Ichthyology Mid term

What is ichthyology?

The study of fish.

What are the characteristics that define a fish?

Cold-blooded; aquatic; vertebrate; fins and gills.

When do we use the word 'fish' vs. 'fishes'?

'Fish' refers to singular or plural for one species, 'fishes' refers to multiple species of fish.

How are fish important in aquatic ecosystems?

1. Bears eat fish and transfer nutrients to land and freshwater. 2. Carcasses from anadromous fish transfer carbon and nutrients from marine to freshwater and terrestrial ecosystems.

How are fish important in economies and culture?

Fisheries and aquaculture sustain food sources for hundreds of millions of people; recreational fishing in the Great Lakes was $4.1 billion for the US and Canada in 2020.

How does fish diversity compare to other vertebrates?

Most species are rich compared to other vertebrates; there are more kinds of fishes than all the other groups of vertebrates combined.

What are fish biodiversity hotspots for freshwater and marine fish?

Freshwater Hotspot: South America; Marine Hotspot: Central Indo-Pacific.

Why do 41% of fish species inhabit freshwater environments?

Due to habitat fragmentation, environmental complexity, evolutionary history, limited dispersal, and adaptation to dynamic environments.

Classify fish based on Kingdom, Phylum, Super Class, and Class.

Kingdom: Animalia; Phylum: Chordata; Super Class: Agnatha (Jawless), Gnathostomata (Jaw); Class: Chondrichthyes (Cartilaginous), Osteichthyes (Bony).

What are characteristics of early fish?

Jawless, cartilaginous, armored, simple fins.

What are key adaptations in the evolutionary history of fish?

Scales for protection and maneuverability; paired fins for locomotion and stability; swim bladder for buoyancy control; fusiform body for energy expenditure; jaws for efficient predation; fins for improved mobility; lateral line system for detecting vibrations.

Name fish that are considered 'living fossils'.

Lungfish and Coelacanths.

What are reasons to conduct fish monitoring?

1. Monitor endangered or threatened species. 2. Monitor population trends for regulations. 3. Fish populations indicate water quality and habitat health. 4. Regulatory requirements for the CWA are based on fish and macroinvertebrates.

Explain common fish sampling techniques.

Electrofishing (Boat, Longline, Backpack), Seine netting, Fyke/hoop nets, Gill nets.

What is the purpose of fish tagging?

1. Tracking migrations. 2. Population surveys. 3. Growth rates. 4. Spawning.

What are properties of water that influence fish?

Viscosity, density, surface tension, oxygen content, temperature stability, and solubility of nutrients.

What are the main functions of the pelvic fin?

Provides stability, aids in steering, and balance while swimming.

What is the function of the caudal fin?

Helps the fish swim against the water by pushing against it.

What do dorsal and anal fins do?

Help with balance and prevent side-to-side rolling.

What is the role of the pectoral fin?

Allows fine control, hovering, breaking, and sharp turns.

What is the function of the adipose fin?

Acts as a precaudal flow sensor, detecting water pressure changes and turbulence.

How has the placement of pelvic and pectoral fins changed over time?

Pelvic fins have moved from abdominal to thoracic positions for greater maneuverability; pectoral fins have higher placement for improved control.

What are the six categories of fish body shapes?

1. Rover Predator - fusiform, e.g., Trout. 2. Lie-in-Wait Predator - elongated, e.g., Pike.

What are Bottom Clingers?

Fish flattened ventrally for bottom adaptation, with large stiff pectoral and pelvic fins.

What are Bottom Rovers?

Fusiform fish with a slightly flattened underside, equipped with barbels or sensory structures for detecting food.

What are Deep-Bodied Fish?

Laterally compressed fish with long dorsal and anal fins, great at maneuverability but not speed.

What are Surface-Oriented Fish?

Fish that are flattened dorsally with an upper facing mouth and large eyes.

What is undulation in swimming styles?

A swimming style where the entire body moves like a travelling wave, seen in Eels.

What is oscillation in swimming styles?

A swimming style involving repeated side-to-side or up-and-down movements, seen in Tuna.

What is Anguilliform swimming?

Swimming style with entire body undulations like a wave, exemplified by Eels.

What is Subcarangiform swimming?

Moderate body undulations with mostly posterior half movement, seen in Salmon.

What is Carangiform swimming?

Moderate body undulation with most movement in the posterior half, seen in Trout.

What is Thunniform swimming?

Swimming style with most movement in the caudal fin, exemplified by Tuna.

What is Ostraciiform swimming?

Swimming style with movement only in the caudal fin, seen in Boxfish.

How do fish use the swim bladder?

Fish regulate buoyancy by adding or removing gas from their swim bladder.

What are the two types of swim bladders?

Physostomous swim bladder is connected to the gastrointestinal tract; physoclistous is not.

What is barotrauma?

A condition caused by rapid pressure changes affecting the swim bladder, often due to quick ascents.

How can barotrauma be treated?

Using a venting tool to release excess gas from the swim bladder.

What are the three types of muscles in fish?

Skeletal (voluntary movement), Cardiac (involuntary, striated), and Smooth (lines organs).

What is the difference between white muscle and red muscle in fish?

Red muscle is oxygenated, used for slow to medium speeds; white muscle is thicker, used for short bursts.

How do fish extract oxygen from water using gills?

Capillaries in gill filaments allow for gas exchange, facilitating oxygen uptake.

What is countercurrent gas exchange?

A mechanism where blood and water flow in opposite directions to maximize oxygen diffusion.

What is external fertilization?

When female fish lay eggs in water and males fertilize them externally.

What are examples of spawning behaviors in fish?

Migrating, courtship displays, broadcast spawning, and nest building.

What are parental care strategies in fish?

Guarding eggs, fanning water over them, and mouthbrooding.

What is broadcast spawning?

Releasing eggs and sperm into the water column for fertilization.

What is nestbuilding in fish?

Constructing nests from rocks or vegetation to protect eggs.

What is substrate attachment in fish?

Eggs have an adhesive to attach to submerged objects.

What is live-bearing in fish?

A reproductive strategy where embryos develop within the mother.

How can otoliths determine the age of a fish?

By counting the rings formed on each otolith, which indicate yearly growth.

What is the circulatory system of a fish?

A closed loop system involving blood flow from the heart to gills and then to the body.

What are the parts of the nervous system in fish?

Includes the brain, sensory nerves, spinal cord, and lateral line.

What is the lateral line in fish?

A sensory organ that detects movement and vibrations in the water.

What are the two main components of the fish endoskeleton?

Axial Skeleton (skull and vertebral column) and Appendicular Skeleton (supports fins).

What are examples of fish families covered in lecture?

Ictaluridae (catfish), Salmonidae (salmon), Esocidae (pike).