electroreception in fish
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Electroreception in Fish. The advantages & function of electroreception in various species of fish . Revett Saffo Molli Simpson Anthony Baldrica . Exploration . Use in communication Patterns of electroreception among fishes Including variations in differing environments - PowerPoint PPT PresentationTRANSCRIPT
Electroreception in Fish
The advantages & function of electroreception in various species of fish
Revett SaffoMolli Simpson Anthony Baldrica
Exploration Use in communication Patterns of electroreception among fishes
Including variations in differing environments Electroreception DetectionConservation
Definition
Electroreception: a biological ability to perceive natural electrical stimuli. Often attributed to aquatic vertebrates
Functions of Electroreception Communication Predation Awareness
One example of an aquatic animal using electroreception comes from the Scyliorhinus canicula, more commonly known as small spotted catshark
Hammerhead Shark The Hammerhead
shark is an electroreceptive species An example of a
far-evolved electroreceptive fish with dense pore abundance
Species of Interest Subclass: Elasmobranchii
Small Spotted CatsharkAfrican Electric Catfish
Malapterusrus electricus South African Bulldog
Mormyrid fish: Marcusenius marcolepidotusMarcusenius altisambesi & Mormyrus rum
Support from Literature: Temporal patterning of electric organ discharges in theAfrican electric catfish, Malapterurus electricus (Rankin and Moller 1992)
Showed variations in electric organ discharge (EOD- electric discharge generated by the electric organ) depending on the fish that Malapterurus electricus (electric catfish) was around
Based on previous experience with the other fish, EOD varies in pattern and pulses
Environment, time of exposure, and predator/prey relationships effected the EOD response of M. electricus
Carassius auratus (goldfish) and Oreochromis niloticus (tilapia)
Avoided M. electricusContact was brief since C.
auratus and O. niloticus fled when M. electricus was present
Polypterus palmas (bichir)Both are bottom dwellersP. palmas freezes in response
to M. electricus Contact time is longerLong duration EODBrief trains with long-train
intervalsClarias (airbreathing
catfishes)• Predator• High EOD• Great number of EOD
pulses• High frequency• Accompanied with visual
displays
EOD Volley TypesDisturbance
Responses to brief encounters C. auratus, O. niloticus, and P. palmas
DefensiveResponses to attacks Clarias
FeedingHigh and long frequency when feeding
Support from Literature:Electrocommunication behaviour during social interactions in two species of pulse-type weakly electric fishes (Mormyridae) (Gebhardt et al, 2012)
Electroreception has been adapted for communication behaviors in mormyrids
Resting behaviors:Mormyrus rume
Decrease EOD Remain in individual shelters,
not visible to othersMarcusenius altisambesi
Found in large groups Both species exhibited EOD
synchronization in resting conditions
EchoingIn general, when fishes in groups
communicate via electroreception a echo is produced
The echo has various functions including aggressive displays, courtship signals, and jamming avoidance
M. rume and M. altisambesi respond to the echo produced
Echoing is advantageous when EODs are colliding since fishes will respond by not overlapping EODs A fish produces an EOD right after its neighbor where the EOD
occurs during a time when the neighbor will be silent and the other wont produce another EOD and so no overlap occurs
Synchronization Definition:
“Temporal correlation of electric discharges between individuals of a group is a complex social interaction, which both species displayed during foraging.” (Gebhardt et al., 2012)
M. altisambesi showed positive signaling between group members
M. rume showed similar mechanism where both fishes simultaneously emit similar EOD patterns
Fixed-order SignalingDifferent than synchronization Rather then occurring between two fishes
(synchronization), this occurs between the whole group
Three or more fish repeat order of their EODs relative to one another more than four times in a row
Further decreases overlap because each fish would have its own time to conduct their EODEOD may not be a problem when looking at only two
fishes, but looking at groups it is advantageous for fishes to have their own time to eliminate overlap.
M. altisambesi implies that the species has a stronger group cohesion supported by different EODShorter EODs are advantageous because it decreases
the probability of EODs overlapping.
