Crystal Davis, Female, Male? How do you tell? July 2, 2014


Common Octopus

This Common Octopus was found in a 7-Up can.

NOAA Teacher at Sea The fish board that measures the length of marine organisms

Crystal Davis

Aboard NOAA ship Oregon II

June 23-July 7, 2014

Mission: SEAMAP Groundfish Survey

Geographical area of cruise: Gulf of Mexico

Date: Wednesday July 2, 2014

Weather: Clear and sunny with isolated showers and thunderstorms

Winds:   5-10 knots

Waves:   2-3 feet

Science and Technology Log:

Shortly after boarding the Oregon II, the science crew had orientation with the Operations Officer LTJG Thomas reviewing  basic procedures for emergencies on board. But what stuck out for me the most, was when Operations Officer LTJG Thomas said we were on a S.A.D. boat. It turns out that S.A.D. means no sex, alcohol or drugs are allowed on the Oregon II. This ensures that the boat is safe and reduces the number of accidents on board. This is the opposite of SAD and makes me feel much safer on board. But luckily for KISS fans, rock and roll is still allowed and is on consistently. Sometimes there’s so much rocking and rolling that I fall on the floor, but that’s happening less frequently as I’ve found my sea legs.

In the Groundfish Survey, after the organisms are separated by species, they are sexed. Overall, this gives the scientists an idea of what future generations will look like. Although all the organisms vary in the way you differentiate their gender, the following are some of the most common organisms found in the groundfish survey.

Sexing Shrimp

Brown Shrimp Female (top) Male (bottom)

Paneaus Aztecas Shrimp Female (top) Male (bottom)

As shown in the pictures on the left, male shrimp have a set of claspers (they look like an extra set of legs) called the petasma that is the equivalent of a penis. Females do not have a petasma.

In young (juvenile) shrimp, it can be difficult to identify the males from females as the petasma is very small and not easily visible. At this age they can easily be confused for females. When this is suspected, they are input into the computer as unknown so as not to generate inaccurate data.

Sexing Crabs

When you pick up a crab you have to be very careful to stay away their claws (cheliped). I have found that they like to grab onto you as soon as you pick them up. My roommate had a large blue crab grab her finger that would not let go and she still has bruises from it.

Shame Faced Crab

Shame Faced Crab

Mature female crabs are called a “Sook” and have a dome or bell shaped abdomen.  This is shown in the top row and looks like the U.S. Capitol Building.

Male crabs are called a “Jimmy” and have a T-shaped abdomen that looks like the shape of the Washington Monument.

To mate, the male crab will carry the female until her shell softens and she is able to mate. During mating, the female stores the males sperm to fertilize her eggs later. Once her shell hardens, the male releases her and she will fertilize her eggs later.

Female Lesser Blue Crab with eggs

Female Lesser Blue Crab with eggs

After fertilization, the eggs are stored outside the female’s abdominal area and look like a sponge. They’re very squishy when you touch them. Although this shows orange eggs, they can also be a gray or black color. I have been told that the darker the egg color, the closer to hatching the offspring are. I am not sure that this is scientifically valid and am still trying to verify this.

 

 

 

Sexing Flatfish

Photos courtesy of Robin Gropp

Photos courtesy of Robin Gropp

Flatfish include fish such as flounder, halibut and turbot. These fish begin their life swimming vertically in the water. However, as they get older they sink to the bottom and their eyes move to one side of their body. They then spend the rest of their life on the bottom of the ocean floor. Luckily their top half matches the ocean floor and they are easily camouflaged from predators. The bottom half of the flounder on the ocean floor is clear or white.

The easiest way to sex a flatfish is to hold them up to a bright light. When doing this you will see that the female has a long curved gonad while the male does not.

A Confused Flounder

A Confused Flounder (right) Normal Flounder (bottom left)

This Flounder is very confused. He should be a clear or light white on the bottom but as you can see his bottom half matches his top half. This could be due to a mutation but no one on the boat is exactly sure why he looks this way. This is one of the most interesting things I have seen so far. In fact, no one on the boat had seen this before.

 

 

 

 

Sea Jellies

Sea Jellies

Sea Jellies

Sea Jellies differ from most of the other marine organisms discussed so far. Sea jellies reproduce both sexually and asexually depending on what stage of life they are in. In an early stage of life sea jellies are called a polyp and they attach to a rock. The polyps reproduce asexually by cloning themselves and breaking off (budding). Imagine 300 people that came from you and look exactly like you. It’s actually pretty creepy.  But back to the sea jellies. Eventually the sea jelly will develop into an adult (medusa) that reproduces sexually with sperm and egg.

 

Personal Log:

I have a three day backpacking trip to Mt. Silliman scheduled almost immediately after my NOAA trip is over. Under normal circumstances I wouldn’t worry, but after spending two weeks not hiking or training, I’m a little concerned. Luckily there are weights and a rowing and elliptical machine on board, so I have been able to do a bit of training. Being on a ship that’s moving has made working out even more intense. I have to stabilize every time the boat moves, so I don’t fall over. But even if I did, or have, how could I complain with this view.

Boat Personnel of the Day

Holland waiting for a trawl to come in

Holland on the stern

Holland McCandless-Lamier

Holland is my roommate on the Oregon II and is a member of the scientific party. She was contracted by Riverside in response to the Deep Water Horizon (BP) blowout in 2010. She attended the University of Mississippi and majored in marine biology. During college, Holland had an internship in Florida where she led students (from 4th grade to college) in marine science activities. This included snorkeling, visiting coral reefs and other hands on activities.

After college, Holland met an individual from the NOAA Corps at a job fair. They put her in touch with NOAA FIsheries MSLabs Groundfish Unit, where she began volunteering as a participant on surveys. This hands on experience led to her current job. Holland currently spends most of her time in the NOAA South East Fishery Science Center (SEFSC) Pascagoula lab where she works with plankton. Her current project is updating decapod (crustacean) taxonomy.

Did You Know?

A female sunfish can lay 300 million eggs each year. Each egg is smaller than the period at the end of this sentence.

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