- Burrowing Crawfish Problems: Getting Rid of Crayfish In The Garden
- Crayfish Mounds in Lawns
- How to Get Rid of Crayfish in Your Yard
- Permanent Solutions to Crayfish in the Landscape
- Crawfish In Your Lawn? Hope You’re OK With That
- Here’s how to remove crawfish holes from your lawn
- Worm Castings Problems: What Do Worm Casting Mounds Look Like In Lawns
- What Do Worm Casting Mounds Look Like?
- Worm Castings Problems
- Removing Worm Castings in Lawn
- HAVE FUNNEL ANTS GOT YOU BEAT?
- Other Common East Coast Australian Ants that are Pests
- A surprising defense against cyber harassment
- Ever go fishing in a crawfish hole?
Burrowing Crawfish Problems: Getting Rid of Crayfish In The Garden
Crawfish are a seasonal problem in some regions. They tend to make burrows in lawns during the rainy season, which can be unsightly and can have the potential to damage mowing equipment. The crustaceans aren’t dangerous and don’t hurt any other part of the lawn but often their burrows are cause enough to want them gone. Getting rid of crawfish is not that easy and really should start with re-sculpting your yard. Try these tips for removing crayfish in the garden.
Crayfish Mounds in Lawns
Burrowing crayfish problems are primarily a nuisance and an eye sore. These crustaceans feed on detritus and whatever they can scavenge. They don’t do any harm to landscape plants and their burrows don’t permanently damage turfgrass roots.
About the biggest complaint are crayfish mounds in the lawn. These don’t get as numerous as say, mole hills, but they can be unsightly and a tripping and mowing hazard.
How to Get Rid of Crayfish in Your Yard
If you have a population of terrestrial crayfish living in your landscape, you can try to consider them a unique wonderful creature sharing your space or you can try to get rid of them. In cases where the animals are in great numbers or when they pose a danger, getting rid of crayfish may be necessary.
The first thing to consider is making a more inhospitable area by terra-scaping so there are no boggy areas for crayfish to build burrows. They tend to like the low lying areas of the garden where run-off collects. Another option is to install solid wood or stone fences that are snug to the ground, but this can be costly and time consuming.
Fixing the mounds is a little thing because you can knock them over, rake out the dirt or water it in with a hose. However, just because you got rid of the mound doesn’t mean you don’t still have crayfish in the garden. If your property has a stream nearby and low lying moist areas, the critters are going to persist. They live in the burrows and have a secondary tunnel to the stream where they breed.
During rainy periods you may be able to see the animals on the surface of the soil. There are no pesticides, fumigants, or toxicants labeled safe to use on the crustaceans. Any poisons will contaminate the adjacent water. The best way to remove the animals is with trapping.
Permanent Solutions to Crayfish in the Landscape
Traps are humane and non toxic. You don’t have to worry about poisoning other animals or leaving persistent residue in your soil. To trap crayfish, you need metal traps, some bait and soil anchors.
The best baits are meat that is slightly off or wet pet food. The stinkier the better according to pro baiters. Lay the trap near the burrow and bait it with the food. Anchor the trap with soil staples or something similar so the animal doesn’t drag it off. Check traps daily.
Use gloves when removing the crawfish. If you don’t want to have burrowing crayfish problems again, don’t release them to a nearby waterway. They make excellent bait for fishing or you can take them to a wild area and release them. This method is safe to your landscape, family and even the crayfish.
Crawfish In Your Lawn? Hope You’re OK With That
Call them crayfish, crawfish, crawdads, or mudbugs, ’tis indeed the season for crawfish —- and the clay chimneys they leave for a calling card —- in yards and ditches all over Northeast Texas.
If there’s a love ‘em or hate ‘em animal living deep in the soil beneath your otherwise manicured lawn, it is the crawfish. Foodies and animal lovers love them (for admittedly different reasons); people mowing their yards hate the mounds and holes they leave everywhere.
So let’s say you hate ‘em. Let’s say you want to rid them from your property. What exactly can you do about it? Well, the short answer is, you can get used to them.
Listen Listening… / 6:00 Crawfish are common on menus and in lawns in Northeast Texas. Some people consider them a nuisance. Turns out, they’re pretty hard to get rid of. (KETR/Scott Morgan)
“It’s almost like mosquitoes,” says Dr. Rusty Gaude, a crawfish expert at Louisiana State University. “If your habitat is acceptable to them, then you will eventually have them.”
And, like mosquitoes, they’re not easy to get rid of because they’re ubiquitous, they move fast, and they’re patient.
Gaude is aware that some people might consider using a pesticide to get rid of the crawfish on their property. Don’t. For one thing, there are no pesticides approved for use on crawfish. Those little mudbugs are highly resistant to poisons and they live near the water line under the soil anyway. That means that even if there were a poison for them, you’d have to use supervillain-level amounts of pesticide to reach them. And that would contaminate the groundwater.
