Monday, November 26, 2018

Giant Snails: The Hawaiian Tiger Cowry

            If you have ever been to the observation tanks at the Hawaii Institute of Marine Biology, you may have noticed the large ovoid shells along the walls or hiding under the coral heads.  These majestic creatures are Tiger cowries, Cypraea tigris.1 a large sea snail under the phylum of Mollusca, and over the past two years I have been using them as model organisms to examine the palatability and chemical defenses of sponges found throughout Kaneohe bay.  Yes, these snails are actually nocturnal predators that feed on sponges, very frequently found eating the invasive orange keyhole sponge, Mycale grandis, and they are quite peculiar organisms.

            Tiger cowries fall under the class Gastropoda, translating to head-foot, and although that pink region may look like a mouth, it’s actually its foot!.  As a matter of fact, their mouth can be found in the fleshy cavity between the two antennae that are the main sensory organ used for detecting food by smell and touch.  Tiger cowry mouths consist of a fleshy orifice called a proboscis, containing a scraping conveyor belt structure, a radula, which scrapes off sponge tissue that feeds into its digestive tract.  The spore-like whiskers that look like frosted dreads of the cowry are called papillae, and they are apart of the mantle. The mantle are two tissue layers that secrete calcium carbonate crystals to create, repair, and maintain its finely polished shell.

Tiger Cowry with Brown Mantle
Tiger Cowry with Green Mantle
          Tiger cowry shells can range from white to black, but are usually white, yellowish, or light blue green, with dark brown to black spots. Some researchers postulate that the patterns found on the tiger cowrie shells are determined by the patterns found on the mantle while other research has found a correlation between the density of spot pigments with shell size, as a shell grows larger, the dark spots are spread out, the space between being white.2 Although one could be fascinated by the beautiful design of these shells, I want to draw attention to its size.  Not only are they the largest cowries I have observed throughout Hawaii, but I have come to find that Hawaiian tiger cowries are not like other cowries found throughout the rest of the world.

          Tiger cowries can be found throughout the Indo-Pacific Ocean, off the coasts of Japan, Singapore, Australia, Polynesia, and Hawaii.  Although the average shell size of tiger cowries ranges from 6-9 cm, the average size of Hawaiian tiger cowries is 11-12 cm, the largest size observed size is 16 cm.  This size discrepancy is one of the main features that This is incredibly peculiar, as the environmental or physiological pressures in Hawaii that would influence the size of these cowries to increase.  Could it possibly be due to lack of predators and an abundance of food driving?  Tiger cowries in Hawaii illustrate a 50% size increase from their Indo-pacific counterparts, so would this be considered as tropical, or even endemic, gigantism? One may even hypothesize that the tiger cowries found in Hawaii have significant genetic differences from their Indo-Pacific counterparts that they could be classified as a subspecies C. tigris schilderiana.3
Left = Hawaiian Tiger Cowrie (11cm length)
Right = Tiger Cowrie from Indo-Pacific (7 cm length)

-Andrew Osberg

  1. Linnaeus, C. Systema naturae per regna tria naturae: secundum classes, odines, genera, species, cum characteribus, differentiis, synonymis, locis. 10th edition ed. Stockholm: Laurentius Salvius
  2. Reid, C.E. Comparison of shell pigmentation and size in Cypraea tigris.  Accessed: November 26, 2018.
  3. MolluscaBase (2018). Cypraea tigris schilderiana C. N. Cate, 1961. Accessed through: World Register of Marine Species at: on 2018-11-26

Thursday, October 25, 2018

NOAA OE Teachers Workshop

Aloha Everyone,
    This past weekend the Community Education Program hosted our 10th annual NOAA OE Teachers Workshop here at the Hawai‘i Institute of Marine Biology. We had 16 visiting educators join us Saturday October 13, in the Makers Lab.
     Kicking us off with on mysterious depths of the ocean, Mark Heckman explained "why we explore" and the significance of methane hydrates. He guided us through “Exploring the Deep Ocean with NOAA”with a hands-on module where teachers create methane hydrate models with toothpicks and candy. Pictured is the a activity of the successfully created models!

      CEP Educator Andrew Osberg guided teachers  through “Invent a Robot."  ROVs are essential in deep ocean exploration for gathering high quality imagery and samples.  Teams were able to build their engineering design skills and by fashioning innovative ROV arms that could successfully pick up a cup of water, using only scratch cardboard pieces.  These teams also compared the efficiency between hydraulic and pneumatic systems.
     We also had the privilege of having guest lecturer Joyce Miller, the 'Queen of Multi-beam' unravel her work with multi-beam technology from several research vessels.
Image from:


     The group wrapped up with water column investigations on the Oceanographic Yo-Yos which introduced teachers to the CTD module. A CTD is water column exploration technology that includes a package of electronic devices that measure conductivity, temperature, depth and collect water samples. With simple tools like pH strips, thermometers and vinegar, students are able to recreate open ocean research in a classroom.
     There are many more lesson plans and our educators got to go home with the educator goodie bags! Join the Oceania for opportunities such as this. We hope to see you next time!

