Denise Harrington: Spotlight on a Blacktip Shark, September 24, 2016

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Saturday, September 24, 2016

Yesterday, I was in the crew lounge, working on my next blog, when Eric Hoffmayer, Research Fishery Biologist, called me out to the fantail to see a large deceased female blacktip shark (Carcharhinus limbatus) brought in that morning.

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(deceased) female blacktip shark

The contrast between the gray and white skin caught my eye. The countershading, a dark grey color on top, had a light bronze hue that sparkled in the light. A white band starting at its pectoral fins widened until it merged with the belly at the anal fin.

If there is a mortality, the science team uses the opportunity to dissect the fish, collecting additional information otherwise unavailable.  When we catch a shark, we release it as quickly as possible. The urgency of getting shark back in the water keeps me from carefully studying its detailed characteristics.

While I understand the loss of this particular shark touches many of us on board, understanding the species better through the loss is a practical, necessary approach to  managing the marine environment.  Without an in depth understanding of sharks, their populations, life cycle, and reproduction, there is no way we can sustainably manage fish populations.  Some may find dissection unappealing, and for those folks you may want to skip this blog, but not without first thanking the biologists who do this work compassionately. They keep our fisheries sustainable.

I rubbed my hand from the head to the tail.  It was smooth. Rubbing from the tail to the head felt just the opposite, rough like sandpaper.  Tiny dermal denticles allow sharks to move quickly through the water, an adaptation so amazing, it was put to use by designers of swimsuits in the Olympics and engineers of Navy ships.

Eric, Adam, and Chrissy, placed the shark on the table.  Eric cut the shark and pulled out a long sack that looked like empty sausage casing. At the end of the casing was a tiny shark pup. Trey joined the crew as they took data on each of the six pups.  The shark was pregnant.

The golden colored egg casing is still about six times the size of the pup, giving it plenty of room to grow.

The golden colored egg envelope is still about six times the size of the pup, giving it plenty of room to grow.

 

Here, Trey stretches out the casing demonstrating the significant amount of room left for the pup to grow,

Here, Fisheries Biologist Eric Hoffmayer stretches out the egg envelope demonstrating the significant amount of room left for the pup to grow. In the background you can see the egg envelop of another pup stretching across the table.

From the number of pups in a brood, to the possibility of immaculate shark conception, the reproduction of blacktip sharks is of interest to fishery biologists.  Without knowing all about shark reproduction, how many, and where sharks reproduce, we cannot sustainably manage this species, or fisheries in general.

Trey takes me through each stage of reproduction. The blacktip shark is viviparous, like humans. They are born alive, “vivi,” and develop within the mother getting nutrients through a placenta.

life-cycle-diagram

 

Egg

The shark life cycle begins in the female shark’s ovary with an egg.   Trey hands me an ovary that holds the eggs.  It is a large sack of many small red pinpoint size spheres with about 6 larger marble like balls from the high in the body cavity. These eggs wait to mature until the conditions are ideal for reproduction. At that time, the follicle ruptures, and the egg comes out.

Shark eggs are fertilized inside the female’s body.  The male fills his siphon sacs with seawater, and then flexes his abdomen to shoot the seawater and semen into the female shark through his clasper.

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Now I understand why we spin the clasper of a male shark to determine its maturity.  I was able to rotate this male Gulf smoothhound shark (Mustellus sinusmexicanus) clasper 180 degrees and reported it as an adult male.

Embryo/Pup

The male blacktip shark is often ready to mate in April to May but the females are often not ready to reproduce until June or July.  With many sharks, blacktip sharks included, the sperm can remain inside the female until she is ready to reproduce.  When that moment arrives, the egg slips through the ostium, down the anterior oviduct, and into the oviducal gland where it is fertilized by the sperm. For the blacktip shark, usually 4-6 eggs will be fertilized and develop into shark pups.  Females usually reproduce every other year.

 

large-yolk-little-shark

Note that different sharks have different modes of reproduction.  For example, Cuban dogfish (Squalus cubensis) reproduce through aplacental viviparity or ovoviviparity. The tiny pups you see here nourish themselves with the yolk “ovo” and have no placental connection to their mother.  They are born live “vivi,” and able to feed and protect themselves. Some sharks are oviparous, which means they lay eggs  that hatch later.

