Welcome to Texas Crawdads

Texas Hill Country Orco Crawfish 

posted November 4, 2008

Review of Texas Crawdads in November issue of the Journal of Crustacean Biology 

Posted June 29, 2008

Crayfish Dipnets and Collection Equipment

You will need a dip net.  A long handled dip net is the most efficient method for sampling crayfish species from numerous collection sites.  For turbid or tannic streams which are too deep to wade or where the depth and bottom conditions are unknown, sweeping the bottom and sides while standing on the bank will generally yield crayfish if they are present.  In clear waters, crayfish that are visible in the water may be “scooped” with the dip net by placing it on the bottom behind them and pulling the net along the bottom towards them.  When wading in clear flowing streams, a dip net held against the bottom and downstream of stones lifted to reveal hiding crayfish increases the odds of capturing the animal should it dart up into the current before it may be grabbed by hand. 

Not all dip nets are created equal.  Inexpensive wire rim, crabbing or bait dip nets available at most bait and outdoors stores (See photo C) are sufficient if nothing else is available, but most do not hold up long to the rigors of serious crayfish collecting.  Abrasive bottoms and underwater snags will rapidly wear and tear up this type of dip net.  Cheap bait nets also have smaller diameter wire which will bend under the weight of nets full of wet debris and vegetation. 

Currently, we use the Cummings 270-12-SG Model D Ring.  It is similar to the Ranger Products Inc. Crawdad Net (See photos A & B).  Both have 42 inch handle and a 16 inch wide net with heavy gauge rim.  At one time we were able to purchase the long handled version of the Ranger with a deeper net pocket from stores within Texas but have been unable to locate a source for some years now.  A good online source for Ranger nets has been difficult to locate.  We now order the 270-12-SG directly from Cummings Nets   http://www.cumingsnets.com/

Please note in the photos that both the Cummings and Ranger nets have an additional bar on the net bottom to prevent wear to the bottom edge of the dip net.  Additionally the netting is sewn into fabric that covers the bar on the Ranger and into a heavy duty plastic on the Cummings. (See Photos A & B)  We own Ranger nets that we have used for years without any bending of the wire.  Occasional holes torn in these nets by underwater snags have been repaired with nylon cord.  The Cummings nets are the closest we have found to the Rangers with the exception of the heavy plastic where the Ranger uses the fabric material.  Time will tell how well the heavy plastic of the Cummings nets holds up.

Smaller inexpensive dip nets such as the one in (photo D) are well suited to being handled by smaller kids.  They are also useful for the adult who wishes to have an easily concealed net along in case the opportunity to crawdad presents.  These small nets are only 28 inches long with an 8 inch diameter ring. 

Additional equipment for collecting crayfish may include containers for transporting the catch home alive.  An ice chestwill protect the crayfish from the heat of being inside a vehicle while the occupants are outside crawfishing.  We use Styrofoam ice chests with wide mouthed Nalgene bottles inside (See photo E).  The bottles are sized so that they fill the ice chest completely, preventing the possibility of falling over and mixing up labeled specimens from separate collection locations.  On very hot days or when the cooler will be left for an extended period of time inside a closed vehicle, an ice pack or frozen bottle of water may be placed in the cooler to help keep the crayfish cool.  The ice pack or frozen frozen water should not be in direct contact with a specimen container or the crawfish may become too cold, too quickly, and perish.  Crayfish specimens retained should be placed one to a container.  Only just enough water to cover the crayfish should be added to the containers, deeper water will soon become depleted of dissolved oxygen and crayfish that cannot reach the water surface may die. 

Knee high rubber boots are the best footwear choice (See photo F).  They allow wading in waters of a safe depth and provide some protection to the legs from heavy vegetation of riparian areas and submerged debris in the water.  Knee high boots also lessen the potential for visits to the crayfish collector’s feet and legs from fire ants, ticks, chiggers and other unwelcome guests.  In deeper water free of obstacles and with firmer bottoms, water shoes or tennis shoes should be worn to protect the feet from hazards.

A good map is essential if one intends to record the locations of collection for specimens.  We use the large Texas Atlas and Gazetteer map books (See photo G).  These maps are helpful not only for recording collection sites but also for planning the route of the crayfishing trip and identifying potential collection sites with good road access.  In Texas, where >94% of land is privately owned, much collecting will be done where streams are accessible from the road.  Planning ones intended route of travel, and having a good navigator along, helps one anticipate stops while they are well ahead and negotiate the pull over without endangering oneself or occupants of other vehicles on the same road. 

A pair of polarized fishing sunglasses is another item that we find quite useful (See photo G).  When attempting to see crayfish below the surface of the water polarized sunglasses reduce reflected polarized light waves allowing the wearer to see deeper into the water.  This is especially useful when turning stones and trying to spot well camoflauged crayfish against the bottom as sediment clears downstream with the current. 

Beyond these few basic collection tools discussed here, the crayfish collector can add equipment for excavation, digital cameras, a GPS, a field book or journal, instruments for recording  climatic variables or collecting water quality data, whatever one can afford or that which is necessary towards achieving the goal of one’s crayfish study.  Many will add some of these other items as they begin to become more serious about their crayfish study.  But for those just getting started, a good dip net is all that is needed.

Posted March 11, 2008

Proposed Amendments to Prevent the Introduction of the Australian Red Claw Crayfish (Cherax quadricarinatus) into Texas Waters 

The amendments proposed will prohibit the possession of this species without a valid exotic species permit issued by the Texas Parks and Wildlife Department. The Texas Parks and Wildlife reports that to the department’s knowledge there are no persons in Texas who are in lawful possession of this species, therefore no persons are adversely affected by compliance with the proposed rule, although there may be persons who possess and sell this species illegally. 

Introduction of exotic invasive crayfish species poses a significant risk to the crawfish biodiversity of Texas.

Please participating in the on-line public comment period for amendments to §57.112 and §57.113, concerning Harmful or Potentially Harmful Exotic Fish, Shellfish, and Aquatic Plants.  The on-line public comment period is 12:00 p.m. February 20, 2008 through 5:00 p.m. March 26, 2008.  You may submit your comments here:

Link

Juvenile Crawfish 1"