This weekend I got the chance to work on one of my favorite mammals: the Rock Hyrax. I’ve been intrigued by these bizarre mammals for quite some time, ever since I first saw one in a zoo when I was young.

Check out that cute face – what kind of mammal do you think it’s related to? A rodent? Maybe a rabbit? What about a Mustelid – the family that includes weasels and badgers? Let’s try to figure it out by looking at the skulls (one of the best ways to differentiate mammals). First, the Rock Hyrax:

It has teeth that look like they’re made for crushing, but also those two dagger-like incisors. Let’s compare it to a Muskrat (a type of rodent):

Now that’s a rodent skull if I’ve ever seen one – look at those incisors that are made for gnawing! Not too similar to that hyrax skull. What about a rabbit?

That looks totally different. As a side note, rabbits skulls are easy to distinguish because of a unique feature called rostral fenestration (circled above). If you see a skull with this feature, you know you’ve found a rabbit. Lastly, let’s look at a badger skull:

This skull is representative of a classic carnivore: sharp teeth useful for tearing up their prey. Again, doesn’t look like the hyrax.

If you compare the hyrax skull to these other three common mammals, you’ll notice that it doesn’t actually look like any of these species. It turns out that hyraxes aren’t related to any of these well-known North American mammals; they’re in a family of their own! In fact, they’re so unique that they’re in their own entire Order, called Hyracoidea. According to molecular data (analyzing the DNA), the closest living relatives to hyraxes aren’t what you might think:

That’s right - hyraxes’ most closely living relatives are elephants, along with manatees and dugongs, collectively with the hyrax known as Paenungulata. Pretty cool, right?

I always find it fascinating that molecular data can change the way we look at species. Something that may look like a rodent or mustelid turns out to be entirely different! Analyzing DNA is a big part of the research that’s currently done at the Academy – you’ve probably seen a researcher up in the Project Lab either working at the DNA extraction table or analyzing DNA sequences on our MacPro computer. Codie and I make sure to keep tissue samples from every specimen that we prepare exactly for this reason.

If you ever have a chance to see a hyrax either in a zoo or if you’re lucky enough to travel in Africa, remember that looks can be deceiving!

Laura Wilson

Curatorial Assistant

Ornithology & Mammalogy

Last time we sorted out the difference between sea cucumbers and nudibranchs and now it’s time to mention another nudibranch imposter. This one is a real trickster. Even I’ve been fooled by these on occasion, at least at first. So who are these tricky nudi imposters? Flatworms. Many species of polyclad flatworms are excellent mimics of nudibranchs.

There are three main reasons why I think these can be so difficult to tell apart from nudibranchs:

• Since flatworms are flattened in shape, they often look like nudibranchs from far away.
• Many of the color patterns of these flatworms match the color patterns of different species of nudibranchs, nearly perfectly.
• Often, the edge of these flatworms is rolled up in two spots on one end of the worm and this mimics rhinophores (nudibranch sensory organs) really well. So if you are looking for rhinophores and see these rolled up structures, you may get fooled without a closer look.

My best advice for distinguishing between a nudibranch and a flatworm imposter is to first look for gills.  Though not all nudibranchs have gills located externally on their backs, many do.  My second piece of advice is to look very closely at what appear to be the rhinophores. If it looks as though this is just the edge of the animal rolled up, you are likely looking at a flatworm and not a nudibranch.

It’s been fun explaining some of the differences between nudibranchs and some of the animals that look like them.  I’ve actually been reviewing various kinds of nudibranchs and other sea slugs myself.  The reason for this is that in a few weeks I will be heading to Papua New Guinea as a part of an expedition to the Madang Province- Our Planet Reviewed’ Initiative, Papua New Guinea 2012-2103 Expedition.

The next time you hear from me, I’m going to be up to my gills in fieldwork- collecting, photographing and identifying sea slugs for 6 weeks!  I will be blogging from the field right here at the Project Lab blog, so stay tuned!

Vanessa Knutson

Project Lab Coordinator

Graduate Student

Invertebrate Zoology and Geology

Since the beginning of life on earth, it is believed that 95% of all the species that have ever existed have become extinct. Biologists today are observing an unprecedented increase in the rate of extinctions, especially since the beginning of the industrial age and the expansion of human populations. It appears that human activities are responsible, either directly or indirectly for much of this, due to habitat loss, invasive species, pollution and global warming. These issues have been brought about by urbanization, industrialization, globalization and an ever-increasing human population.

Sadly, San Francisco can boast of having the first known species of insect in North America to go extinct due to human disturbance, the Xerces Blue Butterfly, Glaucopsyche xerces.