And, Gaude says, even if you killed off all the crawfish on your property, the next rainfall would just bring them skittering over from your neighbor’s yard.
“Their big game is waiting,” he says. “They burrow down into these chambers and basically wait for some sort of water event, be that rain, a flood, dishwasher backs up, whatever. And then they will make a very quick and definitive move to get out and start completing their life cycle.”
For the record, there is one environmentally safe substance that seems to work well against crawfish ‒‒ potassium hydrochloride, a caustic salt known more commonly as lye. But just in case you thought there wasn’t a catch, lye is a key ingredient in making crystal meth.
Technically, it is entirely legal to buy lye, even in bulk. Special Agent Elaine Cesare at the Drug Enforcement Administration office in Dallas says drugmakers use red devil lye — the kind used to make soap and homemade cleaning agents —- to mellow out the GHB in meth. And yes, GHB is the charmingly monikered date rape drug.
Regardless, lye is not regulated, meaning it’s not legally considered a precursor chemical. So you can buy all you want – if you can find it. Turns out, asking a store clerk at a big box home center for a 50-pound canister of lye is a sure way to elicit some stunningly interesting looks.
Beyond the chemicals and meth recipes lie drastic measures like draining the ground. Which would, also for the record, would succeed at killing crawfish. But that’s a whole other problem.
“You’re not going to effectively get rid of all the water in the ditch without effectively getting rid of all the water in your yard that’s underground that you can’t see,” says Dr. Zachary Loughman, a crawfish researcher at West Liberty University in West Virginia. “What you’re doing is, you’re making your yard a desert.”
About a decade ago he did a survey project on crawfish around eastern Texas. And, like Rusty Gaude, Loughman says there really is not a good way to get rid of them. His advice?
“Learn to live with them,” he says.
So instead of than being angry at these hardy ditch dwellers for ruining your mower blades and uglying up your yard, perhaps a change of attitude is the better bet. While Loughman sympathizes with lawn enthusiasts everywhere, he says crawfish in the ground are actually quite beneficial to the environment.
“Crayfish are really, really important to ecosystem functioning in that part of the world you’re in,” he says. “The amount of soil that they’re moving is insane. There was one study that found that there was over 40 tons of soil being moved in these forests by these crayfish over the course of a year, and if you lost that function from the ecosystem, all the plants that live there would probably die.”
This is all well and good for forests and ditches and yards. But when crawfish get into streams or river beds, their aggressive, invasive nature can completely upend an established ecosystem —- like they’ve done in Southern California. Dr. Lee Kats is a professor of biology at Pepperdine University in Santa Monica. His current research is on the causes of amphibian decline in Southern California, and his shortlist of suspects begins and ends with crawfish.
“Ecologically, they’re nothing but negative,” Kats says. “They’ve already driven some of our local amphibian species to extinction from some of our local habitats.”
Kats says that “kindhearted” fishermen in the 1960s, using crawfish as live bait, released leftovers into the Santa Monica waterways, not realizing what ecological damage they were about to unleash.
“Native amphibians were in all of my local streams in the 1970s,” he says. “But by the 1980s they were wiped out and our data show that it’s probably the crayfish that wiped them out in that 10-year period.”
Moreover, Kats says, crawfish insatiably feed on the eggs of amphibians and invertebrates — critters that eat mosquitoes. But they themselves don’t eat mosquito eggs because they’re too small.
So the implications are obvious for Northeast Texas, where mosquitoes are plentiful and known carriers of West Nile virus. But therein lies a pressing question: Do those crawfish in the yards and ditches pose a threat to freshwater aquatic life in this region, if they get into the waterways?
Well… maybe. Dr. Tim Patton, a biologist at Southern Oklahoma State University says Northeast Texas and Southeastern Oklahoma lie just north of the native range for red swamp crawfish —- the type in most yards in the region. And also the type gumbo enthusiasts prize most. The trouble is, it’s hard to know what, if any, negative effects crawfish might have by being almost-native —- because, as it turns out, no one is looking into the matter.
Here’s how to remove crawfish holes from your lawn
The one thing that seems to work is lye, Lutz said. He indicated that this is for small scale areas. Pour 1 tablespoon to 2 tablespoons of lye in each crawfish hole. Knock the burrow over and pour lye directly into the hole. It will kill the crawfish, and as it migrates through the soil, lye turns into harmless by-products.
Wear hand and eye protection when applying the lye.
– Prune flowering roses, ever blooming roses, in late August to early September.
– Dig and store gladiolus corms in a well-ventilated, freeze-proof place for planting next spring.
– Plant sunflowers in late summer for fall flower arrangements.
When should I plant Brussels sprouts for maximum production?
