Introduction: Natural Bridges Setting and Tidepool Habitats 1. Physical setting microcosm of “coast- zone” – influenced by 1) river, 2) waves/tides, 3) wind (NW) Rock Types (wave cut bench) Santa Cruz “Mudstone” hardest rock types resist erosion best- often remain behind forming “islands” of rock. –beautiful pocket beaches…. But soft enough to provide complex animal habitats. 2. Introduction to the inter- tidal AGAIN: this is a STATE PARK PRESERVE- TAKE NOTHING!! Basic concept for tide pool component: 1. Adaptation. – Organisms constantly shaped by pressures of natural selection or competition. Physical Environment Shapes Biology – The fundamental resources, and pressures to which a biological system responds by adaptation “ You cannot understand organisms without understanding their physical environment.” Goals 1. Physical Environmental factors: To understand how specific aspects of a marine environments will determine how life adapts- 2. Describe Main Inter-tidal Environments: definitions of main “zones” in intertidal, and to understand each in terms of main physical factors. Issues: 1. Primary Production- what factors control production ? (base of food chain?) 2. ALL Organisms- what factors will all organisms have to adapt to deal with? Terrestrial Physical Environments Some Terrestrial Physical variables * Water Availability * Temperature * Food Availability (Primary production) * Physical Character of Environment *“Stability” of environment Littoral Physical Settings Littoral or Coastal ocean regions: Temperature: ~varied Food: high Stability: Low! (“High Energy /Low stability”) Phys. Character: Varied, many habitats.. Predict: many many types of life, adapted in many ways. One common factor? Must Adapt to constant changes. Inter-tidal Special factors: ** WATER availability – how much time do you have to spend dry? Other Related factors: • Temperature? Major factor • Salinity- • what other big one..? Inter-tidal factors: **”Stability”? Very very “Low” Special adaptations: Must have way to “hold on” and endure huge energy of breaking waves – Can Consider tide zones as function of “time” out of water.. – ALSO = TIME exposed to pounding waves.. A – (what else?) B Distance Vertical Tidal Range Inter-tidal Organisms: ZONES based on physical environment= Adaptations “Spray Zone” (above highest tides) “High tide Zone” “Mid-tide Zone” “Low tide Zone” “Sub-tidal Zone” Below lowest lows “Spray Zone” (above Shallow: Most highest tides) energy, most change “High tide Zone” “Mid-tide Zone” Deep: Least “Low tide Zone” energy, Least change “Sub-tidal Zone” Below lowest lows Shallow: Least “Spray Zone” (above % time under highest tides) water – “High tide Zone” “Mid-tide Zone” Deep: water “Low tide Zone” 100% of time “Sub-tidal Zone” Below lowest lows Some Adaptations: “Spray Zone” (above highest tides) “High tide Zone” *Thick shells *systems to prevent drying out “Mid-tide Zone” *resistant to high temp/salinity “Low tide Zone” “Sub-tidal Zone” Below lowest lows Natural Bridges Tidepools: example of “Rocky shore” • Most organisms live on the surface (epifauna) • Upper zones have mostly shelled organisms • Lower zones have many soft-bodied organisms and algae Zonation at Natural Bridges High zone Mid zone Low zone SPLASH zone pools Baxter points out classic zonation 2. Main Organism Groups Primary Producers- Q: Based on the physical environment, what would you predict they would be like? 1st: Benthic Primary Producers Algaes: - Groups defined by “pigments” they have (recall the “antenna” used to catch light for photosynthesis) 3 groups: Red, Green, Brown All have some way to “hold” to bottom * specialized cells or structures, often called “holdfasts” (NOT roots!) Green Algae- “Chlorophyta” “pigments” closest to land plants ie “antenna” = chlorophyls, as on land- live in shallowest water Green Algae- “Chlorophyta” Some Species are among most “primitive” Algae Sea Lettuce: 2 cells “Dead mans fingers”: ~ like a thick…No structures colony- a continuous chain of individual identical cells Red Algae- “Rhodophyta” Pigments most different from land plants ie “antenna” = modified chlorophyl-like molecules, adapted for low and filtered light levels = can extend into deepest water Red Algae- “Rhodophyta” Many Species secrete calcium carbonate coverings “Coralline” red algae. Looks a bit like coral * Very common in tide pools! “Crustose” or “Leafy” type- still has encrusting type hard outer armor Brown Algae- “Phaeophyta-” Pigments intermediate (between reds and greens) and very diverse- • A Uniquely Marine group • Contain the “kelps”- among most “advanced” of all alga Offshore: Brown algae (kelp) (Macrocystis) forests