Slimy Slugs, Scary Squid, and Review

Today students compared and contrasted the shells and parts of a clam and a snail. Then they participated in a This or That challenge identifying molluscs. Maria with an S took the prize in first, with Megan earning the award for the most 'test yourself' questions correct. In fourth we ended with a four way tie that had to go to tie breakers. After one tie-breaker we were down to two - Brittany H and Luke, but after two more tie breakers they were both declared winners. Dale and Jacob earned the most correct in the 'test yourself' section.

Students read a historical narrative about sea monsters and how those stories of the Kraken were based on squid sightings. We have known about the giant squid for several hundred years because of dead specimens and pieces found, but the first live one was not observed until 2005. Sailors used to think that the giant squid was much bigger because of a measurement error. Sucker marks on sperm whales were used to estimate size until they relaized that those marks and scars grew bigger as the whale grew.

Students then read a fictional account about a squid attacking the Jersey Shore (article pictured at left) and had to identify what parts of the stories were accurately portraying the squid and which parts were inaccurate.

Students finished class with seat work review identifying characteristics and adaptations and then classifying molluscs into main groups and identifying them. Students will have a test on Friday and a practical on Monday.

I captured some slugs from my yard so students could see a live example of a slimy mollusc. Slugs are also great specimens because they aren't scared to move around and their tentacles are very visible. Gastropods (snails and slugs) have two sets of tentacles - a set with eyes on them which are longer and a short set called sensory tentacles. Today Kelly got slimed by a slug (but Morgan, Luke, and Brittany S had been slimed before). Albert decided he wasn't afraid of slugs and wore one as a mustache... until it started crawling towards his mouth. :) Albert is pictured above; Luke is pictured below.

Cephalopods

Today students explored the wonders of cephalopods. Cephalopod means head-foot and includes octopi, squid, cuttlefish, and the chambered nautilus.

Cephalopods are characterized by their large well developed eyes, numerous tentacles, a parrot like beak in the center of the tentacles, and well developed chromatophores in their skin that allow them to change color.

We watched numerous videos today to see and understand how and why cephalopods make ink clouds, to see how an octopus can swim with jet propulsion or use its tentacles to crawl around, and we also saw how a octopus can eat a shark! Below is a video that I took at an aquarium that shows how an octopus uses its tentacles and suckers to move.


For more information about cephalopods, check out CephBase and the Australian Cephalopod Research page.

Gastropods

Today students learned about gastropods. Gastropod means "stomach foot" and includes all snails and anything else that makes one shell. Gastropods have one foot, one shell, and one siphon.

Some shells are spiral and have an operculum to act as a door for when they hide inside.

Other shells are not spiral and the snail has good suction power so that predators have a difficult time pulling the snail off the rocks.

Students separated shells into bivalves and gastropods. They also practiced identifying shells and sorting them based on other characteristics.

This is me... pretending to be a gastropod.

Bivalves

Today students learned about bivalves. Bivalves are molluscs that have two shells and two siphons. Bivalves include some of the more well know shellfish liek scallops, clams, oysters, and scallops as well as a few like jingles, ark shells, and cockles.

Students built a model of a bivalve and had to put in the mantle (the soft squishy part), the gills, siphons if it had them, adductor muscles (used to keep the shell shut), and maybe one other thing unique to the type.

Mussels make byssal threads for attaching and scallops have eyespots to see predators. Sam and LaQuin are making scallops.

On Monday students will compare and contrast the different models to get a true understanding of the similarities and adaptations of bivalves.

Starting Molluscs

Today students learned the basics about sea shells

• The shells found on the beach are from dead organisms.
• Any mollusc that has a shell, makes it shell.
• Sea shells are made of calcium carbonate.
• Shells are smooth on the inside because slimy molluscs don't want to rub their soft bodies on something rough. If they are smooth on the outside, then the mollusc also wears its body on the outside of its shell.
  

Students also learned what a chiton was. A chiton doesn't have just one shell, it has 8 overlapping plates. These plates are held together by the soft squishy mantle, and the plates come apart when the animal dies. Chitons are built like armored cars and have great suction to stay on the rocky coast in waves and storms. They spend their days sliming around scraping algae.