Answer: Brussels sprouts will produce best when daytime temperatures average about 65 degrees or less. In Louisiana, they do best planted in late summer for early winter harvesting.
What are some leaf lettuce varieties that do well in Louisiana?
Answer: Red Salad Bowl, Grand Rapids, New Red Fire, Tango, Red Sails, Salad Bowl, Simpson or Elite. Most leaf-type lettuce varieties will mature in six weeks to seven weeks from seeding.
Barton Joffrion is a horticulturist with Terrebonne Parish’s LSU AgCenter office, 511 Roussell St., Houma. He can be reached at 873-6495 or [email protected] For information, visit www.lsuagcenter.com.
Worm Castings Problems: What Do Worm Casting Mounds Look Like In Lawns
Worms are more than slimy fish bait. Their presence in our soil is crucial to the health and nutrient level of this growing medium. Lawn worm castings are the result of these organisms eating and processing detritus and organic debris. Worm mounds in yard and garden areas can be annoying and make holes in turf grass, however.
In order to manage these piles of castings, it is important to answer the question, “What do worm casting mounds look like?” Once you are armed with a bit more information, you may decide that worm castings problems are worth living with when compared to the benefits they provide for your garden.
What Do Worm Casting Mounds Look Like?
If you have small, quarter sized piles of dirt in your yard or garden, you are lucky! Worms eat organic garbage and excrete it out as nutrient rich castings. Their activities increase the tilth and overall health of your soil.
The little domes of soil are proof you have a large populations of beneficial
earthworms. Their tunneling activities aerate the soil and bring oxygen to plant roots. The tunnels also increase the percolation and water penetration of soil and sod.
Worm Castings Problems
The nutrients in worm castings are important for plant growth. Worm mounds in yard areas are more of a problem than those in garden beds. Worm mounds in soil are just concentrated nutrients and cause no harm to most plants. Worm castings in lawn area, however, cause more of an issue.
They make the turf lumpy and uneven, and the grass around the area yellows and dies. This is due to the extreme concentration of nutrients, which burn the grass. The gardener who desires perfect green grass will find lawn worm castings annoying but the benefit to the entire garden may outweigh the desire to eradicate the worm population.
Removing Worm Castings in Lawn
The little mounds may pose a tripping hazard and small dead spots in the lawn destroy the beauty of a well cared for grassy area. If these details send you over the edge and you need to kill the earthworm population, think twice! There are chemicals you can use to kill worms, but they generally kill other beneficial soil organisms too.
You can use a heavy roller to smooth out the hills and then core aerate to decrease the compaction. Worm mounds in yard sites can also just be knocked over with a rake. Spread out the nutrient rich casting to benefit more of the sod area and prevent the concentrated burning.
If you want to minimize worm activity on the surface of the soil, reduce watering. Moisture is attractive to the worms and they are busiest when soil is soggy. The best and easiest idea is to just sit back and enjoy the work of these wonderful organisms and the benefits they bring to the rest of your garden.
HAVE FUNNEL ANTS GOT YOU BEAT?
If your neighbours have an infestation they do not need to have a treatment for your funnel ant treatment to be effective, but if you book together, the price can be reduced.
Why wait any longer? Call us now and reclaim the pride you once had in your lawn!
Other Common East Coast Australian Ants that are Pests
The black house ant, white footed house ant and the coastal brown ant are the main pests that will invade your home. Most often they will nest in the wall cavities of your home, foraging outside to feed and bring food back to the nest.
You have most likely discovered loose grit at the bottom of skirting boards, window frames and under light fittings. This debris is the result of the ants throwing out their rubbish such as dead ants and unused food. While currently classed as a ‘nuisance pest’ they are becoming an economic pest due to their ability to pack out a power point, fridge and air conditioner motors and smoke alarms with their nesting habits and materials.
We can safely treat these ants with an external treatment that targets just the ants and give a 3 month warranty on treatment with many treatments lasting up to 6 months and still counting.
Please phone or email us to make a booking or for any additional information you need in regard to pest control or termites around your home or business.
Proprietor: Michael Powell.
A surprising defense against cyber harassment
Image by Perkons via .
Summer starts this week, a great time for a fish boil. What would you call the creature above?
No, it is not a baby lobster or an odd-looking shrimp. What you call it probably depends on where you grew up. You might know it as a “crawfish,” “crayfish,” or “crawdad.”
That last one is probably the least well-known, but not the most unfamiliar. People flocked to Merriam-Webster to look up “crawdads” after the author Celia Owens appeared on a television program to discuss her first book, Where the Crawdads Sing. (The answer: Only in the wilderness, when only you can hear them. And then you’re probably imagining it. Crawdads don’t sing.)
