© 2011 Pearson Education, Inc. CHAPTER 14 Animals of the Pelagic Environment

© 2011 Pearson Education, Inc. Chapter Overview Pelagic animals use a variety of adaptations to help them survive. Marine mammals share similar characteristics with land mammals.

© 2011 Pearson Education, Inc. Marine Animals Avoid Sinking May increase buoyancy Use of gas containers –Rigid gas containers –Swim bladders

© 2011 Pearson Education, Inc. Avoiding Sinking Ability to float –Zooplankton – some produce fats or oils to stay afloat Ability to swim –Nekton – larger fish and marine mammals

© 2011 Pearson Education, Inc. Macroscopic Zooplankton Krill –Resemble mini shrimp or large copepods –Abundant near Antarctica –Critical in Antarctic food chains

How do you get THIS from eating only THIS?

© 2011 Pearson Education, Inc. Biomass Pyramid The number of individuals and total biomass decreases at successive trophic levels. Organisms increase in size.

© 2011 Pearson Education, Inc. Ecosystem Energy Flow and Efficiency

© 2011 Pearson Education, Inc. Swimming Organisms Fish, squids, sea turtles, marine mammals Swim by trapping water and expelling it, e.g., some squid Swim by curving body from front to back

© 2011 Pearson Education, Inc. Swimming Motion and General Fish Features

PROTOCHORDATE

Adult form is Sessile

Tunicate Sea squirt

Lancelet

hagfishes Jawless Fish

Hagfish Also called Slime Eels Live ONLY in Marine environment Scavengers So—great sense of smell Tie themselves in knots for leverage to burrow in and eat. JAWLESS

lampreys Jawless Fish

Lampreys Both FW and SW Parasitic Attach to fish, bite through side and live off blood and body fluids. JAWLESS

Lamprey

© 2011 Pearson Education, Inc. Fin Designs in Fish Paired vertical fins as stabilizers Paired pelvic fins and pectoral fins for “steering” and balance Tail fin (caudal) for thrust

© 2011 Pearson Education, Inc. Fin Designs in Fish Rounded caudal fins –Flexible –Maneuver at slow speeds Truncate fins and forked fins –Useful for both maneuvering and thrust

© 2011 Pearson Education, Inc. Fin Designs in Fish Lunate fins –Rigid, little maneuverability – Efficient propulsion for fast swimmers Heterocercal fins –Asymmetrical, –Lift for buoyancy (shark)

Cartilagenous Fish Chondrichthy Heterocercal Tail Bony Fish Osteichthy Homocercal Tail

© 2011 Pearson Education, Inc. Adaptations for Finding Prey Mobility Lungers wait for prey and pounce (grouper). –Mainly white muscle tissue Cruisers actively seek prey (tuna). –Mostly red muscle tissue

© 2011 Pearson Education, Inc. Lungers and Cruisers

Caudal fin of a Tuna? (Non-stop fast swimming)

Yellowfin Tuna Thunnus albacares To 2.1 m. (82 inches) 182 kg. ( 400 lbs.)

Nassau Grouper Serranidae: Epinephelus striatus To 91 cm. ( 3 ft.) 25 kg. (55 lbs.)

Blue Marlin Istiophoridae: Makaira nigricans To 4.3 m. ( 14 ft.) 272 kg (600 lbs.)

Tripletail Lobotidae: Lobotes surinamensis To 1.1m. (42 in.)

© 2011 Pearson Education, Inc. Cold-Blooded vs. Warm-Blooded Most fish are cold-blooded – poikilothermic –Bodies same temperature as environment –Not fast swimmers Some are warm-blooded – homeothermic –Found in warmer environments –Helps them capture prey

© 2011 Pearson Education, Inc. Adaptations of Deep-Water Nekton Mainly fish that consume detritus or each other Lack of abundant food Bioluminescence –photophores Large, sensitive eyes Large sharp teeth Expandable bodies Hinged jaws Counterillumination

© 2011 Pearson Education, Inc. Deep Sea Nekton

© 2011 Pearson Education, Inc. Adaptations to Avoid Predation Schooling –Safety in numbers –School may appear as single larger unit –Schooling maneuvers confuse predator

© 2011 Pearson Education, Inc. Adaptations to Avoid Predation Symbiosis – two or more organisms mutually benefit from association

© 2011 Pearson Education, Inc. Adaptations to Avoid Predation Commensalism – less dominant organism benefits without harming host +/0 Mutualism – both organisms benefit +/+ –Example: clown fish and anemone Parasitism – parasite benefits at expense of host +/-

Candiru