Initially,  the blacktip shark embryo uses the nutrients from a yolk sac for about 10-11 weeks. For the remaining time inside the mother, the pup increasingly gets nutrients from the mother through a placenta.  They are viviparous and remain inside the mother for approximately 10 months until they can survive on their own.  I held a pup, still connected to its mother by the umbilical cord. The similarities between human reproduction and blacktip shark reproduction surprised me so much I began to question the classification of viviparous sharks as fish.

 

holding-pup

I held a pup, still connected to its mother by the umbilical cord.

Immature Shark/Juvenile

For approximately two months after it is born, the immature shark has an umbilicus (like a bellybutton) that is still open.  During this phase of the life cycle it is called a neonate, or newborn.  It is otherwise just like a miniature adult blacktip shark.  It can hunt and hide from predators (including its mother).

immature-blacktip

Here, Eric and Evan Pettis, Texas Parks and Wildlife Fisheries Biologist, tag, measure, and release an immature blacktip shark.

 Mature Shark/Adult

Individual sharks even within a species mature at different rates, just like humans.  Generally, a male blacktip shark matures between 4-5 years of age, and females between 7-8 years.

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This 1385 mm male mature blacktip shark was brought in our second day of the survey.

How does the shark’s life cycle affect fisheries?

Evolutionarily speaking, placental viviparity gave the blacktip shark and others like it an advantage; the shark is born able to survive independently.  But this adaptation has also has a downside:  the females only produce a small brood, unlike other fish that use broadcast fertilization.

During gestation, the female shark we caught most likely migrated to our current location just off the coast of the Mississippi from deeper waters.  Called the Fertile Fisheries Crescent, the Mississippi Sound is one the most productive seafood areas in the nation.  Another risk to this species is pollution and over-fishing in the fragile estuarine habitat, the juvenile shark’s nursery.

There is demand for the high quality blacktip shark meat, the fins, and even the carcasses for fishmeal. The work NOAA Fisheries does to collect information about shark populations over time and over a wide geographic area not only helps keep blacktip shark populations sustainable, it also gives us valuable information about the ocean’s health in general.

 

Personal Log

Today I reached the half way point in my time on the longline crew.  I finally feel like I am getting into the groove, finding my way around the ship, and meeting people beyond my fishing buddies.  Valerie  McCaskill, Chief Steward, and her cousin, Ava Speights cook amazing seafood, grilled veggies, and au gratin everything. Ava showed me a great piece of exercise equipment, Jacob’s Ladder, to allow me to enjoy the great food guilt free.

Each station, each day, a new adventure.

Denise Harrington: First Day Jitters, September 21, 2016

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Wednesday, September 21, 2016

My first day on the longline cruise seems so long ago with three days of work under my belt. The night before my first shift, just like when school starts, I couldn’t sleep. Trying to prepare was futile. I was lost, lost in the wet lab, lost in my stateroom, lost in the mess. I needed to get some gloves on and get to work, learning the best way I know how: by doing.

At noon, I stepped out the fantail, life vest, gloves, hard hat, and sunscreen on, nervous, but ready to work. The Gulf of Mexico horizon was dotted with oil rigs, like a prairie full of farmhouses. Heat waves rose from the black deck.

Fifteen minutes before arriving at our first station, our science team, Field Party Chief Dr. Trey Driggers, Field Biologist Paul Felts, Research Biologist Kevin Rademacher, NOAA Science Writer Matt Ellis, and I began to prepare for our first station by baiting the hooks with mackerel (Scomber scombrus). I learned quickly that boots and grubby clothes are ideal for this task.

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Once all the hooks were baited, Chief Boatswain Tim Martin and Paul release a high flyer, a large pole with a buoy at the bottom and a reflective metal flag on top.

The buoy, connected to the boat by the longline, bobbed off toward the horizon.

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Tim attached the first of three weights to anchor the line to the sea floor.

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As the longline stretched across the sea, Kevin attached a numbered tag to the baited hook held by Paul.

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Paul passed the baited, tagged hook to Tim, who attached 100 hooks, evenly spaced, to the one mile longline.

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On another station, Paul attached numbers to the gangion (clip, short line, and baited hook) held by Trey.  Each station we change roles, which I appreciate.