Identifying sea shells

Today students brainstormed all the things they knew about sea shells. As a group they knew quite a lot including what sea shells are made of (calcium carbonate), who makes them (the organism does), and a little about size, shape, texture, and even distribution. Not many of them knew what the names of the sea shells were though. (Maria and Brooke figure out which shells are which)

Students were given a handout of black and white shell drawings, a bucket of numbered shells and asked to match the real thing with the sketches. In some cases, shells were easily matched and some students really had an eye for it. Some shells were a bit harder.

After matching the drawings with the real shells, students then looked them up in field guides to try to identify what they were and how many shells they have. A variety of books were available and helpful for the students to use. In the photo to the left, Josh, Becca, Jay, Cassandra, and Chase are looking up the shells to figure out their common names. As I was helping Logan match the oyster with it's drawing, I told him to look at the ugly lumpy shell and match it with the ugly lumpy picture. He told me, "It's not ugly; it has undefined beauty." This is a quote to remember.

I went over the names of some of them and many of the students were correct. Nick was particularly speedy at identifying shells and looking them up. Some students found names more specific than what I was looking for or listed the scientific names.

Students will have a lot of review with these shells and there will be a lab practical and a test at the end of the unit on these shells and the other information learned in the Mollusc unit.

Biomes and Zonation

Students have been learning all the different biomes that exist in the oceans. Most people have heard of coral reefs and think about the beach, but there are actually many different biomes i the ocean.

One of the weirdest, but also most interesting is Whalefall. Whalefall is when a dead whale settles to the bottom of the ocean and organisms move in to feed on the carcass until even the bones are decomposed. Hagfish are a dominant scavenger as well as bacteria. It may not seem like a big deal, but this biome boasts over 160 species that are not found on the surrounding benthos. More info can be found at the link above, or here. Listen to a podcast here.

Deep sea benthos is another biome and it is pretty boring. Its a gooey squishy substrate populated by some dd scavengers, but there is not a high biodiversity and not a lot of food to eat.

Not all biomes are found at the bottom of the sea. Along coasts you can find rocky coasts, sandy beaches, salt marshes, mangroves, sea grass beds, kelp forests, and fouling communities.

I think fouling communities are really interesting... because all these organisms need is a hard substrate (surface) to stick on. This could be a dock, a pier, a boat, or anything that's in the water long enough. Most people have seen all the 'stuff' growing on the pole legs of piers and docks, but don't really think of the variety of organisms that grow there - or their importance. Most of these organisms are filter feeders and do a lot for water quality. They also break down the surfaces like scavengers... not something we want for our boats and docks we use, but important nonetheless.

There is a lot of information to learn this unit. Students were given two review sheets today - one general, one biome specific. The Unit 3 Test is one of the hardest of the year, and it will be on Tuesday.

Drawing Plankton

Students started the day with a brief review of seaweed and algae types. Then they learned how some abiotic factors cause different biomes and zonation in the ocean. Today we mostly focused on tidal zonation on shorelines, but students will discuss other biomes and the zonation within them next week.

We finished the day playing catch up. Students were asked to draw plankton following a schematic and then answer some basic questions. Afterward students worked on a variety of assignments that were missing or incomplete.

Check out this collection of plankton drawn by first and fourth period students.

Plankton and Seaweed Observations

Today students watched some Blue Planet about krill and the whales that eat them as well as phytoplankton and the microzoooplankton that eat them and the megazooplankton that eat them... its a fish eat fish world.

Students then completed some observations of seaweeds. The seaweed had either been collected by Miss J in Virginia or North Carolina and dried, or it was fresh seaweed from the shores of Long Island mailed here by a friend named Josh.

Students also observed plankton in a sample from the pond behind the school using slides and microscopes. Students were amazed that there were tiny clear zooplankton zooming around in their samples.

These observations sparked questions and conversations and students gained a greater understanding of the material. I am pretty sure I even heard the word "cool" uttered a few times (and ignored all comments about stinking - everything in the ocean stinks when its out of the ocean!).

Plankton Grand Prix

Students started building their plankton yesterday and raced them on Wednesday. To win the Grand Prix, plankton needed to sink slowly and not float. This task is a lot harder than it looks and requires a delicate balance of weight and surface area or weight and floating materials (foam, air, plastic) that somehow plankton have overcome for millions of years.

Some of the races were exciting; some of them not so much. Plankton were allowed a five minute grace period before they were declared "floaters," and disqualified. Some students did not want to wait that long to see. Luke's plankton definitely started sinking within five minutes, but wouldn't sink any further much to his dismay.

