frst 386 terminology and concepts

what characteristics can we look at to tell species apart?

shape, presence and colour of fins, presence of sensory organs

are there non-morphological ways to distinguish between species?

life history traits

what is this orientation?

anterior

what is this orientation?

dorsal

what is this orientation

posterior

what is this orientation?

ventral

what is the top arrow pointing to, and what components make it up?

top: dorsal fin

left: spine

right: ray

what is this pointing to?

pelvic fin

what is this pointing to?

anal fin

5 major rays

what is this pointing to?

caudal fin

what is this pointing to?

pectoral fin

what is this pointing to?

opercle

what is this pointing to?

maxilla

what is this pointing to?

caudal peduncle

what is this pointing to?

lateral line

what is this pointing to?

anus

what is this pointing to?

parr marks

what is this pointing to?

adipose fin

what length is this?

total length

what length is this?

fork length

what length is this?

standard length

what length is this?

post-orbital hypural

what length is this?

head length

what length is this?

snout length

what types of fins are these?

1. fleshy dorsal fin

2. spiny-fleshy dorsal fin

3. spiny dorsal fin

what types of mouths are these?

1. terminal

2. supra-terminal

3. sub-terminal

4. inferior

what body shapes are these?

left: torpedo

middle: dorsally compressed

right: laterally compressed

population

A group of organisms of the same species that interbreed and live in the same place at the same time

stock

semi-discrete groups of fish with some definable attributes of interest to managers; a harvested or managed group of fish

catadromous

A species of fish that does most of its growing in freshwater and returns to saltwater to spawn (e.g., The American eel - found in St. Lawrence River)

anadromous

A species of fish that does most of its growing at sea and returns to freshwater to spawn (e.g., Pacific salmon, Atlantic salmon, lampreys)

potadromous

A species that migrates entirely within freshwater

semelparous

A species that spawns only once (i.e., dies after spawning).

E.g., All “Pacific salmon”* (5 spp.), lamprey

iteroparous

A species that matures and spawns more than once.

E.g., Atlantic salmon, trout, char

what are three approaches to ageing fish

1. size frequency distributions

2. analysis of body parts/structures that retain growth information relatable to time

3. direct observation of individually identifiable animals whose histories can be followed through time

what are size frequency distributions?

ages are estimated by examining the relationship between fish abundance and length

assumes that fish of the same age are a similar size

what is analysis of otoliths/scales/fin rays?

structures such as otoliths, scales, and fin rays provide a record of growth

all three structures grow in rings, and growth rate is reflected by the space between the rings

what is the direct observation of individuals?

external tags, fin clips/markings, injecting dyes under skin, branding, inserting/attaching transmitters

what are pros, cons, and other uses for size frequency distributions?

pros:

• quick

• potentially cheap

• non-lethal

• no species equipment or training required

cons

• there could be overlap between age groups

• it is subject to sampling bias

• requires a large sample size

other uses

• monitoring fish populations over time

• population dynamics

what are pros, cons, and other uses of analysis of otoliths, scales, or fin rays?

pros

• accurate

• non-lethal (scale and fin rays)

• easy to collect

• can get additional information (e.g. growth rates)

cons

• can be expensive

• lethal (otoliths)

• requires training/knowledge

• time consuming analyses

• human error during collection

other uses

• growth studies

• habitat use

what are pros, cons, and other uses of following known individuals?

pros

• non-lethal

• a lot of additional data can be taken

• 100% accurate

cons

• expensive

• requires training/knowledge

• requires tracking fish over long periods

• tag loss is possible

other uses

• all sorts of behavioral and physiological information

name the two types of paired fins

pelvic fins and pectoral fins

air bladder

• can be open or closed if present

• cavity connected to esophagus (regulates buoyancy)

• open = connected to esophagus (need to go to surface)

• closed = inflate/deflate with blood stream gas exchange (not connected to esophagus)

taxonomy

the practice and science of classification

order

-iformes

family

-idae

sub-family

-inae

genus and species

Genus species or Genus species

salmonidae sub-families

coregoninae, thymalline, and salmoninae

salmonidae main characteristics

1. adipose fin

2. lateral line present

3. no spines in fins, have a fleshy dorsal fin

4. juveniles (most, not all) have parr marks

salmoninae genus

oncorhynchus, salmo, and salvelinus

anadromous salmon life history

• some rear for a year+ in the stream or lake

  • e.g. Chinook, coho (stream)

  • e.g. sockeye (lake)

• some go directly to sea after the emergence

  • e.g. pink, chum

non-anadromous salmon life history

some salmonids spend entire life cycle in freshwater

• e.g. rainbow trout and kokanee salmon (can do a migration from lake to stream but is more likely to spawn on the shores of a lake)