Sea Stars
Zones
Rocky Shore
Adaptions
Vocab
100
Common Name
Ochre Sea Star
100
Name 2 zones.
EX: Middle Intertidal
Spray zone, lower intertidal, etc.
100
What is Interspecific Competition?
Competition between different species.
100
Describe the challenges of the spray zone.
●Always above sea level and exposed to the atmosphere.
●Drying out is a significant challenge.
●Very few species of marine algae.
100
Abiotic vs Biotic factors. Give an example for each.
Abiotic factors refer to non-living physical and chemical elements in the ecosystem. Biotic describes a living component of an ecosystem.
Biotic Factors: organisms, such as plants and animals (answers may vary)
Abiotic Factors: water, air, soil, sunlight, and minerals (answers may vary)
200
What it eats
Mussels, clams, snails, barnacles and sea urchins. Will consume dead animal and plant material.
200
What are characteristics of the habitats found in rocky intertidal? (One sentence Minimum)
The naked face of cliffs, cracks and crevices, intertidal spaces between algae and mammals, and tidepools are all examples of intertidal habitats. The exposure of microhabitats on hard rock surfaces to the light changes them even further. The makeup of the community can vary based on the amount of sun exposure. Different populations exist under the rocks and the communities that live on the top of the rocks, where cobbles and boulders are the norms.
200
What are Physical stressor examples?
drying out, temperature, pH, and salinity fluctuations, etc.
200
2 organisms and there adaption from the spray zone.
Periwinkles (Littorina) - Has a shells to prevent from drying out. Feed on marine algae.
Rock louse (Ligia) - Hide in crevices during the day, scurry about at night, feeding on organic debris.
Limpets (Acmaea) - Has a shells to prevent from drying out. Feed on marine algae. Has a flattened conical shell and a muscular foot use to cling tightly to rocks.
200
Control Group
Control group: the standard to which comparisons are made
300
Predators
Sea Otters and gulls
300
Describe the Spray Zone in 2-3 sentences.
The dark, supratidal, or supralittoral zone is another name for the spray zone. A slick, gray-black region just within the control of the maximum high tide absorbs moisture only from the splash of waves at the highest levels, during floods, or from runoff. Its dark color comes from black patches of Cyanobacteria, also known as blue-green algae, despite the fact that it is a bacteria rather than an algae. These colonies mimic oil splotches clinging to the rocks when they're dry. They become very slippery when wet, as they become physiologically engaged. Periwinkles venture into the spray zone's lower levels. A few barnacles can even be found in this zone, surviving on the spray that falls there.
300
Organisms living within the rocky shoreface different environmental conditions based on the ______ _____ ________.
zone they inhabit
300
Name 2 High tide Zone Organisms and Their Adaptations.
Striped shore crabs ( Pachygrapsus crassipes) - protective shell and can move between spray zone and high tide zone.
Buckshot barnacles (Chthamalus and Balanus) - protective shell, but don’t live above the high tide zone because they are attached and filter food out of the water.
Chiton (Nuttalina) - protective shell
300
Independent variable vs. Dependent variable
Independent variable: What the scientist changes or what changes on its own.
Dependent variable: What is being studied/measured.
400
Scientific name
Pisaster Ochraceus
400
Describe the Lower Intertidal zone in 4-5 sentence
This location is just above low tide. The red algae, Irish moss, has taken the place of the rockweeds here. Only at extremely low tides is this region exposed. Blue mussel beds and species that exist in contact with the mussels can be found here. Pry off a few mussels gently to see how many worms and arthropods use the mussels as a defense source. This region has more diversity than the areas above it. This is indicative of a habitat that is more stable and less stressed. A highly stressful atmosphere is typically characterized by low diversity and high density.
400
First organisms to colonize The High tide Zone.
What are rock weeds?
400
Describe the blue and red circles.
●A small Chthamalus barnacle is circled in red.
●A large Balanus barnacle is circled in blue.
400
Define epifauna.
At a rocky shoreline organisms that live on the surface are called epifauna (epi = upon, fauna = animal).
500
Distribution (where it’s found)
Ochre Sea Stars are the most commonly seen member of their group in many Pacific Northwest coastal areas. Virtual swarms of orange and/or purple starfish are exposed at especially low tides, often clustered under shady ledges or in crevices where they won't get baked by the sun.
500
Describe the Middle Intertidal zone including how tides and physical features that define the region.
This band makes up the majority of the intertidal region. Two brown algae genera, common rockweed, and knotted wrack, also known as rockweed, are dominant in the Boston area. The thallus of Fucus is a flattened drab green color with a midrib running down it. It has a lot of swellings that may be floats or reproductive systems. Ascophyllum is also a drab green color, but it lacks a midrib and has daily swellings that serve as 50 New England Aquarium floats at all times. Other common species found in mussel beds and seaweed turfs include common periwinkles, barnacles, blue mussels, limpets, slipper shells, sea stars, and a few worms. Spirobis, a small, coiled polychaete worm, is often found on algae. This worm has brightly colored gills that extend out into the water when underwater and vanish almost immediately when disturbed. Use a hand lens to observe.
500
Describe the middle tide zone organsims
More consistently covered in seawater.
Allows for more marine algae and soft-bodied animals.
Total biomass is much greater so greater competition for rock space amongst sessile forms.
Gooseneck barnacles (Pollicipes) - protective shell, sessile, filter feeder. Competes for space amongst mussels.
500
Describe 5 soft-bodied organisms and algae.
Sea cucumbers (Stichopus)
Sea anemone (Anthopleura)
Sea slug (Navanax)
Sea stars (Asteria and Pisaster)
Sea Urchins
Brittle stars (Ophioderma)
500
Define high, middle, and low zone.
High tide zone -relatively dry, covered only during the highest high tides
Middle tide zone - covered by all high tides and exposed during all low tides
Low tide zone - usually wet, but exposed during the lowest low tides.