Dr. Lamp


"Freshwater Biology" is designed for upper undergraduates and beginning graduate students with interests in aquatic ecology and the biology of organisms inhabiting lentic (e.g., lakes, ponds, wetlands) and lotic (e.g., rivers, streams, creeks) habitats. One feature of the course is the extensive hands-on experience through field trips and demonstrations during the first half of the course. This experience will provide background and reinforcement of principles and facts from lectures and discussions on the ecology of freshwater organisms and the community/ecosystem structure of freshwaters. The identification portion of the laboratory during the second half of the course will emphasize aquatic insects, which are often the most diverse and abundant group of organisms associated with freshwater habitats. However, other components of freshwater ecosystems, e.g. plankton and periphyton as primary producers, and fish as higher level consumers, will be included in both lab and lecture material. A second feature of the course is the use of primary research articles to introduce key ecological concepts and to generate discussion on the process and growth of knowledge within freshwater ecology.

Educational Objectives

The proposed course is designed for students to:
1. Develop an understanding of the biology and ecology of organisms found in freshwater,
2. Develop skills and knowledge required to collect and identify common invertebrate freshwater taxa,
3. Become familiar with the diversity, function, and adaptation of invertebrates in freshwater habitats,
4. Examine monitoring techniques and ecological responses of freshwater organisms in association with water quality deterioration and habitat destruction, and
5. Learn to critically read, with an understanding of salient points, original research articles relating to freshwater ecology.


Dr. William O. Lamp, Associate Professor
Department of Entomology, 4120 Plant Sciences Bldg.
University of Maryland, College Park


Four credits: two lectures and two 3-hour laboratories per week. Two Saturday field trips are optional.

Frequency of Offering

Fall semesters.


BIOL 106 and ENTM 205 or ZOOL 210.

Relationship to Other Courses

ENTM 428, "Ecology of Aquatic Insects", has been taught for 3 credits since 1993 by Lamp. ZOOL 384, "Aquatic Biology", is no longer expected to be taught. The new course proposed here will combine the topics of the two courses, replace specifically ENTM 428, and increase in the number of credits from 3 to 4 for additional laboratory time.

Outside of ENTM 428 and ZOOL 384, no other introductory course on freshwater biology is offered on campus. Among entomology courses, ENTM 424, "Insect Diversity and Classification," includes orders of aquatic insects, however identification is not beyond the family level. The proposed course will consider more families and generic-level identification for insects living in aquatic habitats, as well as include other common invertebrate taxa. Furthermore, the proposed course will place greater emphasis on the ecological and physiological relationships between aquatic organisms and their environment.

Several courses discuss the ecology of aquatic systems. For example, ZOOL 484, "Experimental Aquatic Ecology", emphasizes experimental methods and hypothesis testing beyond the coverage of the proposed course. Also, ZOOL 481, "The Biology of Marine and Estuarine Invertebrates," covers those invertebrates, largely non-insect, associated with saltwater. Other courses, such as ZOOL 390, "Vertebrate Zoology", and ZOOL 472, "Protozoology", cover taxa outside the proposed course. None of these emphasize ecology and identification of invertebrates inhabiting freshwater systems. Thus, the proposed course will complement existing courses.

Course Description for Schedule of Classes

ENTM 482 and ZOOL 482 Freshwater Biology (4) Two hours of lectures and six hours of laboratory per week. Biology and ecology of freshwater invertebrates in lotic and lentic habitats, their adaptation to aquatic life, their function in aquatic ecosystems, and their relationship to environmental deterioration. Laboratory will include field trips, demonstrations, and identifications.

The Course's Targeted Audience

The course is being offered as an upper level lab course for undergraduate students in biology (GENB, BEES, and MARB specializations) and environmental science majors, and for graduate students in entomology, zoology, conservation biology and MEES. The maximum enrollment is 25.

Required Text

The text is: Merritt, R.W., and K.W. Cummins (eds.). 1996. An Introduction to the Aquatic Insects of North America, 3rd ed. Kendall/Hunt Publ. Co. This edited book provides up-to-date keys to genera of North American aquatic insects, as well as general introductions to major topics such as feeding groups, respiration, and biology of all aquatic insect orders. Supplemental information on non-insect taxa will be provided.

In addition, a packet of required readings will be made available for purchase. See attached list as an example. These readings, derived from primary research journals, will be the focus of discussions of original research on the biology and ecology of freshwater invertebrates.


