Robert Day

Graduate Teaching Associate

The Ohio State University

Department of Zoology

1735 Neil Avenue

Columbus Ohio 43210

Phone: (614) 292 1806

email: rjday@magnus.acs.ohio-state.edu

As part of a recent review of the undergraduate curriculum, faculty and graduate students at The Ohio State University began exploring new ways to teach animal diversity. Traditionally, instructors in this field relied on descriptions of preserved specimens, charts and models. Live specimens appeared rarely, usually only as a curiosity. In order to realistically prepare our students for careers in zoology, we looked for a new pedagogic approach that would integrate observations of anatomy, behavior and the ecology of live animals. We also wanted to find an environmentally friendly way to promote students' understanding of microscopic diversity without unacceptably increasing preparation time or cost. We have been able to meet many of these demands using a set of carefully managed natural aquaria and a versatile video imaging system. We believe that the ability to non-invasively demonstrate the biology of small specimens to a large audience may also prove useful in public aquaria and zoos.

Over the last two decades, many universities have consolidated or down-sized traditional biological science departments like "zoology" and "botany" to make way for the applied research and material rewards of new molecular labs. Ironically, this trend has led to a shortage of classically trained taxonomists at the very time they are most needed to catalogue and protect what remains of earth's living diversity. In view of this, what new tools can science educators use to inspire the next generation of biologists and prepare them for their role as stewards of the natural world? At The Ohio State University Department of Zoology, we considered this question carefully during the construction of our new animal diversity class. From the outset, we wanted to adopt a hands-on approach, in tune with contemporary educational theories that stress the importance of active learning and student participation (Bonwell, 1991). After studying instructor and student evaluations of existing classes, and comparing them with the needs of employers and graduate schools, we came up with the following list of goals:

1) Include as many live animals as possible. Zoology majors invariably respond best to visual aids that slither, wiggle or bite.

2) Reduce the use of black and white line charts and text diagrams. Wherever possible replace these with images of real organisms.

3) Reduce wear and tear on our preserved specimen collection. Preserved specimens don't inspire students much and often bare little resemblance to their formerly- animated selves. They are also becoming increasingly expensive to replace.

4) Incorporate modern technology to help prepare students for the job market of the twenty-first century.

5) Encourage students to search for and observe live animals in their natural environment. Teaching students basic observational skills has become especially important, given their typically urban upbringing and consequent lack of exposure to the natural world.

6) We felt that contemporary biological education has a responsibility to promote respect for living things and help students appreciate the value of biological diversity in a dynamic ecosystem.

7) Finally, our solution must not exceed the limits of available space or funds, and must be permanently sustainable, enabling us to teach multiple classes throughout the year.

After exploring several approaches, we found that our needs could best be met using a carefully managed set of small aquaria and terraria. Our collection includes displays that mimic tropical marine, temperate marine, freshwater, bog, leaf litter, and savanna habitats. Although the displays are not large, or particularly technically complex, they collectively hold many hundreds of animal and protist species including representatives from about fifteen of the major phyla we cover in our animal diversity class. The displays are able to sustain a high level of diversity with less expense and supervision than traditional aquaria, despite the year-round onslaught of sampling and examination by multiple classes of up to forty students. I will limit my discussion to the general nature of our displays and how we optimized them for their educational role. The technical specifications of each are available from the author and (eventually) by computer download from OSU.

To ensure that the displays are used as a fully integrated part of our classes we assembled a video imaging system that has proven invaluable to the "hands-on" approach. The basic components are listed in table one. Note that although, the total system boasts a wide range of capabilities, most of the components, considered individually, are not particularly "cutting edge". Many pieces were "handed down" as semi-obsolete research equipment we then modified for use in teaching. The remainder was purchased using a $9000 grant from Ohio State's Board of Regents. This grant allowed us to complete two independent, cart-mounted systems that can be used anywhere in the department. The components can be configured for teaching in lecture, lab or tutorial scenarios. Alternatively the equipment can be concentrated in the department's dedicated graphics area. This includes a rapidly expanding archive of video and still images, and is used as a departmental resource for both teaching and research. The system's applications can be further extended using the more advanced computer animation, video production and graphic capabilities available at OSU's multimedia lab.

Table 1. Basic Components of Video Imaging System

System 1 System 2

Sony CCD camera , (VHS/SVHS/RGB ) Hitachi CCD camera (VHS/SVHS)

Panasonic VHS / SVHS time lapse VCR RCA VHS VCR

JVC VHS / SVHS VCR with editing features Laser 486sx, 8MB ram,100MB HD

Mac ii ci, 8MB ram, 70MB HD, Mac monitor SVGA monitor

Mitsubishi multi-scan monitor Video Blaster video card

Truevision Nuvista-plus video card Iomega Zip drive, 100MB discs

Iomega Zip drive, 100MB discs Proscan TV monitor

Proscan TV monitor Epson Stylus color printer

Epson Stylus color printer compound or dissecting scope

cost * : $12000

Shared equipment: Zoom lens, close focus adapters, tripod, copy stand. Cost * : $900

OSU multimedia lab: Scanners, 35mm film recorder, additional capabilities.

* Approximate total cost of listed components or equivalents, excluding microscopes.

