On Monday, I asked readers what the American Bittern is eating in Walt Staab's amazing photos from last weekend. (Thanks, Walt!)
Readers all thought it was an eel. I thought it was a Mudpuppy.
I asked the experts.
Fish expert Bob Schmidt writes:
This is NOT an American eel. Eels have a continuous dorsal and anal fin.
Your photos show a fish that has no visible anal fin and a small discrete dorsal.
Also note the spotting on the caudal fin.
This is an Oriental Weatherfish, an exotic species that I have seen and published on in the Hudson Valley. You may want to contact NJ Fish and Game, they may not know that this species is in your area.
Most environmental agencies are concerned with the spread of this species, but data showing environmental damage is sparse.
In the study we did (published in Northeastern Naturalist, available from my ResearchGate page), weatherfish inhabited deep silty backwaters where almost no other fish were found. They feed on all kinds of invertebrates at night.
Also Bob Schmidt writes::
I don't know how thankful anyone can be to discover this creature in their area.
These fish love marshlands and they have potential to develop high population densities. We sample them with backpack electroshockers in wadeable water.
The NYS DEC guys found that they can be caught in minnow traps baited with dog biscuits. You might try this out to get a feeling for how dense the population may be.
Despite lack of data, I feel their presence is a degradation of the environment. This species will spread from your area and people may wish to look for it in downstream localities.
I contacted NJ Fish and Game.
The agency's Principal Fisheries Biologist, Mark Boriek sent me several helpful websites on NJ's invasive fish species and said that the Oriental Weatherfish is on the state watchlist of invasive fish:
NJDF&W has documented them in White's Pond, Waldwick; an unnamed tributary of the Saddle River, Saddle River and in the Raritan River drainage.
Mark also gave me a webpage where you can get more info: here.
Lorrimer Snctuary's Patrick Scheuer adds:
I found one back in 2007 in the smaller pond at the CF.
I knew it wasn't a native so I brought it back to Lorrimer and looked it up.
I sent a report to NJ Fish and Game and they confirmed the ID. That one is no longer alive.
Since then my students and I have been finding lots of them in several places--White's Pond, Ridgewood Duck Pond.
Any we find are brought back to Lorrimer and put in our big aquarium where they become food for the sunny and catfish.
A few years ago some biologists came to the center a took a bunch to preserve are type specimens for their collection.
(Thanks, Bob, Mark and Patrick!)