Wildlife bio lecture 1 and F1 and F2 (fish and sharks)

D, K, P, C, O, F, G, S

domain kingdom phylum class order family genus species

taxonomy mnemonic

Darn King Philip came over from great spain

binomial nomenclature

organisms known by their genus and species

how to write scientific name

capitalize first letter then put second word (italic if type, underline if writing)

biological species concept

two organisms are considered to be of the same species if they can interbreed and have viable offspring for multiple generations

faults of the biological species concept

does not account for asexual reproduction, extinct creatures, species separated by distance

2 major groups of vertebrates

non amniotes and amniotes

conditions of the eggs of nonamniotes and examples

a moist environment, includes sharks, amphibians, bony fish, hagfish and lampreysd

amniote meaning and examples

having amnion, which is amniotic fluid, includes both live birth and laying eggs, ex: mammals reptiles

evolution definition

change in gene frequencies over multiple generations and leads to differences in survival/reproduction

evolutionary mechanisms (everyone eats bananas separately)

the species evolved from an individual

allopatric speciation

ancestral species separates into 2 groups because of a physical separation such as water, glacier, etc.

sympatric speciation

no physical barrier but become behaviorally separated (hunt at different times, evolve different diets, etc.)

adaptive radiations or diversifications and example

a lot of allopatric speciation happening at once, ex: Galapagos finches

ecological niche definition

individual environmental parameters that make an organism unique

Hutchison 1959 line of thinking

there are many habitats, all containing a variety of foods which means individuals can specialize and make food chains, specialization in diet expands to specialization in other things such as habits and recourses.

proximate mechanisms examples in relation to animal behavior

genes, hormones, instinct, parental upbringing, reflexes, maternal effects

ultimate mechanisms examples in relation to animal behavior

natural selection: those who evolved it did it better than whose who didn’t

requirements for natural selection

a requirement is variation in traits that are heritable

why is fish vision bad

it changes based on water quality, light travels differently through water, fish are nearsighted because they cannot focus the lens of their eye because the lens are so big

the muscle that moves the fish eyeball lens is called the

retractor lentis, it allows a little bit of focusing and moves back and forth like binoculars do.

anterior and posterior nostrils (fish)

incurrent and excurrent tunnels in skin that are paired organs

fish chemoreception general location on fish

taste bud organs in mouth, around head, and on anterior fins (catfish have them on their whiskers too)

function of fish olfaction

find food, find young, identify and detect predators, fins possible mates, migration, smell injured fish

chemoreception more specific information

• Taste and smell are distinct only because nerve signals from taste buds in mouth are received in the brain at different locations compared to olfactory pits on head and chemoreceptors elsewhere on head and fins.

• Chemoreceptors on head and fins are features of the epidermis only; the olfactory pits are not like the nasal passages of terrestrial animals.

• Water must be made to flow across olfactory pits

fish hearing general info

the inner ear receives sound waves through the skull swim bladder and skin, no eardrum because the skin acts as that, bone conduction, collects air within swim bladder

fish lateral line organ information

• Located within tubular canals or epidermal depressions.

• Uses hair cell mechanoreceptors to help fish maintain a horizontal position while swimming and to recognize unusual water currents that might indicate food or predators

• there are also freestanding receptors

electroreception and electrolocation general information

• detect voltages as small as 0.01 microvolts

• also detects the presence of prey or conspecifics

• helps with navigation in that it can detect ocean currents of different temperatures, Earth’s magnetic field

• electrolocation helps a fish detect non-moving features of environment

Electroreception in fish

nerve receptors called ampullae of Lorenzini that are embedded in epidermis of head (plus fins of rays, too), the structure and function is similar to a volt meter

distances of shark senses

• hearing: 1400 m

• olfaction: 400 m

• vibration through lateral line: 100 m

• vision: 25 m

• electroreception: 1 m

why do sharks use the reverse lek for mating?

• sharks have indeterminate growth, or grow for their whole lives

• larger females tend to have more eggs

electrolocation definition

generating electrical pulses and to listen to disturbances that indicate surroundings

shark eating specifics

• if prey unfamiliar, shark circles and then shark bumps into it

• upon attack, the nictitating membrane closes to protect eyes so other senses must be used to get prey into mouth

• jaw bones work independently of each other

shark diet examples

• mammals like seals and sea lions- larger prey are disabled and killed by exsanguination (shaking around to bleed out/incapactiate)

• many fish, particularly fish that live towards the bottom

• bottom-dwelling invertebrates

shark mating assemblies

• Sharks live independent lives except when seeking mates

• Females and males segregate into schools

• Males tend to choose the largest females which is known as a reverse lek

shark fertilization general information

• Males have pelvic claspers- sperm flows along it rather than through it

• Males may bite female fins to hold on while copulating

shark development general info

• Some sharks are oviparous; a few are viviparous, Most sharks are ovoviviparous, which is in between ovoviviparous.

• Long-lived animals have fewer offspring each year

ovoviviparous definition

eggs form and remain in reproductive tract and develop inside egg. They hatch inside the mom and leave during birth

viviparous definition

develops in the mom and has a live birth

oviparous definition

lays eggs and the eggs hatch

why do sharks have less offspring

they evolved to put a lot of time and energy and effort into offspring quality instead of quantity, also because they are predators they don’t have the need to reproduce that often

where ray finned fish reproduce

ray finned fish can reproduce in freshwater and saltwater, some live in one and travel to reproduce in the other

anadromous migrants definition and examples

adults migrate from salt to freshwater to breed, ex: some sturgeon, shad and salmon

catadromous migrants definition and example

adults migrate from freshwater to saltwater to breed, ex: some eels

ray finned fish habitats

• Freshwater streams

• Benthic or ground-feeding

• Coral reefs

• Pelagic

• etc….