First Period Place winners:
1. Logan (8 sec)
2. Ricky (7 sec)
3. Zac (4 sec)

Fourth Period Place Winners
1. Nathan (55sec)
2. Raven (7 sec)
3. Dale and Amber (both with 4 sec)

Please watch the video to see the students compete.

Plankton!

Today students got new seats and started a new unit on Plants, Plankton, and Biomes. This is probably our longest and most difficult unit because of the large amount of information that needs to be learned and applied.

We started class with a discussion about phytoplankton (cyanobacteria pictured above) and its importance to the ocean and to the world. Phytoplankton are responsible for feeding most of the creatures that live away from the shore and they are important for adding oxygen both to the water and to the atmosphere.

What is that? This is a meroplankton - meaning its a creature that is a plankton for only part of its life - usually egg, larvae, or juvenile (one or all three) before growing up and swimming around (nekton), or settling to the bottom (Benthos). Can you guess what this grows up to be? Students tried their hand at guessing life stages with a challenge. I can't remember from first period, but in fourth period the high score was 4/9. Ouch. Guess those meroplankton change a lot as they develop!

If you guessed Sea Star for the meroplankton above, then you are awesome! Check out this website Beyond the Reef for some great photos and information about plankton in general and some wonderful stages of meroplankton metamorphosis.

We finished class today by starting the Plankton Grand Prix. Students were given a sample of clay, a straw, and access to other materials to build a plankton to race. Plankton are designed to sink slowly, so for this race students want to design a plankton that sinks - just sinks slowly. Floaters will be disqualified. Some of the designs look awesome already and Ricky's plankton rocked in his test run today.

We'll see which design wins the Plankton Grand Prix tomorrow...

Unit 2 Ecology Test and Preparation

It would be impossible for me to tell you all the smart students who excelled at the review challenges we had in the last two days. One of the best review tools we have are matching cards.

One set is three way matching - matching up a vocabulary word, a definition, and a picture. The other one is more like a puzzle grid where students have to match words with definitions correctly to make a big square. And I don't make it easy - there are a lot of trick answers to look at too. In this photo Raven and Alisa are working on three way matching and Dale is working on a puzzle square.

Sam and Lawrence challenge themselves to outdo each other and due to some helpful hints I gave one of them, it was impossible to determine a winner. To try and settle the score, they wanted another one. Only having one prepared for this unit's review, they tried the shark puzzle and learned that they have a lot to learn about sharks. Sam and Lawrence are competing for a higher score on today's test and they, along with everyone else, will find out how they did on Tuesday.

Happy Labor Day weekend!

School Picture Day

I think school picture day should happen more often because a lot of students dress up and they look really nice!

Maria C and I laughed about how people should pose for school picture day. What do you think?

More on Fish Coloration

Today students started with a BrainPop on camouflage and then competed in a This or That Challenge. There were 15 picture questions based on concepts taught. The students had two choices to pick from, but they were still tricky. In first period, Brittany got a perfect score while Maria S and someone I cant remember only missed one question. In fourth period, Dale got a perfect score and Connor only missed one. Winners were given pencils with fun marine ecology facts on them.

One of the tricky questions was about this blue ringed octopus. Most cephalopods (octopus, squid, cuttlefish) have active coloration which means they can change the color of their skin at will - often changing quickly and dramatically. The blue ring octopus is about 8 inches long or less. This particular octopus is actually venomous and packs enough punch to kill a 26 humans within minutes with one bite of its beak. Whoa!

Students will review some more tomorrow and have a Unit 2 Test on Friday. All Unit 2 assignments are also due on Friday.

Fish coloration and camouflage

Today we finished talking about symbiotic relationships including commensalism, parasitism, and mutualism.

Then we talked about fish coloration and camouflage. Some of the tricks these fish have up their fins to blend in or advertise or trick predators are quite ingenious. One of my favorite organisms is the nudibranch - basically a slug that lives in the ocean. These soft squishy slimy critters would make excellent snacks, but they are all poisnous! They have warning coloration to let would-be predators know that they would not taste good at all. You can click here for a National Geographic Article about nudibranchs.

Conservation Report - Can you see me? Is a link to an awesome website with many examples of amazing animal camouflage - some on land and some in the sea. Check it out!