ICYMI: Hand signs are useful—but not universal
“Crawdad,” M-W helpfully explained, “is the synonym of the words crawfish and crayfish that is used chiefly west of the Appalachians to mean the aquatic animal that looks like a small lobster and lives in rivers and streams.” In our experience, they are also called “crawdaddies,” a diminutive. And in a few places, The Dictionary of Regional English says, they’re called “crawdabs.”
But they’re not fish; they’re crustaceans, cousins of lobsters and shrimp and crabs and other species. They didn’t get their fishy names because they live in the water. In fact, some “crawfish” live on land as well as in water. Instead, as M-W says:
Crayfish is an altered form of the Middle English word crevis, which derived from the Anglo-French word creveis, which had the stress on the second syllable. This syllable was heard and repeated as -fish frequently enough to alter the word toward the more English-sounding name.”
“Crawfish” is probably the most common usage in the United States. Expand the regionalism even farther, though, and you might find “crawfish” in London fish markets. But there, it’s really a “spiny lobster,” also called a “thorny lobster.” Those are lobsters with nice tails, but without the big claws.
Image via Wikimedia Commons.
There is yet another cousin, which the French call “langoustine,” and they look like this:
Image via Wikimedia Commons.
Those look more like “crawfish” than “lobster,” with longer claws.
Wait. It gets worse: These “langoustine” are also called “Dublin Bay prawns,” M-W says. “Prawn” is usually thought of as a synonym for shrimp, though, scientifically speaking, the “prawn” family includes, M-W says, “any of various widely distributed edible decapod crustaceans” including what we’re calling here “langoustine.” (The French word for “shrimp” is “crevette,” taking us back to “creveis.”)
But wait. There’s more! You can also find “langostino.”
Despite its Italian-sounding name. “langostino” comes from the Spanish for … “spiny lobster” or “little lobster.” Though they are sometimes marketed as lobster (and also called “squat lobsters”), they are more closely related to hermit or porcelain crabs. This helpful chart from seafoodsource.com shows the difference.
In the United States, food labeling is supposed to tell you what you’re eating. As Seafoodsource says, menus and other food labels can call “langostino” “lobster” as long as a modifier is added, like, um, “langostino lobster” or “squat lobster.” But in 2016, Inside Edition tested the “lobster” at 28 restaurants nationwide and found that more than a third were charging for lobster but selling something cheaper, including “langostino.”
Restaurants and seafood stores, seeking to attract classier audiences and higher prices, might be prone to crustacean inflation, where the fancier word replaces accuracy in labeling.
So the next time you go to buy some “langoustines,” make sure they’re not really “crawfish,” “crayfish,” or “crawdads,” which you might be able to pick up in a muddy backyard.
Or just order a burger.
ICYMI: How cadence influences sentence structure
Ever go fishing in a crawfish hole?
Did you ever go crawfish fishin’ in a crawfish hole?
If not, well, you’ve missed out on a grand childhood activity.
Maybe you know the crawfish as a crayfish, crawlfish, crawdad, crawdaddy or even mud bug. Names vary by region. There are hundreds of species of this lobster-like crustacean and just about as many names. Most people would think it was a shrimp.
The scary little buggers live in a hole they dig in the ground, piling up mud above it in what looks like a chimney. Such holes can be 2-3 feet deep or more, depending on the water table. They dig down for safety, but mostly to get to water. It is said the crawfish is about as wide as the hole it creates, and I have seen crawfish holes bigger than two inches in diameter. They can breathe outside of water, but must stay moist to survive for long.
Holes can interconnect. In wet areas, I have stomped on one hole and seen water spout out of other holes many feet away. An old and dangerous way to get rid of crawfish was to place carbide pellets in the water, cover the hole, and light the resulting gas. The explosion can be a sight to see, if you don’t blow your foot off or get mud blown in your eyes.
Crawfish are common in many wetland areas around the world, but not so much in others. I remember a schoolteacher friend who moved to Bullitt County. He had never heard of crawfish holes and, upon noticing a yard full of them for the first time, was told by fellow teachers that they were snake burrows. For the longest time, he was scared to death to walk outside.
Crawfish, of course, also live in creeks. I have netted many a one over the years out of creeks to use as bait for real fishing. You have to be careful of those pincers, though. Man, can they hurt!
Ah, but catching crawfish in a crawfish hole takes special patience that perhaps only a child on a long summer evening can possess.
The good thing is that you need no special equipment. As a young boy, my favorite gear was simply a long weed stem with a seedpod on the end. Some people like to use a green onion stalk or maybe a bit of bacon on a string. You take the “bait” and slip it gently down the hole, making it seem like a bug. Sooner or later, the crawfish either attacks the bait as food or gets irritated at it and snaps it with its pincer. When you feel the nudge, quickly yank the bait out and the crawfish comes with it before he thinks to let go.
