Notes First Record of the Large-Scale Loach Paramisgurnus dabryanus (Cobitidae) in the United States Joseph E. Kirsch,* Richard F. Feeney, Alisha Goodbla, Christopher Hart, Zachary J. Jackson, Andrea Schreier, Ronald Smith J.E. Kirsch U.S. Forest Service, P.O. Box 545, Copperopolis, California 95228 C. Hart, Z.J. Jackson, R. Smith U.S. Fish and Wildlife Service, 850 S. Guild Avenue, Lodi, California 95240 Present address of Z.J. Jackson: U.S. Fish and Wildlife Service, P.O. Box 39, Pinetop, Arizona 85935 R.F. Feeney Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007 A. Goodbla, A. Schreier Genomic Variation Laboratory, Department of Animal Science, University of California, 1 Shields Avenue, Davis, California 95616 Abstract Exotic species have been implicated as a major threat to native freshwater fish communities in the Unites States. The San Francisco Estuary watershed has been recognized as one of the most invaded systems where exotics often dominate the fish community. On October 6, 2014, members of the U.S. Fish and Wildlife Service (USFWS) detected a previously unknown exotic fish in a disconnected pool immediately upstream from the Chowchilla Bifurcation Structure in the San Joaquin River, a major tributary of the San Francisco Estuary. A member of USFWS initially identified the fish as an Oriental Weatherfish Misgurnus anguillicaudatus using external morphological characteristics. We conducted additional fish sampling near the Chowchilla Bifurcation Structure in November 2014 and collected a total of six additional specimens in disconnected pool habitats. Unexpectedly, genetic and meristic techniques revealed that these specimens were Large-Scale Loach Paramisgurnus dabryanus. To our knowledge this is the first confirmed occurrence of Large-Scale Loach in the United States and the suspected pathway of introduction is release from aquaria. Very little is known about the population in the San Joaquin River. We recommend further evaluation of the ecology, distribution, and abundance of Large-Scale Loach to better understand their potential impact on the fish communities of the San Joaquin River and the likelihood of establishment throughout the United States. Keywords: exotic fish; United States; San Joaquin River; Large-Scale Loach; Paramisgurnus dabryanus; Oriental Weatherfish; misidentification Received: February 2, 2017; Accepted: December 18, 2017; Published Online Early: January 2018; Published: June 2018 Citation: Kirsch JE, Feeney RF, Goodbla A, Hart C, Jackson ZJ, Schreier A, Smith R. 2018. First record of the Large-Scale Loach Paramisgurnus dabryanus (Cobitidae) in the United States. Journal of Fish and Wildlife Management 9(1):xx–xx; e1944-687X. doi:10.3996/012017-JFWM-008 Copyright: All material appearing in the Journal of Fish and Wildlife Management is in the public domain and may be reproduced or copied without permission unless specifically noted with the copyright symbol &. Citation of the source, as given above, is requested. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service. * Corresponding author: [email protected] Journal of Fish and Wildlife Management | www.fwspubs.org June 2018 | Volume 9 | Issue 1 | 1 First Record of Large-Scale Loach in the United States J.E. Kirsch et al. Introduction detection of Oriental Weatherfish in the San Joaquin River would constitute a range expansion of the The introduction of exotic (i.e., nonnative) fish species within California. However, misidentification species is a topic of concern throughout North often occurs among cobitids when relying solely on America, where approximately 46% of the described external morphological characteristics (Bohlen et al. native freshwater fish taxa are considered imperiled 2005). Further, Oriental Weatherfish are known to (Jelks et al. 2008). The decline of native fish species is hybridize with Large-Scale Loach Paramisgurnus dab- largely attributed to habitat degradation coupled with ryanus and the hybrids exhibit morphological similar- the introduction of exotic fish species (Richter et al. ities to that of the Oriental Weatherfish (You et al. 1997;Jelksetal.2008).Ingeneral,exoticspeciescan 2009). As a result, the true identity of the exotic loach negatively affect native fish through multiple mecha- was unknown. The objectives of this study were to nisms including habitat alteration, competition, preda- collect additional loach specimens near the Chowchilla tion, hybridization, and pathogen transfer (Douglas et Bifurcation Structure in the San Joaquin River and al. 1994; Mooney and Cleland 2001; Dunham et al. validate the species identification using meristics and 2004). The impacts of exotic fish on a fish assemblage is genetics. often