L8 Lateral Line and Electrical Flashcards
Lateral Line
Flow of water allows ‘distant touch’
- navigation, prey detection
Clupeidae: line physically connected to inner ear.. processing info
Bass: lots of cephalic lateral line networks - importance for feeding. Innervation runs parallel to acoustic nerves and enters hindbrain —-> forebrain perhaps sound and lateral line being processed simultaneously for more general perception of sound
What are the sensory cells in lateral line
Neuromast : made up of hair cells with their stereocilia, grouped together in the cupula.
Movement deforms cupula –> bends hair cells –> nervous signal
Neuromasts often in canals, pits or grooves especially for swimming fish so they aren’t set off as easily.
specializations of lateral line
Lines displaced when:
- fins movement would cause signal
- want focus on signals coming from above/below
Slow moving fish: more free neuromasts on surface
- ex: cave fish uses on head for navigation/predation
Canal Diameter can contract/dilate to get response to specific frequencies
- ex: ice fish tuned for frequencies of swimming plankton
Electroreception Passive
Especially elasmobranchs
Sense currents already present :
—Alternating current from muscular activity
—Direct current from potentials between organism to medium
Active Electroreception
Generate currents and perceive their distortions
- electrolocation and signaling
Some teleosts : electric catfish, elephant fish
Organs for electroreception
Ampullary organ
- Elasmos : Organs of Lorenzini
- Have conductive gel filled canal opened to water, sensory cells, and kinocilium (elasmo) or microvilli (teleosts) extended into lumen of canal
Tuberous organ
- No opening, or if canal filled w loose epithelial cells
- More sensitive to high frequencies, not simple DC
Elephant Fish
Communicate
- mating signals, can discriminate the signals
Organ: have caudal electrical organ
