Animal Adaptations
Project Oceanology has been monitoring the health of coastal Long Island Sound since 1972. This includes sampling the health and density of local animal populations. One strategy of sampling we commonly use is the Otter Trawl. This method involves sending a large, conical net down to the bottom of the water column, and trying to catch whatever animals are down there. We call these animals “benthic epifauna;” they live deep in the water, on the outside of the bottom substrate.
Step 1: Watch this video to see how we sample using an otter trawl net!
Step 2: Once we’ve hauled in the net, and obtained some specimens, we need to accurately identify them. In order to properly identify each species we catch so that we can accurately add the data to our records, we use a dichotomous key. This method uses a series of “either-or'' choices that direct us to the next pair of choices (also known as a couplet) or to the point of identification.
The following is an example of a dichotomous key with four couplets. For practice, identify a nickel using this key.
Key to American Coins Dated after 1965
Question 1
Choice 1A: Coin is copper-brown color.......................................................................................penny
Choice 1B: Coin is silver color...................................................................................go to question 2
Question 2
Choice 2A: One side of coin displays an eagle.........................................................go to question 3
Choice 2B: Neither side of coin displays an eagle.....................................................go to question 4
Question 3
Choice 3A: Coin is less than 2.5 cm (1") in diameter................................................................quarter
Choice 3B: Coin is greater than 2.5 cm (1") in diameter......................................................half-dollar
Question 4
Choice 4A: The word "liberty" appears behind the head on one side of the coin........................nickel
Choice 4B: The word "liberty" appears in front of the head on one side of the coin.....................dime
Since a nickel is silver color (choice 1B), you would move from question 1 to question 2. Your response to question 2 should be that the coin does not display an eagle (choice 2B) and therefore you should proceed to question 4. Your response to question 4 should be that the coin has "liberty" behind the head (choice 4A) and therefore you you have identified the coin as a nickel.
Use a dichotomous key to identify each of the unidentified animals linked below. Each page will show a video of the unidentified animal and questions. For each question there will be 1 - 3 choices for you to decide between based on what you observe in the video. To move to the next option, click "Choice A", "Choice B", or "Choice C". If you answer a question incorrectly, you will be directed to a drawing of an organism. Click the blue button below the drawing to return to the question to try again.
Unidentified Animal 1
Unidentified Animal 2
Unidentified Animal 3
Unidentified Animal 4
Unidentified Animal 5
Unidentified Animal 6
Unidentified Animal 7
Unidentified Animal 8
Unidentified Animal 9
Unidentified Animal 10
Unidentified Animal 11
Step 3: Identify Animal Adaptations
An important part of wildlife research is understanding how specific animals interact with their ecosystem--the habitat in which they live, and other animals in their community. We want to choose an animal from our trawl and investigate how it might be physically adapted for these interactions.
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What is the common name of the animal?
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How does this animal obtain food and what do you think it might eat? What physical traits did you observe to make this conclusion? What behaviors did you notice?
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How does this animal move? What physical characteristics and behaviors did you observe?
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How is this able to protect or defend itself? What physical adaptation or behaviors did you observe in the video?
Step 4: Comparative Anatomy
Now choose another animal from our sampling, and compare it with your first.
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How are the animals similar? How are they different?
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What can these physical differences tell us about how our animals interact with their environment? (Ex. Do they live in different habitats? Do they eat different things? etc).