Observations on Oriental Weatherfish (Misgurnus anguillicaudatus), an Exotic Species in the Hudson River Valley, New York.

We collected data on the distribution, sex, size, fecundity, and food habits of a newly discovered population of Misgurnus anguillicaudatus (Oriental Weatherfish) in the Hudson Valley, NY. Oriental Weatherfish were distributed throughout the Dwaar Kill in Orange and Ulster counties and at least 7 km of the Wallkill River, principally in the soft substrates of stream margins. Males were smaller than females and apparently had shorter life spans. Sexual maturity and spawning attributes were evident. Mature males had pronounced dorsolateral ridges on at least the posterior third of the body, and females exhibited post-spawning abrasions dorsal and anterior to the vent. Female Oriental Weatherfish are batch-spawners producing up to 18,000 eggs at one time. Oriental Weatherfish in the Dwaar Kill consumed a variety of aquatic macroinvertebrates and exhibited generalist feeding habits. This species does not seem to be affecting other vertebrates where currently found, but potential negative interactions with the native Umbra pygmaea (Eastern Mudminnow) merit attention. Monitoring of the Hudson Valley populations is needed to determine if Oriental Weatherfish abundance or range changes dramatically, and to determine if their presence is causing any lasting effects on the ecosystem. [ABSTRACT FROM AUTHOR]