Finishing Sharks

Today students answered some questions about stingrays based on a short article from the Richmond Times Dispatch. Students then identified which senses a shark could use to detect a person in the water whether they were bleeding, splashing, or just floating.

Students participated in a tough challenge about sharks some students made up during zero block and only Maria S got a perfect score though there were lots of folks who only missed one.

Students tested their knowledge with a shark puzzle and Zac was the fastest. Afterwards students finished up some odds and ends and took the shark test.

We finished the day with a film called Anatomy of a Sharkbite which follows a scientist Erich Ritter and his experience with a Bull Shark bite as well as analyzing shark attacks and bites on others in an effort to understand sharks. We will conclude the video tomorrow.

Build a Shark

To review shark anatamoy, students constructed paper models and labeled them. The project was simple, but fun, even though some students couldn't remember the last time they cut and paste something. Students were allowed to color their shark any color, so there was a lot of diversity in the sharks. Some students even added some funny things into the shark's stomachs like tires, people, seals, and others.

Shark Conservation

Today we discussed conservation of sharks. Millions of sharks are killed each year by humans. Some are caught by sport fisherman, some are harvested for oils, meats, and other things; many of them are being harvested for their fins. Finning wastes 95% of an animal, and the sharks are often tossed back in the ocean alive after being finned to die a slow painful death. For more information, click here.

The fins are harvested for shark fin soup. Shark fin soup is considered a delicacy in some countries and can sell for upwards of a hundred dollars a bowl.

The next thing we talked about was shark attacks. Most shark attacks are actually provoked by humans. Other shark attacks like bump-and-bites and hit-and-runs are the shark investigating a human to see if it is something good to eat. Once the shark tries it, it finds it doesn't like humans, it will swim away. Unfortunately for us humans, we are not so tough and kind of squishy and shark attacks damage us.

Skates and Rays

Today in class we talked about skates and rays. Skates and rays are depressed relatives of sharks that often spend most of their time on the benthos. (There are a few exceptions like manta rays pictured in the upper right)

Skates and rays are really similar and often hard to tell apart. Some rays look like flat sharks and some flat sharks look like rays, so we are going to be general in identifying skates and rays. In general, skates have fins on the tips of their tails.

Only rays can have stingers, and not all of them do. They can have 1 to 3 stingers from 5 to 15 inches long. See the picture below.

I often get asked about Steve Irwin, the famous Crocodile Hunter when we talk about stingrays. Yes, Steve Irwin was killed by a stingray, but his type of accident was very rare. Steve got stabbed in the heart which injected venom right into an important organ. Also, he removed the barb which caused just as much damage going in as it did coming out because of the sharp serrated edge. For more information about Steve Irwin's death check here and here.

Shark senses

Today we learned about shark senses. Sharks have a large brain to help process the sensory overload they must get from the SEVEN senses they have. They have the five we have plus a lateral line (pressure and vibrations) and the ampullae of lorenzini (electro-reception).

Follow this link for a cool interactive about how shark jaws stick out when they attack their prey! The interactive is down at the bottom.

If you are doing a final project on a shark... check out this new link! www.shark.ch

And once again... one try only... how much do you know about sharks? MsJ scored a 1467. Try Shark Weeks Ultimate Shark Challenge to see how much you know.

SHARKS!

Today students learned an introduction to sharks. We talked about the history of sharks, common characteristics of cartilaginous fish and then the reproductive strategies of sharks.

Not a lot is known about shark reproduction because in many cases it has never been observed.

Some sharks are oviparous and lay eggs (pictured). These egg cases are known as mermaid's purses. You can see the baby shark and its nutrient-rich yolk through the leathery egg case.

Some sharks are viviparous and have live birth a lot like mammals.

And some sharks are ovoviviparous and keep their eggs inside the uterus before releasing them... so its making eggs and then kind of having live birth.

Fe fi fo fish

Students have finished up fish for now and took their test today. Students have excelled at the many fishy challenges set before them and it would be impossible for me to say who the winners were of the many challenges we have completed.

Next up is SHARKS! Students got a little preview after finishing their tests today. We watched a little video about great whites in the waters off the coast of South Africa that leap out of the water to chase the fur seals they want to eat that also leap out of the water.

