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Crayfish, Crawdads, Ditch Bugs Identification

Related Articles: Forget Crawfish Pie, Let's Make a Crawfish Tank! By Gage Harford, Invertebrates for Freshwater Aquariums by Neale Monks, Freshwater Shrimp, Crayfish, "Lobsters", Prawns Freshwater to Brackish Crabs

Related FAQs: Crayfish 1, Crayfish 2, Crayfish Behavior, Crayfish Compatibility, Crayfish Selection, Crayfish Systems, Crayfish Feeding, Crayfish Disease, Crayfish Reproduction, Freshwater Invertebrates/Use in Aquariums, Freshwater Crustaceans for the Aquarium, FW Crustaceans 2, Fresh to Brackish Water Crabs, Hermit Crabs,

Please I.D. crayfish     4/15/16
I got this one from a goldfish feeder refugium at a pet store. It was kept in the dark for quite some time. So I think its color is faded a bit. It's about 5 inches long.
<It would appear to be a Procambarus clarkii of some sort. There are numerous varieties beyond the standard red form normally traded. Not 100% sure though. I'd suggest joining the planetinverts.com forum and posting your photos there. Those guys are the real experts! Luckily, crayfish care is pretty standard. Room temperature water; gentle filtration; hard water chemistry; diet based on a mix of fresh vegetables and shelly invertebrates for calcium (krill, for example); and NO TANKMATES. Cheers, Neale.>

Orange Procambarus clarkii vs. CPO        4/6/16
Hi Bob,
How to identify whether an orange crayfish is a CPO dwarf or whether it's the bigger clarkii one? The images online look very similar.
Because I was expecting this to grow to only around 3 inches max and it's in a 5 gallon tank. But I noticed it was already 2.5 inches plus.
So I'm wondering if it's a fully grown cpo or a very young clarkii? And I'm not really sure about the scientific names as well. Sorry for any mistakes! The pet store guy has no idea about it. And I'm not from the US.
Thanks a lot!
- Matthews
<Let me refer you to the diagnosis of the genus Cambarellus, here: "First pleopod of first form male terminating in only 3 distinct parts; the three terminals may be spiniform, somewhat truncate, spatulate or even troughlike. In the male hooks are present on the ischipodites of the second and third pereiopods. All species very small, not often reaching a length of 50 mm." Grab yourself a dissecting lens, spin your crayfish onto its back, and make the diagnosis as described. Cheers, Neale.>
Re: Orange Procambarus clarkii vs. CPO

Thanks Neale!
<You're welcome! FWIW, the "Bright Orange Crayfish" is an artificially bred form of Procambarus or similar. True Cambarellus, at least in the UK, are rarely traded, and when they are, sold at small sizes and premium prices.

Procambarus clarkii?     4/26/13
Hi WWM crew, attached are pictures of my new little crayfish - any idea what species he/she is?
<Mmm, no; there are many species... even just in the U.S.>
I thought perhaps Procambarus clarkii?
<Don't think so... I've kept this popular (to eat) species... it's more "robust" and darker and more consistent in colour>
 "He" is very small, about 5cm in length and orange in colour. Thanks for your help! Catherine (South Africa)
<Ask around at the fishing/bait shops in your area re... It is likely introduced (non-native)... They will most likely know.
Bob Fenner>

