On November 21, 2018, the U.S. Fish and Wildlife Service (“Service”) published a final rule listing the candy darter (Estheostoma osburni) as endangered and proposing critical habitat for the species. The candy darter is a small, freshwater fish species native to Virginia and West Virginia. The Service’s announcement finalizes its proposed rule to list the candy darter, which was published on October 4, 2017, with one significant difference – the Service originally proposed to list the candy darter as threatened, but the final rule lists the candy darter as endangered.
The candy darter, which is named for its vibrant colors, has been extirpated in approximately half of its historical range. One of the main drivers for the candy darter’s population decline is hybridization (or cross-breeding) with a different darter species – the variegate darter (Etheostoma variatum). Due to the severity of this threat to the candy darter species, the Service predicts that under the three most likely future scenarios, the candy darter will only occur in four isolated populations in twenty-five years. In its final rule, the Service indicates that it previously underestimated the risk of hybridization of the species in one specific population – the Upper Gauley – and that this initial underestimation was a factor in listing the darter as endangered, rather than threatened. Concurrent with its final rule, the Service proposed critical habitat for the candy darter, composed of five critical habitat units that cover the five main watersheds in which the candy darter occurs, and indicated that it will be preparing a recovery plan. The Service’s proposed critical habitat designation indicates that the Service is not, at this time, considering any areas for exclusion from the proposed critical habitat pursuant to Endangered Species Act section 4(d). The proposed critical habitat designation indicates that the Service will accept comments on the proposed designation until January 22, 2019.