Hearing, touch, taste, etc.

Sound transmission in water water is 83x denser than air sound travels 4.5x faster in water - not rapidly attenuated; difficult to localize low frequencies propagate better, faster

Sound transmission in water water is 100x denser than air sound travels 4.5x faster in water - not rapidly attenuated; difficult to localize low frequencies propagate better, faster sound: small vibrations with particle displacement near source - “near field” (a few meters) sound pressure component – “far field”

Hearing and lateral line (acoustico-lateralis system) Ears - sound reception in near field - acceleration, equilibrium detects pressure waves Lateral line – sound reception in far field - "distant touch" detects particle displacement

Lateral line system superficial (free) neuromasts on body surface, or in shallow pits or grooves canal neuromasts in lateral line Perciformes, Centrarchidae: black crappie Perciformes, Moronidae: white perch

superficial neuromast

canal neuromasts superficial neuromast

Lateral line system location and type of neuromasts optimized for particular prey, environment, etc. Cypriniformes, Cyprinidae: golden shiner

Science, 27 July 2012, p. 409

Ears equilibrium and balance: three semicircular canals detect roll, yaw, pitch also acceleration

(balance, acceleration) Ears equilibrium and balance: three semicircular canals detect roll, yaw, pitch also acceleration semicircular canals pars superior (balance, acceleration) utriculus (lapillus)

(balance, acceleration) Ears sound reception fish vibrates with sounds in water otoliths vibrate slower, impinge on sensory cilia semicircular canals pars superior (balance, acceleration) utriculus (lapillus) lagena (astericus) pars inferior (hearing) sacculus (sagitta)

Sagittal otolith Left and right ears of a deep-sea cod. Xiaohong Deng, Neuroscience and Cognitive Science Program, University of Maryland. http://www.life.umd.edu/biology/popperlab/research/deepsea.htm.

Ears Otoliths

How can hearing sensitivity be improved? Fish hearing is limited to lower frequency range, limited sensitivity to high frequencies How can hearing sensitivity be improved? Consider human hearing: normally transmitted from a drum (tympanum) via bones; or, artificially, directly from bone transmission

Ears hearing sensitivity improved with 1. Weberian apparatus – derived from vertebral bones connects air bladder with ear labyrinth present in ostariophysan fishes (Cypriniformes, Characiformes, Siluriformes) gives wide range of hearing (20-7000 Hz)

Ears hearing sensitivity improved with 1. Weberian apparatus connects air bladder with ear labyrinth present in ostariophysan fishes gives wide range of hearing (20-7000 Hz) 2. direct connection of swim bladder and ear squirrelfishes (Holocentridae) herrings etc. (Clupeidae)

Ears hearing sensitivity improved with 1. Weberian apparatus connects air bladder with ear labyrinth present in ostariophysan fishes gives wide range of hearing (20-7000 Hz) 2. direct connection of swim bladder and ear 3. airbreathers maintain bubble in superbranchial cavity, near to ear

Sound production homepage.univie.ac.at/friedrich.ladich/Topics.htm http://www.fishecology.org/soniferous/waquoitposter.htm Web page link has fish sound recordings

Sound production stridulation due to friction - grinding of teeth - movement of fin spine in socket, etc. (catfish, triggerfish, filefish, sticklebacks)

Sound production stridulation due to friction - grinding of teeth - movement of fin spine in socket, etc. (catfish, triggerfish, filefish, sticklebacks) via gas bladder - release of air

Sound production stridulation due to friction - grinding of teeth - movement of fin spine in socket, etc. (catfish, triggerfish, filefish, sticklebacks) via gas bladder - release of air - vibration of muscles (toadfishes, Batrachoididae; searobins, Triglidae; drum, Sciaenidae) Perciformes, Sciaenidae – freshwater drum)

Sound production stridulation due to friction - grinding of teeth - movement of fin spine in socket, etc. (catfish, triggerfish, filefish, sticklebacks) via gas bladder - release of air - vibration of muscles incidental to other behaviors - swimming and muscular motion - breaking surface and splashing - feeding, e.g., coral and crustacean-feeders - production of bubbles

