N61 2015 Southeastern Naturalist Notes Vol. 14, No. 4 W.I. Lutterschmidt, R.A. Fiorillo, and S.M. Anderson Predation on the Toxic Red-Spotted Newt (Notophthalmus viridescens viridescens) by Lepomis macrochirus (Bluegill) and L. auritus (Redbreast Sunfish) within an Urban Watershed William I. Lutterschmidt1,2,*, Riccardo A. Fiorillo3, and Sidney M. Anderson4 Abstract - Predation on Notophthalmus viridescens viridescens (Red-spotted Newt) is rare due to their toxic skin excretions, which provide chemical defense against potential predators. Here we document the occurrence of the Red-spotted Newt in the stomach contents of Lepomis macrochirus (Bluegill) and L. auritus (Redbreast Sunfish), common sunfishes within an urban watershed in Columbus, GA. The chemically mediated toxicity and unpalatability of Notophthalmus viridescens viridescens (Rafinesque) (Red-spotted Newt) has been well documented (e.g., Brandon et al. 1979, Brodie 1968, Brossman et al. 2014, Hurlbert 1970, Marion and Hay 2011, Webster 1960). Thus, predation on the Red-spotted Newt is rare, and Rohr and Madison (2002) stated that no significant predation on adults has been documented in the wild. If Red-spotted Newts are preyed upon in number (e.g., 27 reported in Shure et al. 1989), only the viscera are consumed and the toxic skin is discarded (Petranka 1998). Here, we cite a few reported predation accounts from the literature and report on the occurrence of the Red-spotted Newt in the stomach contents of 2 common sunfishes within an urban watershed within and surrounding Columbus, GA. As part of a study investigating helminth parasite-communities (Anderson et al., in press), we dissected 222 Lepomis macrochirus (Rafinesque) (Bluegill) and 205 L. auritus (L.) (Redbreast Sunfish) from 8 creeks within the Bull and Upatoi Creeks Watershed, Muskogee County, GA. We used a backpack electro-fisher (Smith-Root® Inc., Vancouver, WA) to collect fishes, and transported them live to our field laboratory. We noted no abnormal behavior prior to euthanizing and dissecting the fish. We measured the body mass (g) and standard length (mm) of each fish prior to dissection. We examined the eyes, eye cavities, viscera (heart, spleen, liver, kidney, and gonads), and intestinal tract (intestinal mesentery, intestinal lumen, pyloric ceca, and stomach) to detect helminth parasites. Upon examining the stomach and intestinal tract of each sunfish, we found Sphaeriidae (finger-nail clams), insect larvae, algae, partially digested fishes (Anderson et al., in press), and a partially digested salamander in each of 3 sunfishes. We were able to identify 2 of the 3 salamander specimens to subspecies as Red-spotted Newt by using the distinctive orange pigmentation, the 2 distinct rows of reddish-brown dorsal–lateral spots encircled by darker pigment, and the reported subspecies distributions (Petranka 1998). Each newt’s partially digested tail did not allow us to examine for the presence or absence of a laterally compressed tail, which would have helped confirm whether the newts were adults or terrestrial efts (i.e., adults have laterally compressed tails). However, each newt lacked gills, and their snout–vent lengths (SVL) were smaller than those reported for aquatic adults (31–54 mm, Petranka 1998; 29–51 mm in Georgia, Jensen et al. 2008) 1Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77341. 2Texas Research Institute for Environmental Sciences, Sam Houston State University, Huntsville, TX 77341. 3School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA 30043. 