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Fish predation can structure zooplankton communities; however, the impacts of other organisms on zooplankton communities, alone or interacting with fish predation, are less known. We used two mesocosm experiments to study the impacts of Bluegill (Lepomis macrochirus) and tadpoles on temperate zooplankton communities, one with American Toad tadpoles (Anaxyrus americanas) and the other with Bullfrog tadpoles (Lithohates catesbeianus). In both experiments Daphnia (a larger bodied cladoceran) were virtually eliminated and rotifers were more abundant with Bluegill. Bluegill slightly reduced cyclopoid copepods in the American Toad experiment but not significantly, whereas cyclopoid copepods were more abundant with Bluegill in the Bullfrog experiment. Bostnina (a smaller bodied cladoceran) in the Bullfrog experiment were more abundant when Bluegill were absent, but there was no significant effect of Bluegill in the American Toad experiment. Tadpoles in general had no effect on our zooplankton communities. Our experiments confirm the influence of Bluegill on zooplankton communities, whereas tadpoles of the two anuran species had 110 widespread effects on zooplankton., INTRODUCTION Predators can influence the relative abundance of individual taxa in a zooplankton community. In particular size-dependent predation by zooplanktivorous fish can structure many zooplankton communities. For example, Bluegill (Lepomis [...]

Using module-based courses has been suggested to improve undergraduate science courses. A course based around a series of modules focused on major environmental issues might be an effective way to teach non-science majors about ecology and ecology's role in helping to solve environmental problems. I have used such a module-based environmental science course for non-majors. The course is divided into 5 modules, with each module addressing a key environmental issue, specifically global climate change, human population growth, sustainable use of natural resources, habitat loss, and the value of biodiversity. Each module follows the same basic structure: 1) an introduction to the question, 2) an investigation of the basic science underlying the question, and 3) an investigation and discussion of the human aspect of the question (i.e., what can we do?, what are the costs and benefits of addressing the question?, are there any social, economic, or cultural factors that affect our ability to address the issue?, etc.). Each module has associated laboratory exercises that culminate with field-based student-designed surveys of biodiversity on the Denison University Biological Reserve. The module-nature of the course allows for the integration of science and non-science disciplines around basic environmental questions, and appears to be an effective means of teaching environmental science and ecology to non-majors. (Contains 2 tables.)

Herein, we present an updated list of the species of amphibians and reptiles that inhabit Nayarit, Mexico. In the years since the publication of a previous list in 2016, threats to amphibians and reptiles in Nayarit have continued unabated and efforts to more fully catalogue the richness of Nayarit's herpetofauna have continued. Nayarit harbours 162 native species of amphibians and reptiles, representing 35 families and 85 genera. These include 37 species of amphibians (35 anurans and two salamanders) and 125 species of reptiles (one crocodile, 44 lizards, 69 snakes and 11 turtles). Of the amphibian and reptile species in Nayarit, 102 are endemic to Mexico and two endemic to Nayarit. The ecoregion with the highest richness of amphibians and reptiles in Nayarit is the Trans-Mexican Volcanic Belt followed closely by the Sierra Madre Occidental and then the Sierra Madre del Sur, the Pacific Lowlands and the Nayarit Islands. Just 5.8% of the species of amphibians and reptiles in Nayarit is IUCN-listed as Vulnerable, Endangered or Critically Endangered, 11.1% are placed in a protected category by SEMARNAT and nearly a third are categorised as high risk by the Environmental Vulnerability Score. The herpetofauna of Nayarit overlaps the most with Jalisco (88.9%). One of the main conclusions of our updated list of the amphibian and reptile species of Nayarit is that our understanding of the full complement of species is not complete, especially the reptiles. [ABSTRACT FROM AUTHOR]