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National Hagfish Day is October 20th

October 19, 2010 by Leave a Comment

You may not know it, but, tomorrow is National Hagfish Day. The day was created to draw attention and appreciation of all marine animals and plants. So please do not forget to appreciate not only the charismatic bottlenose dolphin, but, also the not-so-charismatic hagfish, sea cucumbers and horseshoe crabs.

Here is a little bit of background information on the hagfish.

The hagfish was thought to be a jawless lamprey when first discovered in Norway in 1747. This cartilaginous fish has no jaw, scales or fins and lives in temperate regions in the southern and northern hemispheres. When a hagfish is born it is born with both female and male reproductive organs. They often change from male to female by seasons. The over 70 species belong to the family “Myxinidae”. The prefix myxi- means slime and relates to the animals ability to produce a slime as a form of defense.

Another interesting fact is that the hagfish is practically blind as it has its eyes located under its slimy skin.

Filed Under: Fish Tagged With:

Whales don’t have scales

October 10, 2010 by Leave a Comment

That’s right. Whales are covered in blubber because they are mammals like you and I. Now the fish in the sea are another story. You might not realize it, but, if you’ve ever had the opportunity to touch a shark they are covered in scales just like other bony fish. There are several main types of scales that cover fish. See if you can figure out which cover sharks.

1.) Ctenoid scales: These scales are comb-like with the ends having small teeth-like structures.

2.) Ganoid scales: These scales are heavy and diamond-shaped.

3.) Cycloid scales: These are round scales with smooth edges.

4.) Cosmoid scales: These scales are very hard and covered in enamel.

5.) Placoid scales: These scales have teeth-like edges. They are different than ctenoid scales because they lack they rounded front.

Scales grow out of the skin and have modified to quite a few different versions over the years. In fact, the feathers of a bird are a type of evolved scale!

Filed Under: Bony Fishes, Fish, Sharks, Skates and Rays

12 good non-fiction books about fish

September 29, 2010 by 3 Comments
  1. Four Fish: The Future of the Last Wild Food by Paul Greenburg (read a review here.)
  2. Cod: A Biography of the Fish That Changed the World by Mark Kurlansky
  3. On the Run: An Angler’s Journey Down the Striper Coast by David Dibendetto
  4. Giant Bluefin by Douglas Whynott
  5. The Last Fish Tale: The Fate of the Atlantic and Survival in Gloucester, America’s Oldest Fishing Port and Most Original Town by Mark Kurlansky
  6. The Unnatural History of the Sea by Callum Roberts
  7. Tuna: A Love Story by Robert Ellis
  8. The Most Important Fish in the Sea: Menhaden and America: H. Bruce Franklin
  9. The End of the Line: How Overfishing Is Changing the World and What We Eat by Charles Clover
  10. The Empty Ocean by Richard Ellis
  11. 5 Easy Pieces: The Impact of Fisheries on Marine Ecosystems by Daniel Pauly
  12. Striper Wars: An American Fish Story by Dick Russell

Beach Chair Scientist also has list of great movies, fiction books and blogs about the sea!

Image (c) Island Press.

Filed Under: Fish, Random Fun! Tagged With: , , , , , ,

What is bioluminescence?

September 26, 2010 by 1 Comment

Bioluminescence means light (as in ‘illuminate‘) from life (prefix ‘bio‘).

It is produced by a chemical reaction in many marine or terrestrial organisms. The reaction begins with a chemical called luciferase that catalyzes another chemical, luciferin, to then make oxyluciferin and light.

If you see bioluminescence from a boat it is most often tiny dinoflagellates near the surface of the water that begin this chemical reaction once they’re excited. A boat or a passing porpoise can trigger this excitement. On land we are familiar with bioluminescence in fireflies and a glowing fungus, called foxfire.

But, did you know bioluminescence is responsible for illuminating the majority of our habitable world? That’s right, the deep sea is the largest area of habitable space on our planet. A large number of species that utilize this adaptation live in that environment. Here are some images of the inhabitants of the deep sea that use bioluminescence:

Deep sea shrimp, Acanthephyra purpurea

Deep sea fish, Photostomias guernei

Blackdevil angler fish, Melanocetus johnsonii

All images (c) NOAA.