Can you tell me what kind of Crayfish I have? 6/21/11
Last week, on Thursday, my husband mentioned something about a tower by the porch. He, points to the ground by the back porch. There is a tower of Mud that stands about 10 in tall with a hole in the middle. He said, I'm watching to see what comes out. We figured a mole, or some kind of frog.
Friday we had a hard rain, and it washed away some of the tower, so he is standing there watching to see what comes up. It started coming to the top to rebuild the tower. When he saw what it was he knock over the tower and put what came out in the fish tank (it didn't have any fish anyway).
I know it is a Crawfish but not what kind. (I believe it is a male). We live in Eastern Alabama middle of the state 10 miles from the Chattahoochee River that separates GA and AL. We had a creek that went through our back yard, it finally went underground about 17 years ago. I have attached two pictures of it.
About 7 years ago, we had been doing some digging in the back yard and came upon some old rusty barrels, they were full of water and it had a bunch of little ones in it, we caught 2 little ones and one big one (not as big as this one). But they only lived six months. I think the big one ate the little ones (along with the rest of my fish). The big one also kept escaping the tank.
With this one, we have removed all the fake plants and moved the two fixtures that are left to the middle of the tank. And taped over all the openings. It has a filter and heater, with gravel on the bottom. I gave it a piece of cooked shrimp and put in flake food. It has not eaten the shrimp. I would like to know what kind it is and I have been reading your site for feeding tips. Won't lettuce float? And should I just cut up small pieces of carrots and zucchini? How much do you feed them?
Thanks for your help.
<Hello Michelle. At first I thought this was Procambarus pygmaeus on account of its small size and the orangey tips to the pincers. But I do wonder if it is actually the common species Procambarus clarkii. In any case, I'm fairly sure it's a Procambarus species of some sort. As for care, do read here:
Basic care is generally straightforward. Crayfish eat both plant and animal foods and under aquarium conditions are very omnivorous. Algae wafers, cooked peas, small bits of fish fillet, unshelled shrimps all make good foods. Variety is important. Dose the tank with iodine (sold for marine aquaria) at 50% the dose stated on the bottle -- this is very cheap to do, and ensures they moult properly. They tend to be aggressive as well as predatory, so will harm one another as well as fish. They like to dig, and yes, they will escape given the chance. Hope this helps, Neale.>

Re: Can you tell me what kind of Crayfish I have? 6/21/11
Thank you for letting me know what it is. I have read the basics already and I've been reading everything else on your site. I bought the Algae wafers and shrimp pellets for bottom feeders. I only found 1 store with the iodine and it was such a large bottle, I saw somewhere on your site that I should use, 1 drop for a 10 gallon tank a week. Does that sound right?
<Hmm'¦ there's no rush here, so why not mail-order a small bottle? Going without iodine won't hurt for a few weeks; it's in the long term, once the animal uses up the iodine it still has from its diet in the wild.>
Also, the girl at the store said I didn't need it, "we don't use it here". I have seen your thoughts on things like that.
<She may well not use iodine, and if she only keeps crayfish in stock for a month or two each specimen, she doesn't have to worry about the long-term health of these animals.>
I also have read some of the comments and thought I trust your information more than hers. I will go back and get the big bottle.
You mentioned its' small size, I thought it was pretty big. When it is still and straight out from the tips of his claws to the tip of his tail he is approximately 5 inches long. Does that mean he will get bigger?
<Not by very much; this sounds like an adult P. clarkii.>
I took the solid house out and replaced it with a new longer fake log that had several openings in the sides and open at the bottom so it could dig out and get comfortable.
I have see several listings of foods for them but not sure how much to feed, it also says to remove un-eaten food. But no suggestions on volume or duration to leave it there. Any suggestions for me? I don't want to under feed it or leave extra for too long.
<Plant food can be left in indefinitely, so if you're away for a couple weeks, just leave a bunch of Canadian Pondweed or similar (as sold for ponds and Goldfish aquaria) and leave the chap to graze at his leisure. But meaty food put out at night should be removed if any remains in the morning. Feed sparingly. One algae wafer (about the size of a penny) should be adequate per night, 4-5 nights per week. Once a week supplement with something meaty, perhaps single piece of fish or shrimp about the size of your thumbnail. Leave live plants in as often as you want for grazing. Also provide regular offerings (once or twice a week) of something mostly calcareous for calcium. Squished pond snails would be ideal, but otherwise try whole krill (from the pet store), whole lancefish (again, from the pet store), or unshelled mussels or prawns smashed with a rock or hammer. Again, a thumbnail-sized portion is about right.>
<Glad to help, Neale.>

Re: Can you tell me what kind of Crayfish I have? Sys., nutr. 6/21/11
Thank you Neale! The information on what and how much to feed it wonderful. The algae tables are not as big as a penny and the seem to dissolve in about 5 minutes.
Did I get the wrong thing?
<Sounds like it. Use these for now; if the substrate is sandy rather than gravel, the crayfish will "sift" the sand and extract the nutrients.
Smooth, non-calcareous sand, like pool sand, is ideal for crayfish tanks. The best algae wafers for crayfish are the sort sold for Plecs, for example, Hikari Tropical Algae Wafers. These take hours to fall apart. A German company called JBL also make a whole range of foods expressly formulated for freshwater crustaceans.
Although pricey, like most German products, they're excellent. A pot used to supplement the foods outlined earlier would be an excellent approach, and economical too.>
Re: Can you tell me what kind of Crayfish I have? 6/21/11

