Detection of Invasive Red-eared slider (Trachemys scripta elegans) by Allegheny Crayfish (Orconectes obscurus) Presented by: Joshua Brennan Hypotheses Allegheny crayfish will spend more time away from the native painted turtle cue than from the invasive red-eared slider cue. Allegheny crayfish will be less active when exposed to invasive red-eared slider cue than when exposed to indigenous painted turtle cues. Conclusions In both tests, the data did not support the hypotheses. Maybe Allegheny Crayfish rely more on combination of visual, chemical, and tactile senses to detect surroundings. Introduction Invasive species which become established into a new region may pose a serious threat to the indigenous species. Difficult for prey to detect invasive predators. Crayfish detect their surroundings by rapidly flicking their antennules and sensing chemical cues. Native painted turtles and invasive red- eared sliders both inhabit Tyler Run and feed on Allegheny Crayfish. Crayfish exhibit behavioral response by hiding and limiting movement when exposed to predator cues, no reaction when exposed to invasive species cues. (Martin, 2014) The present study aims to determine if native Allegheny crayfish (O. obscurus) can detect the presence of invasive species red-eared slider (T. scripta elegans). Acknowledgements I would like to thank Dr. Nolan for the support and encouragement she gave me through the duration of this experiment and Leah Allnutt for helping with data collection. Collected 14 Crayfish from Tyler Run Spring Ice Red-Eared Slider Ice Randomly Assigned Order Observed Behavior for 9 Minutes Recorded Occupied Quadrant Every Minute Counted Quadrants Crossed Painted Turtle Ice Conspecific Cue Ice Literature Cited Gherardi, F., Mavuti, K.M., Pacini, N., Tricarico, E., and Harper, D.M. (2011). The smell of danger: chemical recognition of fish predators by the invasive crayfish Procambarus clarkii. Freshwater Biology. 56, Martin, C.W. (2014). Naïve prey exhibit reduced antipredator behavior and survivorship. PeerJ. 2. Polo-Cavia, N., Gonzalo, A., López, P., and Martin, J. (2010). Predator recognition of native but not invasive turtle predators by naïve anuran tadpoles. Animal Behavior. 80(2010): Walsh, S. (2014). A comparison of the allegheny crayfish (Orconectes obscurus) and the red swamp crayfish (Procambarus clarkii) eating behaviors when exposed to predatory and conspecific stimuli. York College of Pennsylvania Sr. Thesis. Future Studies Repeat experiment using larger sample size. Conduct similar experiment testing visual or tactile cues instead. Figure 3. Average distance from stimulus spent by Allegheny crayfish (O. obscurus) over nine minute exposure to spring water, red-eared slider (T. scripta elegans), painted turtle (C. picta picta), and conspecific alarm cue treatments. (n=14). According to one- way ANOVA, means did not significantly differ (p = 0.052). Error bars show standard deviation. Figure 4. Number of quadrants crossed by Allegheny crayfish (O. obscurus) over 9 minute exposure to spring water and chemical extracts of red-eared slider, painted turtle, and conspecific Allegheny crayfish alarm cue. (n=14). According to one-way ANOVA, means did not significantly differ among groups (p = 0.435). Error bars show standard deviation. Figures 1-2. Apparatus showing position of crayfish relative to location of chemical stimulus. In alternative set-up, treatment net and blocked-off net are swapped. Main Results Negative and positive controls not significantly different Average distances not significantly different Activity differences not significant (Walsh, S. 2014)