Welcome to Ecology of Fishes Laboratory Zoology 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.”

Pomaxis annularis Black crappie…or… How fish are named speckled perch, specks, papermouth, bachelor perch, calico bass, strawberry bass, or white perch. White Perch, Morone americana

Fish Ecology….? Ecology is the study of the distribution and abundance of living organisms and how their distribution and abundance are affected by interactions between organisms and their environment (Krebs).

An extensive subject… 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

Some definitions of terms you’ll hear 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!

Anatomical terminology of a fish… Dorsal Anterior Lateral Lateral Posterior or caudal Used for relating different parts….Eye is posterior to the mouth Ventral Conversely the mouth is anterior to the eye

Fins of a fish… Dorsal Caudal Pectoral Anal Pelvic Adipose Pelvic

Bowfin (Amia calva) Bowfin (Amia calva) Dorsal Giant snakehead

Fins spines vs. rays Black Crappie Bluegill

Heterocercal Protocercal Homocercal Diphycercal

Fish Scale Types Most bony fishes (Teleosts) Overlapping = Flexibility!

Fish Scale Types Bowfin, paddlefish, gar, sturgeon Sharks and rays Shark teeth and spiny tail on rays = modified placoids Sharks and rays “riblets” decrease drag. Nanotechnology

Scutes are a modification of scales

Mouth placement superior terminal vs. inferior

Premaxilla Maxilla

Internal anatomy – the basics that help understand the ecology! Stomach Swim bladder Liver Heart Intestine Ovary Fat deposits

Gills and Gill Rakers Gill arch Gill filaments Gill rakers

Ecology influences anatomy

FISH WITH TEETH Muskie Walleye Northern Pike Chinook Salmon Burbot Not all Teeth are pointy! vomerine teeth Longfinned Eel

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