4Texas Veterinary Medical Diagnostic Laboratory, Texas A&M University, College Station, TX 77843. *Corresponding author - lutterschmidt@shsu.edu. Manuscript Editor: David Steen Notes of the Southeastern Naturalist, Issue 14/4, 2015 2015 Southeastern Naturalist Notes Vol. 14, No. 4 N62 W.I. Lutterschmidt, R.A. Fiorillo, and S.M. Anderson suggesting that they were terrestrial efts. We fixed in a 10% formalin solution, preserved in 70% ethanol, and deposited in the Sam Houston State Vertebrate Museum, Huntsville, TX (SHSVM# 0008-2015, collector # WIL-02-2002) and (SHSVM# 0009-2015, collector# WIL-03-2002) these 2 salamander specimens. We removed the first newt specimen (SHSVM# 0008-2015, SVL = 28.7 mm) from a Bluegill (126.5 mm standard length (SL), 30.94 g, data #: Lm-dz-04-w02) collected from Dozier Creek on 21 February 2002. We removed the second newt specimen (SHSVM# 0009-2015; SVL = 22.8 mm) from a Redbreast Sunfish (108.7 mm SL, 42.08 g, data #: La-rc-01-w02) collected from Randall Creek on 21 February 2002. We removed the third unidentifiable salamander from a Redbreast Sunfish (112.0 cm SL, 21.39 g, data #: La-bc- 13-s02) collected from Bull Creek on 8 August 2002; this third salamander specimen was not deposited due to our inability to identify the specimen to at least genus. Respective creek-capture localities of each fish were the intersection of each creek with Macon Road (US Highway 22). Georeferenced maps of creek localities are presented in the literature (Anderson et al., in press; Martin and Lutterschmidt 2013). Some documented accounts of predation on Red-spotted Newts include amphibians (e.g., Lithobates catesbeianus (Shaw) [Bullfrog; Marion and Hay 2011] and Siren intermedia Barnes [Lesser Sirens; Fauth and Resetarits 1991]), reptiles (e.g., Chrysemys picta (Schneider) [Painted Turtle; Hurlbert 1970] Chelydra serpentina (L.) [Snapping Turtle; Hurlbert 1970], Thamnophis sirtalis (L.) [Garter Snake; McGlothlin et al. 2014], and Heterodon platirhinos Latreille in Sonnini and Latreille [Eastern Hog-nosed Snake; Feldman et al. 2015],), and fish (e.g., Semotilus atromaculatus (Mitchill) [Creek Chub; Caetano and LeClair 1996]). However, fish such as Salvelinus fontinalis (Mitchill) (Brook Trout) are highly susceptible to the skin toxins of newts (Webster 1960) and almost never ingest them (e.g., “Cursory observations on the stomach contents of several hundred trout from these waters over the past ten years have failed to disclose the ingestion of a single newt, although ecologically this salamander is readily available to the fish.” [Webster 1960]). Centrarchids (e.g., Micropteris [bass] and sunfish) also seem to avoid these newts as prey due to their unpalatability (Hurlbert 1970, Marion and Hay 2011). Our observation supports the seemingly rare predation on the Red-spotted Newt (i.e., 2 newts observed within 427 sunfishes sampled) but provides documentation of the occurrence of this newt as a potential prey item for both Bluegill and Redbreast Sunfish. Acknowledgments. We acknowledge a research grant awarded to W.I. Lutterschmidt by the Engineer Research and Development Center (ERDC) and the Civil Engineering Research Laboratory (CERL) of the US Army Corps of Engineers (ERDC-CERL Contract #DACA 42-00-C-0047). All fish were collected under a permit (29-WMB-01-147) issued to W.I. Lutterschmidt by the Georgia Department of Natural Recourses. We thank Hugh Westbury of the Strategic Environmental Research and Development Program (SERDP), Ecosystem Management Project (SEMP), and Harold (Hal) Balbach of the US Army ERDC and CERL for their dedicated interest in and support of this project. Our sincere thanks to Brian R. Chapman for reviewing a draft of this manuscript, Clayton Sublett for depositing specimens within the Sam Houston State University Natural History Collections and database, and Danté Fenolio for discussing (with W.I. Lutterschmidt) aspects of this natural history observation. Literature Cited Anderson, S.M., R.A. Fiorillo, T.J. Cook, and W.I. Lutterschmidt. In press. 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