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Hydrologist
New member
Any photos? That would help alot
BEASTIEPENDENT
Member
There are more than 7.000 species of crabs. How should one answer this with such a vague description?
Bongo Shrimp
P. ceratophthalma
Dude chill out. Agitation is not welcome here.
Black and white sounds like some sort of xanthid crab. I would grb him next chance you get, put him in a cup with some tank water and begin the photo shoot.
BEASTIEPENDENT
Member
What? I'm not agitating, I'm just talking facts. Black and white crab is as I would ask "I have seen a silver car with black tires – can You tell me the vendor and model?" Black and white does not sound like a Xanthid crab, it sounds like ANY crab out of any of the 36 other super familys. Most crabs are not identifiable down to species level even _with_ photos because for ID You would need the specimen itself or good macroscopic photos. Often one can say only a family or the genus which may help in sorting wether the crab is aggressive against other tank inhabitants.
Anyway if the crab is always picking algae the possibility is big that it is a herbivorous species which feeds mainly on algae (it will eat carrion when it gets too). If You can see the pincers look if they are spoony (algae and detritus eater) or sharp (maybe predatorous crab).
Anyway if the crab is always picking algae the possibility is big that it is a herbivorous species which feeds mainly on algae (it will eat carrion when it gets too). If You can see the pincers look if they are spoony (algae and detritus eater) or sharp (maybe predatorous crab).
AaronM
New member
Lol no, but you a bit hyped up now, hey?
If it looks like an emerald, then its probably a Mithrax.
If you can't identify a crab without a maco shot, then you're not the crab expert you think you are. Here, this isn't a macro shot, whats this? If you identify this crab, then you've just snapped yourself.
Whats predatorous? Tryantasourous?
"It's hard to identify without a pic, pic pls?"
If it looks like an emerald, then its probably a Mithrax.
If you can't identify a crab without a maco shot, then you're not the crab expert you think you are. Here, this isn't a macro shot, whats this? If you identify this crab, then you've just snapped yourself.
Whats predatorous? Tryantasourous?
"It's hard to identify without a pic, pic pls?"
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BEASTIEPENDENT
Member
Seems reasonable arguing isn't welcome here either.
Then it's predatory, okay. Shall I laugh when You speak German? My, what level is this here? Silly.
If it is an "emerald" it's a Mithraculus and not Mithrax.
Then it's predatory, okay. Shall I laugh when You speak German? My, what level is this here? Silly.
If it is an "emerald" it's a Mithraculus and not Mithrax.
AaronM
New member
Did you offer any help initially? No. You had a little ego pump.
How is your car analogy helpful?
If it looks like an emerald, then its probably a Mithrax.
Anyway if the crab is always picking algae the possibility is big that it is a herbivorous species which feeds mainly on algae (it will eat carrion when it gets too). If You can see the pincers look if they are spoony (algae and detritus eater) or sharp (maybe predatorous crab).
Why did you just say that instead of jumping up on you high horse and poking at the plebs?
How is your car analogy helpful?
If it looks like an emerald, then its probably a Mithrax.
Anyway if the crab is always picking algae the possibility is big that it is a herbivorous species which feeds mainly on algae (it will eat carrion when it gets too). If You can see the pincers look if they are spoony (algae and detritus eater) or sharp (maybe predatorous crab).
Why did you just say that instead of jumping up on you high horse and poking at the plebs?
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AaronM
New member
Why don't i attempt more help instead of butting heads with someone...
http://species-identification.org/search.php?search_for=crab&search_mode=basic
http://www.chucksaddiction.com/
[edit] info links> hitchhikers> crabs
http://museumvictoria.com.au/crust/comlist.html
http://www.marinespecies.org/aphia.php?p=taxdetails&id=106673
http://species-identification.org/search.php?search_for=crab&search_mode=basic
http://www.chucksaddiction.com/
[edit] info links> hitchhikers> crabs
http://museumvictoria.com.au/crust/comlist.html
http://www.marinespecies.org/aphia.php?p=taxdetails&id=106673
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BEASTIEPENDENT
Member
In making clear how useless a description as "white and black" crab is and that more details are necessary (at least I thought it was helpful for this). In fact that it is totally impossible to ID a crab without even photos. Just that is what I wanted to say with my first posting (!) and what I tried to clearify with the car analogy.
I hoped jbeard82 would realise it that way and try to make a picture. Then (!) one could help him in ID'ing.
Why this upsets anyone and encourages so aggressive and arrogant answers is beyond my knowledge and understanding. I really don't get the point.
But anyway I won't discuss or defend further each one of my sentences why I said this thing one way and that thing another way, this is no psychology board. For me this is EOD.
Bongo Shrimp
P. ceratophthalma
Well said^
You don't need a pic to id a crab. Saying it is impossible is going too far. A good description is quite enough for a seasoned crab expert (I am not claiming to be one of these). There are ways to help someone (like giving links) other than just in effect saying "what are you thinking? No pic? Impossible.".
But I can tell that a hairy crab with black claws is not good.
I'm not trying to egg this on, just givging a simple explanation.
