Transcript Just Keep Swimming

Just Keep Swimming
MUSCLES
• Attach to backbone
• Red myomeres – high myoglobin content
stores oxygen for long distance swimming
• White myomeres – less myoglobin content
allows for short bursts of speed.
CIRCULATORY &RESPIRATORY
• Heart has 2 chambers: atrium &
ventricle
• Gills have high surface area for gas
exchange with lamellae on filaments
• Spiracles (openings behind eyes) let in
water when mouth is closed in sharks.
EXCRETORY
• Marine fish drink seawater continuously
– Release salt across gills
– Excrete thick urine
• Freshwater fish do not drink water
• Water moves into cells constantly
• Excrete lots of dilute urine
Reproduction
• Most are separate sexes
• Types:
- Oviparous – release eggs & external
fertilization
- Ovoviviparous – internal fertilization of eggs,
hatch internally & born live
- Viviparous – internal fertilization,embryo gets
food from female’s tract
Reproductive Behaviors
• Mating rituals – dancing, stirring sand
• Hermaphrodites – both sexes to improve
offspring success
• Sex reversal – dominant male or female
gone, replaced by strongest
Sensory Adaptations
• Taste bud – on mouth, lips, fins, skin
• Smell – olfactory sacs in nostrils
• Vision – round lens focuses by
Moving closer or farther away
Some fish have color vision
Sharks have nictitaing
membrane for protection
Sensory Adaptations
• Hearing – inner ear helps with balance &
equilibrium
• Lateral line – canals on sides have
sensory cells to detect vibrations
• Ampullae of Lorenzini – detects weak
electrical fields of prey (in sharks)
SCHOOLING BEHAVIOR
• MOVE IN UNISON, SAME
SIZE & MAINTAIN
DISTANCE.
FEEDING,
MATING &
PROTECTION
WHY MIGRATE??
• Regular mass movement from 1 place to
another for: feeding, mating & birthing
• Anadromous – spawn in freshwater,
spends most of life in sea. EX: salmon
• Catadromous – spawn at sea, return to
freshwater to live. EX: eel
BODY SHAPE
• Matches lifestyle
– Streamlined: fast swimmers (nektonic)
– Laterally compressed: quick turns & short
bursts of speed
– Flattened: bottom dwellers (benthic)
– Elongate: live in narrow spaces
– Irregular: concealment
COLORATION
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Pigments called chromatophores
Bright colors: tropical habitat or poisonous
Cryptic: blends with background
Disruptive: stripes, bars, spots, eye
shapes will confuse predator
COLORATION (cont.)
• Countershading: light on ventral (white or
silver) & dark on dorsal disguise in open
water.
• Dark shades: black, red, blue and purple
in deep water where there is no light