remove one of its (regenerating) pincers and “launch” it at its opponent with a lot of force! (...This isn’t far off from something real crabs can do, by the way. Some can simply yank off one of their arms and ditch it in an attempt to confuse predators. There’s a gif of this floating around somewhere...)

#pokemon #doodledex #crabominable #so you might be wondering... how the heck does a terrestrial coconut crab turn into a species that hangs around hydrothermal vents? #i looked it up... and there's actually a bit of biological basis behind this! #both coconut crabs and yeti crabs are part of the infraorder anomura! #which also contains hermit crabs king crabs and crustaceans called 'squat lobsters' #...but wait. what are 'lobsters' doing in a group with crabs? #well... all of the crustaceans called 'crabs' in this group aren't 'true' crabs! #which means crabrawler and crabominable have more in common with dwebble and crustle than they do krabby and kingler! #(...and i'm now extra confused about crabrawler not being a bug type! #crabominable ditching that typing for ice would have been fine tbh... but crabrawler should've been a 'bug'!)

[montereybayaquarium]

Squat lobster? More like bench-press lobster, look at those crabulous arms!

Also known as pelagic red crabs, tuna crabs or even lobster krill, these crustaceans are neither crabs nor krill! They belong to the infraorder Anomura, which includes squat lobsters, hermit crabs and sand crabs—you know, the not-so-crabby “crabs.” Pelagic red crabs are vertical migrators, and tend to appear near the surface just after sunset. Like many organisms at the bottom of the food chain, the pelagic red crab plays a critical role in its ecosystem as an abundant food source. So the next time you admire a speedy tuna or an elegant whale, think of the contributions of the small but mighty pelagic red crab.

#monterey bay aquarium #squat lobster just over here krillin it #every day is leg day for the squat lobster #feeling crabulous today

[xcherry-popx]

[teddy] 🦀🦀 !! double crab for double facts

carcinization is when things evolve into crabs, but but everything that does this is actually a crab. a lot of crabs aren’t actually crabs. theres a distinction between “true crabs” and “false crabs”! 

the physical differences are that usually ‘real crabs’ have four pairs of walking legs, while fake ones have only two or three pairs. real crabs also tend to have short abdomens that are hidden under their shells, while fake crabs have longer and less protected ones. 

out of the five living lines of carcinized crustaceans (one line is extinct), four are in infraorder ‘anomura’ (the king crabs [evolved from hermit crab ancestors!!!], porcelain crabs [closely related to a type of lobster??], the hairy stone crab [the lone species in its family], and hermit crabs!!) and one line (the true crabs!) are in infraorder brachyura! the extinct line was order cyclida, who existed before true crabs even evolved!! the og crabs that dont even get to be true crabs....

side note, im fascinated that these lines of crab evolved separately, but are still in the same order (decapoda, because crabs are decapods [and actually take up around half the creatures classified as decapods!!]). orders are supposed to be composed of animals evolving from a similar ancestor, but not only did anomura evolve separately from brachyura, but three of the lines within anomura evolved separately!

there seems to be some evidence that some reclassification is needed among anomura! this text (https://bmcecolevol.biomedcentral.com/articles/10.1186/1471-2148-13-128) seems to indicate that within anomura, while most families/superfamilies are monophyletic (descended from a common ancestor), the three lines that evolved separately are either para- or polyphyletic, (descended from different ancestors) meaning that they shouldn’t be in the same taxon! they’re misclassified and shouldn’t  be considered related to each other as much as they are currently thought to be!

so tldr; a crustacean thats been carcinized isn’t always ‘actually’ a crab, because there’s a distinction between ‘real crabs’ and ‘fake crabs’. There’s physical differences that can tell them apart, but it all boils down to they evolved separately.  the ‘real crabs’ are infraorder brachyura, and the ‘fake ones’ are all grouped under infraorder anomura. however, its weird that all fake crabs are anomura, because they evolved separately from each other. research indicates that’s a misclassification that it hasn’t been corrected yet.

