marine bio exam

• Convergent evolution = when different species evolve similar characteristics due to the environment
• 8 levels of taxonomic classification = DKPCOFGS
• pelagic = open ocean, benthic = ocean floor
• plantonic vs nektonic = carried by tides vs free swimming
• filter vs deposit feeders = filter food from water vs from substrate
• spicules found in sponges, used for structure and defense
• parapodia = found in invertebrates, used for locomotion and sometimes digging
• Herbivore’s radula scrapes algae (most gastropods)

  Carnivore’s radula drills hole in prey’s shell, scrapes flesh (nudibranchs and some snails)
• Water vascular system unique internal hydraulic system for locomotion and attachment, tube feet stick out (walk and some use it to catch food), found in echinodermata
• Intertidal = the part of the seafloor between the high tide and the low tide water lines

  Subtidal = below the tides
• “Mixed semidiurnal” tide = 2 highs and two lows everyday but the highs and lows are not of equal height ie. high high, low high, low low, high low
• 1. Spring tides: Periods of more extreme tides (higher highs and lower lows), when the gravity of the sun and moon combines

  Can happen at full moon and new moon
• 1. Neap tides: periods of less extreme tides (more moderate), when the gravity of the sun and moon partially cancel out

  2 times every month at quarter moons
• Pisaster sea stars are a keystone species eat the mussels and barnacles that destroy kelp
• Two primary forces that cause tides = gravitational pull of the moon on oceans and the centrifugal force as Earth spins
• Low Zone

  • Submerged most of the time
  • Only exposes to air at lowest tides
  • Community is crowded and very diverse
  • Most algae, seagrass
  • Echinoderms, large green anemones, invertebrates
• Mid Zone (“Middle Intertidal”)

  • Alternately exposed to air and submerged underwater with the daily tides
  • Community is still crowded but with lower species diversity
  • Mussel beds, mussels produce byssal threads to anchor themselves down to rocks and or neighboring mussels
  • Barnacles, molluscs, aggregating anemones
  • Less abundant algae like rockweed
• High Zone

  • Exposed to air most of the time- only fully submerged at highest tides
  • Some moisture from wave splash
  • Sparsely populated, low species diversity
  • Barnacles, limpets, periwinkle snails, photosynthetic bacteria
• Biotic factors = the living components of the environment that affect a species

  • Ex. predators, competitors species, prey abundance
  • More stressful in lower zones

  Abiotic factors = the nonliving components of the environment (physical or chemical conditions)

  • Ex. temperature, salinity
  • More stressful in higher zones
• sunlight is an abiotic challenge for organisms in the upper intertidal zone because it can dry them out, shells protect them from the sun and help them hold moisture
• What lives in the low zone?

  algae, seagrass, echinoderms, large green anemones, invertebrates
• What lives in the mid zone?

  barnacles, molluscs, aggregating anemones, rockweed
• What lives in the high zone?

  barnacles, limpets, periwinkle snails, photosynthetic bacteria
• Accessory pigments


  Pigments other than chlorophyll that assist in photosynthesis by absorbing different wavelengths of light
• Division Rhodophyta

  • Characterized by red pigments and multicellular structures, such as seaweeds
• Division Phaeophyta

  • Characterized by brown pigments and large, complex structures, such as kelps
• Division Chlorophyta

  • Characterized by green pigments and a wide range of forms, including unicellular, colonial, and multicellular species
• Pneumatocyst


  A gas-filled bladder that provides buoyancy to certain types of algae, helping them float toward the surface for better access to sunlight
• Macrocystis (giant kelp)


  • A genus of brown algae known for its large size and ecological importance in kelp forests
• Phylum Chordata


  • A diverse phylum of animals characterized by the presence of a notochord at some stage of their development
• Class Agnatha


  • Jawless fish, including lampreys and hagfish
• Class Chondrichthyes


  • Cartilaginous fish, such as sharks, rays, and skates, with skeletons made of cartilage
• Class Osteichthyes


  • Bony fish, which have skeletons made of bone and include most fish species
• Swim bladder

  An internal gas-filled organ that helps bony fish control their buoyancy
• Lateral line


  A sensory organ along the sides of fish that detects changes in water pressure and movement
• Electroreception


  The ability of certain fish to detect electrical fields, often used for navigation and prey detection
• Otolith


  Small calcium carbonate structures in the inner ear of fish that aid in balance and hearing
• Brooding eggs


  A reproductive strategy in which fish carry and protect their eggs until they hatch
• Five Sensory Systems of Fish

  • Vision
  • Olfaction
  • Lateral line
  • Electroreception
  • Hearing