Setting the longline is rather predictable, so with Rush and Van Halen salting the air, we talked about our kids, dogs, riots in the news, and science, of course. The tags will help us track the fish we catch. After a fish is released or processed, the data is entered in the computer and shared with the scientific community. Maybe one of these tagged fish will end up in one of the many scientific papers Trey publishes on sharks each year.

The line soaked for an hour waiting for snapper, tilefish, eels, sharks, and other fish to bite. While the line soaked, Mike Conway, skilled fisherman, and I lowered the CTD, a piece of equipment that measures conductivity (salinity), temperature, and depth, into the water.  Once the biologists know how salty, cold, and deep the water is, they can make better predictions about the species of fish we will find.

We attached a bag holding a few Styrofoam cups to see how the weight of the water above it would affect the cup.  Just imagine the adaptations creatures of the deep must have developed to respond to this pressure!

The ship circled back to hook #1 to give each hook equal time in the water. After an hour, we all walked up to the well deck, toward the bow or front of the ship. We pulled in the first highflyer and weight.  We pulled in the hooks, some with bait, and some without.  After 50 hooks, the middle weight came up. We still didn’t have a fish.  I began to wonder if we’d catch anything at all.  No data is still data, I thought. “Fish on eighty three!” I heard someone yell.   I wake from my reverie, and get my gloves on.

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It was a blacknose shark (Carcharhinus acronotus), “pound for pound, the meanest shark in the water,” says Trey. He would know, he’s the shark expert. It came up fighting, but was no match for Kevin who carefully managed to get length, weight, and sex data before releasing it back into sea.

With one shark to process, the three scientists were able to analyze the sexual maturity of the male blacknose together. I learned that an adult male shark’s claspers are hard and rotate 180˚, allowing them to penetrate a female shark. An immature shark’s claspers are soft and do not rotate. For each male shark, we need to collect this data about its sex stage.

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Here, you can see Trey rotating the clasper 180 degrees.

Later, Paul talked about moments like these, where the field biologists work side by side with research biologists from all different units in the lab.  Some research biologists, he notes, never get into the field.  But Kevin, Trey, and others like them have a much more well-rounded understanding of the data collected and how it is done because of the time they spend in the field.

Fortunately, the transition from inexperienced to novice was gradual. The second line was just as easy as the first, we only brought in two fish, one shark and one red snapper (Lutjanus campechanus).

For the red snapper, we removed the otoliths, which people often call ear bones, to determine age, and gonads to determine reproductive status.  I say “we” but really the scientists accomplished this difficult feat. I just learned how to process the samples they collected and record the data as they dissected the fish.

We set the longline a third time. The highflyer bobbed toward the orange sun, low on the horizon. The ship turned around, and after an hour of soaking, we went to the well deck toward the front of the ship to pull in the longline.  The sky was dark, the stars spread out above us.

“One!” “Three!” “Seven!” “Nine!”  The numbers of tags with fish on the line were being called out faster than we could manage.  It seemed like every other hook had a shark on it.  Two hours later we had collected twenty-eight Atlantic sharpnose (Rhizoprionodon terraenovae) sharks and had one snapper to process. Too busy working to take pictures, I have nothing to document my transition from inexperienced to novice except this data sheet.  Guess who took all this data? Me!

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Personal Log

NOAA Ship Oregon II is small, every bunk is filled.  I share a stateroom with the second in command, Executive Officer (XO) Lecia Salerno, and am thankful she is such a flexible roommate, making a place for me where space is hard to come by.

Last night, as I lay in my bunk above XO Salerno and her office, I felt like Garth on Wayne’s World, the thought that “I’m not worthy” entering my head.  All members of the crew are talented, experienced, and hard-working, from the bridge, to the galley, to the engine room, and out on the deck where we work. I’ve made a few mistakes.   I took the nasty thought and threw it overboard, like the slimy king snake eels (Ophichthus rex) we pull from the deep.

o-rex

King Snake Eel (Ophichthus rex)

In the morning I grabbed a cup of coffee, facing the risk of being the least experienced, slowest crew member to learn, with curiosity and perseverance.  First day jitters gone, I’m learning by doing.

