Barbs and Backlashes


Crayfish by whitetips
July 6, 2010, 3:43 pm
Filed under: Fishing | Tags: ,

Alright, from the very beginning I am telling you this blog post is not going to mention fish.  It is going to mention another aquatic organism, an important prey for fish in many habitats, and the more anyone knows about that, the better angler they will be.  And, this will allow me to make a point or two in the process.  So, read on, you might learn something.

I am not a crayfish biologist and I will not proclaim to be any kind of crayfish expert.  However, I have had to learn a thing or two about Nebraska crayfish and let me share some of that with you.  Here is the only website I know of that has information specific to Nebraska crayfish, http://iz.carnegiemnh.org/crayfish/country_pages/state_pages/nebraska.htm .  There are 4 species of crayfish listed for Nebraska, but I believe by far two species are most common; the calico or papershell crayfish, Orconectes immunis and the virile or northern crayfish, Orconectes virilis.  Another great website that I have found for crayfish is a Missouri website, but it lists a lot of different species of crayfish including those found in Nebraska waters, http://mdc.mo.gov/discover-nature/field-guide/search?kind_selector=713&form_build_id=form-78c9d24c964fed36073eae53147a5750&form_id=mdc_field_guide_generate_field_guide_form&field_guide_type=959&op=Search .

calico or papershell crayfish

Virile or northern crayfish (note: I do not name 'em)

Crayfish are common throughout Nebraska and can be found in a variety of habitats; rivers, streams, pits, ponds, natural lakes, and reservoirs.  You will find crayfish in almost all of our waters and most of them will be one of these two common species.  The other species that are listed as having been documented in Nebraska waters are less common and confined to limited habitats.  Regardless of the species or the habitat, crayfish can be an important prey item for a variety of fish living in those waters.  Panfish like bluegills and yellow perch love small crayfish as well as larger predator fish like largemouth and smallmouth bass.  At times even walleyes will prey on crayfish and the largest predator fish in Nebraska waters, flathead catfish, often start their predatory careers eating crayfish.

Unfortunately, there are exotic species of crayfish that can cause problems in waters where they are not native.  One of those crayfish species that has caused problems in some parts of the United States is the rusty crayfish, Orconectes rusticus.  Rusty crayfish are native to the Ohio River basin in Indiana, Ohio, Illinois, Kentucky, and Tennessee  but have been introduced to many other “Midwestern” states.  Once introduced into waters outside their native range, rusty crayfish have caused some major problems.  Rusty crayfish have literally elminated aquatic vegetation from some waters and thus dramatically altered the aquatic habitat and food chain.  They also out-compete native crayfish and may have significant impacts on other aquatic macroinvertebrates (e.g. aquatic insects).  In some cases it is suspected that rusty crayfish prey on fish eggs.  So, once again this is another example of an exotic species that we would like to keep out of our waters.

So, let me tell you a couple of stories about rusty crayfish in Nebraska.  The first one started several years ago when a knowledgeable and concerned angler called me to report that he had purchased some rusty crayfish from an Omaha bait shop.  The angler sent me some photographs and from the little bit I knew at the time they sure looked like rusty crayfish.  My son and I then went on a little “under-cover” operation.  We drove over to the bait shop in question and I sent Daniel in to purchase a couple dozen crayfish; I used my son because I did not want to tip anyone off by going into the bait shop and having someone recognize me.  To make a long story shorter, yes, they were rusty crayfish and yes, an investigation resulted.  In the end, the bait shop owner was out nothing more than a tankful of crayfish, but the supplier who imported those crayfish into the state ended up with some hefty fines.

That was the last we heard of rusty crayfish in Nebraska until just a couple of weeks ago.  Unfortunately, we have now confirmed the presence of rusty crayfish in a small pond in Omaha.  I am going to guess that a bait bucket with some rusty crayfish in it got dumped there once upon a time.  There is no way crayfish can end up in a new state, in a new body of water, unless there was some human “assistance” involved.  So once again, let me remind folks that it is illegal to dump your bait into the “lake” when you are done fishing, and it is a very bad idea to dump any unused bait or even the water from your bait bucket into any body of water.

For more information on invasive species, and what you should be doing to prevent their spread, go here, http://snr.unl.edu/invasives/ansplan.htm .  If you want more details on the rusty crayfish, here is a short paper, Rusty crayfish Fact sheet .  We simply do not know what impacts invasive species may have in our aquatic habitats; in some cases they may end up to be nothing, but in all cases we would be better off not finding out!

If you see one of these, a rusty crayfish, in any Nebraska waters, let me know about it. Note the rusty spot on the side; that is characteristic of rusty crayfish.

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6 Comments so far
Leave a comment

didnt know of different kinds, will be on the lookout! all we need is more problems.

Comment by james gasper

That is something I’d like to see our game wardens cracking down on is dumping bait buckets in our lakes. I’d rather see (and we should be seeing)blogs bragging about new state records on game fish instead of carp, suckers, rudd etc. These junk fish can get in the lakes through feeder creeks but dumping bait buckets will ruin a lake. G&P puts bluegill in lakes to feed the other fish we don’t need minnows chubbs goldfish stocked in our lakes.

Comment by Jeff

I agree, I wish we could catch every “bucket biologist”! We will never catch all of them, so I will continue to “preach” how important it is to NOT dump your bucket in the “lake” when you are done fishing.

I wish we would see more sport fish state records broken too, but keep in mind that many of the records we have established for those sport fish species are records that will be hard to beat. One reason we have seen more nongame fish records broken in recent years is because the “bar” for many of the nongame fish has not reached the potential for those species, yet. We will continue to see some of those nongame fish records exceeded, but there are enough folks pursuing records for those fish that eventually the sizes of those nongame fish records also will be out of reach or nearly so. For example, I am predicting the 50 pound 5 ounce common carp bow and arrow record that was just established (https://barbsandbacklashes.wordpress.com/2010/06/17/stop-the-presses-another-record-fish/) is going to stand for a LONG, LONG time.

Daryl B.

Comment by whitetips

why do you want these type of crawdads?

Comment by Andrew S

nevermind. i understand!

Comment by Andrew S

[…] couple of weeks ago I had a post about crayfish, https://barbsandbacklashes.wordpress.com/2010/07/06/crayfish/ .  That post generated some interest and questions.  I said then that I was no crayfish biologist […]

Pingback by Odds and ends, July 21, 2010 « Barbs and Backlashes




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