Fixed-order Signalinga. Marcusenius altisambesi
b. Mormyrus rume
Relationship to EcologyM. rume used a discharge behavior that functioned
as an agonistic signal. M. altisambesi are more social and less aggressive
then M. rume evident by the lack of EOD aggressiveness pattern.
M. altisambesi sociality may be related to its ecology which live in streams where floods increase the amount of potential habitat area.
Thus, this entails that competition for spawning sites may decrease which decreases aggressive interactions. M. rume has not adapted this type of behavior which means that aggressiveness increases in the species for territories and mates.
Applications and Value to current
research
How is electroreception related to biodiversity?Conservation efforts exist in fishes that
possess electroreceptionGymnotiform knife fishes ElasmobrachiiSea Lamprey
Electro-receptive fish important to biodiversity
Gymnotidae (electroreceptive fish) Use electrosensory
organs to detect prey within close range (Maclver, 2001) Implications
water conductivity affects prey capture via electrosensory organs
Food web relies on predator-prey interaction
Sea Lamprey control Sea Lamprey
(petromyzonmarinus) Highly predatory,
invasive species of Great Lakes
Important species in conservation management
Elasmobranchii
ElasmobranchiiK-selected
Slow grow, long gestation, late maturity, and low fecundity
Highly trophicA study done by R.A Martin, 2005 suggests some
species susceptible to endangerment or extinctionSpecies with limited geographic ranges prone to
extinctionSpecies who breed in sea at risk to be endangered “As K-selected creatures that compete for aquatic
resources against humans who widely regard them to be dangerous vermin, freshwater and euryhalineelasmobranchs present significant challenges to conservation biologists” (Martin, 2005).
Tools for Conservation in Electroreceptive fish ERA’s (ecological risk assessment) (Gallagher et
al., 2012)Behavior
Movement Migration
Fishing efforts and exploitation Molecular tools (Dudgeon et al., 2012)
Genetic applications Help understand needed conservation management
with use of molecular genetics
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SummaryIncreased capabilities due to electroreception
Communication & AwarenessSynchronizationEchoingFixed-order Signaling
Predation Environment & time of exposure effect EOD
EOD types: Disturbance, Defense, & FeedingConservation efforts exist
Important to biodiversity Important to food web
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Future ResearchM. altisambesi and M. rume’s echoing
techniquieNot properly explained
(May decrease amount of EOD collision)Elasmobranch’s pore abundance
Correlation to feeding ecology and predator avoidance not fully understood
Conservation of ElasmobranchiiElectroreceptive behavior’s relationship to life
strategies and thus, conservation
References Dudgeon, C. L., Blower, D. C., Broderick, D., Giles, J. L., Holmes, B. J.,
Kashiwagi, T., Krück, N. C., Morgan, J. A. T., Tillett, B. J. and Ovenden, J. R. 2012. A review of the application of molecular genetics for fisheries management and conservation of sharks and rays. Journal of Fish Biology, 80: 1789–1843.
Gallagher, A. J., Kyne, P. M. and Hammerschlag, N. 2012. Ecological risk assessment and its application to elasmobranch conservation and management. Journal of Fish Biology, 80: 1727– 1748.
Gebhardt, K., Böhme, M. and von der Emde, G. (2012), Electrocommunication behaviour during social interactions in two species of pulse-type weakly electric fishes (Mormyridae). Journal of Fish Biology. doi: 10.1111/j.1095-8649.2012.03448.x
Maclver, M.A. 2001. Prey-capture behavior in gymnotid electric fish: motion analysis and effects of water conductivity. Journal of experimental biology, 204: 543.
Martin, R. A. 2005. Conservation of freshwater and euryhalineelasmobranchs: a review.Journal of the Marine Biological Association of the United Kingdom, 85: 1049-1073.
Rankin, C. H. and Moller, P. (1992), Temporal patterning of electric organ discharges in the African electric catfish, Malapterurus electricus (Gmelin). Journal of Fish Biology, 40: 49–58. doi: 10.1111/j.1095-8649.1992.tb02553.x
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