Jeff Miller: Wrestling Sharks for Science, September 9, 2015

NOAA Teacher at Sea
Jeff Miller
Aboard NOAA Ship Oregon II
August 31 – September 14, 2015

Mission: Shark Longline Survey
Geographical Area: Gulf of Mexico
Date: September 9, 2015

Data from the Bridge
Ship Speed: 9.4 knots
Wind Speed: 6.75 knots
Air Temp: 29.4°C
Sea Temp: 30.4°C
Seas: <1 meter
Sea Depth: 13 meters

GPS Coordinates
Lat:  N 29 25.103
Long:  W 092.36.483

Science and Technology Log
The major goal of our mission is to survey shark populations in the western Gulf of Mexico and collect measurements and biological samples.  The sharks are also tagged so if they are re-caught scientists can learn about their growth and movements.

Sharks are members of the class of fishes called Chondrichthyes,which are cartilaginous fishes meaning they have an internal skeleton made of cartilage.  Within the class Chondricthyes, sharks belong to the subclass Elasmobranchii together with their closest relatives the skates and rays.  There are about 450 species of living sharks that inhabit oceans around the world.

Sharks, or better put their ancient relatives, have inhabited the oceans for approximately 450 million years and have evolved a number of unique characteristics that help them survive and thrive in virtually all parts of the world.  The most recognizable feature of sharks is their shape.  A shark’s body shape and fin placement allow water to flow over the shark reducing drag and making swimming easier.  In addition, the shark’s cartilaginous skeleton reduces weight while providing strength and flexibility, which also increases energy efficiency.

Blacktip shark

Measuring a blacktip shark on deck. The blacktip shark shows the typical body shape and fin placement of sharks. These physical characteristics decrease drag and help sharks move more efficiently through water.

When I held a shark for the first time, the feature I noticed most is the incredible muscle mass and strength of the shark.  The body of a typical shark is composed of over 60% muscle (the average human has about 35-40% muscle mass).  Most sharks need to keep swimming to breathe and, therefore, typically move steadily and slowly through the water.  This slow, steady movement is powered by red muscle, which makes up about 10% of a sharks muscle and requires high amounts of oxygen to produce fuel for muscle contraction.  The other 90% of a sharks muscle is called white muscle and is used for powerful bursts of speed when eluding predators (other sharks) or capturing prey.

Since sharks are so strong and potentially dangerous, one lesson that I learned quickly was how to properly handle a shark on deck.  Smaller sharks can typically be handled by one person.  To hold a small shark, you grab the shark just behind the chondrocranium (the stiff cartilage that makes up the “skull” of the shark) and above the gill slits.  This is a relatively soft area that can be squeezed firmly with your hand to hold the shark.  If the shark is a bit feisty, a second hand can be used to hold the tail.

Holding a sharpnose shark

Smaller sharks, like this sharpnose shark, can be held by firmly grabbing the shark just behind the head.

Larger and/or more aggressive sharks typically require two sets of hands to hold safely.  When two people are needed to hold a shark, it is very important that both people grab the shark at the same time.  One person holds the head while the other holds the tail.  When trying to hold a larger, more powerful shark, you do not want to grab the tail first.  Sharks are very flexible and can bend their heads back towards their tail, which can pose a safety risk for the handler.  While holding a shark sounds simple, subduing a large shark and getting it to cooperate while taking measurements takes a lot of focus, strength, and teamwork.

Holding a blacktip shark

Teamwork is required to handle larger sharks like this blacktip shark, which was caught because it preyed on a small sharpnose shark that was already on the hook.

 

Measuring a blacktip shark

Collecting measurements from a large blacktip shark.

 

Holding a blacktip shark

Holding a blacktip shark before determining its weight.

When a shark is too big to bring on deck safely, the shark is placed into a cradle and hoisted from the water so it can be measured and tagged.  We have used the cradle on a number of sharks including a 7.5 foot tiger shark and a 6 foot scalloped hammerhead shark.  When processing sharks, we try to work quickly and efficiently to measure and tag the sharks to minimize stress on the animals and time out of the water.  Once our data collection is complete, the sharks are returned to the water.

Tiger shark in the cradle

Large sharks, like this tiger shark, are hoisted up on a cradle in order to be measured and tagged.