My brother and I had the chore of removing the crawfish hills, or “chimneys,” from the yard so Dad would not damage his lawnmower while cutting the grass. Those sun-baked-mud chimneys could be very hard, or like clay when wet. Either way, they hurt when Dale and I, being the boys we were, would throw them at each other. They made great pretend hand grenades as well when we would lob them up into the air.
Believe it or not, I have seen crows fish crawfish holes. For quite a few years in my yard I would watch several crows land, each selecting a crawfish hole, and then just stand there with beak just above the hole, set to spring like a trap. Eventually, SNAP!! When I checked later, I would often find the empty shell of the unlucky crawfish lying by its home. The crows did a good job of it, almost wiping out the crawfish population in my yard.
Honestly, I don’t remember what I did with the crawfish when I caught them. One at a time was no good for a meal to me. I probably showed them off to my buddies like a hunting trophy. Ah, the days of youth …
♫-You get a line and I’ll get a pole, Honey,
You get a line and I’ll get a pole, Babe.
You get a line and I’ll get a pole,
We’ll go down to the crawfish hole,
Honey, Baby mine. ♫ (folk song)
The Question: What kind of animal builds a 3-4 inches (8-10 cm) high mound of mud balls with a 1 inch (2.5 cm) hole in the top? They look like mini volcanoes. I have found a couple of these in a swampy area near a river. I live in Michigan.
Submitted by: Debbie, MI
The Short Answer: Debbie, that sounds like one of the many species of burrowing crayfish (also called crawfish or crawdads). They dig tunnels down to dampness or even to the water table. And they push up muddy soil out of their burrow into a mini volcano shape, with a neat hole at the top. They’re generally nocturnal, so during the day, all you’ll see are the volcanoes, which can be quite numerous. I have spent most of my life in New England, where I don’t believe any of our native crayfish are burrowers. But when I lived in Wisconsin and Kentucky, they were very common. This site has a checklist of the native species of crayfish in Michigan: http://iz.carnegiemnh.org/crayfish/country_pages/state_pages/michigan.htm. There are two burrowers on the Michigan list, the digger crayfish (Fallicambarus fodiens), and the devil crayfish (Cambarus diogenes). The digger crayfish is primarily aquatic, but sometimes digs burrows out of the water. The devil crayfish, however, is a primary burrower, meaning that it lives most of its life in its burrow. So I’m going to guess that’s what you have. For a picture, go to: http://iz.carnegiemnh.org/crayfish/NewAstacidea/species.asp?g=Cambarus&s=diogenes&ssp
More Info: Burrowing seems to be a good strategy for crayfish, as crayfish all over the world have developed a very similar lifestyle of digging complex burrows down to damp or wet soil. Like all crayfish, burrowing crayfish have gills in their abdomen under their shell. The gills are capable of gaining oxygen from air instead of water as long as they are wet.
Crayfish, as you might expect, are classified with the clawed lobsters (Nephropidae. There are over 600 species of crayfish, in three main groupings. The Astacidae and Cambaridae are restricted to the northern hemisphere and centered on Asia and North America, respectively. The Parastacidae are distributed throughout South America and Australia. There are no crayfish native to Africa. The Cambaridae are centered on the Southeastern United States, which has the most diverse crayfish assemblage in the world – more than 300 species, a remarkable number when you realize that they seem to occupy very similar ecological niches. There is also an only slightly less impressive collection of crayfish species in Australia. But that part of the world includes some interesting oddballs, including burrowing crayfish that can live far from any surface water. Then there’s the Tasmanian Giant Crayfish, which can reach 4.5 kilograms (10 pounds) – big even by the standards of an ocean-dwelling lobster. To see a picture, go to: http://yhsbiology.wikispaces.com/Crustacea
Trivia #1: The Tasmanian Giant Crayfish (Astacopsis gouldi) is the largest freshwater invertebrate in the world.
Trivia #2: There are two continents with no native crayfish. One is Antarctica. The other is Africa.
The interesting science: It’s easy to understand why Antarctica might not have crayfish. It’s too cold there, and there is no ice-free fresh water. It hasn’t always been that way, and at least one crayfish has been found in Antarctica, so they probably lived there when the continent was located away from the pole. But why are there no native crayfish in Africa? To read more, click here to go to Curious Nature.net, where you’ll find a companion article about the strange distribution of crayfish species around the world.
Cite this article as: Pelletier, TC. (May 12, 2010). Burrowing Crayfish Retrieved from https://askanaturalist.com/burrowing-crayfish/ on February 1, 2020.
Crayfish, aka “crawfish” or “crawdads,” are freshwater crustaceans who live on nearly every continent around the world. Sadly, in the U.S., these fascinating animals are caught by the thousands to be killed for food. 😞
When I was growing up in the South, crayfish were on nearly every restaurant menu. But after discovering that they have feelings, I decided it was time to veganize my gumbo and po’ boys.