[swampgallows]

People often talk about carcinization as the process of convergent crab evolution, but the details are pretty cool, the infraorder brachyura (true crabs) evolved independently twice from a common ancestor, and the infraorder Anomura evolved from that same common ancestor. From Anomura, crabs evolved independently three times, into king crabs, porcelain crabs, and hairy stone crabs. We know this through fossil records and DNA differences between the crabs!

crabs are earths most optimal lifeform

#anon #ask #tell me things

[distinguishedbluevoid]

Kiwa hirsuta

Kingdom: Animalia

Phylum: Arthropoda

Subphylum: Crustacea

Class: Malacostraca

Order: Decapoda

Infraorder: Anomura

Family: Kiwaidae

Genus: Kiwa

Wow look at the turn of events. Another week, another bad blog written immediately before the due time. Whda thunk? Oh yeah! Everyone. 

This is the afamed “yeti crab.” Fun times. He has some weird fur covering his body so they decided to name him that. He is mostly found around the Pacific-Antarctic ridge. He is also thought to be blind, poor little man.  For food he farms his own food in his claws, which I find pretty badass personally.  I mean it’s just bacteria, but still. No information is known yet about the mating of the Yeti crab and since they are blind scientists assume that the crabs must feel their hairs to feel for a mate. We can assume that after that it is pretty similar sex to that of a regular crab. They will sort of “hug” each other and stay like that for several days? Um okay crabs that’s a little long, even for you.

They will grow and develop from eggs. The Yeti crabs evolutionary origins are unknown but knowing them? That family tree is pretty wild. Okay guys I did it and am quite tired, goodnight kids, goat or otherwise.  

[weirdocores-inactive]

Squat lobsters are dorsoventrally flattened crustaceans with long tails held curled beneath the cephalothorax. They are found in the two superfamilies Galatheoidea and Chirostyloidea, which form part of the decapod infraorder Anomura, alongside groups including the hermit crabs and mole crabs.

lovely biography about the BEST animal on Earth

[n0rtist]

This is a concept from @reptile_rick_34 and @spencerhoadley on Insta, the other winners of a Instagram contest I held last month. The concept is the about carcinization which fit well for the other fossil of my region. Around the Cretaceous period, there was a notable increase of crab-like species despite previously being less-crab-like decapods. This process of turning into more like a crab is called carcinization, and the at least 5 independent lines that carcinized are grouped into the infraorder of Anomura.

Fistikoff (Rock/Fighting): Although, Fistikotts can attack either with their claws or their tails, they prefer to attack with their fists. Their unwieldy tails doesn't allow them to evade opponents easily, forcing Fistikotts to fight back.

Anodukes (Rock/Fighting): Anodukes take great pride in their body as their body shape allows them to fight and manuever themselves more efficiently. Anodukes seem to be the ancestor of the Dwebble and Crabrawler lines but interestingly not the Krabby line.

#education #art #oc #science #Logic & Passion #carcinisation #crab #pokemon fossil #fossil #anomura

[encyclopika]

Animal Crossing Fish - Explained #115

Brought to you by the marine biologist with the imposter!

CLICK HERE FOR THE AC FISH EXPLAINED MASTERPOST!

So, at the beginning of this crab...thing I’ve been on, I said one of these crabs was an imposter and indeed! Today’s crab is not really a true crab. Ya see, there are a ton of ocean-dwelling animals that have little pincers, and hard exoskeletons, and jointed leggies, and round, squat bodies...and although all of these features represent “CRAB” in our brains, I gotta tell ya...not all of them are. Today’s crab, the Red King Crab, is one such imposter. 