Personal Log
We are now in full work mode on the ship.  My daily routine consists of waking up around 7:30 and grabbing breakfast.  After breakfast I like to go check in on the night team to see what they caught and determine when they will do their next haul (i.e. pull in their catch).  This usually gives me a couple hours of free time before my shift begins at noon.  I like to use my time in the morning to work on my log and go through pictures from the previous day.  I eat lunch around 11:30 so I am ready to start work at noon.  My shift, which runs from noon to midnight, typically includes surveying three or four different stations.  At each station, we set our baited hooks for one hour, haul the catch, and process the sharks and fishes.  We process the sharks immediately and then release them, whereas we keep the fish to collect biological samples (otoliths and gonads).  Once we finish processing the catch, we have free time until the ship reaches the next survey station.  The stations can be anywhere from 6 or 7 miles apart to over 40 miles apart.  Therefore, our downtime throughout the day can vary widely from 30 minutes to several hours (the ship usually travels at about 10 knots; 1 knot = 1.15 mph).  At midnight, we switch roles with the night team.  Working with fish in temperatures reaching  the low 90°s will make you dirty.  Therefore, I typically head to the shower to clean up before going to bed.  I am usually in bed by 12:30 and will be back up early in the morning to do it all over again.  It is a busy schedule, but the work is interesting, exciting, and fun.  I feel very lucky to be out here because not many people get the opportunity to wrestle sharks.  This is one experience I will always remember.

Jennifer Goldner: Sharks 101, August 18, 2011

NOAA Teacher at Sea
Jennifer Goldner
Aboard NOAA Ship Oregon II
(NOAA Ship Tracker)
August 11 — August 24, 2011

Mission: Shark Longline Survey
Geographical Area: Southern Atlantic/Gulf of Mexico
Date: August 18, 2011

Weather Data from the Bridge
Latitude: 26.05 N
Longitude: 84.05 W
Wind Speed: 5.20 kts
Surface Water Temperature: 30.30 C
Air Temperature: 31.20 C
Relative Humidity: 67.00%

Science and Technology Log

Living in the landlocked state of Oklahoma, I am unfamiliar with sharks.  Thus today, with the help of the scientists, I’m going to give some basics of sharks that I have learned this week.  Class title:  Shark 101.  Welcome to class!

Let me start by telling you the various sharks and amount of each we have caught this week in the Gulf of Mexico. We have caught 7 nurse sharks, 2 bull sharks, 4 sandbar sharks, 73 Atlantic sharpnose sharks, 15 blacknose sharks,  5 blacktip sharks, 5 smooth dogfish, 2 silky sharks, and 4 tiger sharks.  For those of you that took the poll, as you can see the correct answer for the type of shark we have caught the most of is the Atlantic sharpnose shark.   The sharks ranged in size from about 2 kilograms (Atlantic sharpnose shark) to 100 kilograms (tiger shark). Keep in mind a kilogram is 2.24 pounds. 

In addition to the sharks caught we have also caught yellowedge, red, and snowy grouper, blueline tilefish, spinycheek scorpionfish, sea stars, and a barracuda.

From the last post you now know that we soak 100 hooks at a time. Throughout the survey we have had as little as no sharks on the line in one location and up to 25 on the line in other locations.

Me holding a spinycheek scorpion fish

Me holding a spinycheek scorpionfish

Blueline tile fish

Blueline tilefish

Drew, Scientist, holding a barracuda

Drew, Scientist, holding a barracuda

yellowedge grouper

Yellowedge grouper

When a shark is brought on board, it is measured for total length, as well as fork length (where the caudal fin separates into the upper and lower lobes).  The sex of the shark is also recorded.  A male shark has claspers, whereas a female shark does not.  The shark’s weight is recorded.  Then the shark is tagged. Lastly, the shark is injected with OTC (Oxytetracycline) which can then be used to validate the shark’s age.  It should be noted that for larger sharks these measurements are done in the cradle.  For perspective, I had Mike, fisherman, lay in the cradle to show the size of it. Also on this trip, some of the scientists tried out a new laser device.  It shoots a 10 cm beam on the shark.  This is then used as a guide to let them know the total length.  Thus, the shark can actually be measured in the water by using this technique.