Sound production Problems associated with human sound production boat motors sonar dredging, construction naval activities

canoe < trolling motor < outboard time to recover: Graham A L, Cooke S J. 2008 The effects of noise disturbance from various recreational boating activities common to inland waters on the cardiac physiology of a freshwater fish, the largemouth bass (Micropterus salmoides) Aquatic Conservation - Marine And Freshwater Ecosystems 18: 1315-1324      heart rate and stroke volume responded to canoe paddling, trolling motor, and outboard motor: canoe < trolling motor < outboard time to recover: canoe ~15 min, trolling motor ~ 25 min, outboard ~ 40 min concluded that boating activities can have ecological and environmental consequences

Taste and smell: communication individual recognition, especially of mates species recognition, esp. schooling species offspring recognition (cichlids) scent mark territories (gobies) dominant-subordinate relationships aggression-inhibiting pheromone produced by bullheads living in groups

Olfaction (= chemoreception at "long" range/gradients) more sensitive than taste used for: food finding migration, e.g., salmon intra, interspecific communication

Olfaction (= chemoreception at "long" range/gradients) more sensitive than taste used for: food finding migration, e.g., salmon intra, interspecific communication semiochemical – chemical used for communication pheromone – elicits social response in same species kairomone – benefits receiver, not emitter – between species e.g., food, scent, necromone

Olfaction (= chemoreception at "long" range/gradients) “Schreckstoff” alarm pheromones (Ostariophysi)

Olfaction (= chemoreception at "long" range/gradients) “Schreckstoff” alarm pheromones (Ostariophysi) originate in specialized ‘club’ cells in skin, released when fish is damaged effect is to alert other conspecifics potent highly specific (generally species-specific) pass through gut of northern pike

Taste (= chemoreception at close range) taste organs can reside on exterior surfaces: barbels of bottom-dwelling fishes lips of suckers over much of body of ictalurids

Other cutaneous senses touch few detectors – shark fins; head, barbels of bullheads mating behaviors (use of breeding tubercules) parent-young communication in catfish, cichlids, damselfishes

Other cutaneous senses temperature teleost cutaneous temp. sensitivity to 0.03C change can distinguish rise from a fall in temperature elasmobranchs detect temperature change with ampullae of Lorenzini

Electrogeneration and electroreception Why? Because they can (instantaneous transmission) – but note that pure water is an insulator Because it’s useful (murky water)

Production of electricity muscular contractions generate electrical signal ‘stack’ specialized cells (electrocytes) to amplify signal (in series) with insulating material around them

Production of electricity Types of electricity produced: strong current - for stunning prey or escaping predators 10 to several hundred volts in ‘volleys’ of discharges

Production of electricity Types of electricity produced: strong current - for stunning prey or escaping predators weak current - for electrolocation - conspecifics in school, - prey emit continuous signal; objects entering field are detected by distortion of field discharge 200 - 1600 cycles/sec

Production of electricity used by most elasmobranches, some teleosts strong-electric fishes weak-electric fishes Osteoglossiformes (Mormyridae) - African electric fishes Gymnotiformes (Gymnotidae) – electric eels Torpediniformes (4 families) – electric rays (Gymnarchidae) Perciformes (Uranoscopidae) - stargazers Siluriformes (Malapteruridae) - electric catfish Rajiiformes (Rajiidae) – electric skates

Production of electricity electricity-producing fishes tend to be slow-moving, sedentary active at night, or in murky water w. low visibility have thick skin: good insulator emhance signal-to-noise ratio with stiffened body

Electroreception types of signals received movement through earth’s magnetic field current from muscular activity of other fish (prey) signals produced by conspecifics frequency shifts identify individuals Individuals change frequency when encountering conspecific so as not to mask signal

Electroreception detection via external pit organs ampullae of Lorenzini in elasmobranches open to surrounding water via canals, filled w. conductive gel sensitive to temperature change mechanical and weak electrical stimuli changes in salinity