Try Shark Weeks Ultimate Shark Challenge to see how much you know. (Play only once) MsJ scored 1370.

Fish Review

Today students worked on review sheets for their mid-week test. Then students used matching cards to build fish that satisfied the descriptions I was giving.

Students finished the day by designing their own fish and answering key questions about body shape, tail shape, and mouth shape. First period's are due Thursday and fourth period's are due Wednesday.

Students are being very creative. Here are some fo the ones that are finished. Some even included the biome as the background and those look especially nice.

Fishing Methods

Today we discussed fishing methods and the advantages and disadvantages of different methods. Netting is the most popular method of commercial fishing because a lot of fish can be caught in short amount of time without a lot of effort.

One the major problems with most commerical fisheries is the amount of bycatch. Bycatch is anything caught in the net that you do not want. This could include edible fish that your company is just not equipped to process.

Most organisms brought up in nets as bycatch do not survive because they are crushed or drowned. Sea turtles and dolphins sometimes get swept into nets and drown because they cannot make it to the surface to breathe.

Most scientists and fisherman agree that the oceans have been and are being overharvested. People may not like regulations, but without regulations, many fish species that we used to commonly consume would be extinct.

The Unit 7 Test will be on Thursday.

Thursday Fishies

Today students did a brief reading on Antarctic Fish and their ability to make antifreeze. They make their own version of antifreeze so that ice crystals do not form in their blood.

Next students participated in a challenge identifying fish mouths, fish tails, and more. Students were very competitive and were trying to get the top score. In first period, Megan scored the highest and in fourth period Terelle beat out Dale by one point. Students were amazed at this picture of the Mekong catfish (which has forked tail).

Fish ID and Marine Harvests

Today we started the day with a BrainPop about fish followed by a quiz and an opportunity to earn a fishy sticker. Next students looked at a variety of plastic fish and fish magnets and observed their characteristics - specifically the tail shape, mouth shape, and body shape. Students also looked at other characteristics and tried to pick what biome that fish could be found in.

We started discussing marine harvesting and fishing today by talking about who harvests the most seafood (China), who eats the most seafood (China), and which people eat the most seafood pounds per person (the Maldives). Americans are about sixth on the list as far as consumption, but we are the number one consumer and importer of shrimp. Importing shrimp is damaging to the environment for two reasons.

1. Shrimp that are farmed in other countries are not as regulated as here in the states, so shrimp farm pollution is not as regulated and it damages coral reefs. Also many mangroves are cleared to build these farms.

2. US boats are required to have turtle excluder devices (TED) on trawl nets so that turtles do not get caught in shrimp nets and drown. Other countries do not regulate this and as a result catch and drown sea turtles.

To make a environmentally responsible seafood choices, choose shrimp that are farmed or caught in the US. For more sustainable seafood choices, check out Seafood Watch.

Virginia Aquarium Photos

So I have some photos from some students that I gathered on the bus with my laptop. I put them together quickly so folks can see how much fun we were having. Climbing inside the shark mouth is always a highlight. Thank you to Raven, Steven, Zac, and Jessica for sharing your photos. And thanks to my group for tolerating me and Jess taking millions of photos of you!

Fish Spawning & Project DIscussions

Fish reproduce in a variety of ways. Most are broadcast spawners, meaning that when the time is right, the females release their eggs, the males release their sperm and they both meet and mix producing fertilized eggs that develop into fish fry and eventually into adult fish. These snapper are spawning and you can tell by the large cloud of gametes in the water.

By producing a lot of eggs, the snapper hope to overwhelm any predators trying to make a meal so that there is no way all the fry are eaten and some will have a chance of surviving.

Today we also discussed invertebrate projects and upcoming final projects on vertebrates.

Invertebrate projects were graded over the weekend and quite a lot of them were incomplete. We discussed the high quality of their writing and the poor quality of required information. We also discussed how if this quality of work was submitted for final projects, some of the students would have very disappointing grades. Students will have a chance to resubmit invertebrate projects by the end of this week.

Final projects are on vertebrates and will be in powerpoint form. These projects will count as 10-20% of a student's grade depending on if they are exempt from the final. Students will have six to seven computer lab days to work on these projects as well as guidelines to follow. Any additional time will need to be made up by the student during zero block or after school.