Welcome to Welcome to Ecology of Fishes Ecology of Fishes

LaboratoryLaboratoryZoology 511Zoology 511

What is a Fish?

• Poikilothermic – body temperature is identical to surrounding water• Chordates – have developmental characteristics of all vertebrates• Appendages developed as fins• Chief respiratory organs are gills• Body generally covered with scales

“A fish is an aquatic vertebrate with gills and with limbs in the shape of fins” (Nelson 1994)

There are over 25,000 fish species, so there are exceptions to these general characteristics.

Fish vs. Fishes

“This tank is full of fish.” “The ocean is full of fishes.”

How fish are named

Common name, Genus species

speckled perch, specks, papermouth, bachelor perch, calico bass, strawberry bass, or white perch.

Black crappie, Pomaxis annularis

Fish Ecology….?

What’s Ecology -is the study of the distribution and abundance of living

organisms and how the distribution and abundance are affected by interactions

between the organisms and their environment (Krebs).

• In my analysis, the spectrum ranges from ichthyology (evolution, taxonomy, structure and function, and biogeography of fishes); fish biology (metabolism, energetics, tolerances sensory process, behavior, reproduction, age/growth principles, demography, etc.); fish ecology (generally relating fish to their biotic environment at the individual, population, community and ecosystem levels); fish assessment (I say fish, instead of fishery, because we sometimes need to assess non exploited populations) that includes sampling methods tagging, analysis of sampled data (e.g. population size or structure); fishery resources (global and regional fisheries and their economic, sociological values (commercial and recreational), gears, markets, etc.; and finally fishery management (how to analyze fisheries (stock assessment, modeling, etc) and apply everything else to manage exploited or protected resources). PHEWWW!

• An Excerpt from an email of Dr. Randy Edwards

Ichthyology: (Fish biology) is the branch of zoology devoted to the study of fish.

Fishery: A fishery (plural: fisheries) is an organized effort by humans to catch fish or other aquatic species, an activity known as fishing.

Fisheries Management: The effort to regulate where, when and how people fish, and how many fish they catch, to protect fish populations so that people can continue to fish.

Fisheries Science: Think of fisheries science as all the math behind fisheries management. That is, how do you make informed decisions on how to regulate people to protect fish populations?

All of these are incorporated into fish ecology and fish ecology plays an important role in all of the above!

Some definitions of terms you’ll hear

Dorsal

Anatomical terminology of a fish…

Ventral

Posterior or caudal

Anterior Lateral Lateral

Used for relating different parts….Eye is posterior to the mouth

Conversely the mouth is anterior to the eye

Fins of a fish…Dorsal

Anal Pelvic

Pectoral

Adipose

PectoralPelvic

Caudal

Bowfin (Amia calva)

Giant snakehead

Dorsal

Fins spines vs. rays

Bluegill Black Crappie

Fish Scale Types

Fish Scale Types

Scutes on a sturgeon are a modification of scales

Mouth placement

vs.

superior terminal

inferior

Maxilla

Premaxilla

Swim bladder

Ovary

Heart

Liver

Stomach

IntestineFat deposits

Internal anatomy – the basics that help understand the ecology!

Gills and Gill Rakers

Gill arch

Gill filaments

Gill rakers

Ecology influences anatomy

Northern Pike

FISH WITH TEETH

Not all Teeth are pointy!

vomerine teeth

Muskie Walleye

Burbot

Longfinned Eel

Chinook Salmon

Barbels: nothing is easier to identify!!

Yellow Bullhead Brown

Bullhead

Burbot Burbot

Oddballs: Rostrum

Measure anatomy to do ecological studies

Enough lecture, lets look at some fish

Why in the $#%* do we have to do all this writing in our fishes course?

• Get lots of instruction on writing…not as much on scientific writing, what is the difference?

• Importance of being able to express your thoughts, regardless of what career you choose

• Research techniques are universal

• If you go on in science, it is the only currency that matters?.......what do I mean by that?

Peer Review…?

• Criticism is important…”constructive criticism” is best!

• Two types: Internal and External. Point of internal review is to make external review go well

• When you are reviewing someone else’s work think how you would want to be reviewed…..You want to do the best job you can…but you don’t want to be yelled at to do it!

• You are going to do this for each other

The paper process…

• Observation or idea– It looks like every time we catch white suckers, we are sampling in a deeper portion of the stream…?– I wonder if the biomass of non-trout species is related to the biomass of trout species?

• Develop Hypothesis– It looks like every time we catch white suckers, we are sampling in a deeper portion of the stream…?– I wonder if the biomass of non-trout species is related to the biomass of trout species?

• Hit the literature– What does everyone else have to say about this

Where do you find information…

1. Web, Google and Google Scholar

2. Online Databases1. Biological Abstracts2. ISI Web of Science

Hypothesis Testing

An educated guess or prediction about an experiment, behavior, outcome, relationship etc.

Statistical TermsThe null hypothesis (H0)

fish growth 1 = fish growth 2The alternative hypothesis (H1)

fish growth 1 fish growth 2

Order of a scientific paper (on paper)

1. Title2. Abstract3. Introduction4. Methods – study site, data analyses5. Results – graphs, tables analyses6. Discussion7. Literature Cited

Order you write a scientific paper

1. Observe or Read primary literature2. Results – start with a picture, tell your story3. Discussion – what’s cool about your story,

also relative to what other people found4. Methods – what did you do to get your results5. Introduction – background on what you found6. Abstract – just the highlights7. Title – make it work for your story8. Literature Cited

How to do the first step.....1. Observe or Read primary literature

Use your fish from class

1. Web, Google and Google Scholar

2. Online DatabasesBiological AbstractsISI Web of Science