Neale, it has gravel not sand.
<Acceptable, but less fun, and I'd argue less easy to keep clean -- dirt sits on sand and can be pipetted out with a turkey baster (a great tool for the aquarist!). Gravel has gaps that let dirt sink down, so while it
*seems* cleaner, it's not.>
Where is the best place to get the sand?
<In the US, pool sand seems to be the easiest and cheapest option. Here in England, I tend to buy something called smooth silica sand (also called smooth silver sand as opposed to sharp sand) that is widely sold in garden centres. In either case, the stuff is very cheap.>
Do they have it at a pet shop?
<Some pet shops have non-calcareous sand (as opposed to the coral sand used in marine tanks). But they usually charge several times what garden centres charge.>
And I know I sound stupid but what is a "Pot" you mentioned to supplement the diet?
<Pot, as in a container. I meant you could buy one container of fancy-pants JBL food, and use it to supplement the kitchen and frozen foods.>
<Cheers, Neale.>
Re: Can you tell me what kind of Crayfish I have? 6/21/11
Thank you for the information. You were most helpful and patient with me
for stupid questions. Have a great day.
<Glad to help. Cheers, Neale.>

Crayfish Identification 3/19/11
I recently bought two crayfish from Petco that were labeled as "Vanilla Lobster" and "Asian Blue Shrimp." Both look exactly identical except the Vanilla Lobster is completely white and the Asian Blue Shrimp is, well, blue (but not a dark hue like that of and Electric Blue).
<These are rather odd. >
I live in WA and LFS label crayfish as lobsters and shrimp to get around a law preventing the selling of crayfish as they are an invasive species and people release their pets into the wild regardless of how wrong it is.
<Indeed. In the UK, the only crayfish that is routinely and legally sold as an aquarium pet is Cherax quadricarinatus, a tropical species from Australia that cannot survive in UK waters. Unfortunately, for you, there are other Cherax species from Asia and New Guinea that share the same blue colouration, such as Cherax sp. "Blue Moon" and Cherax destructor. On top of that, some of the North American Procambarus species occur in blue morphs as well, including Procambarus clarkii "blue" and the standard form of Procambarus alleni. Incidentally, Procambarus clarkii is also available in a white morph, Procambarus clarkii "white". Some of the larger fan shrimps can be mistaken for crayfish, most notably Atyopsis gabonensis, but I don't think that's the issue here. Similarly, big Macrobrachium species do turn up in the trade, notoriously the giant species Macrobrachium rosenbergii, but these are so distinct in terms of the length of their arms that they're unlikely to be confused with crayfish, despite the same blue colouration.>
I was wondering if you could please help me identify what species of crayfish they are.
<Not really; but if Google some of the Latin names I've given you, and visit the better crayfish sites like http://www.crusta10.de (you'll need to be able to read German to make much headway there) and compare my suggestions to what you have, you might be able to pin things down yourself. Cherax species shouldn't be viewed as "bad" in the sense of being pests in your part of the US, because they're all warm-climate animals with minimal tolerance for freezing conditions in winter. But further south in the US they may be less welcome, and on the whole, the very limited usefulness of crayfish doesn't (in my opinion) offset their potential for causing harm. Since you CANNOT keep non-dwarf crayfish safely alongside other fish -- they're ALL opportunistic predators to some degree -- they're really of interest only to those very few aquarists willing to set up a crayfish-only system.>
I have enclosed pictures to hopefully help. The picture of the Blue Crayfish is not a picture of my specimen (mine was avoiding my camera at all costs) but of one that is identical.
Thank you for your time and effort.
P.S. Sorry about the two pictures of my white crayfish being so large. I don't know how to make them smaller.
<On the Macintosh at least, use the default image viewer, Preview, choose "Adjust Size" from the Tools menu, and then use the pull-down Fit Into'¦ option to choose a useful size, say, 640 x 480. Then choose "Save As'¦" from the File menu, and save the resized photo where you want it. Easy as pie! I assume there's something broadly similar on Windows. Cheers, Neale.>

