Swimming insect?fish?
September 21, 2009
I found hundreds of these swimming in a small man made lake in the backyard of my home in Winnipeg Manitoba, no one can seem to tell me what they are.
I have tried other identifying sites before but never seem to get a reply. They were out swimming around the beginning of summer. They seem to swim by fluttering the green fleshy/gill like stuff on their back. I also noticed that some of them had what looked like long egg sacks running along the top of their backs. Can someone please tell me what these are?
Carly
Winnipeg Manitoba

Fairy Shrimp

Hi Carly,
First we need to say that we went back through the past week’s mail to try to answer a few additional questions when we stumbled upon your letter.  We are very excited to post your images of Fairy Shrimp, freshwater crustaceans.  Fairy Shrimp often live in ponds that dry up, and their eggs are laid and eventually dry in the mud when the water evaporates.  Then the next spring, the temporary pond fills with water again and the eggs hatch, beginning a new cycle.  We have never seen green Fairy Shrimp, and in a few minutes, we are going to try to research something more specific for you.  In our childhood home of Ohio, we would catch Fairy Shrimp in March and April, so we find your September sighting unusual.  You also didn’t indicate if the lake dries out.  The one site we found in a brief search indicates vernal pools as the typical habitat, and none of the images show green Fairy Shrimp.

Fairy Shrimp

Found in some leaves
Wed, Mar 11, 2009 at 7:09 PM
I found my dog attacking one of these last night and it sure does look like a scorpion to me, but living in Indiana I have been led to believe that they are not native to this area. We have recently had a lot of water activity and this was found nighttime on cement…i think they are living in some leaves that blew onto the cement. I would really like to get at least an idea of what type of bug this is.
Ashley H.
North Eastern Indiana

Crayfish Carnage

Hi Ashley,
This is a Crayfish or Crawfish, or Crawdad in the South, a freshwater Crustacean that can survive on land, in damp conditions, that is found throughout much of the U.S.  We are uncertain if the mortal wounds were inflicted by your dog or by you, but we are posting this image to our Unnecessary Carnage page nonetheless.  Crayfish are edible and taste much like lobster.

desert wiggle-womper
in the desert of southern Utah i like to take the kidz out for a hike every now and then. there is a place on top of a messa where there is a lot of petrified wood and indian arrowhead and just really neat things to find and discover. Well any how. there is a place on top of some sandstone clifs where water will gather in various pockets that create a shallow pond of water. there are only 2 places that i have found that the water will stay in for more thain two or so weeks. this little pool right now is dry, so i gathered a jar of dirt and brought it home to put in a bucket of water. 2 dyas later boom!!! these cool little bugs hatched out and about doubled in size every day. the one on my hand is approx. 2 weeks old.
I can give you more ifo on just what i have observed, but cand put my finger on what to call them. i figure they can obviously live in dry sand for many years.
Phil Dunn
Southern Utah

Tadpole Shrimp: Dorsal View

Hi Phil,
We are very excited to get your letter and wonderful photos. Your creatures are Crustaceans known as Triops or Tadpole Shrimp. Triops are a very ancient life form that have developed a unique survival strategy. They often live in areas where there is limited or sporadic rainfall. Much like your home experiment, when water fills a dried up pond with the seasonal rains, the dormant eggs hatch and quickly develop to maturity. Adult Triops then mate and lay eggs that will eventually dry up awaiting the next rain. We have found a Triops Information Page on the internet that indicates the species Triops longicaudatus is found in the Western U.S., Central and South America. Encyclopedia Britannica Online mentions a species Triops cancriformis, but sadly, we have not paid for our Encyclopedia online access so we cannot read the information. We do have our ancient hard copy of Encyclopedia Britannica dating from 1956 that includes some information on the genus Triops under the subject heading of Branchiopoda, a subclass of the Crustaceans that includes other primitive forms like Fairy Shrimp, Clam Shrimp and Water Fleas. Tadpole Shrimp are in the order Notostraca and are characterized by the “broad, shield-shaped carapace covering the fore part of the body.” We feel compelled at this point to bring up the controversial “E” word. We personally believe that due to the nature of the life cycle of the Triops, isolated populations do not share gene pools, potentially giving rise to different species and subspecies that have Evolved independantly of one another from distant shared ancestors. In the interest of opposing view points, it is also possible that individual populations of Triops were Created about 7000 years ago.

Tadpole Shrimp: Ventral View