Do you see the 2 laser dots on the shark?  This 10 cm increment helps scientists estimate the length of the shark.

Mike, Fisherman, in the shark cradle- It is approximately 8 feet long.

Mike, Fisherman, in the shark cradle — It is approximately 8 feet long.

Shark diagram

Shark diagram

Mark Grace, Chief Scientist, weighs a shark

Mark Grace, Chief Scientist, weighs a shark

Male shark on the left (with claspers), female shark on the right (no claspers)

Male shark on the left (with claspers), female shark on the right (no claspers)

Mark Grace, Chief Scientist, and Adam, Scientist, measure a nurse shark in the cradle

Mark Grace, Chief Scientist, and Adam, Scientist, measure a nurse shark in the cradle

Mark Grace, Chief Scientist, assists me tagging an Atlantic sharpnose shark

Mark Grace, Chief Scientist, assists me tagging an Atlantic sharpnose shark

Tim, Lead Fisherman, holds the bull shark while I tag it!

Tim, Lead Fisherman, holds the bull shark while I tag it!

Giving antibiotics to an Atlantic sharpnose shark

Injecting OTC into an Atlantic sharpnose shark

Here are some things I learned about each of the sharks we caught.

1.  Nurse shark:   The dorsal fins are equal size.  They suck their food in and crush it.  Nurse sharks are very feisty.  See the attached video of Tim, Lead Fisherman and Trey, Scientist, holding a nurse shark while measurements are being taken.

The skin of nurse sharks is rough to touch.  Incidentally, all  types of  sharks’ skin is covered in dermal denticles (modified scales) which is what gives them that rough sandpaper type feeling.  If you rub your hand across the shark one way it will feel smooth, but the opposite way will feel coarse.

Dermal denticles, courtesy of Google images

Dermal denticles, courtesy of Google images

Cliff, Fisherman, getting a nurse shark set to measure

Cliff, Fisherman, getting a nurse shark set to measure

2.  Bull shark– These are one of the most aggressive sharks.  They have a high tolerance for low salinity.

Bianca, Scientist, taking a blood sample from a bull shark

Bianca, Scientist, taking a blood sample from a bull shark

bull shark

Bull shark

sandbar shark

Sandbar shark

3. Sandbar shark– These sharks are the most sought after species in the shark industry due to the large dorsal and pectoral fins.  The fins have large ceratotrichia that are among the most favored in the shark fin market.

4.  Atlantic sharpnose shark– The main identifying characteristic of this shark is white spots.

Atlantic sharpnose shark

Atlantic sharpnose shark

5.  Blacknose shark– Like the name portrays, this shark has black on its nose.  These sharks are called “baby lemons” in commercial fish industry because they can have a yellow hue to them.

blacknose shark

Blacknose shark

Me holding a blacknose shark

Me holding a blacknose shark

6.  Blacktip shark- An interesting fact about this shark is that even though it is named “blacktip,” it does not have a black tip on the anal finThe spinner shark, however, does have a black tip on its anal fin.

Jeff and Cliff getting a blacktip shark on board

Jeff and Cliff getting a blacktip shark on board

Tagging a blacktip shark

Tagging a blacktip shark

7. Smooth dogfish– Their teeth are flat because their diet consists of crustaceans, such as crabs and shrimp.

Travis, Scientist, weighing a smooth dogfish

Travis, Scientist, weighing a smooth dogfish

8. Tiger shark– Their teeth work like a can opener.  They are known for their stripes.

A large tiger shark got tangled in our line.  Notice the 2-3 foot sharpnose shark. The tiger shark is about 5 times larger!

A large tiger shark got tangled in our line. Notice the 2-3 foot sharpnose shark at the left. The tiger shark is about 5 times larger!

Me with a tiger shark

Me with a tiger shark

Daniel, Scientist, holding a tiger shark

Daniel, Scientist, holding a tiger shark

9.  Silky shark- Their skin is very smooth like silk.

Daniel, Scientist, holding a silky shark

Daniel, Scientist, holding a silky shark

Another thing I got to see was shark pups because one of the scientists on board, Bianca Prohaska, is studying the reproductive physiology of sharks, skates, and rays.  According to Bianca, there are 3 general modes of reproduction:

1.  oviparous–  Lays egg cases with a yolk (not live birth).  This includes some sharks and all skates.