Another super-rare critter now living right off your beaches, this is another one that you’ll have to give chase to. They move FAST. My strategy with these is to trap them against the border-net, otherwise, I think it’s impossible. Good luck! It’s available now until March in the Northern Hemisphere, and that makes a lot of sense, considering the real life animal prefers the waters of the North Pacific, particularly the Gulf of Alaska, the Bering Sea, and other cold places it’s been introduced, such as the Barents Sea. Could also explain why it’s put into the cold, ice tank with the Sea Butterfly and other cold-water friends. As you can imagine, the Red King Crab is in the game because there is a HUGE market for it, and like most crabs I’ve tried, it’s delicious. 

But wait! This isn’t a crab! Even though the Red King Crab (Paralithodes camtschaticus) has all the hallmarks of being a crab, it just isn’t. Remember when we went through what a crab is when we covered the Mitten Crab? Well, if you don’t, here it is, but basically, crabs are Arthropods (Phylum), Crustaceans (SubPhylum), Malacostracans (Class), and then Decapods (Order). Decapods are so frickin’ diverse, even though the lay-person would probably put these animals in one of 4 (unofficial) “groups” - crabs, shrimp, lobsters, and crayfish. After that, it’s really hard to convince people that hermit crabs, king crabs, porcelain crabs, mole crabs, and the hairy stone crab are not true crabs under the true crab InfraOrder Brachyura (the group in which all previous crabs we’ve covered this week have been a part). Instead, all of those are in a totally different InfraOrder called Anomura, the sister group to Brachyura. So, really, these animals are just “crab-like decapods”. (And yes, I feel like an entire nerd right now, but bare with me.) 

Take a good hard look at the Red King Crab...notice how it only has 8 visible legs like a spider? This is because the very back pair of legs on Anomurans are highly reduced and are usually tucked up into the body to clean their gills. This is definitely NOT a feature of the majority of crabs (there are always exceptions), so if you see a “crab” with 8 legs, you are most likely looking at an Anomuran.  

From : https://www.saildrone.com/news/tagging-red-king-crab-acoustic-tracking

All these groups of “fake” crabs have actually all evolved this “crab-shape” independently. It seems to be a popular thing to do, to turn into a crab. It’s so popular, that we actually have a word for it in science: carcinisation. And I’ll leave you with a very good video that explains why this happens, from one of my favorite channels on YouTube, PBS Eons!

What a great way to end crab week. :3 And there you have it. Fascinating stuff, no?

#marine biology #red king crab #animal crossing #crabs #evolution #acnh #animal crossing new horizons #animals #ocean #science #science in video games #animal crossing fish explained

[chericecornner]

Yeti Crab

Here, you see, is a Yeti Crab. They are very unique. The crab was discovered in 2005 and was announced its discovery a year later. Only the third species of yeti crab known to science. Its scientific name is Kiwa Hirsuta. They are known for having hair-like material on their legs and claws. Their taxonomy classification:

Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Decapoda Infraorder: Anomura Family: Kiwaidae Genus: Kiwa Species: K. Hirsuta

1“The animal has strongly reduced eyes that lack pigment and is thought to be blind.”  The crabs range in length from half a foot (15 centimeters) to under an inch (0.5 centimeters). They live in extremely cold water but by sea vents that are extremely hot. Therefore, they are in a comfortable environment. 2“The cold takes a visible toll on the females, deteriorating their bodies over time...Female crabs likely breed only once before death.” The team studying the Yeti crabs believe that the crabs have to be in a cold climate to reproduce. Female crabs lay larvae which are younger forms of the crabs. They eat the bacteria on their claws but are also known to be carnivores. 3“The earliest unambiguous crab fossils date from the Jurassic,[9] although Carboniferous Imocaris, known only from its carapace, may be a primitive crab.”

https://www.google.com/

https://www.nature.com/news/yeti-crab-grows-its-own-food-1.9537

1https://en.wikipedia.org/wiki/Kiwa_hirsuta

2https://news.nationalgeographic.com/2015/06/150624-new-species-yeti-crab-antarctica-oceans/

3https://en.wikipedia.org/wiki/Crab#Evolution