Can you identify, please? 3/15/11
I have found lots if great info on your site, and was hoping you can tell me what species my lobster/crawfish (not sure) is?
<Looks like the Electric Blue "Lobster" to me, Procambarus alleni. It is in fact a crayfish, despite the name. Doesn't do well at tropical temperatures, usually succumbing to a bacterial or fungal infection; keep
at room temperature instead. This species is primarily a scavenger that consumes a good mix of plant foods alongside carrion, but under aquarium conditions will attack fish and shrimps during the night -- do not mix with fish or other tankmates! Dose the tank with iodine as per marine aquarium requirements, but at 50% the dose stated on the bottle. Without iodine these crayfish often fail to moult reliably. Cheers, Neale.>

Re: Can you identify, please? Crawdaddy, now incomp. 3/16/11
Thanks; I suspected he was an electric blue. I do add iodine, started adding shortly after discovering your site, just after I acquired the crayfish.
Just to let you know my experience with him - I got him when he was just under 2" (he's molted once that I know of, its been a few months that I have had him), & added him to my community fish tank. I have a mix of guppies, platys, tetras, Danios, & mollies; 'Krusty' and the fish seem to get along well - the platys actually hang out in his cave with him, and he doesn't seem to mind them visiting.
<Cool. But don't trust him completely! Any signs of physical damage, especially to the slow-moving Guppies, and whip him out. Yes, these animals are largely herbivorous in the wild, but they will catch small fish given the chance.>
I do make sure I drop food at the entrance to or just inside his cave, as the fish tend to not leave much for him otherwise. He cruises the tank at night, sometimes in the morning as well, provided I leave the light off.
<Indeed, they are very nocturnal.>
All that being said, I don't think I would recommend anyone add one to their fish tank, unless its a large enough space with sufficient shelter and cover (I have lots of live & plastic plants, so even when not in his cave my crayfish has plenty of hiding places).
<Are indeed fascinating pets, but on the whole, best kept in their own tank. Cheers, Neale.>

Dear Crew,
What species of fish is this and how do you care for it? 8/5/10
[image: Blue Cray's Avatar] <http://www.fishforums.com/forum/members/blue-cray.html>
Thank you, Dante G.
<No idea. We're not members of that forum so can't see the pictures. For what it's worth, the Electric Blue Crayfish is Procambarus alleni, an Australian species that's easy to keep in -- it's own!!! -- tropical aquarium. Cheers, Neale.>

Keeping Freshwater Crayfish (Yabbies, Koonac, Crawdad) Using WWM 1/23/07 I live in Australia, in Australia we call freshwater crayfish "Yabbies" or "Koonac". In America I think they call them "Crawdads", I wanted to find out some info on keeping them. Thanks Dylan <Mmm, yes... See WetWebMedia.com re... the indices, search tool... with these terms... We have articles, FAQs files re these crayfishes. Bob Fenner>

Differences between lobsters/crayfish/species....? 1/26/06 I recently purchased an "electric blue lobster" from a trusted pet store, but when I search the internet for information, I find many different names/species/varieties. <Yes... you start to understand the value in scientific names... many organisms have more than one common moniker, and these are often applied to more than one species> I called the pet store to see if they knew the Latin name of the species they sold me, but to no avail. I have searched for hours for a way of determining what it is that I have actually purchased. Could you enlighten me as to what the physical differences are between lobsters versus crayfish, species of crayfish, and how to identify what variation I have? <Can... a beginning... both common names are applied to a few groups of crustaceans... marine and fresh... that is, the terms crayfish and lobster are often used for different taxonomic groups... They are not definitive as to their systematic classification> I also wanted to commend you on the fantastic website you have here. I am extremely impressed (almost a little overwhelmed) by the enormous amount of information you supply. Thank you!! Tammy <A photograph will be useful here. Have you read through the freshwater and marine articles on crayfish and lobsters posted on WWM? There are some pix, systematic information, identifications there. Bob Fenner>