First described in 1852, the Xerces Blue is a member of the Lycaenidae (gossamer-winged butterflies), the world’s second largest family of butterflies. Their food plants are legumes in the genera Lotus and Lupinus, and the larvae were known to have a relationship with ants, in which the ants helped tend the larvae. The range of this species was small, found in the sand dune habitats around the Sunset District of our city. The last known specimens were collected in 1943, and some specimens reside in our collection.

Though the exact reason or reasons for their loss remain unknown, habitat loss certainly played a part in their demise, as the dunes and vacant lots where they were found disappeared to development. Another possible reason was the introduction of the Argentine Ant, which may have displaced the species with which the larvae were associated with. Argentine Ants are now the most commonly found ant in the Bay Area, and are not known to have any association with butterfly larvae.

In 1971, the Xerces Society for Invertebrate Conservation was founded as a non-profit organization dedicated to the conservation and protection of invertebrate species in the United States.

Sadly, the Xerces Blue is not the only butterfly of San Francisco to go extinct, and I will explore these in future blogs.

Until next time,

Vic Smith

Curatorial Assistant in Entomology, and Imaging Specialist at the Project Lab

Two weeks ago in our Project Lab blog, Laura spoke about masceration and briefly touched on the role dermestid beetles play in skeletonizing specimens for the O&M department. Working with the beetles is one of my favorite aspects of my job here at the Academy and I thought I would go into a bit more detail regarding our wonderful, interesting dermestid colony!

Dermestid beetles (family Dermestidae) are a large group of scavenger beetles that feed on a variety of organic materials from hair to skin to dead flesh. Dermestids can be found on carcasses almost anywhere in the world! Taxidermists and scientific preparators have long used these beetles to help quickly and efficiently clean bones of flesh because the beetles do most of the work for us! Out in the O&M Bones Lab, we use a colony of Dermestes maculatus, a small black beetle with a white ventral side, to help prepare skeletons for the research collection.

Dermestids are perfect for terrarium life as the right hand “man” of the preparator. Although capable of flight, our Dermestes maculatus don’t take to wing unless they get too hot, so we keep our terrarium case pleasantly warm to keep the beetles happy just strolling around. This makes opening and closing their case much easier and prevents beetles from escaping and munching on other specimens. They also require little care aside from feeding and the occasional spritz of water. The work they do for our department vastly outweighs their salary (all paid in food!).

The first step in skeletonizing a specimen is to remove most of the flesh off the animal, leaving only a small amount of muscle on the bones. Up in the Project Lab, you can find O&M staff and volunteers regularly skeletonizing specimens for our research collection. Once the muscle has been removed, it is time for the dermestid colony to begin their work.

A large colony will be able to strip a small bird clean in just a few days! Dermestid beetles are excellent for cleaning small, delicate skeletons like fragile passerine birds and tiny mammals, and also juvenile species whose bones have not yet fused. Sometimes with water masceration (as described by Laura in her previous post), skeletons can fall apart from being submerged in liquid for long periods of time. In contrast, the dermestid beetles will eat the flesh off the bones and generally keep the skeleton articulated and this can be preferable for some specimens to prevent important sutures from falling apart.

Once cleaned by the dermestids, the skeleton will be brightened and degreased and then integrated into our collection, ready to be used by a curious researcher… maybe you!

Codie Otte
Curatorial Assistant and Specimen Preparator
Ornithology & Mammalogy Department

Taxonomy entails the description, naming, and classification of living things. Why is taxonomy so important? Well, it helps us categorize organisms so we can more easily communicate biological information. Taxonomy uses hierarchical classification as a way to help scientists understand and organize the diversity of life on our planet. Hierarchical classification basically means that we classify groups within larger groups.

The basic hierarchy of classification is described below for the sea slugs I study in the Project Lab. This listing is an oversimplification of hierarchical classification since there are categories between those shown.  The hierarchical names of organisms reflect the general physical attributes of the organisms placed within these groupings.   For example, all of the animals within the Mollusca share the feature of being soft-bodied.

You may have heard of scientific names before, and perhaps you noticed that they contain two parts. Scientific names of organisms include the genus followed by the species name.  An example of a species within the sea slug family I am researching is Doto ussi.  Taxonomy is important since other scientific disciplines like conservation and drug discovery hinge on organisms being classified and named.

Prior to being able to sequence DNA, organisms were described and categorized solely by their distinct morphologies (physical characteristics) and ecological roles.  The ability to sequence DNA has revealed a great deal more about where an organism belongs taxonomically and helps pinpoint new species.  DNA is now used alongside morphology and ecology to substantiate an organism’s distinctiveness in the biological world.

