Fish - Exam 1

What are fish and some of the exceptions

Free-living, aquatic, cold-blooded, gill-breathing, craniates that have fins and not pentadactyl limbs

Exceptions:

• sea lamprey are not free living

• walking catfish are not soley aquatic

• mackerel sharks are not cold-blooded

• walking catfish are not gill-breathing

• coelocanth has pentadactyl limbs

How are some fish warm-blooded

all fish have their gills running on a counter current exchange system where water and blood flow opposite. Warm-blooded fish such as the mackerel sharks have two counter current exchange systems that allow for the blood to remain warm and allow for the original purpose fo maximizing oxygen uptake

How many species of fish are there

20,000-40,000

monoletic vs paraphyletic vs polyphyletic

monophyletic is when there is a single common ancestor among these species

paraphyletic is the crocodiles and birds

polyphyletic is the largest set where we look on both sides of the single common ancestor, but dont necessarily need to include all of them

What are the classes of fish

He gave us 3.5

Agnatha (Hagfish and lamprey)

Chondrichtyes/Cartilaganous (sharks, skates, and rays)

Osteichthyes/Bony fish: tuna

0.5 for lobed-fin fish like the coelocanth

What evovles into gill slits

pharyngeal clefts

How do different fish use their pharyngeal slits

Lancelets use their pharyngeal slits for suspension feeding

craniates gill slits use their gill slits for pumping water through their gills

What fish have an external minteralized skeleton

gnathostome and other fossil jawless verts

What percent of fish live in freshwater

41.2%

What are some of the organs craniates have that help with digestion

pancreas for hormones and digestive ensymes

liver for food storage and bile

What are some of the severe conditions fish live in

below freezing - arctic cod with the help of antifreeze in them

above 40C in hot springs like Julimes pupfish

varying levels of salt water

David Starr Jordan - who is he and what did he do?

He was an author that wrote

• Synopsis of the fishes of North America

• Fishes of North and Middle America

• The Genera of Fishes

• The Classification of Fishes

• Guide to the Study of Fishes

He was aggissiz student that learned and believed in evolution and was inspured by Darwin. This led him away from Aggassiz

Who initiated the US fish commission

Spencer Baird

Agassiz

believed in creationism and that all species were a product of God

Who put fish into classifications

Willoughby

How did Willoughby organize fish

he used their characteristics to group them

apomorphic: these are dervied

plesiomorphic: primitive characteristics

syn-whatever: shared.

synapomorphic specifically is what is used to group species together. If species are monophyletic (one common ancestor), then they have synapomorphic traits that relate them. Animals more distance, such as crocodiles vs mammals, will be synplesiomorphic where thet do have common traits but not recently derived. Their similiarities are more primitive

General Geological Time Scale

Precambrian

Mesozoic

Paleozoic

cenozoic

Tertiary

What are the two superclasses of fish under the Phylum chordata

Agnatha (jawless like maprey)

Gnathostoma (jaws from gill slits)

5 purposes of the skin

First line of defense against disease

protection from and helps to adjust to environment

sensory receptors

resp, excretory, and osmotic functions

glands and electric organs

Squamation

1) Naked: catifsh who dont have scales

2) Partially scaled: paddlefish

3) Large, bony plates like sturgeon

4) Deeply imbedded like eels

5) small scales like salmon

6) Scaled like sunfish

Scale shapes

Placoid: platelike with cusp

• sharks

Rhombic: diamond

• lungfish

Cycloid: disk

• minnows

ctenoid: sunfish

fish often have multiple types of scales

Scale derivatives

teeth in sharks

dorsal spines of dogsharks

tail spines of stingrays

Belly scutes of clupeids on herring

dermal armature on sturgeons

How to age a fish

temperate fishes only:

• you can count the annuli. The number of annuli is the number of years. The summer is when fish grow more, so we see annuli in the summer and not overlapped areas for the winter.