Midterm exam

Final exam

Lab practicals and participation

Lab notebook




Overview of Laboratory

The laboratory period will be divided into two parts: field trips and in-lab demonstrations during the first half of the semester, and labs for identification of families and genera of specimens within individual orders during the last half of the semester. Students are paired to help each other with both field collection and lab identification.

The field trips will give students an opportunity to observe and collect aquatic invertebrates in their natural habitat. Each field trip, students will make a collection from one or more sites, and later separate specimens by order into separate vials. Each vial should be labelled clearly with location, date, and collector's name. Each student will be expected to record observations during each field trip in a notebook.

During each identification lab session, an overview of the biology and classification of the taxa will be provided. Students will use both the collected specimens and selected demonstration specimens to learn identification using the key and noting primary characteristics. Each student will be expected to record these observations in their notebook as well. Notebooks may be used during practicals for key identifications.

Lab Practicals

The lab practicals will be oral or written tests to determine students' knowledge of the habits and ecology of collected organisms as well as their identification. Students will be expected to know all aquatic subclasses/orders of invertebrates by sight, common families by sight, and selected families and genera by key.

List of Required Readings (to be updated each semester)

Bothwell, M.L., D.M.J. Sherbot, and C.M. Pollock. 1994. Ecosystem response to solar ultraviolet-B radiation: influence of trophic-level interactions. Science 265:97-100.

Heard, S.B. 1994. Pitcher-plant midges and mosquitoes: a processing chain commenalism. Ecology 75:1647-1660.

Hopkins, P.S., K.W. Kratz, and S.D. Cooper. 1989. Effects of an experimental acid pulse on invertebrates in a high altitude Sierra Nevada stream. Hydobiologia 171:45-58.

Kaitala, A. 1987. Dynamic life-history strategy of the water strider Gerris thoracicus as an adaptation to food and habitat variation. Oikos 48:125-131.

McAuliffe, J.R. 1984. Resource depression by a stream herbivore: effects on distributions and abundances of other grazers. Oikos 42:327-333.

Moore, K.A., and D.D. Williams. 1990. Novel strategies in the complex defense repertoire of a stonefly (Pteronarcys dorsata) nymph. Oikos 57:49-56.

Palmer, M.A., A.E. Bely, and K.E. Berg. 1992. Response of invertebrates to lotic disturbance: a test of the hyporheic refuge hypothesis. Oecologia 89:182-194.

Power, M.E. 1990. Resource enhancement by indirect effects of grazers: amored catfish, algae, and sediment. Ecology 71:897-904.

Svensson, B.W. 1985. Local extinction and re-immigration of whirligig beetles (Coleoptera, Gyrinidae). Ecology 66:1837-1848.

Williams, D.D., A.F. Tavares, and E. Bryant. 1987. Respiratory device or camouflage? - A case for the caddisfly. Oikos 50:42-52.



Lectures Labs


Objectives and procedures, definitions, morphological characteristics Identification of orders
Sampling of campus aquatic habitats


Characteristics and trophic structure of lotic and lentic freshwaters Field trip: Middle Patuxent River
Demo: Invertebrate diversity


Invertebrate evolution
and diversity
Field trip: Beltsville pond
Demo: Invertebrate life histories


Trophic relationships
Feeding adaptations
Sat Field Trip: Garrett Co.
Demo: Feeding behavior and morphology
Practical I


Physiological adaptations
Morphological and behavioral adaptations
Field Trip: Catoctin Mts
Demo: Respiration, swimming behavior, response to current


Relation to water quality
Eutrophication, acidity, heavy metals, pesticides
Field trip: Paint Branch Creek to demonstrate biotic index
Sat Field Trip: Baltimore Co.


Community structure
Population dynamics
Biology and identification:
Meiofauna, Plankton, Periphyton


Intra- and interspecific competition
Biology and identification:
Annelida, Mollusca, Crustacea


Herbivory and predation
Top down - bottom up controls
Biology and identification:
Ephemeroptera, Odonata


Life history strategies Biology and identification:
Plecoptera, Heteroptera
Practical II


Response to declining conditions
Diapause, migration, and drift
Biology and identification:
Trichoptera, Megaloptera, Lepidoptera


Population conservation
Biology and identification:


Spatial and temporal
Sediment/microhabitat relationships
Biology and identification:
Chironomid identification


Long-term prospects
Final lab practical


Course evaluation

View some slides from the course.