A component of my graduate project is looking at the DNA of Doto sea slugs of two different morphologies from the Indo-Pacific. These morphologies include specimens with a short body and elongate body from Indonesia, Papua New Guinea, and the Philippines. Prior to in-depth study, these elongate individuals were placed within the sea slug family Dotidae, despite their unique appearance.

DNA sequences from these individuals will be compared to those of the short bodied to determine if these elongate specimens should in fact stay within the Dotidae. We do not really know where these specimens belong taxonomically, since they are new to science. This is very exciting since a new genus or family may need to be created to accommodate these individuals. It is discoveries like this that make science so rewarding and fun! DNA has truly changed how we do science and has made the classification of organisms more concrete.

Carissa Shipman

Masters Student

Invertebrate Zoology & Geology Department

Do you know how many bones a bird has? What about a cat? A shrew?

Honestly, neither do I. It would be rather painstaking to count each bone, especially since it varies among species. All I know is that there are a LOT!

If you’ve been by the Project Lab, you’ve likely seen myself or Codie (or maybe one of our wonderful volunteers) working on preparing study skins. Have you ever wondered what we do when we want to keep the skeletons of these animals?

Depending on the condition of the specimen and the rarity of the species, we can either choose to make both a study skin and what is called a “partial skeleton,” or a full skeleton. Study skins still have a few bones left in them for structure (feet in mammals and skull, wings, legs and feet in birds), so if we want to keep both the skin and a skeleton, the skeleton wouldn’t be complete. If a specimen comes to us too damaged to make a nice skin, we can strip away as much of the meat as possible and keep just the bones. From there, we do one of two things in order to clean off all of the muscle: macerate it or give it to our colony of dermestid beetles.

Maceration is the process of rotting the tissue off of the bones in water. Sound disgusting? It absolutely is, but it does the trick! We simply place the body of the animal, with as much muscle removed as possible, in a container filled with warm water and let it soak for a couple of weeks. After a few series of rinses with clean water, we have a beautiful skeleton! You can see a clean skeleton going through its last soak here:

Admittedly, the cooler way to clean these skeletons is with our dermestid beetle colony. These are flesh-eating beetles that, luckily for us, only feed on dead flesh. We don’t have to worry about them munching on us when we add carcasses to their tanks! A few weeks with the beetles and our skeletons come out nice and clean. Here are two rodent skeletons that are almost ready to be taken out from the dermestids:

Both maceration and our beetle colony allow us to prepare skeletons without the use of harsh chemicals that may damage the bone over time. Now “dem bones” are clean and will remain in our collection for hundreds of years!

Laura Wilson

Curatorial Assistant

Department of Ornithology & Mammalogy

I recently started working in the Project Lab here at the California Academy of Sciences and one of my favorite aspects of working in here is sharing my research with museum visitors. Many visitors do not realize that the Academy is a place of active scientific research. We have researchers studying everything from viruses to plants to spiders and everything in between, including some enigmatic creatures that you may have never even heard of before… sea slugs.

I can’t quite pinpoint how or when I first learned about sea slugs— it may have been an IMAX movie, or it may have resulted from having a dive buddy who was an underwater photographer and sea slug junkie. Whatever it was, little did I know that my fate was tied to these amazing animals.

Today I find myself in a master’s program working on sea slugs, and my research project fills most of my days and many of my nights and dreams as well. I realize that not everyone knows what sea slugs are, so I’d like to do a little bit of explaining.

On September 1^st of this year, Entomology Curator Emeritus Dr. Edward S. Ross will turn a young 97 years old! Ed started his Academy career in 1939, and became Curator Emeritus in 1980. As I was photographing spider type specimens, I came upon a specimen collected by Ed in Berkeley in 1936!

For the past 60 years or so, Ed has traveled the globe as a major explorer and collector, visiting and collecting in the Americas, Africa, India, Asia, Australia, the Philippines, the Middle East and tropical Pacific Islands.

Ed is the world’s foremost authority on the little-studied group of insects known as embiids or webspinners, primitive insects that spin silk for their nests from glands in their front legs.  He has collected thousands of these insects for study, often raising them live in culture to better study their life habits. Ed is also a world-renowned photographer, pioneering in insect macrophotography since the 1950s. He has documented his world travels, photographing insects, wildlife, amazing scenery and fascinating portraits of people, many of which have been published in National Geographic and other magazines, textbooks and publications, including children’s books.

Ed’s knowledge of insects and their behavior is amazing, and he has inspired many budding entomologists and students. The Academy Board President and entomologist John Hafernik once served as teaching assistant to Ed when he taught entomology at UC Berkeley.