• only in temp fish and environmental changes may also result in this, causing innaccuracies

All fish have otolith (ear bones)

• count rings on otolith

• dont always need to kill fish if you have a CT scan. also good for fish in tropics that dont grow annuli

petrel spine, which is good for spineless fish like catfish

• count annuli on petrel spine

Use a graph and Linfinitiy, wihch is the intersection of growth rate and age

• issue with this is for long-lived fish that grow slowly

Structural scale types

placoid: sharp cusp

cosmoid: thin and hard

ganoid: garr

bony ridge

Barbels and flaps

prescence/absense as well as number of these can help us ID fish.

evovled independently meaning they just “popped up”

analogous vs homologous

analogous is when two things functions similarly but have no evol relationship/uses totally diffedrent bones, like bat vs bird wing. Evolved independently

hmologous is when a structure is derived from the same place and may or may not have similar functions

something may be both of these

parallel vs convergent evolution

parallel evol is when two species in diff niches are similar enough to eventually evolve the same stuructures. Species start out as similar and the environmental pressurs contribute to them evolving the same structures.

converg evol is when two entirelt diff species face the same impacts for long enough that they evolve the same structures. Species dont start out as similar and only evovle similarities through envrionmental pressures

In what ways does the environment influence coloration

open water: dark top, silver sides

weedbeds: intricate marks and often pale

ocean fish: depends on where in ocean they live

• upper zones: silver

• middle: red

• deep: violet and black

What physiological things can cause changes in color

skin pigment

underlying tissues

body tissue

gut cavities

Two sources of color

Schematochrromes: color is not due to pigment at all but instead the way the structures bend like/physical configuration

• iridescence in scales and intenstines, whites in skeleton, Tyndall white scattering

Biochromes: true pigments

• melanins like black and brown, carotenoids causing yellow and red

How does a fish eye work

the bottom half measures light coming from above

the upper half recieves reflected light from the substrate

what are chromatophores, where are they found, and what are the types

pigment-containing cells

dermis, outside or beneat scales, and in abdominal lining

types: eryhtrophores for red/orange, Xanthophore for yellow, melanophore for black

How do fish disguise and conceal

Ink sacs like unicorn fish, stone fish blend in

Types of Mimicry

1) Batesian: an edible species that mimics and inedible one (Marine betta and comet)

2) Mullerian: copies appearence of two or nore unplataable fish (Fang blennies)

3) Mertesian: a deadly fish mimics an aposematic trait (fake warning trait) of a less harmful one, like a coral snake (venom) mimicing a less venomous snake (false corals) - Squirrelfish and Tiger cardinalfish

Bioluminescence

living light

Common in midwater and deep water fish that have light organs

what are the two types of luminescence

1) Symbiotic bacteria

2) Photophores that cause light under nervous an endocrine control

Types of Diets

Parasitic: lampreys that live on tissue

grazer: includes parrotfish that have cutting teeth

strainers: whale shark with elongated gill rakers

suckers: bottom feeders like many minnows

piscivores: gar that have well developed grasping teeth

Traits of carnivorous fish

well defined stomach

strong acid secretion

short intestine

Four types of carnivores

active hunters like blue fish

ambush hunters like pike

anglerfish with lores

archerfish that shoot water jets with mouth: Toxotes

What three things to most predatory fish rely on

Sight, esp sunfish

taste and smell, esp catfish

lateral line sense, esp sharks, skates, and rays

What are paedeophages

baby eaters

cichlids

two structures of lips

plicate: having folds

papillose: having papillae

Types of lips by functionality

1) Suction type that are used to hold and move stuff like stones or other fish

2) Protractile lips that are used to engulf prey and are adjusted to give them a wide gape

Types of dentition

sharp pointed teeth fpr predators

toothless for plankton

molariforms for crushing mollusks

razor like for pirhanas

inciscorform for cutting veg

What are gillrakers

they protect sensitive filaments from abrasion and are variable depending on food type

How to increae absorption in gut

add lengthwise folds

add transverse folds

add villi-like projections

What can produce insulin in fish

Islets of langerhans

Is growth in fish deteminate

no its indeterminate, meaning they can keep growing

Food movement occurs in…

Peristalstic waves via voluntary uscles in gut and involuntary in other parts of the body

What groups have an endocrine system

lampreys

hag fish

sharks

boney fish

types of pituitary hormones

Group 1 that controls endrocrine glands

group 2 that influences endosomatic processes

What promotes the growth of fish

GH

Oxytocin in fish

not entirely sure of what it does, maybe helps to maintain salt and water balance. Mammals have it for reproductive purposes

female and male fish sex glands

female is estrogens

male is androgens

purpose of sex glands

maturation and elaboration of gametes

sex traits

reproduc behavior

What happens if you remove the pituitaty gland in fish

it stops the development of gonads

Where is the adrenal cortex

varies, usually either postcardinal veins of between kidneys (only in sharks)

what does the adrenal cortex do

it secretes adrenal cortical steroids that are then used to utilize stored fat, metabolise carbs and proteins and electrolytes, retain salt

