many Of the Daylight hours I spend in the summer are spent outdoors photographing plants mostly and other wildlife. One day along a dirt trail that borders the Passaic River in NJ. I decided to look into a puddle out of sheer curiosity. These puddles are common occurce when the summer rains saturate the ground . they are no more than 2-3 inches deep on average and span one meter, typically. upon looking a soup of daphnia pulex. pale yellow ostracods, and a more striking organism. A clam shrimp. Maybe 2-3 cm long these tiny branchiopods were actually very numerous in some of these little puddles. And upon Inspection of the puddles along the 2 mile trail. It appears that some puddles had a lot more of these clam shrimp than others. It dawned on me this species must be very special, as the 10 years of living in NJ. And being a curious teenager for most of those years I would check any puddles everywhere I would go for signs of life to admire. I had never found any until now.
The branchiopoda of NJ is understudied. We have couple species of fairy shrimp (which I have never seen) Eubranchipus vernalis, Eurbranchipus bundyi & Streptocephalus sealii. But that’s it. We do not have the diversity that the west does so any members of this odd grouping of crustaceans is certainly something to be estactic over. I sampled some to put under the scope at home. After some research the most plausible ID for this species is Caenestheriella gynecia. Based off an article I found on researchgate of a population of this species found In a nearby county. The specific epithet “gynecia” hints to a unique feature to this species. In that it is all female. And from what I have seen from animals I have cultured at home all develop eggs. to Get a positive ID I need to send them out to a few researchers. unfortunately this year was a quite dry in the east coast and the ephemeral puddles they reside in remained dry. My issue with this species is that it is very difficult to get their eggs to hatch. They are extremeophiles and many of the pools they resided in were actual very hot. Some if I had to guess were 90F. I’d imagine that I would have to keep them very warm In Order to culture them. And that I want to do. This species. Whatever it is, has a very small range (only around 2 miles!) and the trail resides on is in a very urban area. If their habitat is developed this species will be locally extirpated forever.
2 individuals of Caenestheriella and one ostracod
Neat! There is limited information available on branchiopods on the east coast. Various methods of hatching can be used depending on the species, such as freezing the eggs in water, then thawing them and maybe adding an aquarium heater to achieve those warm temperatures. I’ve found this method has been successful with several temperate region species I’ve worked with. For most part hatching occurs within 1-2 days of thawing.