BIOL606: Communication

Red (longer wavelength)

wavelength that dissipates first

orange and red

In oceans and oligotrophic lakes, these colors are lost first

red and orange

inland/inshore waters color

Density effects on scattering

with increasing depth due to thermal stratification or currents, vscattering values increase and alters visiability

Precipitation

Thermocline visiability

light refracts different as it passes through water layers with different temperatures and densities

above the thermocline has more visiual ctivity due to mixing

Effect of Freezing/thawing on visiability

cold snaps: clear water

turnover in spring: mixing increases, clarity decreases

Retractor muscle

eye muscle on teleosts pulls lens back to focus

retina pigments associated with benthic fw fish

Green and orange (530 nM and 620 nM)

Retina pigments associated with shallow FW fish

blue (430 nM)

retina pigments associated with tidepool fish

shorter wavelegnths/ similar to terrestrial animals

retina pigments associated with deepsea fish

blue (470 nM)

how does turbid water effect green wavelengths

in turbid waters, green does not pentrate as far due to high refreactor index

Juvenile FW Fish retina pigments

UV light pigments, usually loss on the onset of migration or movment into different habitats

Suborbital photophores

far red bioluminsece, used by Stomiidae to communicate with conspeciics in the deep ocean

Tapetum Lucidum

Layer of guanine crsytals in the chorioid gland that acts as a mirror behind the retina. Teleosts will dispere pgiments across the tapedial layer when

Pineal gland

light senstive organ locted on the top of the brain

Melatonin

Amino acid hormone that is released by the pineal gland when it is sart. Secretion is not large enough to create a big effect when injected, but is an indicator of season and photo period

in spring , melatonin levels decrease

Carotenoids

yellow, red, and orange pigments accessed through their food

Melanins

dark pigments within cells

When dispersed, fish are lighter colored

when condensed, fish are darker colored

Purines

form structural colors, guanine crystals act as a mirror

Red coloration patterns

• Coloration pattern that indiciates sexual maturity improves identification in small streams.

• Camouflage: deep-sea fish have bright red colors; intertidal species blend in w/ algae

Poster colors

bright bands and stripes intertwined w/ banding color to stand out

Common in gregarious species

Disruptive coloration

• Associated with schooling behavior or habitats to confuse predators’ habitats

• May also be used to blend into heterogeneous substrate

Counter shading

• used for concealing in a large pelagic environemnt

• light on the bottom dark at the top

Eye ornamentation

• can make the eye inconspicuous (band across eye design)

  • confuse predators by feigning movemnet in a different direction by having an eyespot near the tail

• stand out aganist background to signal for conspceifics

refractive index of blue and greens

high, so reflected quickly in turbid environments (espeically green)

Purposes of chemoreception

• presence and location of food

• Mates

• Predators

• Spawning sites

7th Cranial nerve

responds to the cutaneous taste buds co

9th cranial nerve

responds to the internal taste budes (vagal loves, large # tastes buds onthe roof of mouth)

Optic lobes

main brain morphology invested in for visual predators

enlarged facial lobes

main brain morphology invested for fish with barbels (benthic feeders)

optic, facial, and vagial

main morphology adopted for fish that feed by sight and taste

Olfactory pits

structure that contain receptors for olfaction

water flows through the pits, either caused by cilia beating or swimming

Rosette

nare structures with primary and secondary lamellae that increase the surface area

packed with cilliate microvillius

highly senstivie

varies by species, becomign more compelx and elaborate for nonvisiual predators

Factors effecting rosette structure

• Species

• Age/growth: parr have fewer

• Sexual dimorphism

Bare nerve in rosette recognization of smell

Lock-and-key theory: molecules responsible for odor have a specific shape that fits into corresponding receptors. Binding triggers a series of chemical reactions that send signals to the brain

Gonadotrophin releasing hormone

hormone released by the pituitary gland that signals gonadal growth, rainbow trout are sensitive to low levels of this

Testosterone

developed by 17B-estradiol and androstenedione, signals to Atlantic slamon parr females and males that are spawning in an area

Bile acids and Amino acids

sensitive to these compounds as a way to find conspecifics

negative rheotaxis

in the absence of homing orders, fish will travel back downstream until it finds imprinting odor

positive rheotaxis

adult fish will migrate upstream to their homing location, based on odor. Suggests that imprinting happens at an early life stage

Theories on homing scent

• Population specific odour

• Inherited pheromone imprint

• follow phermone trails (juveniles produce constant population odor)

• follow the most extensive smell (

Thyrod hormone and Cortisol

hormones in charge of oflactory imprinting

TSH and Gonadotropin

Hormones used to increase the ability ot track odour upstream (associated with increased locomotory activity)

Estradiol/Testosterone

hormones associted with a discrimination of homestream order, which fish have high sensitivty to.

Post-spawners hormonal regulations

low sex steroid released and do not repsond home stream order due to senescence

Reproductive pheromones

• Ovarian fluid: elicits courtship behavior

• 
  

steriods and prostaglandins

phermones released by goldfish after ovulation to attract males

Schreckstoff

fright and antipredator response by Ostariophysi due to a compoiund in fish tissue being release by tissue breakage. May cause one fish to react, with the others reacting visually. Evolutionary driver of this response is unknown, but the development of the compound might be used for something else and this is a secodnary benefit.

Taste buds locations

• Mouth

• Skin

• Fins

• Barbels

stridulation

the rubbing ot he pharyngeal teeth or pectoral fins to create sound

hydrodynamic sound

sound produces by creating a pressure wave to be received

swim baldder

The muscles on top of these organs pull on the swim bladder through contraction to make a long sound. Rapid synchronous contraction, innervation is similar but INDEPENENT of trunk muscles

muscle fibers of swim bladder

rich blood supply, high myoglobin content, no tetany

sagital, utriculus, and lagena

otolith types that receive sound

Otoliths are denser than the rest of the body tissue; sound waves and water vibrations move at a different inertia. Hair cells surround and support the otolith. Fibers will be displaced due to vibrations and have direct reception to the brain,

how do ototliths percieve sound

gravty receptor

linear acceleration

sound reception

otolith functions

as swim bladder volume increases, the frequencies heard increase because the elastic air vibrates the ar within the sac, improving perception. Swim bladders may also be situated forward close to the cell, which increases fish sensitivity

How do swim bladders affect hearing

Weberian Apparatus

series of bones in catfish and minnows that articulate around a certain point serves as another section vibrbationg to improve hearing. Is conected from the swim bladder wall to the fluid-filled space of the ear

lateral line system

a series of pores along the fish body with neuromasts that allows for mechanoreception from the displacement of neuromasts, including pressure changes and low-freqeuency migration

mid-level pelagic swimmers

fish that contain a discontinous alteral line correpond to this environment

flat fish

lateral line goes all the way to the caudal peduncle to sense diffeences

benthic fish that feed on food above

fish with a lateral line system by orsal fin

surface fish

fish with a lateral line near the anal fin

tuned to freqs produced by swimming motion, sounds detected by water displacement of neuromasts,

role of lateral line system in sound

more concentrated

in more turbid environemnts, lateral lines are ?

obstacale entrainment

lateral line system detects where the least amount of flow is, finding flow refuge

cupula

flexible gelatinous cap with cilia, located within the neuromasts

mechaniscs of lateral line system

cilia on neuromasts moves in direction of the current, decreases or increases action potential and varies impluses to the brain