Explore over 25,000 species

Learn how scientists identify and classify the most diverse vertebrate group on earth.
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Authoring Scientists

Adriana Aquino
Ichthyologist
Dr. Aquino is a postdoctoral research fellow in the Ichthyology Department.
Melanie Stiassny
Ichthyologist
Dr. Stiassny is the Axelrod Research Curator of the Department of Ichthyology.

About the Course

Fishes were the first creatures with brains and bony jaws. But their incredible diversity—fishes make up half of all vertebrate species alive today, and live everywhere from mountain streams to ocean depths—makes it easier to determine what's not a fish. This seminar explores this paradox by demonstrating how ichthyologists pursue the evidence through the study of evolution, diversity ecosystems, and biogeography. Read more.

Key Science Concepts

Fishes are the most diverse of all vertebrate groups.

Fish have breathing, feeding, sensory, locomotion and reproductive structures that make them specially adapted for life in water.

Many groups of fishes are among the most endangered vertebrates.

Collection-based research provides crucial scientific underpinning for conservation policy and planning.

Cladistics is a method of classifying living things by reconstructing their evolutionary relationships. It uses shared derived characteristics—features that evolve for the first time and are passed on to all an organisms' descendents—to establish relationships. Cladistics is the method used in modern systematics.

Systematics is the branch of Biology that discovers and classifies the diversity of life, both living and extinct. When studying a group of organisms, a systematist typically looks for evidence (in the form of shared derived characteristics) that supports evolution from a common ancestor.

In biological terms, success is based on different criteria, These include how diverse a group of organisms is (for example, there are 24,000 ray-finned fish species compared to about 820 species of sharks and rays), how long a species has lived on Earth, the development of specialized adaptations and how many individuals belong to a species.


Course Textbook

The Science Times Book of Fish
Author: Nicholas Wade
Publisher: Lyons Press
Edition: September 1997
Paperback: 231 pages
ISBN: 1558216049
Buy online: Amazon

Graduate Credit

This course is approved for graduate credit and continuing education units from leading institutions at an additional cost. Read more.

Adams State UniversityBank Street College of EducationCity University of New YorkFramingham State UniversityHamline UniversityNova Southeastern UniversityWestern Governors University

Related Courses

Interested in more from Seminars on Science? Consider these related offerings:

In the Field with Spiders
Classification, Anatomy and Morphology
Sharks and Rays
Ecology, Classification and Evolution
The Ocean System
Integrated Science

Course Preview

Explore an interactive of fish skull animations, read about the diversity of fish species, and explore a sample discussion.

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Testimonials

"The resources provide me with mounds of material to use in my vertebrate zoology class."
—high school biology teacher
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Evaluation

73% of educators say this course was more valuable than professional development available at the local level.

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