Evolution on the Half-shell 101: Laboratory exercises using bivalves
The laboratory exercises presented here were developed by Dr. Deirdre Gonsalves-Jackson at Virginia Wesleyan College, Norfolk, Virginia, as one of the outreach products for the BivAToL Project. The labs accompanied a Marine Invertebrate Evolution course for undergraduate biology majors, and were taught in Fall 2010 and Spring 2012 before posting. There were 10 labs for this course, eight of which are presented here; the remaining labs were spent at local field situations for which lab worksheets were not produced.
Other class exercises, including dissection guides, can be found in The Teacher-Friendly Guide to Evolution Using Bivalves as a Model Organism
- Laboratory 1: Diversity of Bivalve Form
This exercise stresses the structure-function relationships in various species of bivalves. It emphasizes a) shell structure, b) bivalve diversity, and c) the diversity of habitat diversity in which bivalves occupy.
- Laboratory 2: Bivalve Fossil Record
This exercise stresses the rich fossil record of bivalves due to their calcium carbonate shell. The focus is to examine the diversity of fossils from the major eras of geological history and to develop an understanding of their evolutionary history.
- Laboratory 3: Bivalve Anatomy I
In this exercise, students examine and dissect two important bivalve species. Comparisons are made between these species as they occupy distinct habitats and have evolved structures that enhance their lifestyle in each habitat.
- Laboratory 4: Bivalve Anatomy II
In this exercise, students examine and dissect three additional important bivalve species. Comparisons are made between these species as they occupy distinct habitats and have evolved structures that enhance their lifestyle in each habitat.
- Laboratory 5: Oyster Recruitment
This exercise focuses on conservation of an ecologically important oyster species, the populations of which have become decimated due to overharvesting, disease, and habitat degradation.
- Laboratory 6: Bivalve Beach Community Structure
This exercise focuses on the community structure of bivalves in a sandy beach habitat. The students characterize bivalve species abundance and diversity and create a size class distribution to gain an understanding of how species are associated within this habitat. The site for this lab, First Landing State Park, is located at the mouth on the Chesapeake Bay in Virginia Beach; however, any sandy beach habitat can be utilized for this lab exercise.
- Laboratory 7: Bivalve Cladistics
The focus of this exercise is to introduce students to phylogenetic analysis (cladistics) and how it is a tool for analyzing taxonomic and phylogenetic relationships among Bivalvia.
- Laboratory 8: Bivalve Physiology
This exercise examines the physiology of representative species of bivalves. Exercises test heart rate as it relates to change in temperature and ciliary feeding action, and compares the presence of coliform bacteria in the gut of several species.
“One thing I liked about the lab was we focused on attention on the different types of bivalves, both Recent and fossil species. By participating in these labs, it made me realize how unique and special bivalves really are and I gained an appreciation for them that I didn’t have before this class.”
“The labs were the best part of the whole class. They were interesting and we were able to put all the knowledge we had learned to use.”
“I enjoyed going on field trips and getting real-world experience. It was an eye-opener seeing all the work and effort put towards studying and preserving certain bivalve species. Going to the beach is always fun, [but] it was the first time I went there to look at the different species of animals. I always took the animals for granted.”
“Field trips were exciting. The beach collection of shells was interesting. [It] brought a twist that they were once living.”
“Had fun dissecting live bivalves, and observ[ing] their heart beat. Didn’t like the smell of my hands afterwards, but that’s science.”