Here are four of the many reasons why you should respect crayfish as sea life, NOT treat them like “seafood”:
1) They’re complex, ancient animals.
These neat crustaceans come in a variety of colors—even bright blue or green! They can regenerate their legs or claws if they lose them in a fight with a predator, and they have impeccable eyesight. Having found ancient crayfish fossils in Australia, scientists believe the species has existed for more than 115 million years. When left in peace in their natural habitat, they can reach the age of 30.
2) They feel pain.
Just like their lobster cousins, crayfish have a nervous system and suffer when they’re ripped apart. It’s clear that they feel pain—they limp when injured, release adrenaline-like hormones when hurt, and fight for their lives to escape being boiled alive. Which leads to our next point …
3) They’re killed in horrific ways.
Imagine if your last moments on Earth involved being boiled alive while fully conscious. Just because crayfish can’t scream in agony when they’re scared or in pain doesn’t mean that they’re suffering any less than we would. 😱
4) Eating them can make you sick.
Shellfish poisoning is no joke. According to the Centers for Disease Control and Prevention, every year in the U.S., 80,000 people become ill—and 100 die—after becoming infected by Vibrio, a type of bacteria sometimes found in shellfish. Numerous studies have also found high levels of mercury and other toxic chemicals (including DDT, PCBs, and dioxin, which have been linked to cancer, nervous system disorders, and fetal damage) in fish flesh.
Pro tip: You don’t have to worry about getting sick from eating vegan fish.
The best way to help crayfish, lobsters, crabs, and all other animals is to go vegan.
Need help finding recipes? Sign up for a peta2 vegan mentor!
By Justin Pierce
Many people associate crayfish with their youth. Mention the word “crayfish” and people respond with something like “oh ya, I used to catch them down at the creek when I was a kid”.
However the hobby of keeping crayfish in captivity has been rampantly growing in popularity among people of all ages. Being able to observe them in an aquarium fosters appreciation beyond the simple childhood curiosity. This is especially true in Japan and some European countries where they have been quite en vogue for decades. The United States usually plays catch-up with aquarium trends, and is following suit with its own crayfish craze. Crayfish are becoming more commonly seen for sale in aquarium stores and in Internet auctions and websites.
This gain in popularity comes at no surprise to the people that are familiar with crays. Once exposed to their interesting behaviors, individual personalities and attractive colors and patterns people often develop the extreme fascination that borders on obsession, similar to many other aquarium genres. I thought I would take a moment to write an article that covers the very basics of keeping crayfish. This should give all those people interested in becoming involved with crayfish a foundation on what it takes to do so.
Hopefully you will see that they are very easy to care for, which is one of the endearing qualities making them so popular.
Crayfish are among the least demanding animals kept as pets, making them suitable for both children and adults. Compared to other aquatic and semi-aquatic animals, they only require the simplest living conditions, with filters and air pumps being optional extras rather than essential pieces of kit. That said, most people keep crayfish in a typical aquarium-type set up that includes a filter, and if you choose to keep your crayfish this way, so much the better. But at the bare minimum all you need for a crayfish enclosure is a small body of fresh water deep enough to cover the animal completely, and a rock or branch that allows it to climb out of the water (without being able to escape, of course!). Note that being able to climb out of the water is an essential requirement if the water is not aerated or filtered; crayfish need lots of oxygen, and in still water conditions, such as in a tank without a filter or airstone, they will get the oxygen they need from the air. But if they can’t climb out of the water easily, they will effectively drown.
Crayfish do not need to be kept a true aquarium, although this provides the best viewing of these creatures. The container can be as simple as a 5-gallon bucket or a plastic shoebox. Just make sure that the rim of whatever container you use is taller than the crayfish is long: they are amazing escape artists! If the container is not tall enough, they will probably need a vented lid to keep them contained. Crayfish are capable of climbing air hoses or anything else that extends high enough for them to reach the top.
Most crayfish burrow to some extent, whether a full-blown tunnel with complex chambers dug into the mud or simply a depression excavated underneath a submerged rock or branch. In captivity they will feel much more secure if given some type of cave within which they can reside. PVC tubes at least partially buried in the gravel are particularly welcomed by those crayfish species that build extensive burrows in the wild. Otherwise ceramic or plastic pipes cut in half lengthwise and placed on top of the substrate can be used for form shelters appreciated by most crayfish. Alternatively you can allow the crayfish to dig its own home by resting a large flat rock (like a slate) on top of several inches of gravel.
Having plenty of hiding places is especially important when attempting to keep more than one crayfish in a container. Some species are are fairly tolerant of one another provided they are not overcrowded, but others are very territorial and aggressive. Even the ones that are not aggressive toward each other most of the time may decide to attack and consume a tank mate who has recently molted. During the molting process the crayfish is weak and the body is soft and vulnerable, making it an easy meal for a hungry tankmate. Providing plenty of hiding places gives the molting crayfish a chance to escape attack during this dangerous time.