of the sea •Extensive growth in cold, high nutrient near-shore environments. •Grow in water 20-40 m depth. •Fasten to hard substrate with holdfast. •Gas-filles floats (pneumatocysts) •Highly productive –grow 6-25 cm/day •Eaten by sea urchins •Support extensive diverse ecosystem Brown Algae- (Fucus sp.) 2. Inter-tidal Animals: Almost all are “Invertebrates” - A main evolutionary division in animals: Invertebrates vs. Vertebrates: Invertebrates vs. Vertebrates: What separates the groups? Have “backbone” (or similar structure) or not? * eg: Hollow “Nerve Tube”- running up and down the animal. • Or “notochord” A rigid structural support, like our spine. proxy for complex nervous system. Amazingly diverse adaptations! Some Major Invertebrate groups - Mollusks (squid, snails, octopus) - Crustaceans (= crabs, shimp- BUT also barnacles! ) - Echinoderms (starfish, sea cucumbers, sand dollars) - Coelenterates (jellyfish, anemones, corals) Adaptations: Some modes of making a living 1. Grazing: ( “Grazer” = Herbivore) Adaptations : Some modes of making a living 2. Scavenging: ( = Omnivores) Filtering Filter-feeders: can take many different forms, depending on environment.. Ambush prey with poison darts! Predator, Secondary consumer.. Mollusks (snails, squid, octopus, banana slugs) *Enormous group! 100,000 + species in all environments • All have soft, muscular “foot”: used for moving, capturing prey • Some have shells, some don’t • Cephalopod molluscs: squid and octopus highly specialized predators Invertebrates: Mollusks Mollusks in Littoral: many adaptations. *Key Grazers: • Graze on all kinds of alga in littoral environments. • Often have heavy shells to protect from drying out, and from pounding surf. But, also other important types: • Filter feeders: eg: mussels, clams, etc • Hunting carnivores!: small rock snail species which drill into prey and eat them! Mussels: the dominant animal in much of inter-tidal Adapted to high energy- pounding surf: 1) very tough shells 2) held to rocks by tough fibers (“bissel fibers”) “beds” of mussels form major habitat for other animals ( “protection” from surf) Many other mollusks in littoral- many are “grazers” of alga What is this area? What is this area? Owl LimpetWhat is this area? Crustaceans Subset of: Arthropods ”jointed legs” *Sizes: Microscopic to Huge: (Copepods to Alaskan king Crabs) • All have jointed Legs, Eye stalks, hard body ‘armor” made from “chitin” • All oceanic members have gills • Very important in oceanic food webs! (both predators and prey!) Crustaceans In Littoral environments: Important Scavengers: *Crabs, lobsters, shrimps *But also, a real Surprise: Barnacles! (both sedentary and “goose- neck”) * An interesting evolutionary story: they settled on their heads, and use adapted “feet” to filter the water! Barnacles: so common, they define most rock surfaces c o l l Barnacles a Large size p s i n g c o l l Barnacles : a Solitary p s i n g c o l l Barnacles a p s i n g c o l l Barnacles a p s i n g c o l l Barnacles a p s i n g Invertebrates: ”Echinoderms” (“spiny skin”) (Starfish, Sand dollars, sea urchins) *Very important marine group! Occupy almost all modes of life- from herbivores to hunters Invertibrates: ”Echinoderms” 1) Radial Symmetry *2) Spiny skin: More obvious in some than in others… Invertebrates: ”Echinoderms” Have Sucker- tip Tube Feet: for motion Focus on two: A major Grazer: sea urchins A major Predator (hunter): sea stars Purple Urchin .. Purple Urchin .. Urchin Beds…(notice anything about rocks?) Urchin hollows Blue water gold? “Uni” = sea urchin roe (eggs) “Uni” sushi at Benihana Where it really comes from.. Where it really comes from.. Stars: mussel predators Stars: mussel predators Stars limit mussel distribution Cnidaria (sea anemone) •Over 6000 species of Class Hydrozoa •Sea anemones, found from the intertidal to 10,000 m •Capture prey with stinging nematocysts •Same phylum as corals Inter-tidal: Sea Anemones –Giant Green Sea Anemone Sunburst and aggregating anemones Giant green anemones Anemone fight! Giant green anemones: mussel predators? One more Special Adaptation: How can an animal get more food (especially in a low food environment) 5. Symbiosis: (ie teamwork) Zooxanthellae: A dinoflaggelate- autotrophic primary producer Special Adaptations: How can an amimal get more food (especially in a low food environment) 5. Symbiosis: (ie teamwork) Zooxanthellae: A dinoflaggelate- Lives symbiotically inside tissues of a range of invertibrates! Zoozanthellae symbiosis: Animal + a photosynthetic protist Zooxanthellae symbiosis: Animal + a photosynthetic protist `“Solar Powered Slugs” END. Look for email on Friday!!! .