Marine Ecology: Adaptations to life in the ocean Adaptations to life in the ocean Stresses Stresses Sex value Sex value Salinity Salinity Temperature Temperature Trophic relationships Trophic relationships Movement groups of marine life Movement groups of marine life Body size Body size Reproductive strategies Reproductive strategies

TemperatureSalinity Dissolved oxygen LightFoodSpace Need to adapt ecologically (immediate) and evolutionary (over time) Adapt to:  Accommodate physical and chemical environment  Secure food and avoid being eaten  Successfully reproduce Its all about Food, Sex, and Death Stressors to adapt to:

 Asexual reproduction  Exact copy of self  Fast, no need mates  No diversity  Sexual reproduction  Half self, half other  Complex, slower, need to find mates, costly  Diversity, co-exist with different needs  Hermaphrodites—adults function as both male and female roles  Simultaneous—both active at one time  Sequential—only one active at one time  VALUE OF SEX— ADAPTATION TO REPRODUCE:

Asexual

Sexual

Animals that change sex—hermaphrodites

1. Free spawn (currents carry gametes) 2. Guard eggs (mouth, brood pouch) Maternal/parental care after hatch Pair or no pair (promiscuous) Seasonal to all year active 6. High number of eggs to low number Species—organisms capable of breeding, reproductively isolated from others, produce viable offspring Different Reproductive Strategies and adaptations:

 What is the best size or age to reproduce at?  How many times should an individual reproduce?  How many eggs should there be per clutch?  How large should the eggs be?  When in the year should reproduction occur?  How to locate a mate?  How can young locate an appropriate habitat? Evolutionary Questions

Two strategies:  Planktotrophy  Very small and numerous eggs with little yolk.  watch?v=2j5ECTtXCik watch?v=2j5ECTtXCik watch?v=2j5ECTtXCik  Eggs are of low cost to make, so many can be made. The larvae must feed in the plankton column after hatching.  Lecithotropy  Relatively large, few, yolky and costly eggs.  watch?v=-IB9B94zaKo watch?v=-IB9B94zaKo watch?v=-IB9B94zaKo  Some are nursed.  Larvae are non-feeding, simple in form. Found in plankton or benthic

 Factor Planktotrophs Lecitrophs  Cost to adult Low+High –  Individual Care of YoungN0 +High -,+  Fitness of juvenilesLow -High +  Survival of youngLow -High +  StarvationHigh -Low +  PredationHigh -Low +  Access to adult habitatLow -High +  DispersalHigh +Low -/+ Modes of development

A case of 2 sea stars Size at reproductionEgg sizeEgg numberLarval survival PisasterLarge20-90 mgMillionslow LeptasasterSmall2 g100’s-1000’shigh

 Budding,  Cloning Asexual reproduction

Cloning

Splitting

Hydra budding

Fission

 Select any marine invertebrate  Find out everything about its reproduction that you can find in 15 minutes  Be prepared to discuss this with the class and have a picture of your organism ready to share with us. Mini-project

 Homeostasis—regulate internal body conditions  Diffusion across a membrane  Isosmotic—internal equals external  Salt animal placed in FW  Water flows into animal and swells  Little or no way of balancing osmotic stress  Limited to regions where no salinity range occurs  Pelagic regions SALINITY—ADAPTATIONS TO SALT

 Estuary Animal  Handle wide range in salinity  Drink water—excrete excess salt  Salt loss through gills/absorbed also  Kidney function also  Osmoconformers  Internal state constantly changes as external does—must stay in areas of similar salinity  Osomoregulators  Control internal state  Drink water, excrete little urine, excrete salt, kidney and gill function

 Mostly related to dissolved oxygen and desiccation  Ectotherms—most marine animals—same temp as environment  Endotherms—birds, mammals—set body temp  Increase temp—decrease oxygen TEMPERATURE— ADAPTATION

 What an individual eats and when it eats it  Producers, consumers, decomposers  Autotroph  Self nourishing  Absorb solar energy  Build high energy organic molecules  Use inorganic molecules (N, P, water, Si)  First tropic level—primary producers  detail&mid=D23AC8B36F068CE6F27DD23AC8B36F068CE6F 27D&first=0&FORM=NVPFVR detail&mid=D23AC8B36F068CE6F27DD23AC8B36F068CE6F 27D&first=0&FORM=NVPFVR detail&mid=D23AC8B36F068CE6F27DD23AC8B36F068CE6F 27D&first=0&FORM=NVPFVR   d=C02C9B0FEB488B83066DC02C9B0FEB488B83066D&fir st=0&FORM=NVPFVR d=C02C9B0FEB488B83066DC02C9B0FEB488B83066D&fir st=0&FORM=NVPFVR d=C02C9B0FEB488B83066DC02C9B0FEB488B83066D&fir st=0&FORM=NVPFVR Trophic Relationships and food--adaptations

 Heterotrophs  Consumers and decomposers  Can not make own food from inorganics  Depend on autotrophs  Herbivores—eat autotrophs  Carnivores—eat herbivores  Decomposers—eat detritus  Help cycle nutrients in biogeochemical cycles

Sediment detritus consumers autotrophs Mixing, upwelling Inputs from rivers Dissolved nutrients *10% energy efficiency level from one tropic level to the next

 Benthos  Live on sea bottom  Epifauna (on top of bottom)  Infauna (in sediment)  Nekton (swimming)  Plankton (wanderers)  Current moves  Little ability to swim  Phytoplankton (in photic zone)  Zooplankton (photic and aphotic zones)  Suspension feeders (barnacles ex.)  Depend on small phytoplankton for nutrition  Use many techniques to extract small food particles Types of marine life by habitat:

 Salt, heat, nutrients, wastes, gases move across surface of marine organisms body  SA/V ( surface area to volume) determines how much and how fast lost or gained…potato cube experiment  High SA/V: smaller size, more diffusion  Low SA/V: larger size, develop mechanisms using respiratory and excretory systems Body size adaptations:

 Lungs: Marine mammals, Reptiles, Birds  Gills: Fish, Molluscs, Arthropods, Echinoderms   Diffusion: sponge, jellies, some worms Breathing: how do they get oxygen?