Perhaps the most important advantage of the video equipment is its ability to display live specimens as they are discussed in class. We have found that no amount of description can replace actual observation of a living animal. To introduce students to our larger specimens (> 1cm), the camera is mounted on an adjustable stand and fitted with a 6 - 20x zoom lens. For smaller animals and protists, the camera is coupled to a standard compound or dissecting microscope. Images are displayed on one or more high resolution TV monitors. The ability to demonstrate the biology of microscopic specimens has proven particularly useful, since students respond very positively to these sometimes bizarre organisms. Even specimens that are relatively infrequent can usually be located by a trained instructor, observed and discussed by the class, then quickly returned to their tank unharmed. The VCR allows students to record and review images at their own pace. Thanks to the falling price of ink-jet printers, we also have the capability to computer-capture, manipulate and print color images of our specimens. Students use this technology as a cheap alternative to photography that complements their own sketches and helps them illustrate special projects effectively. A summary of the system and its capabilities is shown in figure 1.

We avoid over-representation of vertebrates and ignore mainstream ideas about which animals are "desirable" or "undesirable". Instead we try to find cheap, (better yet, free) hardy species that can stand frequent removal and examination. Especially favored is anything that can breed explosively and establish a sustainable population. Whenever possible, we involve students in the collection of specimens from unthreatened field locations using environmentally friendly techniques. Most of our freshwater specimens are collected locally from any old pond, pool or puddle within walking distance. In the summer we employ another high-tech collection method called "leaving the windows open". This allows an amazing variety of flying beasties to invite themselves into our displays. Our marine specimens arrive mainly as juveniles, attached to algae we collect ourselves along the coasts of Massachusetts and Florida. If we buy specimens, we look for common or captive-bred species. We have found that environmentally friendly collection and purchase strategies reduce costs and show students that a responsible scientist can study life without impacting natural populations.

Drab or cryptic species are welcome because they teach students to be observant and patient. Even species sometimes considered "troublesome", like bristle worms (Hermodice) and pale anemones (Aiptasia) find a home in our tanks. They demonstrate the biology of their taxa perfectly well and our system contains nothing expensive for them to exclude or consume anyway.

Since our displays are small, but are intended to represent ecosystems, the laws of thermodynamics require that our specimens be small. Small organisms have a number of practical advantages; they breed and mature quickly, help improve student microscopy skills and, since many are transparent, they often make superior anatomical models that negate the dissection of a larger representative. At the phylum, class and even ordinal taxonomic levels, very little diversity is excluded by our preference for small specimens. Far from being a constraint, the small size of our displays allows easy access and increases the variety of sample types available for microscopy. This means that students tend to observe more taxa from small displays (ranging from one to ninety gallons) than they would from large ones. The only major taxa necessarily under-represented in our displays are the Aves and the Mammalia. We hope that even these will eventually find a home in a somewhat larger system planned for the future.

We make no attempt to discourage predation or grazing in our displays. Rather, we use these to show ecological relationships between organisms. We try to include all the elements of a natural food chain and often look for specimens that will make use of specific, unexploited food sources. Generally, only the smaller species feed exclusively on material produced within their display, however, almost all of our specimens forage naturally for at least some of their diet. This makes our specimens behave naturally, and their healthy diet seems to prevent illness. For the most part, we allow our tanks to live out successional changes just as the natural environment does. Ongoing change in the diversity of our communities means that students will always have something new to find. Allowing realistic ecological interactions also teaches students about the mechanisms that control diversity and, occasionally, demonstrates the finality of extinction.

Lush plant and algal growth are encouraged because they increase the number of micro-habitats and helps us to inexpensively feed our specimens. To keep primary productivity rates high, we typically supply 5-10 watts of fluorescent light per gallon of display size and add generous doses of trace elements. In sharp contrast to mainstream aquarium maintenance dogma, we also add nitrates and phosphates to most of our displays. Interestingly, when we test our tank's nitrate and phosphate levels, they are very low or undetectable. We have found that natural filtration by plants, algae, and a generous layer of natural substrate is so effective that we rarely need to bother with water changes.

The type of aquaria we maintain at OSU is certainly not for everyone. The dense plant growth, swarms of small invertebrates and absence of rare fish may even lead some aquarists to consider them ugly. Beauty, however, is in the eye of the beholder. Natural aquaria are easy to maintain, relatively cheap to run and spectacularly diverse. They make an ideal tool for biological education at the undergraduate level because of their ability to hold students' interest and develop observational skills. We believe that because of increasing emphasis on conservation and education in public aquaria, small, resilient, natural systems, coupled with the ability to display images to a large audience, could be an educationally fruitful, cost-effective and environmentally friendly addition to more traditional displays.

If you would like to learn more about The Ohio State University's introductory animal diversity class (course number: Zoo 405) or the technical specifications of our aquarium displays, the lab manual and (eventually) the maintenance manual for the displays will be available from Ohio State's Web Site at:

http://www.biosci.ohio-state.edu/~eeob/eeob405/index.html

The author would like to thank Aquarium Systems Inc. for their support, and the Zoology Department's lab technician, Heather Bailey, for her dedicated maintenance of our displays and useful comments during the preparation of this manuscript.

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