Ideally, you should remove a crayfish from its tank mates before the molting process begins and only replace it after the exoskeleton (‘shell’) has completely hardened and it is active and feeding normally. How will you know when a crayfish is getting ready to molt? Crayfish, like most other crustaceans, stop feeding shortly (usually at least a day or more) before shedding the old skeleton. If you notice that a crayfish in your collection is not eating, that could mean that it is about to molt and if maintained in a multi-specimen aquarium now would be a good time to isolate it from its tankmates. Of course loss of appetite can indicate other problems as well, so you should also check water quality and chemistry parameters and look for any signs of disease or physical damage.
If no filtration is used, the water will have to be completely changed on a regular basis, at least once per week. If gravel is used in the tank it should be vacuumed or rinsed to remove excess detritus. Otherwise a bare bottom is fine to use and easy to keep clean. Ornaments and the sides of the tank should be left untouched to leave sufficient beneficial bacteria to keep the water adequately clean. If you detect ammonia or nitrite in the water at any time that means that there aren’t enough bacteria in the tank as it is, and adding a filter will be useful.
Undergravel filters are not the best choice for crayfish since these burrowing animals will move the gravel about creating exposed areas of the filter plate dramatically reduces the efficiency of this type of filter. Internal or external canister filters as well as hang-on-the-back filters that provide for biological filtration are a much better choice. Air-powered sponge filters also work great but I have found that some species like to chew on them. This never seemed to harm the crayfish, but the filter will have to be replaced after they have shaved it down sufficiently. The possibility of their digestive tract becoming impacted from the indigestible sponge material should not be completely ignored, but I have never seen any evidence of this hypothetical problem.
Crayfish come from both temperate and tropical zones, and water temperature will depend upon which species you are keeping. A heater is not required and should not be used in tanks holding most of the North American species, though species from the southern United States can tolerate temperatures as high as 82 degrees F (28 degrees C) without problems. Two very popular North American species are Procambarus alleni and Procambarus clarkii, both of which are species from the southern US. Colorful varieties are grown in large numbers in ponds specifically for the aquarium industry.
But other North American species are showing up in the trade, albeit on a much smaller scale, and in the case of these less frequently seen crayfish you should make sure you know where they come from so that you can maintain them at an appropriate temperature. As a general rule though, erring on the side of keeping North American species too cool is better than keeping them too warm, and most do well left at room temperature.
Australian species are increasingly popular, and most of those require tropical temperatures around 77 degrees F (25 degrees C).
Crayfish are omnivorous scavengers, feeding primarily on plants, algae and organic detritus. Crayfish do not often find sources of animal protein such as a dead fish, and such meals are very precious to them, aggressively defending such a meal against other scavengers.
But will crayfish actually kill and eat your fish? In an aquarium it is uncommon for crayfish to catch and eat healthy fish, though the odds on such an event depend on the size of aquarium, the number of fish in the aquarium, what species of crayfish is being kept, and even whether the crayfish is well fed or not. So while it is unlikely that a crayfish will catch your fish, there is a possibility, particularly where small or slow moving fish are concerned. Most of the time crayfish are seen eating a fish that fish was already dead or dying, and the crayfish was simply doing its natural duty of being a scavenger. Without knowing this, the aquarist might falsely accuse the crayfish of murder when he notices the crayfish chewing on the carcass!
Crayfish need to be fed a small amount of food every other day or so. Any excess food should be immediately removed. Foods to feed your crayfish include leafy green vegetables such as Romaine lettuce (or other varieties); dried seaweed like Nori; sinking pellet foods such as shrimp or algae pellets; flake food; and freeze dried or frozen foods such as fish, krill, tubifex worms, bloodworms, squid, clam, etc. Since animal protein is rarely encountered in the wild, it is best to feed crayfish mostly plant or algae based foods, and only supplement with animal flesh. However, some aquarists feed strictly shrimp pellets with no apparent problems.
If a crayfish remains soft for an extended period of time, i.e., for more than one day after molting, this can mean that it is not receiving enough calcium in its diet or that the pH or hardness of the water is too low. Transferring the soft specimen to water with high hardness can help if this is the problem, but it is best to avoid this problem by keeping crayfish in hard water and feeding them foods rich in calcium. There are some brands of foods specifically formulated for crustaceans that have a higher level of calcium added, such as JBL NovoCrabs Food Chips and Sera Crabs Natural Complete Diet. Calcium can also be added to other foods by dabbing moist food with a small amount of calcium carbonate powder before feeding your cray.
Crayfish sometimes die during the moulting process, a problem apparently caused by an iodine deficiency. Iodine, in the form of potassium iodide, can be added to the water on a weekly basis to alleviate problems with the molting process. Iodine drops sold for use in marine tanks work well for this, though a half dose rather than full dosage is all that is required. Foods that contain the algae Spirulina sp. or Chlorella sp. are naturally high in iodine and can be helpful as well.