FW Crayfish in N. America ID - 1/30/2006 What Would These Interesting Specimen Be Classified As. I Fish Them Out Of The Delaware River. <Are some sort of crayfish... aka crawdad... Use your search tools to find more by putting this word and "Delaware River". Bob Fenner>

Shrimp/Crayfish As a Valentine's Day gift for my two sons, my husband purchased two African Clawed Frogs, while the man at the pet store was trying to catch the albino frog, he came across a little guy my oldest son likes to call "Pincher." He gave him to us for free since he wasn't sure what he was. I think he's either a shrimp or crayfish of some kind. How do you tell the difference between the two? He's about 1 inch long with two pinchers and a grayish/brown color and a flat fan like tail. I would greatly appreciate your answer. Thank you. Susan <Hi Susan, generally crayfish are larger than shrimp. It's hard to say without a picture. Does it look like any of these: http://www.thekrib.com/Fish/Shrimp/ Regards, Gage>

Shrimp/Crayfish I am going to try and get a picture sent to you of "Pincher". <Awesome> I looked at the site you sent and couldn't find any one shrimp that looked enough like him, they all resembled him but not enough for me to say he's a shrimp. The only other way I can describe him is he likes to hoard food, he at first didn't mind the African Clawed Frogs but then suddenly started to chase them around and even pinched off some of the little albino frogs toes. <Maybe a crayfish, they are pretty aggressive.> He has dug himself a little home in the gravel under a decoration in the tank. I know this probably doesn't help you much more, so like I said I'm going to try to get a picture sent to you. Thanks for all your help. <In my experience freshwater shrimp will usually do their best to hide and avoid confrontation with anything and everything. This sounds like a crayfish to me, I named mine "fish pinchin' crawdad" I'm working on a country song about him. A picture would be great. Regards, Gage> Susan

Blue Water Lobster Dear Bob <Hey there - I'm not Bob, but I am the freshwater invert-obsessed Sabrina - hope I can shed some light on your new critter.> We have a Blue fresh water Lobster but are having a few tiny problems with him/her and wonder if you may have any answers? <Hmm.... I've seen a few different animals that fall under this name, any of which might be the critter you've got. It could be any of a handful of Procambarus species (crayfish) that is blue or has a blue form; or could be either of two blue Macrobrachium shrimp species - M. rosenbergii from Thailand or another species from Mexico. A picture would go a long way to identifying it, if you've got one.> He is attacking the big Plec and ripping the Pleco's fins. He has also started recently to kill the smaller fish by grabbing them with his claws. <For any of the species above, this is quite normal.... they don't play well with fish.> Is there any way we can stop this? <No, not really. Separating him from the fish is pretty much the only way to end the carnage.> We have now put in a ceramic pot and cave entrance to give him a safe cover, will this help combat the problem? <No, unfortunately. Regardless of which of the above critters it is - they're aggressive, and fish-hungry.> We feed him on prawns <Excellent food for 'em> and specially bought crab cuisine which states is ok for Lobsters. Should we be feeding him anything else? <Ocean Nutrition's frozen Formula One is a good food choice.> We have looked everywhere for a book on Lobsters but have had no luck. <Do some Google searches on 'blue crayfish' and 'blue prawn', as well as the above Latin names.> He is now about 4 inches long without counting the claws. <And will grow about twice that> He is shedding about every three to four months and eats his shell afterwards. We have had him now for ten months and has shed three times. He is showing signs of being due for another shed as he is constantly laying on his side and acting as though he is dead, which we have noticed he does this just prior to shedding in the past. <I don't think that's a good sign.... perhaps try adding iodine to the tank (use Kent's marine Iodine supplement); one drop per ten gallons every week.> He is constantly shoveling the stones about, we have had to change from a sand bottom as he kept blocking the filter with the constant moving of the sand. We now have an undergravel filter. If you have any information that will help our Lobster Rocky to have a good life, would you please be so kind and inform us? <I am sorry for the news that he'll be always incompatible with most fish; he may warrant a tank of his own. There are a few fish compatible with these animals; do some Google searches to try to find out exactly what you've got, and hopefully that'll help you out some. Wishing you well, -Sabrina> Thank you in anticipation. Yours sincerely Mr. John Edwards

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