In my role as curatorial assistant and imaging specialist here at the Academy, I access many areas of our entomology collection to prepare loans for researchers and to produce images for our databases and publications. I am often amazed at the number of specimens of all types of insects, spiders, scorpions and other invertebrates in our collection listing Ed as the collector. Some estimates are that he may be responsible for up to 1/3 of the 13 million insects in our collection!

While Ed is no longer actively collecting, he continues to work on producing books and publications, and continues his research on embiids.

Happy Birthday Ed, and many returns!

Until next time,

Vic Smith,

Curatorial Assistant/Imaging Specialist

Marine natural products research and its application to pharmacology is a relatively new scientific discipline. The biomedical potential of marine chemicals is infinite since much of the life in the oceans has yet to be uncovered and the compounds within most known marine organisms still require investigation.

The chemicals originating from marine life are valuable since their unique structures can be applied differently than those discovered from terrestrial organisms, like plants. The increased discovery of marine novel compounds indicates that research in this field is a worthwhile investment. Papers are published each year on the description, synthesis, and economic value or biomedical significance of marine natural products. Marine compounds can be utilized as probes to study cellular and biochemical processes at the molecular level and possess therapeutic value for treating certain diseases like cancer and AIDS.

Sponges, algae, and bryozoans among many other marine organisms are important sources for chemicals toxic to numerous mouse, rat, and human cancer cells. For instance, the sponge Dercitus sp., found in the deep-waters of the Bahamas, harbors the compound dercitin. Dercitin was found to prolong the life of mice with leukemia tumors and is active against melanoma and small cell Lewis lung carcinoma. Dercitin may work by halting the replication of DNA within cancer cells. A second example comes from the Caribbean seaweed, Stypopodium zonale. S. zonale contains stypoldione, which disrupts the cell cycle by inhibiting the formation of the spindle. Further, Amathia convoluta, a bryozoan, possesses convolutamide A, a compound which has been successful in treating mouse leukemia and human epidermoid carcinoma cells.

The diverse capabilities of marine slugs to synthesize and seize defensive compounds from their food renders them as a valuable resource for the extraction of anticancer agents. Opisthobranchs, marine slugs, feed on an assortment of marine organisms; including sponge, algae, and bryozoan, from which they acquire or synthesize secondary metabolites to prevent predation. Their extraordinary ability to incorporate and build new toxic compounds from food has lead to the reduction, internalization, or loss of a protective shell. Anticancer compounds have been discovered from many marine slugs including Hexabranchus sanguineus, Jorunna funebris, and Elysia ornata.

Systematics, taxonomy, and the study of natural products are intricately woven together. The names of natural products originate from the scientific names of the organisms from which they are obtained. Studying the evolutionary relationships of marine organisms can be utilized as a tool to pinpoint new species, which may contain useful chemicals for drug discovery. This emphasizes the importance of taxonomy and systematics to other science disciplines such as biochemistry.

The discovery of valuable chemicals within marine organisms highlights the importance of the ocean to human lives. Protection and conservation of vulnerable marine ecosystems, like coral reefs, is paramount since the cure for cancer, AIDS, and other diseases could be discovered from life inhabiting these underwater jungles.

Carissa Shipman
Masters Student
Invertebrate Zoology & Geology Department

You may think your last Karaoke session sounded great, but we’ve got nothing compared to the natural ability birds have to sing from early on in life. Birds use sound to attract a mate, defend their territory, sound a danger alarm to nearby birds and communicate with their mate, young and flock members. Although most birds will sing one song for their entire life, some species of birds such as parrots, starlings and some songbirds can incorporate new sounds into the repertoire over time.  This week in the Project Lab I prepared a Zebra Finch, a species that has been studied for their vocalizations.

Young male Zebra Finch (Taeniopygia guttata) learn their song from a father or mentor.   Without this guidance, the Zebra Finch can have a song that sounds very different from the typical melody heard in most Zebra Finches.  The brains of the young males need to process their mentor’s song at a specific age to make the connection between their own sounds and the song they will need to learn to attract a mate.  The resulting song is the song of their mentor plus a few notes acquired from random environmental noises.  Many researchers use these Finches and the neurological pathways that are used to learn their specific song to study acquisition of speech in humans.  Although these little birds can be studied for their human applications, bird song can also be used in systematics.

In some bird songs there are distinct differences in vocalizations between populations.  Researching these differences in bird songs can help identify and discover subspecies or genetic lineages.  Many researchers use the Ornithology and Mammalogy research collection to collect genetic and morphological data for their studies. Using this in conjunction with audio recordings, researchers are able to better address their research goals.

Codie Otte
Curatorial Assistant and Specimen Preparator
Ornithology & Mammalogy Department