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Explore how marine organisms adapt to various stressors in the ocean, from reproduction strategies to ecological challenges like salinity and temperature, through evolutionary processes and immediate responses. Discover the intricate trophic relationships and survival mechanisms that ensure the continuity of species in marine ecosystems.
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Adaptations to life in the ocean Stresses Sex value Salinity Temperature Trophic relationships Movement groups of marine life Body size Reproductive strategies Marine Ecology:
Temperature Salinity Dissolved oxygen Light Food Space 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 • http://www.youtube.com/watch?v=6lp87hrb-5I VALUE OF SEX—ADAPTATION TO REPRODUCE:
Free spawn (currents carry gametes) • Guard eggs (mouth, brood pouch) http://www.youtube.com/watch?v=fKJ8Z3UeSPE • Maternal/parental care after hatch http://www.youtube.com/watch?v=TIxGVM_v9i0 • Pair or no pair (promiscuous) http://www.youtube.com/watch?v=iCKug2iu0JQ • Seasonal to all year active • 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
Planktotrophy • Very small and numerous eggs with little yolk. • http://www.youtube.com/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. • http://www.youtube.com/watch?v=-IB9B94zaKo • Some are nursed. • Larvae are non-feeding, simple in form. Found in plankton or benthic Two strategies:
Factor Planktotrophs Lecitrophs • Cost to adult Low+ High – • Individual Care of Young N0 + High -,+ • Fitness of juveniles Low - High + • Survival of young Low - High + • Starvation High - Low + • Predation High - Low + • Access to adult habitat Low - High + • Dispersal High + Low -/+ Modes of development
A case of 2 sea stars Size at reproduction Egg size Egg number Larval survival Pisaster Large 20-90 mg Millions low Leptasaster Small 2 g 100’s-1000’s high
Budding, • Cloning Asexual reproduction
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 • http://www.bing.com/videos/search?q=phytoplankton&view=detail&mid=D23AC8B36F068CE6F27DD23AC8B36F068CE6F27D&first=0&FORM=NVPFVR • http://video.about.com/marinelife/Types-of-Algae.htm • http://www.bing.com/videos/search?q=algae&view=detail&mid=C02C9B0FEB488B83066DC02C9B0FEB488B83066D&first=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
autotrophs Dissolved nutrients Mixing, upwelling consumers Inputs from rivers detritus Sediment *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 • http://www.youtube.com/watch?v=YLsmEhnYdM0 • Diffusion: sponge, jellies, some worms Breathing: how do they get oxygen?