Fish briefs and buckets of fish: Conforming ichthyology to needs of students with natural resource career paths

Traditional ichthyology courses often focus on objectives related to fish evolution and skills required for museum work. Students in natural resource disciplines often perceive these objectives and skills as having little relevance to their future careers. In some ichthyology courses, memorization of fish taxonomy and phylogeny may outweigh emphasis on the development of critical thinking skills. Guided by objectives to develop critical thinking and information gathering skills, we have developed two instructional methods that incorporate the practical needs of students in natural resource disciplines without sacrificing important subjects in the ichthyology course offered at Michigan State University. The first method consists of a requirement to write two brief papers (500 words or less) that address a specific question of interest to the student. The objectives for this assignment are to develop professional skills involving information retrieval and interpretation and to write a concise, but thorough product. Students are given specific requirements for format and information quality, and are provided assistance in focusing the question so that it is answerable in a brief format. First drafts go through a peer review process to check on aspects of clarity, conciseness, and completeness and students may incorporate the comments and revisions in the final draft. In the second exercise, Buckets of Fish, students are presented with specimens from the Great Lakes fauna (100 species) and are assigned to learn to identify these species with identification keys provided by the instructor. They have four laboratory periods to study specimens and then four examination periods to demonstrate their proficiency in identifying a collection of fish specimens in a jar of unknowns. This exercise is meant to simulate the experience of bringing a sample of fish back from the field and then identifying the fish in the sample. Student proficiency in identification increases through the examination series. In both of the instructional methods, the relevance and focus of the assignment generated greater student interest in learning information basic to an ichthyology course, and developed critical thinking and technical skills needed for students directed towards research or natural resource management career paths

Relations between habitat variability and population dynamics of bass in the Huron River, Michigan /

"April 1994."Includes bibliographical references (p. 38-39).Mode of access: Internet

Risk Analysis and Bioeconomics of Invasive Species to Inform Policy and Management

Risk analysis of species invasions links biology and economics, is increasingly mandated by international and national policies, and enables improved management of invasive species. Biological invasions proceed through a series of transition probabilities (i.e., introduction, establishment, spread, and impact), and each of these presents opportunities for management. Recent research advances have improved estimates of probability and associated uncertainty. Improvements have come from species-specific trait-based risk assessments (of estimates of introduction, establishment, spread, and impact probabilities, especially from pathways of commerce in living organisms), spatially explicit dispersal models (introduction and spread, especially from transportation pathways), and species distribution models (establishment, spread, and impact). Results of these forecasting models combined with improved and cheaper surveillance technologies and practices [e.g., environmental DNA (eDNA), drones, citizen science] enable more efficient management by focusing surveillance, prevention, eradication, and control efforts on the highest-risk species and locations. Bioeconomic models account for the interacting dynamics within and between ecological and economic systems, and allow decision makers to better understand the financial consequences of alternative management strategies. In general, recent research advances demonstrate that prevention is the policy with the greatest long-term net benefit

\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu