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Project Lab 

July 27, 2013

Western Screech Owl

A few weeks ago, Laura wrote about the importance of multiple research specimens in a museum collection.  This past weekend I prepared a juvenile Western Screech Owl (Megascops kennicottii) that is a good follow up to the previous blog post for two different reasons – the color morphs or variations and juvenile versus adult plumage.

 

In the case of the Collared Towhees mentioned in Laura’s blog post, plumage differences sometimes are as subtle as the width of color on the neck.  With other birds such as this Western Screech owl, sometimes the color difference can be a bit more extreme. Western Screech owls have a few different plumage variations that range from grayish to brownish depending on the location.

Slide1

If our collection were to only have a few specimens of Western Screech owl, the full range of these color morphs may not be represented.  It’s not always clear why some species show a variety of color throughout their range.  Perhaps it is due to environmental factors that allows birds to either stand out or blend in better.  Perhaps it’s a random genetic mutation that has just persisted over time and has no purpose.  We can’t always know the answer to these types of questions until more time has passed and our research collection can provide historical context.

 

We can also use this specimen to highlight the life stages of the Western Screech owl.  Juvenile plumage is often more subtle than their final adult colors.

Slide2

This provides the young birds camouflage at a time when they are more susceptible to predation.  The more this juvenile Western Screech owl looks like tree bark, the less likely it will be spotted by a hungry hawk.

 

Whether we know for sure the reasons why bird plumage can change over time or over geographic space, the research collection can provide a baseline that tells a story of how these birds have lived over long periods of time.  The more data provided, the more accurate the research will be and there’s never any shortage of questions and answers these study skins can provide.

 

Codie Otte

Curatorial Assistant and Specimen Preparator

Ornithology & Mammalogy Department


Filed under: Uncategorized — project_lab @ 10:06 am

July 18, 2013

Nudi Sex-Ed!

Today, I will discuss nudibranch sex! Nudibranchs are extremely colorful sea slugs whose ancestors lost their shells millions of years ago. “Nudi” in the name nudibranch refers to the loss of a shell. So they are more exposed and naked, than a sea snail, which has a shell. Unlike humans, which are either male or female, nudibranchs and other sea slugs are both! That is, they are hermaphrodites, possessing both male and female reproductive parts. You might ask, why on earth would you need to be both male and female? Well, sea slugs are typically slow moving and very small, so being both male and female increases the chances of finding a mate in the vast expanses of the ocean. When nudibranchs mate they fertilize each other and then both can lay eggs! To do this, they line up their genital pores, the openings on the right sides of their body, and then copulate.

 

Photo 1

 

Recently, it was discovered that the nudibranch, Goniobranchus reticulatus, detaches its penis after mating and regrows another in 24 hours! Scientists think this mating strategy has evolved so the sperm of rival nudibranchs stored in the vagina of their mate will not accidentally get passed on to future mates. Sea slug sex is very bizarre!

 

Photo 2

 

The male and female reproductive organs are adjacent to one another inside the slug’s body. The anatomy of the reproductive system varies between species. The female portion of the reproductive system in the slugs I study includes a vagina, receptaculum seminis, and glands that produce different components of the eggs. The receptaculum seminis, is a sac that stores sperm for prolonged periods of time. The male portion of the reproductive system includes the prostate, vas deferens, and ejaculatory duct. As you can see, some of the names for the parts of sea slug reproductive systems are the same as those for humans!

 

Photo 3

 

 

Photo 4

 

This concludes nudibranch sex-ed! Thanks for checking in!

 

Carissa Shipman

Graduate Assistant in Public Programs

Department of Invertebrate Zoology and Geology


Filed under: Uncategorized — project_lab @ 10:36 am

July 10, 2013

Why have collections?

One of the most common questions I get here is why we have so many individual specimens of the same species. It’s a valid question, considering that “collecting,” as far as personal collections go, involves obtaining individuals of a set. What we do here, however, is not like collecting baseball cards; we are essentially a library for researchers to reference when studying a particular organism. In order to have an effective sample size for a study, researchers must look at more than one individual of a species.

The way that we explain this to younger visitors when they come in to tour our collections is: if an alien came into your classroom and wanted to study humans but could only pick two of you as a representation of the entire human species, which ones should the alien take? The students quickly realize that, while they’re all the same species (Homo sapiens), no one person is the “ordinary” example of a human. It’s the same for all species.

If you were studying a bird species, such as a Towhee, would you prefer to look in a drawer like this:

photo1 copy

 

Or like this?

 

photo2 copy_sm

 

photo3 copy_sm copy

We clearly have a much larger collection of Collared Towhees than White-throated Towhees. Even though all of these Collared Towhees are the same species, it’s easy to see the variation between each individual. This is why we keep every specimen that is brought to us (given that we know where and what date it was found). Even if not in good enough condition to make a study skin, we can keep the skeleton, a wing, or even the entire specimen stored in ethanol. In fact, we prefer to not make study skins out of every single specimen, or else we wouldn’t have a broad variety of preparations. If a researcher was studying muscle attachments in birds, he/she would want to look at our collection of whole specimens in alcohol. Similarly, if a researcher was interested in studying the leg bones of weasels, he/she would use our skeletal collection instead of study skins.

This is what our collection is all about – having as many reference materials for researchers as possible. Consider how much of research these days relies on DNA and molecular analysis, yet museum curators had no idea about DNA back in the 1800s. Imagine what researchers may be able to do with our research collection 100 years from now that we don’t have a clue about today. It’s exciting to think about how these specimens will be used in the future!

The next time you visit a museum, think about all of the specimens that are kept in collections off of the main floor. While the main floor has a lot of educational material, scientific collections are necessary to further understand life around us.

Laura Wilkinson

Curatorial Assistant and Specimen Preparator

Ornithology & Mammalogy


Filed under: Uncategorized — project_lab @ 10:06 am

July 5, 2013

What do malacologists do on their days off?

Malacology- the study of mollusks (clams, squid, snails, etc.)

WSM opisthobranch symposiumwcap

An important part of being a scientist, is sharing your research with colleagues.  Last week, a few of us from our nudibranch lab took a break from lab and computer work to attend the Annual Meeting of the Western Society of Malacologists in San Diego.  The meeting consisted of three days of oral presentations and a poster session all based on mollusk-related research.  Some talks were about the history of the use of shelled mollusks for food, tools, and adornment. Other talks were about the change in the composition of mollusk species in certain areas over time, which can be heavily influenced by human settlement.  The whole second day of talks was devoted to sea slugs.  Both my labmate Carissa and I presented talks on our graduate research on nudibranchs and our advisor, Terry, presented on some new species of sea slugs (genus Philine).

 

A couple of the days (only one for me!), a bunch of us slugsters got up extra early (5AM!) to head out to the tidepools to see what kind of nudibranchs we could find.  We found several species of nudibranchs, including a few that I’ve never seen up here in the Bay Area.  Here are some of the species we encountered:

 Austraeolis stearnsi_1

Cadlina flavomaculata1

Limacia cockerelli_1

Doriopsilla gemela_1

F.porterae singlewcap

 

 

That’s all for now.  Till next time!

 

Vanessa Knutson

Graduate Student, IZG Dept

Project Lab Coordinator


Filed under: Uncategorized — project_lab @ 10:08 am

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