It is a very bad idea to mix together crayfish from different continents. While there is a risk of spreading disease when crayfish are placed in the same tank as another one, one disease in particular poses a very great threat. Known as the Crayfish Plague it is carried by North American crayfish species. It is a fungus, Aphanomyces astaci, and American crayfish have apparently evolved to tolerate the fungus without much problem. However, it is lethal to many other types of crayfish, including those from Australia and Eurasia.
Never place any crayfish native to another continent together with those from North America. In addition, be very careful not to share any equipment such as nets or buckets when working with North American and non-North American species. The same precautions hold for gravel, pipes and other decorations.
Another disease that can threaten crayfish is White Spot Disease. This is primarily a disease that effects shrimps, but may be transmittable to crayfish if they are fed with raw food made from infected shrimp. Be sure that any food containing shrimp has been cooked in order to destroy the virus.
If you intend to keep multiple crayfish specimens in a single aquarium, be sure to quarantine all new crayfish specimens for at least a month before adding it to the main aquarium. That said, realize that crayfish diseases are often difficult to recognize and even more difficult to treat.
A final and very important comment!
Do not ever release any crayfish maintained in captivity into the wild. Also make sure that there is no possible way for the crayfish to escape into the wild; this is particularly an issue when keeping crayfish in ponds or outdoor fish houses.
Crayfish can disrupt entire ecosystems if they are introduced into areas where they are not native, as has been the case in many parts of the US and UK. Some US States have begun imposing regulations on the transport of crayfish for this reason, and in other parts of the world there may be restrictions on what crayfish can be legally sold as pets. Even if you think that a particular crayfish is native to your area, there is still the risk of introducing diseases into the wild crayfish population.
Many crayfish are only found in specific microhabitats within larger bodies of water. So even if they are native to your general area, you may be placing them in inappropriate waterway in that area. Furthermore, while there are many crayfish species with very wide distributions in a general sense, in terms of genetics and morphology there may be very distinct populations of crayfish within certain areas. It’s likely some of these populations may end up being recognized as distinct races, subspecies or even new species, so let’s make sure the genetics of different populations stay in their natural state so that researchers can get this issue straitened out!
Crayfish can make fascinating pets, but please be responsible and ensure that your crayfish stays contained. Any unwanted crayfish should be humanely euthanized or given to a responsible person who understands this issue and will house or destroy the crayfish as required.
| Crayfish on WWM:
Forget Crawfish Pie, Let’s Make a Crawfish Tank! By Gage Harford & FAQs on: Crayfish 1, Crayfish 2, Crayfish ID, Crayfish Behavior, Crayfish Compatibility, Crayfish Selection, Crayfish Systems, Crayfish Feeding, Crayfish Disease, Crayfish Reproduction,
Moulting: Crayfish need to moult as they grow because their hard exoskeletons do not allow much room for expansion. Baby crayfish can moult on a daily basis but as they grow older, the regularity of moults decreases to a period of weeks or even months. The first few days after a moult, a crayfish’s skin is very soft and it is very vulnerable to attacks from other animals and crayfish.
Early Signs: The early signs of moulting include lack of appetite and a slowdown in activity. During this period the crayfish ingests calcium into an internal organ, not into the exoskeleton.
Hiding: When the crayfish is ready to moult, it will try to find a hiding spot. Then it will move onto its back and begin fanning its pincers, legs and swimmerets (under the tail) in order to get as much oxygen as possible. The carapace will begin to crack behind the head; the new appendages then pierce the old shell; and then after about five minutes, a sudden, violent movement will detach the old shell from the crayfish.
Vulnerable: The freshly moulted crayfish will invariably be larger as part of the growing process, but is vulnerable on several fronts. Firstly, the shell is very soft and vulnerable to predators, including other crayfish and fish. The crayfish needs to eat the old shell to replace the lost calcium and stengthen the weakened carapace.
Pets: Crayfish are sometimes kept as pets in freshwater aquariums. They prefer foods like shrimp pellets or various vegetables but will eat most leftover fish food. They also have a big appetite for plants and will eat most aquarium plants. They can be aggressive and may attempt to eat fish. However, crayfish are actually fairly shy and may often attempt to hide under leaves or rocks. If you are going to keep a crayfish as a pet, remember to give it some hiding space. At night, some fish become less energetic and settle to the bottom. The crayfish might see it as a danger and hurt or kill it with its claws. Crayfish are great escape artists and may try to climb out of the tank so any holes in the hood should be covered. In nations where imported alien crayfish are a danger to rivers, such as England, catching and keeping crayfish as pets is one of the main means of the spread of destructive species – since they are often flung back into a different river.
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