Needlefish are saltwater fish that sometimes swim up the Hudson estuary into fresh water. Their long, thin, fragile beaks have lots of teeth. These fish live near the surface, where their blue-green backs and silvery sides make it hard for predators to see them. Needlefish caught in the Hudson are generally young ones only a few inches long. Adults can reach a length of three feet.
Sometimes needlefish are confused with the pipefish. The pipefish’s small mouth is at the very end of its tube-like snout, and the fish has bony rings around its body. The needlefish’s mouth is long like a set of tweezers, and the fish does not have bony rings. Both are found in salty and brackish water, though needlefish can sometimes be caught in fresh water as well.