Now, back to helping jbeard. Try these links too:
http://www.saltcorner.com/AquariumLibrary/browsesectiongroups.php?SectionID=25
http://www.poppe-images.com/?t=9&catid=5
http://www.reeflex.net/kategorie/58.html
Hope this helps, and happy to help as always.
greenbean36191
Premium Member
Beastie is absolutely right on this. You cannot identify a crab without a photo, and even then, with the exception of a few very distinctive species, identifying it beyond family is difficult if not impossible for even professional crab taxonomists. Color is simply not a character that's commonly used in speciating crabs or most other inverts. It's essentially useless. Rather than being a sign that Beastie doesn't know crabs, saying that there's no way to make a meaningful guess based on color is exactly the response I would expect to hear from even a world authority on crabs. Helpful? Not necessarily, but then neither is a bad ID, and Beastie's reply is the most accurate answer.
Bongo Shrimp
P. ceratophthalma
Ok fine, but there are ways to help other than just saying "idiot- we need a pic". Besides, most of the time we are just trying to figure out if a crab is reef safe or not. That doesn't always require a pic.
For an EXACT id (if it is possible to get one) you're basically right that there is really no way to get an EXACT id without a pic.
PS- Out of the 5 people who responded, only two actually made an attempt to help in some way.
For an EXACT id (if it is possible to get one) you're basically right that there is really no way to get an EXACT id without a pic.
PS- Out of the 5 people who responded, only two actually made an attempt to help in some way.
LeslieH
Premium Member
In his first post Beastie just said what I think every time I see one of these pleas for help with just an extremely vague description and no photos. He's absolutely right and I don't think he was being snide or agitating, Bongo. I've said the same thing before, the only difference is I tend to use smilies in that hope that no one takes it the wrong way.
What's surprising to me is that sometimes reefers can put reasonably good names on these vague descriptions (or really bad photos) when crab experts can't. That's because reefers see the same, comparatively few species/ groups of crabs over & over again. A crab expert, with 36 superfamilies & many minor ones, 7000+ species to consider, and a very very specialized vocabulary for describing crab features, can't do anything with a vague description. A reefer's "good description" may be meaningless to a crab expert. A picture really is absolutely essential even for family & maybe genus & species. Some genera & species are separated by characters that don't show in pictures - like the shape of internal organs or mouthparts.
Judging whether something is reef safe or not, well, a picture helps there too. Hairness, spoon tips, sharp tips, black claws, smooth shells - none of these are 100% guaranteed as to safe or not-safe. If I want to know what a crab eats I don't look at any of these. I figure out what it is & then check to see what's known about it's diet. Even then, crabs in tanks don't always feed the way we think they're supposed to, either because they're not getting enough food or individual preferences. Some fan-waving-filter-feeding porcelain crabs will eagerly accept chunks of meat or scavenge.
Posting links is a great way to help. Please keep in mind that a lot of the sites - even the best ones - have mistakes, ranging from just a few for the best to mega bloopers for the worst.
Incidentally, that last link Bongo put up....http://www.reeflex.net/kategorie/58.html.... Beastie's a major contributor of photos & information.
Getting back to the idea that reefers see the same few crabs over & over again, so they actually can id something from a vague description, take a look at Chlordiella nigra. http://www.reeflex.net/tiere/1892_Chlorodiella_nigra.htm This is what most "black emeralds" or "black & white emeralds" tend to be. It's in the superfamily Xanthoidea, and either in family Xanthidae or one split off from Xanthidae depending on who's taxonomy is followed.
What's surprising to me is that sometimes reefers can put reasonably good names on these vague descriptions (or really bad photos) when crab experts can't. That's because reefers see the same, comparatively few species/ groups of crabs over & over again. A crab expert, with 36 superfamilies & many minor ones, 7000+ species to consider, and a very very specialized vocabulary for describing crab features, can't do anything with a vague description. A reefer's "good description" may be meaningless to a crab expert. A picture really is absolutely essential even for family & maybe genus & species. Some genera & species are separated by characters that don't show in pictures - like the shape of internal organs or mouthparts.
Judging whether something is reef safe or not, well, a picture helps there too. Hairness, spoon tips, sharp tips, black claws, smooth shells - none of these are 100% guaranteed as to safe or not-safe. If I want to know what a crab eats I don't look at any of these. I figure out what it is & then check to see what's known about it's diet. Even then, crabs in tanks don't always feed the way we think they're supposed to, either because they're not getting enough food or individual preferences. Some fan-waving-filter-feeding porcelain crabs will eagerly accept chunks of meat or scavenge.
Posting links is a great way to help. Please keep in mind that a lot of the sites - even the best ones - have mistakes, ranging from just a few for the best to mega bloopers for the worst.
Incidentally, that last link Bongo put up....http://www.reeflex.net/kategorie/58.html.... Beastie's a major contributor of photos & information.
Getting back to the idea that reefers see the same few crabs over & over again, so they actually can id something from a vague description, take a look at Chlordiella nigra. http://www.reeflex.net/tiere/1892_Chlorodiella_nigra.htm This is what most "black emeralds" or "black & white emeralds" tend to be. It's in the superfamily Xanthoidea, and either in family Xanthidae or one split off from Xanthidae depending on who's taxonomy is followed.
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I think bongo got on here just looking for a fight. im glad we got reefers out there that dont want to help but just bump heads. what does it matter what anyone says if they offend u then be the better person and ignore them u dont have to act like a middle schooler and arguee over the computer. i wish people could put childish things behind them and grow up. this person wanted help on a id on a crab and instead got a jerry springer show going.
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