Facts about ‘Finding Dory’ friends

Maybe it’s because I’m a full-time teacher now, but my favorite character in Finding Dory is the Sting Ray. I mean, if it wasn’t for the class trip to learn about migration Dory – the blue tang with short-term memory loss –  may never had thought about “going home” and the trek to look for her parents may never have happened. She is supported on the journey with Marlin and Nemo – a class act father and son clown anemonefish duo. However, they meet some other amazing new creatures and reconnect with some old friends. Here are some of my favorite facts to share about Hank the Octopus, Destiny the Whale Shark, Bailey the Beluga, Crush the Green Sea Turtle, and – of course, the Sting Ray Teacher!







What are your thoughts on the Finding Dory film? Did anyone catch that Dory should now have been able to speak “whale” because of her friendship with Destiny – given Destiny is actually a fish and not a whale?

Hark! The herald angel (shark) strikes?

Angel Shark

Just one of the 25 Christmas/winter marine themed organisms on the Pinterest board. Check out the others here: http://www.pinterest.com/beachcscientist/christmaswinter-themed-marine-organisms/

Not often. But, the angel shark has been known to strike – if provoked. These strikes are similar to those made by its cartilaginous relatives, rays and skates, coming from the surface of the ocean floor (they’re pretty good with the camouflage as you might notice from the picture on the right). However, unlike rays and skates, the nocturnal angel shark doesn’t have a mouth on the underside of its body, but rather in front. This location is best suited for a diet of crustaceans, mollusks, and flatfish. With their enormous mouth they’ll suck the prey in and swallow it whole.

But, one of the most significant “Did you know?s” about the angel shark are that their lower lobe is longer than the upper lobe, whereas most shark caudal fins are top-heavy.

Also, pretty fun to learn is that angel sharks are ovoviviparous, just like frilled sharks, seahorses, and scorpionfish. This means “The young sharks tend to develop inside the female mothers.”

CITES recognizes important marine species

You might think that sharks are a predator that we want to eradicate, but that’s far from the truth of the matter. For a healthy ocean we need the top predator. For 5 species of sharks – oceanic whitetip, scalloped hammerhead (pictured below), great hammerhead, smooth hammerhead, and porbeagle sharks – there was some inspiring news during the 16th meeting of the Conference of the Parties for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Proposals were adopted that would give them greater protection and provide them with less risk from overfishing (According to the Guardian, “Those fishing for oceanic whitetip, porbeagle and three species of hammerhead shark will now require strictly controlled permits to export the fins”) for these sharks. However, the move will need to be adopted completely by a final plenary session scheduled for Thursday. It’s a particularly significant move considering CITES meetings take place every three years and that CITES has not traditionally leaned towards protecting marine species due to the intense political and economic issues that are related to fisheries issues. According to the Washington Post, “Elizabeth Wilson, who manages the Pew Environment Group’s global shark campaign, said the broad array of countries backing the proposals this year helped produce success this time around”.

Globally,  sharks are in peril and overexploited due in major part to a voracious demand for shark fins, especially in Asian markets, since it’s the primary ingredient in shark fin soup (more affordable and more popular than ever at Asian weddings). While it might be a difficult culture shift for the expanding Asian middle class (a delegate at CITES stated, “It would be like telling the French not to have champagne at their wedding“), ultimately it’s what has to be done since shark populations have fallen to such low levels. As they saw off the coast of North Carolina once sharks were overfished rays thrived and then destroyed the lucrative bay scallop fishery. Here is another resource outlining the importance of sharks to the ocean ecosystem.

Scalloped hammerhead shark (sphyrna lewini)

Scalloped hammerhead shark (sphyrna lewini) from NatGeoTV

How do fish give birth? Revisited

From time to time, I like to revisit the more popular posts and present either new material or the material in a new format. Below is a simplified understanding of the three general ways that fish give birth (i.e., Within each category below there are sub-categories that I did not get into here). Please feel free to comment below or send me an email at info@beachchairscientist.com if you have any additional questions.

What are skates and how are they different from rays?

Recently, a subscriber wanted to learn more about skates. Great question since many of us think of ‘roller’ when we think ‘skate’. Skates are a species that often get overshadowed by rays, especially considering rays tend to be boldly colored while skates tend to be rather dreary and drab in coloration. Rays are also found closer to the coast and skates prefer deep water so we may be more familiar with running into (or focused on learning to avoid) rays. However, there are exceptions to those generalizations within the 100 species of skates and 240 species of rays found worldwide.

They’re both flat diamond-shaped fish with their mouths on the underside of their body. Both of their body types can be described as dorsoventral. Skates and rays are cartilaginous fish, like sharks and chimaera, which all make up the class Chondrichthyes (Con-drick-thees). Cartilage is the material that makes up our nose and ears and is more flexible than bone. Skates and rays  have modified fins, resembling wings, and often look as though they are flying through the ocean.

Here are six general guidelines for differentiating a skates and rays.

  • The pelvic fin of skates is divided into two lobes, while the pelvic fin of rays is a single lobe.
  • The tail on skates lacks a stinging spine. Rays have a distinct, saw-edged spine found midway along their body length. (When swimming in the habitat of stingrays it is important to remember to do the ‘stingray shuffle‘.)
  • Many species of skates have bucklers (thorn-like scales along the mid-line of their back and tail. Rays typically have no bucklers.
  • The tail of skates is rather thick and compact, while rays typically have a slender and long tail.
  • Male skates have enlarged scales near their eyes and wingtips, known as ‘malar’ and ‘alar’ spines.  Male rays do not have these scales.
  • Skates live in cold waters, while rays prefer warm seas and rivers.

For more information about skates and rays, check out the ReefQuest Centre for Shark Research.

Photo (c) www.animals.howstuffworks.com

New ‘marine life encyclopedia’ launched

I think there might be another great bookmark to add to your ocean facts files! Please spend some time reviewing this great new resource, a marine life encyclopedia, compiled by Oceana. Over 500 creatures, places, and concepts can be explored. The pictures are bright and colorful and the information is up-to-date and easy to digest. It seems fantastic if you want a quick answer to a question.

Even if you think you know all the answers, test yourself with this Ocean IQ quiz!

The content on the marine life encyclopedia site has been licensed to Dorling Kindersley, one of the world’s leading educational publishers.

Everybody do the ‘Stingray Shuffle’

Staying safe at the beach this summer can mean more than just applying liberal amounts of sunscreen. If you are going to be visiting the southeastern United States you may want to try the ‘stingray shuffle’ to avoid a venomous injection from a stingray.  A stingray’s main defense is it’s barb which they arc up over their backs and strike in a manner similar to scorpions. Stingrays are docile creatures and do not want to use this defense tactic. Since stingrays are found mostly on the ocean floor it is best to drag your feet lightly and do the ‘sting ray shuffle’ to warn stingrays that you are approaching. If you do get jabbed, hot water can help in the short term. But it is best to seek professional medical attention.

Here is a video from the National Geographic YouTube Channel to teach you some more about stingrays.

Bookmark and Share

It’s as easy as A, B, Sea: O for Operculum

Operculum is the hard scalelike cover of the gills of bony fishes. Cartilaginous fishes (such as sharks, skates and rays) all lack a gill cover.

Image (c) www.webs.lander.ed

Whales don’t have scales

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!

How do fish give birth?

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