Thursday, August 30, 2018

See you soon!

Aloha Everyone! 💥

Today is my last day here at HIMB for my internship this summer, as I will make my way back to Massachusetts and Smith College. I have had a fantastic time here over the past few months, and I am so grateful to have had the opportunity to be a part of our CEP team. Over my time here, I have met many wonderful people who have always been so caring, friendly and inviting to someone far from home like me! I have had the opportunity to run and help with many tours, labs, and an overnight, as well as work on a few different projects, such as creating new signage for our touch tanks and new cue cards for our walking tours. Just the other day I created a worksheet for our labs and classes that will be put into use soon. I have been out almost every day cleaning the touch tanks, one of my favorite activities here since I get to spend time with some of our lovely creatures. Overall, this has been a wonderful experience that I will look back on and cherish. But I won't be gone too long, as I plan on coming to visit this winter, and perhaps running some more tours then!

See you soon,

Ginny Svec 😄
CEP Intern

Wednesday, August 29, 2018

Pacific Portuguese Man-of-War

Aloha everyone!

On a three-day-program with students from Beijing this past month, much of the Community Education Program team was snorkeling on the sand bar, when I had to bring one cold student back to our boat. On my way back to the other snorkelers, I got caught in the long tentacle of a Pacific Portuguese Man-of-War (Physalia utriculus /pa'imalau)!

A Pacific Portuguese Man-of-War swimming in Hawaiian waters.
Its float and some of its medusae are visible,
with the longer fishing tentacle drifting further below the picture.
Photo by
Pacific Portuguese Men-of-War, otherwise known as bluebottles, belong to the phylum Cnidaria, meaning that they have a stomach and mouth, radially symmetric curved bodies which open at one end, and tentacles covered in stingers or nematocysts. These nematocysts help cnidarians to be able to eat and protect themselves. A cnidarian can either be in the form of a polyp or a medusa, where the polyp is attached to a surface with its mouth pointing upwards (i.e. an anemone or a coral) and the medusa form faces down and is free-swimming (i.e. a jellyfish). A Man-of-War is in the medusa form of a cnidarian since it faces downwards as shown on the right.

Though many people refer to these gelatinous creatures as jellyfish, they actually belong to the class Hydrozoa, unlike true jellyfishes which are as scyphozoans and cubozoans. Hydrozoa create their medusae through budding, or asexual reproduction through the creation and cleavage of a clone on the hydrozoan. Syphozoa on the other hand, use strobillation, or the spontaneous segmentation of  their bodies to be able to create their medusae, while Cubozoa polyps metamorphose to become medusae.

The Pacific Portuguese Man-of-War belongs to the order Siphonophora within the class Hydrozoa. Typically, these open-water or pelagic animals use their floats (the puffy-looking polyp above the tentacles and medusae) in order to rise and sink in the water column. They can do this by altering the amount of gas or oil within their floats, or by swimming. Unlike other hydrozoans, the Man-of-War stays at the surface, using its carbon monoxide-filled float to keep it above the water, with a crest to help it move with the wind. Though cnidarians can be either solitary or colonial, and the Man-of-War may look like one solitary animal such as a jellyfish, they are actually made up of many medusae and polyps, which bud from the original polyp (the float) as mentioned above, and attach to it to form a colony. The medusae hanging below the float can also help with propulsion through the water, and each perform specialized tasks such as digestion, fishing, and sexual reproduction via eggs and sperm. A single tentacle extends down into the water column, paralyzing or killing its prey before contracting to feed itself. Check out how these animals move in the videos linked below:

An image of a Man-of-War's float with its
long tentacles trailing behind it.
Photo by Arina Habich.
A picture of me after I got stung. You may be able to
see the red mark from the right side of my mouth across 
my upper lip, and up to where I am pointing on my cheek.
The tentacle got caught around my snorkeling mask!
Photo by me.

Since these creatures are a dark blue or even purple color, they are difficult to spot in the water, until it is too late. Your best chance of seeing one before it stings you is by looking for its float above the surface of the water. If you do happen to get stung, however, recent research by UH suggests that vinegar works well at stopping cnidae discharge which causes the stinging. Other methods of stopping stinging such as alcohols, urine, shaving cream and baking soda actually caused cnidae discharge and did not stop it from happening. This means that these methods which were previously thought to be a better method for stopping Man-of-War stings do not seem to help at all, and may actually harm you more!

