BI451 Lecture 14 Sensory Physiology F23.pptx

BI451 Sensory Physiology Chapters 9 & 10 OUTLINE Chapter 10 – Sensory Perception Vision and Photoreception Chemoreception - Olfaction and Taste Acousticolateralis System - Hearing and Lateral line - Equilibrium and Balance Electroreception and Magnetoreception ensory Perception Spatial scale Si...

BI451 Sensory Physiology Chapters 9 & 10 OUTLINE Chapter 10 – Sensory Perception Vision and Photoreception Chemoreception - Olfaction and Taste Acousticolateralis System - Hearing and Lateral line - Equilibrium and Balance Electroreception and Magnetoreception ensory Perception Spatial scale Signal dispersal fields from prey You are so dead Gardiner etal.2014 PLoS One Mystery of Giant Eye on Beach So 15 Oct 2012 "we believe the eye came from a swordfish," said Joan Herrera, curator of collections at the FWC's Fish and Wildlife Research Institute in St. Petersburg, Fla., said in a statement Monday. "Based on straight-line cuts visible around the eye, we believe it was removed by a fisherman and discarded." Experts will conduct genetic testing to verify their findings. It wasn't immediately clear how large a swordfish this eye might have come from, but the species can http://abcnews.go.com/blogs/headlines/2012/10/mystery-of-giant-eyegrow as largeon-beach-solved/ as 1,400 lbs (635 kg). ision/Photoreception The fish eye - Numerous variations in functions and structure - Continously grows throughout life Designed for Sensitivity Acuity - Functions: - Capture the light - Focus the image on the retina - Transform the image into neural signals ACUITY: sharpness ght penetration and spectrum open ocean coastal water Spectral changes with depth Absorption: Scattering, reflection: Additional factors Turbidity Algae Dissolved substances Why are many deep sea fishes red? Mediterranean: dark blue and aqua colours (light reflected off Rockfish Sebastes Fish at depth viewer At www.fishbase.org Fish at depth viewer Red light attenuated in shalow water first. ision/Photoreception The fish eye - Hemispheric - Main components: - Cornea Iris Lens Retina Choroid Falciform process Sclera ision/Photoreception Air For image forming on the retina need to refract or bend light The fish eye Cornea - Outermost, transparent layer - Conjunctiva and sclera - Thinner in fish - Little refraction between cornea andmore water. Lens (much spherical than ours) - Must refract light more to - Focuses light on retina - Spherical (bony fish and lamprey) - Slightly flattened (elasmobranchs) Water ision/Photoreception The fish eye Sclera - Outer layer - Agnathans – fibrous sclera - Chondrichthyans – cartilagenous plates - Teleosts – sclerotic bones Choroid - Highly vascularized - Reflects light passing through the retina back - Contains reflective guanine crystals – reflective shine in sharks and nocturnal fishes - Falciform process also vascularized but over retina. Rete mirabile: ision/Photoreception The fish eye Retina - Thin, transparent, laminar - Back of the eye - Outer layer - Pigmented epithelium Photoreceptors - Inner layer - Nervous tissue Nuclei of photoreceptors ision/Photoreception The fish eye - Photoreceptors – rods and cones - Rods – respond to dim light – poor sharpness (SENSITIVITY) - Cones (ACUITY). Colour vision in some fishes. Light and dark adaptation in teleosts ision/Photoreception Photoreception – Pineal Gland Adult sea lamprey Zebrafish Rawashdh & Maronde (2012). Front. Mol. Neurosci. 5, 1-6 Image credit to USFWS – Pacific Region Pineal gland (third eye) - Ultrasensitive light sensor - Cues circadian and/or seasonal behaviour Tail? - Photosensitivity in larval sea lamprey sion/Photoreception and Behavio 1. Communication - Visual signals – coloration, patterning 2. Predator avoidance 3. Feeding behaviour 4. Shoaling/schooling ion/Photoreception and Behaviou COMMUNICATION via visual signals - Pigmentation is key – chromatophores in the dermis of the skin - Carotenoids – bright red and yellow - Melanins – dark, red, brown, black, background colour - Purines – colourless crystalline substances - Colouration pattern plays a role in: - intraspecific communication - predator avoidance (camouflage) - thermoregulation (protection from UV light, photon capture) https://en.wikipedia.org/wiki/ File:Fish_Melanophores_Responding_to_Adrenaline.webm#file ion/Photoreception and Behaviou COMMUNICATION via visual signals - Coloration pattern plays a role in intraspecific communication Reproductive success Feeding success for - Mono and foragers polychromatism Lateral stripes for schooling ion/Photoreception and Behavio COMMUNICATION via visual signals - Coloration pattern plays a role in predator avoidance Disruptive coloration asCountershading – Eye spots – focus camouflage disrupts attacks attacks on the tail from above hemoreception-Olfaction Chemoreception - Organs have similar sensitivities to stimuli - Receptor location and processing centers are key Olfaction Northern Pike. Photograph copyright © Natural History Museum, London (specimen catalogue number BMNH 1963.4.26: 1–2) Garpike. Photographs copyright © Natural History Museum, London Blackspotted puffer. Photograph courtesy of Bristol Zoo Gardens, UK hemorecepition-Olfaction Variations in Olfactory Rosette – Structure and Water Flow a) Angler fish (Linophryne species); b) Goldfish (Carassius auratus); c) European eel (Anguilla anguilla). Cox (2008). DOI: ChemorecepitionOlfaction Olfaction Summary • Anatomy of the olfactory organ varies with species • The size of the olfactory organ is dependent on how much the fish relies on olfaction • Integration of olfactory perception is done by the olfactory nerve (ON) and olfactory lobe (OLL) lfaction-smell + taste Taste (gustatory chemoreception) - Perception of chemicals upon contact - Used to identify food and noxious substances - Receptors – taste buds and free nerve endings (external surfaces) - Located in the mouth, gill and gill arches and exterior surfaces (skin, fins, barbels) hemoreception-taste Taste (gustatory chemoreception) Variations in barbels in various fishes. Typically in benthic feeding fishes. Chemoreception-Taste Taste (gustatory chemoreception) Feeding habbits influence brain morphology 1) Fish feeding primarily by taste and sight - enlarged vagal lobes (VLM) - prominent optic and facial lobes (FLM) 2) Fish feeding primarily through the use of barbels - enlarged facial lobes(FLM) - reduced vagal lobes (VLM) 3) Fish feeding primarily by sight - poorly developed vagal and facial lobes - enlarged optic lobes (OL) Chemoreception re paired. Spatial information. mportance of Chemoreception (Olfaction and T 1. Food detection - Nurse sharks - klinotaxis - gradient searching behaviour - Teleosts and elasmobranchs – amines and amino acids as triggers 2. Predator avoidance 3. Parental care 4. Location of spawning streams for adults – triggers of migration - Salmon migrate to natal stream for spawning – imprinted cues during migration as presmolts and smolts - Possible triggers/cues: Ca2+? Skin mucus? Chemoreception mportance of Chemoreception (Olfaction and T ng nares. Blocking a single nare impairs direction find OD DETECTION Chemoreception mportance of Chemoreception (Olfaction and T EDATOR AVOIDANCE. Decreased rates of migration. Predatory avoidance in migrating salmon when various extracts were Chemoreception mportance of Chemoreception (Olfaction and T 3. PARENTAL CARE Cyclid parental care experiment Females were doting to imaginary young Chemoreception hemoreception and Behaviour MIGRATION. Olfactory bulb electrical response. Chemoreception hemoreception and Behaviour Pollutants (pesticides) Can decrease olfactory sensitivity. e.g. e carbamate fungicide iodocarb (IPBC) Electro-olfactogram (% pre-exposure) 4. MIGRATION Coho salmon Time (min) Chemoreception hemoreception and Behaviour 4. MIGRATION WHY? 1) Separation of life-stages – avoids cannibalism 2) Increased probability of larval survival – minimizes predation 3) Maximization of feeding and growth 4) Reduced intraspecific competition for resources 5) Increases the probability of the larvae finding proper habitat 6) Search for better feeding grounds – diadromy (anadromy & catadromy – see lectures 12 & 13), oceanodromy and potamodromy HOW? 1) Gradient cues - temperature, salinity and chemicals 2) Celestial clues - orientation by the position of the sun Sensory perception cousticolateralis System 1. HEARING - Sound detection - Equilibrium, orientation and balance – direction of gravity in a 3-D world - Detection of vibrations – in combination with the lateral line system 2. LATERAL LINE SYSTEM - Detection of water movements - Orientation to the direction of the disturbance – prey detection, predator avoidance cousticolateralis System 1. HEARING - Water is denser than air – efficient conductor of sound waves - Sound travels through water 4.8X faster than air (330 vs 1500 m/s) - Vibration of molecules picked up by the inner ear Illustration from GettyImages.com cousticolateralis System 1. HEARING Swim bladder - Clupeomorpha and Ostariophysi - Swim bladder connection to inner ear Amplifies perception of higher frequency sounds - Ostariophysans - Swim bladder directly connected to the inner ear via Weberian apparatus to improve hearing. Fishes. An introduction to Ichthyology. Fig. 10.3 cousticolateralis System 2. BALANCE Semi circular canals detect linear acceleration (e.g. turning of head) Otolith: aging of fish by counting growth rings. cousticolateralis System 3. LATERAL LINE - Touch at a distant sensory system - Mechanoreceptors detect water movements neuromasts usticolateralis System and Behav 1. Food detection - Sharks, skates and rays – sensitivity to low frequency vibrations and irregularly pulsed sounds (crippled prey) 2. Direction and obstacle avoidance - Head movements push water in front - Displace water by larger objects moves over the neuromasts - Avoidance of clear aquarium walls 3. Equilibrium and balance - Continuous movement of pectoral fins to maintain equilibrium 4. Orientation to water currents - Shoaling behaviour 5. Communication via auditory cues (see Ch11) usticolateralis System and Behav SHOALING - Occurs for social reasons - Different than schooling (polarized, synchronized shoal) - How? - Guided by vision - Lateral line – maintains spacing - Why? - Increased hydrodynamic efficiency - Efficiency of food finding – watch your neighbour - Reproductive success – lots of mates around - Reduced risk of predation - Dilution and confusion effects ectroreception/Magnetoreceptio - Some bony fish can detect electrical fields through pit organs located on their heads (filled with electrically conductive gel) - Purpose: - Locating prey (electromagnetic field) bioelectric field - Migration - Obstacle avoidance - Intraspecific communication - Marine elasmobranchs - Ampulae of Lorenzini - 5-160 mm long Operates over short distance ctroreception/Magnetoreception MIGRATION - Migration using magnetite crystalls in the skull - Geomagnetic orientation in fish - Possible link to the acousticolateralis system Kalmijn (1974) Sensory perception SUMMARY - Fish have evolved various ways of perceiving their environment - Some species rely more on one system of perception than others, depending on their environment - The environment shapes the anatomy of various structures - Behaviour is highly influenced by sensory perception