Filed Under: Fish, Places Tagged With: , , , , ,

The “Osprey”, they’re bone breakers alright

September 24, 2010 by Leave a Comment

The Latin name for osprey, Pandion haliaetus, means “bone breaker” and explains quite well how the bird of prey gets his main source of food, fish. Ospreys plummet down from almost 30 stories  above water and use their barbed talons to grab onto mullet, menhaden, or other fish found in estuaries. These barbs can be thought of as backwards facing scales that allow them to be very precise in clutching their food source.

Image (c) grit.com

Filed Under: Birds Tagged With: , ,

Can you tell what type of whale is under the surface by the spray it produces above the surface?

September 23, 2010 by Leave a Comment

Yes. For instance, the sperm whale will blow forward and to the left. The vapor will be about 6 feet tall. Right whales and bowhead whales will have a v-shaped blow. The right whales will be about 15 feet tall while the bowhead whales will be higher at 21 feet tall. Humpback whales have a low and wide spray. It may reach up to 9 feet. Lastly, the mighty blue whale has the strongest and most distinct spray shooting straight up to almost 21 feet tall.

Filed Under: Marine Mammals

How do fish give birth?

September 10, 2010 by 7 Comments

There are three general ways fish in the sea give birth to a new generation.

I will start off explaining what is most familiar to us, fish that give birth to live young. This is called being viviparous. There is a structure similar to the placenta that connects the embryo to the mother’s blood supply. Some shark species are viviparous. In fact, in some shark species such as the shortfin mako, the embryo has been known to eat other eggs developed by the mother.

Next is something similar called giving birth oviviparously. This is when the embryo develops inside of an egg that is inside the mother. The difference between this and viviparity is that the embryo gets no nourishment from the mother. Nutrients are taken from within the egg. Coelacanths are a type of oviviparious fish.

Lastly, I will go over how 97% of fish species reproduce. These are the fish that lay many, many eggs and hide them in a dark corner so predators can’t get to them. This is called being oviparous. With most oviparous fish species fertilization takes place outside the body. But with many types of skates and rays (pictured right) the male will use his claspers to internally fertilize the female eggs before she lays them.

Image (c) www.gma.org

Filed Under: Bony Fishes, Egg Cases, Fish, Sharks, Skates and Rays Tagged With: , , ,

What would it be like to be a seal pup for a moment?

September 9, 2010 by Leave a Comment

Thanks to the amazing video series called CritterCam produced by National Geographic we can take a sneak peak into the life of a bearded seal pup as he (or she) swims with their mother. The video is shot from the point of view of the seal so don’t expect any sounds other than what the seal would be able to hear. One of my favorite moments from the clip is when mum and pup rubbed their noses together for some gentle affection. Also, don’t miss at 2:30 when you can hear the little one making noises and communicating with his (or her) elder. Technology is just so delightful sometimes!

Filed Under: Marine Mammals Tagged With: , ,

Visit to the Smithsonian

September 4, 2010 by Leave a Comment

I am excited to bring you a look into the Smithsonian’s American Museum of Natural History. We are taking a sneak peek into the Department of Ichthyology with Research Curator, Melanie Stiassny. Ichthyology is the study of fishes. In this collection you will see the ceolacanth, Latimeria chalumnae, the three lobed caudal finned fish considered to be the missing link between fish and tetrapods (animals with four limbs).

Filed Under: Fish

Why don’t fish freeze in the Arctic Ocean?

September 3, 2010 by Leave a Comment

Fish species that frequent the cold temperatures of the Arctic Ocean (e.g., toothfish, cod, ice fish, etc.) have special ‘antifreeze’ proteins within their blood stream that enables them not to freeze in the cold waters of the northern hemisphere. This discovery was made about 50 years ago.

Recently, scientists from the Ruhr-University Bochum in Germany discovered how these proteins work. In the presence of the proteins, water molecules in the blood stream act in a more uniform fashion and are more particular about the bonds that they create. Whereas without the antifreeze proteins, water molecules just create haphazard bonds. Now we understand why fish can survive in the temperatures of the polar oceans which are below what should freeze fish blood.

The scientists made this discovery by using a technique called terahertz radiation on an Antarctic toothfish, Dissostichus mawsoni.

Journal reference:
Simon Ebbinghaus, Konrad Meister, Benjamin Born, Arthur L. DeVries, Martin Gruebele, Martina Havenith. Antifreeze Glycoprotein Activity Correlates with Long-Range Protein−Water Dynamics. Journal of the American Chemical Society, 2010; : 100816142208022 DOI: 10.1021/ja1051632

Image (c) wikimedia.com

Filed Under: Fish Tagged With: , , ,