mediated at local and landscape scales by the suitability of habitat, magnitude and extent of intro- duction, structure of the existing assemblage, and the Methods implementation of management or control actions Study area (Courtenay and Robins 1989; Moyle and Light 1996; Marchetti et al. 2004). Although the United States has a The San Joaquin River basin has a Mediterranean– multitude of regulations to prevent the introduction montane climate (i.e., wet–cool winters and dry–hot and establishment of exotic fishes (Lodge et al. 2006), summers; Null and Viers 2013) where natural flows are more than 138 exotic species have been introduced largely generated during the spring from snowmelt and become established in the United States through runoff. In general, the San Joaquin River downstream of development of gamefish or baitfish stocks, disposal of Millerton Lake (river kilometer [rkm] 430.5 of the San aquarium fish, release of baitfish, or escape from Joaquin River measuring from its confluence with the aquaculture facilities (Nico and Fuller 1999; Pimentel Sacramento River) is subjected to artificial flow regimes, et al. 2000; Fuller 2003). agricultural and municipal contaminants, excessive One group of fishes with great invasive potential is the groundwater pumping, channel confinement, and sur- family Cobitidae, which includes approximately 177 face water diversion and export (Galloway and Riley freshwater loach species from 26 genera (Nelson 2006; 1999; Traum et al. 2014). As a result, the San Joaquin Kottelat 2012). The most widely introduced species, the River is currently dominated by losing or effluent reaches Oriental Weatherfish Misgurnus anguillicaudatus, has where flows become intermittent and habitat becomes become established in several areas in the United States disconnected between Gravelly Ford (rkm 370.0) and the including Southern California, Florida, Hawaii, Idaho, Merced River confluence (rkm 187.6) during nonflood Illinois, Michigan, New York, Oregon, and Washington (Courtenay et al. 1987; Tabor et al. 2001; Simon et al. conditions with the exception of where irrigation water 2006) and has been largely introduced by aquaculture from the federal Central Valley Project is conveyed. We escapes or releases by aquarists or fisherman (Courtenay sampled for the exotic loach in all disconnected pools and Stauffer 1990; Chang et al. 2009). The potential occurring within 1 km of the Chowchilla Bifurcation negative impacts of invasive loaches such as the Oriental Structure (rkm 347.8; Figure 1). Weatherfish on native fishes include predation of eggs or larvae, increased competition for macroinvertebrate or Sample methods algal prey, introduction of foreign parasites, and the On November 12, 2014, USFWS and California elevation of ammonia, nitrate, and turbidity levels within Department of Fish and Wildlife staff members sampled the environment (Logan et al. 1996; Keller and Lake 2007; four disconnected pools. Before sampling the pools, we Lintermans et al. 2007). collected dominant substrate and water-quality data On October 6, 2014, members of the U.S. Fish and along the shoreline of all pools but one. We used a YSI 85 Wildlife Service (USFWS) collected a previously un- or YSI PRO 2030 meter to measure water temperature to known exotic loach in a disconnected pool during a the nearest 0.18C, specific conductance to the nearest 0.1 fish assemblage survey on the San Joaquin River lS/cm, and dissolved oxygen to the nearest 0.1 mg/L. We immediately upstream from the Chowchilla Bifurcation Structure in Madera County, California. They sacrificed, measured turbidity using a HACH 2100Q turbidity meter measured, photographed, and discarded the specimen. to the nearest 0.1 nephelometric turbidity unit. We Following Moyle (2002) and Nelson (2006), a member determined dominant substrate type visually and broad- of the USFWS later identified the specimen as an ly classified it on the basis of particle size diameter as Oriental Weatherfish using the morphological charac- mud (, 0.5 mm) or sand (0.5–5.0 mm). We also broadly teristics visible in the photographs (e.g., veliform body classified pool size as either small or large. Small pools shape, subterminal mouth, five barbels present on each were, on average, shallow (i.e., , 2 m in depth) and , 15 side of the jaw; C. Castle, personal communication). The m wide or long. Conversely, large pools were, on Journal of Fish and Wildlife Management | www.fwspubs.org June 2018 | Volume 9 | Issue 1 | 2 First Record of Large-Scale Loach in the United States J.E. Kirsch et al. (LACM) Section of Ichthyology for radiograph-based identification. Genetic analysis We extracted DNA from dried barbel clips