#Brachyura

[birdblues]

Atlantic Ghost Crab

[vii-spider]

doing a mermay-style thing focused on bugs this may! so...

may-fly 2nd: hatsune michura

i'm the number one "crustaceans are bugs" proponent, so, what better way to start off may-fly than with a crab? more info n stuff under the cut!

michura is, obviously, based on a crab! she isn't any one specific species or clade, i just kinda took the general look of a crab and put miku into it. her name comes from miku (duh) and brachyura, which is the infraorder under decapods that all so-called "true crabs" fall into

the idea for this came from when, a couple days ago, i just Completely misinterpreted miku fanart i saw on twitter, and thought she had crab eyes. immediately fell in love with the idea after hastily scribbling this out on my phone at like 12:30 in the morning

so! i had to learn crab anatomy for this. and it is. fucked up.

first and foremost: understanding how the hell their faces work. surprisingly, it's not as complex as you'd think. those rectangular "jaws" you see?

yeah, those are a pair of modified legs, neatly folded up, called maxillipeds. all the other mouthparts (including two other pairs of maxillipeds!) are tucked away behind those. so, thankfully, i only needed to give michura one pair of maxillipeds if i wanted to be particularly accurate!

something else i've learned that people tend to get wrong is how crab claws work. most people draw them opening from both sides, with a jagged and sometimes even hollow inside. but if you take a look at them on a real crab...

see that divide between the lower and upper "fingers?"

that's because only the top part of a crab's claw can move! the bottom part is just an extension of the "wrist" segment!

as for what's up with her arms... well, it's simple, really. i wanted to keep the claws because that's what crabs are known for, but i also wanted her to have more dexterous grasping appendages. originally both pairs of arms were on the torso, which was... more than a bit cluttered. i almost completely ditched the second pair, until-

"why not do two smaller front legs?"

in reference to how people give spider characters those weird stupid chelicera/palp/leg things. while i despise it on spiders... it's actually pretty in-line with how crabs are built, given their claws are just modified front legs! so, naturally, instead of putting the claws down there, i moved her hands down to where her frontmost legs would be, because i thought that would be kind of funny. i think it was a good call, honestly! since, i'd argue it's better for the more precise and dexterous grasping appendages to have the wider range of motion, and be able to reach the ground more easily, and i think it gives the design that "fucked up kind of weird" factor i really really like

uhhhh tldr, crab miku. i learned some stuff about crab anatomy in drawing her and now you have too

[alphynix]

Strange Symmetries #20: The 16 Million Year Fiddler Crab Rave

Many decapod crustaceans have slightly asymmetrical pincers, often with one claw being chunkier and specialized for "crushing" while the other is more slender and used for "cutting".

But fiddler crabs take this sort of asymmetry to the extreme as part of their sexual dimorphism – males have one massively oversized claw, which is used for both visual display to potential mates and for physical fights against rivals.

Some of the earliest fiddler crabs are known from the Miocene of what is now northern Brazil. Although the fossils have been given several different taxonomic names since their discovery in the 1970s (including Uca maracoani antiqua, Uca antiqua, and Uca inaciobritoi) they're currently considered to be indistinguishable from the modern Brazilian fiddler crab, Uca maracoani, meaning that these crabs have remained externally unchanged for the last 16 million years.

Up to about 4cm in carapace width (~1.6"), modern Uca maracoani are found in coastal mangrove swamps and tidal mudflats around the northern and eastern coasts of South America – and some of these environments have also undergone little change since the Miocene. Males of the species can develop their enlarged pincer on either side of their bodies, with lefties and righties seeming to occur in equal numbers.

———

NixIllustration.com | Tumblr | Twitter | Patreon

[snototter]

An arrow crab (Stenorhynchus lanceolatus) in Lanzerote, Canary Islands

by Verheyen Stefan

[crabsinvideogames]

Vampire Survivors

As with other bosses in the Ode to Castlevania DLC, Brachyura originally appeared as a boss in that series, specifically first appearing in Castlevania: Order of Ecclesia.