What are the two hormones in intestines

Secretin and pancreozymin

What is the difference between endo and exocrine and what produces them

produced by pituitary gland

endo is straight into blood while exo has ducts

What is orientation in fish and why is it important

it is the process by which an animal establishes its position with respect to a reference point in time or space

• controlled, nonrandom movment uses oritentation

• for fish, aspects such as temperature, salinity, smells, and sounds are relative

  • animals often use environmental fixtures

acclimation temp

temperature is critical for fish. acclimation temp is hwere fish can survive. there is also a preferred temperature that fish can have. for example, sick fish prefer warmer waters

Where does the ideal temp lie

about half degree Centrigrade from lethal temp

What arfe some exmaples of biological rhythms

feeding and activity patterns and navigation

How do fish react to the sun and account for movement of it

they can swim with the sun

they react to the suns height and the movement around the horizon

Is the lunar cycle important for fish

yes because some use it to know when to spawn (specifically grunions)

How do fish “home”

tidal currents

chemical cues

salinity gradients

earths mag field

for exmaple, migrating salmon have issues migrating when theyh cannot use these senses via smell

What are the 6 navigational systems

vision

audition

internal guidance

temperature

electrical and magnetic fields

taste

Lateral Line sense

it is important because it helps them orient themselves through taste and thermal receptors

some fish have two lateral lines

How do fish see

its hard for them as water bends light wierd

they often need to use nearby refeences to see and some have the bottom half and op half of their eye slightly different to account for variation

Fish uses electrolocation

the electric currents are from fish moving through the magnetic field

mormyrids use this

Ampullae of lorenzini

receptors of electromagnetic fields

common on sharks

why do things dissapear if we dont need them

developing things rewuires energy. better use if we put that energy into something that we do ened

phenotypic variation

phenotype can vary if two things have nearly the same genetics

environment is a huge factor on how you look

How do fish sue taste

not often used extensively

catifsh use it though and ha ve good tastebuds on barbels

what is metaphysics, ontology, and epistomology

the study of what is real in a more psycological sense like fate vs free will and stuff

ontology is “what is real” like are numbers real?

epistomology is “how do we know if tis real (how did we come to conclusion from ontology)

Inertial guidance

semicircle canals in ears help fish navigate

Protogyny vs proandry

whatever forms first in hermaphodites

beenfits of protogyny: grow big and strong for reproduction and makes it easier to find territory. can then switch to being a male

beenfits of protoandry: can take time to develop well and then focus on egg production and development

What are the three ways fish reproduce

being bisxual (male and fexamle fert)

hermaphodite (selffert)

parthenogensis: cloning itself. In fish, always female children

4 embryonic tissues

the yolk to digest nutrients

allantois to collect waste and to gas exchange

chorion to enclose egg. needs to be pierced to see cell division

amnion to protect the embryo against shock and dehydration

what is gynogenesis

this is a form of parthenogensis when sperm from a different animal is used to pierce the yolk

the sperm is only used to pierce the yolk and is then killed so it doesnt contribute at all to the fertilization itself

Reproductive glands

tested and ovaries

ducts associates to transport gametes and nourish young

copulatory organs to aid in internal fertilization

hormones to inffluence sex characteristics

gonad development

How do gnathostomes reproduce

sperm rpoduced outside of tubes and eggs then shed into the coelem

Viviparity

embryo inside of body and is a live birth

mosquitofish

oviparity

egg is depositied and then fertilized and is sustained only be that yolk. not inside mother at all

clownfish

ovoviviparity

egg is interallt fertilized and kept inside mother but is only nourished through the yolk and not the mother via placenta or anything

great white shark!

what form of fertilization is considered advanced

internal

cloaca

opening of digestive and urogenital system

lungfish has a well developed one while clownfish dont have one

chondrichthyes fertilization

takes place internally before egg descends

sharks skates rays

r strats

rapid reprpductions with little parental care in an unstable environment

salmon

k strats

more effort in quality and parental care than sheer amount

sharks - stable environment

Cranial nerves in fish

Olfactory

optic

oculomotor

trochlear

trigeminal

abducens

facial nerve

auditory

glossopharyngeal

vagus

Maybe:

accessory

hypoglossal