2.  aplacental viviparous – Develops internally with only the yolk.  This includes rays and some sharks.  Rays also have a milky substance in addition to the yolk.  Some sharks are also oophagous, such as the salmon shark which is when the female provides unfertilized eggs to her growing pups for extra nutrition.  Other sharks, such as the sand tiger, have interuterine cannibalism (the pups eat each other until only 1 is left).

3. placental viviparous– Develop internally initially with a small amount of yolk, then get a placental attachment.  This includes some sharks.

Yet another thing that scientists look at is the content of the shark’s stomach. They do this to study the diet of the sharks.

Skate egg case, Courtesy of Google images

Example of oviparous- Skate egg case, Courtesy of Google images

Placental viviparous

Example of placental viviparous

Dogfish embryo, courtesy of Google images

Example of aplacental viviparous- Dogfish embryo, courtesy of Google images

Contents from the stomach of a smooth dogfish (flounder and squid)

Contents from the stomach of a smooth dogfish (flounder and squid)

Personal Log

Anyone who knows me realizes that I appreciate good food when I eat it.  Okay, on NOAA Ship Oregon II, I have not found just good food, I have found GREAT cuisine!   I am quite sure I have gained a few pounds, courtesy of our wonderful chefs, Walter and Paul.  They have spoiled us all week with shrimp, steak, prime rib, grilled chicken, homemade cinnamon rolls, turkey, dressing, mashed potatoes, and gravy, and the list goes on!   Just talking about it makes me hungry!

Walter is a Chef de Cuisine.  I want to share with you two of the wonderful things, and there are many more, he has prepared for us this week.  The first is called ceviche.  On our shift we caught some grouper.  Walter used these fish to make this wonderful dish.

Grouper used to make ceviche

Grouper used to make ceviche

In addition to the grouper, the ingredients he used were lemon juice, vinegar, onions, jalapeno, kosher salt, and pepper.  He mixed all the ingredients together.  The citric acid cooks the raw fish.  It has to be fresh fish in order to make it.  Instead of lemon juice, apple juice or orange juice can be substituted.  All I know is that since I arrived on NOAA Ship Oregon II, I heard from the entire crew about how great Walter’s ceviche was and it did not disappoint!

Walter, Chef de Cuisine, with his award winning ceviche

Walter, Chef de Cuisine, with his award winning ceviche

Walter's maccaroons

Walter’s macaroons

Another thing Walter is famous for on board NOAA Ship Oregon II are his macaroons.  These are NOT like ANY macaroons you have ever tasted.  These truly melt in your mouth.  Amazingly, he only has 4 ingredients in them: egg whites, powdered sugar, almond paste, and coconut flakes.  They are divine!!

On another note, I would like to give a shout out to my 5th grade students in Jay Upper Elementary School!  (I actually have not had the chance to meet them yet because I am here as a NOAA Teacher at Sea.  I would like to thank my former student, Samantha Morrison, who is substituting for me.  She is doing an outstanding job!!)

Dolphin swimming alongside the ship

Dolphin swimming alongside the ship

Jay 5th Grade:  I cannot wait to meet you!  Thank you for your questions!  We will have lots of discussions when I return about life at sea.  Several of you asked if I have been seasick.  Fortunately, I have not.  Also, you asked if I got to scuba dive.  Only the dive crew can scuba dive.  We are not allowed to have a swim call (go swimming) either.  As you can see, there is plenty to do on board!  Also, you may have noticed that I tried to include some pictures of me tagging some sharks.  Lastly, this dolphin picture was requested by you, too.  Dolphins LOVE to play in the ship’s wake so we see them every day.

Enjoy the view!

I LOVE the scenery out here!  I thought I’d share some of it with you today.

I thought these clouds looked like dragons. What do they look like to you?

I thought these clouds looked like dragons. What do they look like to you?

The vertical development of clouds out here is amazing!

The vertical development of clouds out here is amazing!

Starboard side at sunset

Starboard side at sunset

Sunset from the stern

Sunset from the stern

Sunset in the Gulf of Mexico aboard NOAA Ship Oregon II

Sunset in the Gulf of Mexico aboard NOAA Ship Oregon II

Sunset, port side

Sunset, port side