Water Ecology

FISH ECOLOGY

Unit 2. Fish Ecology
Lesson 1. --What is a Fish?
Lesson objectives:
Students will understand external fish anatomy, and that fish come in many shapes and sizes
The students will be able to identify the different zones of the ocean
Students will become familiar with the methods that are used to study fish are diverse, and each has a purpose. Vocabulary words: vertebrae,planktonic, nektonic, benthic, continental margin, and many more pertaining to ocean zonation

What is a Fish?
A fish is defined as an aquatic or marine animal with vertebrae. All fish have vertebra, except sharks and rays that have cartilage. Cartilage is more flexible than bone, but strong enough to support the body. They usually possess gills in the adult stage and have limbs in the form offins. Fishes also include the jawless vertebrates such as the lamprey and hagfish; and the shark, ray, chimaera, lungfish, and bony fishes. The bony fishes are the most common. A bony fish has jaws that are well developed, formed by true bone rather than cartilage. Fish are very different in appearance, size and shape. This all depends on the environment that it lives in.

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Fish Habitats
Fish occupy almost every conceivable aquatic habitat. Describing the ocean is difficult, as there are many words that are used to explain the land and water realms. These habitats are defined by the critters that live in each. Visualize a column of water. This is the pelagic (the water, not associated with land) realm of the ocean.Geographic zonation defines the coastline, and submerged land. Scientists use these words to help in the identification of animals that live on the substrate (land).

Some fish live in man made habitats in peoples homes. These habitats are called aquaria.

There are other terms that describe the geographic zones that pertain to the continent and landmasses under the water. Between thecontinental land and seafloor is the continental margin. It is the submerged part of the continent, and makes up a transition zone

between the continents and ocean basins. The continental margin includes the coast (also known as the littoral zone), the continental shelf, the continental slope, and the continental rise. The continental rise ends where the abyssal plain begins. The deepest parts of theocean are located in the trenches, or hadal areas.

(Activity 1 is an illustration that is to be labeled with the different vocabulary words found in this section.)

©PROJECT OCEANOGRAPHY FALL 1999

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Prefix (most English have Greek definition origins)

Realm
(water or land)

Depth
no specific depth, just pertaining to the water realm, NOT the land0-200m

Example of what lives there
all organisms found in the water column plankton, fish larvae, very small fish active swimmers such as the tuna, squid and marine mammals crabs, juvenile fish, plankton, larvae deep sea organisms, gulper eel deep-water organisms flounder, stargazers, crabs, starfish, urchins, snails, christmas tree worms deep sea organisms, some eels, lantern fish

pelag(os)of the sea

water

epi

outer, exterior

water

meso

middle

water

200-600m

littoral (littoralis)
origin is Latin

of or pertaining to the edge of a lake, sea or ocean depth deep area or space, chasm

water and land boundary

seashore area 4000m and deepter 4000m to 6500m

batho- or bathy-

both

abyssos

both

benthos

depth of the sea, bottom

land0 (beach zone) to deepest ocean bottoms

hadal

deepest part of the sea, trenches

land

6500m and deeper

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How Do We Study Fish?
Scientists study fish in many ways because sometimes they want to observe them in their natural environment, and other times, scientists need to observe the internal body structures....