[unofficial-sean]

Shellfies with a handsome rock sole (Lepidopsetta bilineata) and a red rock crab (Cancer productus)

[birding-with-tortoise]

Fiddler Crab

Sighted at Pulicat lake, Tamil Nadu, India

[frumpytaco]

Got out on the rocks this weekend to celebrate Tiny Crustacean Fest.

Top: the tide was really fuckin low

2nd row: A very distressed mother and the brood of babies she released from her marsupium when I put her in the water to look at. :( Absolutely refuse to make an ID on her.

3rd row, left to right: Ischyroceridae (Ischyrocerus?), Aoridae (Aoroides?), Sphaeromatidae

4th row, left to right: Melitidae, Ericthonius sp.

5th row, left to right: Petrolisthes cinctipes, Romaleon branneri, Cancer productus

6th row, left to right: Hemigrapsus nudus (I've never seen one so big in CA!), Lophopanopeus bellus, some weird orange thing without an exoskeleton idk (jk i'm pretty sure it's Triopha maculata)

[thoughtlessarse]

Fishermen and scientists were alarmed when billions of crabs vanished from the Bering Sea near Alaska in 2022. It wasn’t overfishing, scientists explained — it was likely the shockingly warm water that sent the crabs’ metabolism into overdrive and starved them to death. But their horrific demise appears to be just one impact of the massive transition unfolding in the region, scientists reported in a new study released Wednesday: Parts of the Bering Sea are literally becoming less Arctic. The research from the National Oceanic and Atmospheric Administration found warmer, ice-free conditions in the southeast Bering Sea — the kind of conditions found in sub-Arctic regions — are roughly 200 times more likely now than before humans began burning planet-warming fossil fuels. The study underlines “how much this Bering Sea ecosystem has already changed from what it was even within the lifetime of one snow crab fisherman,” said Michael Litzow, lead author of the study and the director for Alaska’s Kodiak lab for NOAA Fisheries. It also suggests “we should anticipate many more [very warm] years,” he said, while truly Arctic conditions — cold, icy, treacherous — will be few and far between. Snow crabs, a cold-water Arctic species, thrive overwhelmingly in areas where water temperatures are below 2 degrees Celsius, though they can physically function in waters up to 12 degrees Celsius. A marine heat wave in 2018 and 2019 was especially deadly for the crabs. Warmer water caused the crabs’ metabolism to increase, but there wasn’t enough food to keep pace. Billions of crabs ultimately starved to death, devastating Alaska’s fishing industry in the years that followed.

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[squigliez]

My daughter Hillary

[seabeachobjects]

[bimbinis]

@paravian-girl​

A 500-pound stained glass crab sculpture at BWI Marshall Airport, Maryland.

[unofficial-sean]

Graceful Crab (Metacarcinus gracilis)

[na-bird-of-the-day]

BOTD: Slaty Spinetail

Photo: Ryan Mandelbaum

"Small, dark, and long-tailed. Difficult to see well. Overall gray with rufous wings and crown. Sexes alike. Stays hidden in weedy, tangled undergrowth at the edges of fields and secondary forest. Distinctive song often heard emerging from impenetrable thickets: a low, stuttered chatter."

- eBird

[crabmeiser]

it... not... crab...

Coconut crabs are not a branch of brachyura (or; "true crabs").

Coconut crabs are anomura.

What is and isn't a crab isn't binarily sorted into brachyura and anomura, there's also podotremata, which is an umbrella category full of non-crabs.

it blue...

[birdstudies]

October 10, 2023 - Slaty Spinetail or Slaty Castlebuilder (Synallaxis brachyura) These spinetails are found in scrub, thickets, and undergrowth at forest edges, overgrown clearings, the edges of swamps, and gardens in southern Central America and in parts of Ecuador and Colombia to northern Peru. They feed on invertebrates including beetles, butterflies, larvae, and spiders, as well as seeds, usually foraging in pairs. Their bulky nests are made from twigs and sticks, often with thorns, soft green leaves, spiderwebs, and sometimes snake or lizard skins. Both parents incubate the eggs and feed the chicks.