After being stung, the burning for me personally lasted about an hour until it was completely gone. However, I had been touching it before I knew not to do that, and instead to rinse with salt water and vinegar. Some people and sources seem to suggest that this feeling will only last for about 20 minutes, while others say that they had pain and red marks in those areas for about a week! I suppose that everyone's pain tolerance is different, and some people may have sensitive skin or allergies as well. For me, though, the pain just felt like a very bad razor burn.

An image showing the relative size of a Pacific Portuguese Man-of-War compared to a person's foot. That thin tentacle is what wrapped around my snorkeling goggles, stinging me across the face. Even though these creatures are fairly small compared to us, their sting sure packs a punch!
Photo by

Fortunately I got stung by the Pacific Portuguese Man-of-War, which can have a float of about 1 to 2 inches in length and a long tentacle below, instead of the Atlantic version which can have a float up to a foot long, with many fishing tentacles up to 30 feet long! Though I was the only person to get stung out of our snorkeling group, some of our other staff members noticed a cloud of Men-of-War floating towards the school group on their way back to the boat after I had been stung, since it was such a windy day. It looks like this intern took one for the team!

Mahalo nui,

Ginny Svec
Our group of students snorkeling with one of our CEP staff members, Kyla. A short distance away was where all of the Men-of-War were swimming.
Photo by Leon Weaver.

Bouillon, Jean, et al. An Introduction to Hydrozoa. Publications Scientifiques Du Muséum, 2006.

Hoover, John P. Hawai'i's Sea Creatures: a Guide to Hawai'i's Marine Invertebrates. Mutual Pub., 1999.

Wilcox, Christie L., et al. “Assessing the Efficacy of First-Aid Measures in Physalia Sp. Envenomation, Using Solution- and Blood Agarose-Based Models.” MDPI, Multidisciplinary Digital Publishing Institute, 26 Apr. 2017.

Friday, July 13, 2018

New Website


A new website has recently been created for HIMB. There, you can find resources needed to learn more about us, such as our contact information, the various visiting programs that we offer as well as their costs, and more. This site is still being updated and more from the old website will be available soon, so make sure to be on the lookout for updates. This blog will still be maintained, and there is even a link for it on the new website! Click here to visit our new site.

Moku o Lo'e from a bird's-eye view. Images from HIMB blog.
Mahalo nui!


Thursday, July 12, 2018

New intern in the HIMB Community Education Program: Ginny

Aloha everyone!

Me in our office at HIMB
In Leverett, Massachusetts
with the Mt. Toby mudslide rock
formation behind me
My name is Ginny Svec and I'm a new intern here in the HIMB Community Education Program until the end of August. I'm from Westfield, Massachusetts near Springfield, and I'm going to be a junior at Smith College in Northampton, Massachusetts this upcoming fall. At Smith, I'm majoring in environmental geology, minoring in marine science and policy, and considering a concentration in climate change. I have always had a love of the ocean and beaches, and in the future, I would like to pursue a career in oceanography of some sort. Since I've mainly been focusing on the geological side of things for the past few years at school, I think that this internship will be a great opportunity for me to learn more about the biology of the marine world. I'm also excited to be orienting myself a bit better with the interesting geological and anthropological histories of Moku o Lo'e, O'ahu and the Hawaiian Islands as a whole.

 I'm so grateful that I have been given the opportunity to be a part of  this state-of-the-art research institute. Over the past few days of being here, I realize just how much I'm going to be learning from this experience, and I am ready and excited to do just that. I'm currently learning about the layout and history of the island, as well as the biota present in Hawai'i, and the research being performed at HIMB. Soon I will be giving tours to convey all of the interesting information that I've learned here to the public. I can't wait to start giving tours and learning as much as I can during my internship here on Moku o Lo'e!



Wednesday, November 8, 2017

SOEST Open House at UH Mānoa


Another successful Open House here in beautiful Hawai’i Nei.

 This year the Community Education Program had a very popular interactive booth with a splash pool with the theme – “Cool the Oceans!” Our table focused on how climate change is warming the oceans, how HIMB research is helping find solutions, and how the students have 5 simple ways they can help make a difference in the coming years. Once a group went through our questions and answers one brave volunteer would get to sit the SPLASH SEAT while others pulled a cord and poured cold water on their head, draining down to cool the blue ocean pool!

The 5 R’s!
1. Refuse
2. Reduce
3. Reuse
4. Recycle
     and our newly added category for HIMB

It is estimated that we are able to reach over 600 students over the two days. One student was so excited, he brought his mom back on Saturday to visit us again. Thanks to Leon, Mike C., Brenda, Joyce, Sherine, as well as our newest member Kyla for helping out!


Mahalo Nui,