Thursday, August 20, 2015

Mantis Shrimp

Mantis Shrimp

If you have ever had the opportunity to take part in one of our algae labs, there is a very good chance that you have encountered the mantis shrimp. The name ‘mantis shrimp’ is derived from the terrestrial praying mantis. Like the praying mantis, the mantis shrimp keeps its front arms folded up like a jackknife, ready to strike at any moment. Hawaii has 17 known species of mantis shrimp with three of these being endemic to the Hawaiian Islands.

Mantis shrimps, also known as stomatopods, are a highly evolved crustacea that are distantly related to true shrimps.  The have an advanced sensory system and are very intelligent animals, often compared to the octopus.  The visual capabilities of the mantis shrimp are unimaginable. Literally unimaginable! Humans have the ability to see ‘visible light’ comprised of four different colour pigments. The mantis shrimp can see up to sixteen different colour pigments, allowing their vision to go into the ultra-violet and infrared spectrum, colours that are not visible to the human eye.  They also have four built-in colour filters. This allows them to sharpen and fine-tune their vision under many different water conditions.  Mantis shrimp have the ability to move their eyes horizontally, vertically, and independently of each other. This coupled with the fact that each eye has trinocular vision means that the mantis shrimp knows exactly where everything in its environment is located.

There are two main types of mantis shrimp; the smashers and the spearers. Spearers are the most common form of mantis shrimps.  They are ambush predators, concealing themselves in burrows until their prey swims by. The spearing action is incredibly quick, impaling their prey in less than five milliseconds. On the other hand, smashers do not always require such stealth.  If their target prey is a mollusk or hermit crab, they have been known to push the prey up against a rock systematically smashing the shell until they have access to the animal inside. The power of the punch is astonishing.  Large smashers can have the same power in one punch as a 22-caliber bullet.

Researchers from the Hawaii Institute of Marine Biology have discovered that stomatopod larvae make up a significant proportion of small yellowfin tuna's diet. When the tuna grows over 45cm in length they change their feeding patterns to primarily feed on Oplophorus gracilirostris, a mesopelagic shrimp. Another study that involved HIMB researchers looked at behavioural adaptations of the mantis shrimp to deal with increased vulnerability during molting periods. When the mantis shrimp molts is external skeleton, it looses its hard protective covering and will have a soft body. Having a soft body with no way to protect itself makes the mantis shrimp very vulnerable to predators such as fish.  The study showed that the mantis shrimp would would change its behaviour, becoming far less aggressive and will even cover the entrance to it burrow until it has regrown it external skeleton. Once this has happened, the mantis shrimp will reopen its burrow and return to its normal aggressive behaviour

Although mantis shrimp are amazing animals, they are not the best pets.  In an aquarium setting, slashers will attack and slice the other fishes, while the smashers have the power to break the glass of the aquarium.  If you are out swimming or snorkeling and you run into the mantis shrimp, the best idea is to observe them from a distance.  The last thing that you want to get is a sliced up finger or in the worst case scenario, have a finger amputated by a mantis shrimp!

Aloha, Jardine 

Holland, K., Grubbs, D., Graham, B., Itano, D. and Dargon, L. (2003). THE BIOLOGY OF FAD-ASSOCIATED TUNA: TEMPORAL DYNAMICS OF ASSOCIATION AND FEEDING ECOLOGY. In: 16th Meeting of the Standing Committee on Tuna and Billfish.

Hoover, J. (1998). Hawai'i's sea creatures. [Honolulu, Hawaii]: Mutual Pub.

Reaka, M. (1976). Lunar and Tidal Periodicity of Molting and Reproduction in Stomatopod Crustacea: A Selfish Herd Hypothesis. Biological Bulletin, 150(3), p.468.

Friday, July 31, 2015

Brittle Stars

Brittle stars, one of our invertebrates in our touch table, belong to the class Ophiuroidea.  The class name derives from ophis, the Greek word for snake and they are often referred to as serpent stars. There are over 2000 species of brittle stars in the world, however Hawaii only has about 57 known species.

Hawaii Institute of Marine Biology
Most of you have probably seen the tiny bodies of the these invertebrates attached to coral, sea cucumbers and different things in our touch table. Unlike traditional seastars, which have suction tube feet to hold on to things, brittle stars have only non-suction, pointed sensory tube feetThey use their long spiny arms to hold onto things instead. Their arms are extremely flexible when moving side to side, but not when moving up and down. As they move, the long arms grip and pull their bodies along, with one arm serving as the forward directing point and other arms pushing/pulling the body along the path. Some brittle stars can move surprisingly fast; but generally, having several long and lanky arms to manage can make travelling time consuming, so most move very slowly along the seabed, taking that time to feed on dead organic matter.  When doing so, they gather in large groups and collectively filter food from the circulating water around them. Teamwork! We often see just their legs sticking up out of sponges on the reef, looking like fireworms as they collect food.

Hawaii Institute of Marine Biology

 Brittle stars are in the Echinoderm phylum. Like other echinoderms, they have a five-part body plan, with a distinct central disk and 5 arms.  However, one of the more common brittle stars manages to add one more arm to make a total of six, so don't be surprised if they have gone beyond the norm.  They vary radially in size and color. Many are tiny, like the 6 armed ones in our touch table which generally do not reach over 2 cm or so.  But others found inter-tidally in Hawaii under rocks and such can have arm spans of 10 inches or more. They do not have a head or brain. Instead they have a simple ring of nerve cells that moves information around the body. Their small tube feet located along the arms can also sense light and smells, making them a key part of the brittle stars body plan. 

Because these invertebrates are, well "brittle," their arms tend to break off.  However, they have the ability to quickly regenerate their arms.  If they are grabbed by a predator, they can drop an arm allowing for escape as a defense mechanism.  Try to keep this brittle star tactic in mind and be very cautious when handling them.  The arm may grow back, but they will be hindered in movement and feeding.

Aloha, Mckenzie. 

About Fish Online-Brittle Stars. N.p., 2008. Web. 2015.

"Brittle Star | Class of Echinoderms." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 29 July 2015.

John P.Hoover - Mutual Pub. - 1998

Friday, July 24, 2015

Update: Make-A-Wish Teen's Visit

The UH Manoa News staff recently published a feature on our Make-A-Wish Teen's visit a few weeks ago.  The following video of Camron's experience shows how the UH community came together to make her dream of becoming a marine biologist come true.

For additional details about her visit, please see our previous blog post regarding the Make-A-Wish program: Make-A-Wish Visit - Camron Island

Friday, July 17, 2015

Sea Cucumber Harvest Ban

On the 26th of June 2015, the Hawaii Board of Land and Natural Resources announced that it would be illegal to harvest any species of sea cucumber from Hawaii State waters for 120 days. This emergency ruling has been implemented to immediately stop the continued depletion of sea cucumber numbers, after an investigation by officers from the DLNR Division of Conservation and Resources Enforcement confirmed that a new commercial fishery had begun (Department of Land and Natural Resources, 2015).

(Clayton Wakida, KITV, 2015)

Sea cucumbers along with other echinoderms are described as a “keystone species” as they play a major role in structuring many marine ecosystems (Skillings, Bird and Toonen, 2014). They work as the “vacuum cleaners” of the sea floor consuming organic detritus (waste) and help to prevent the growth of slime algae that can damage coral reefs (Skillings, Bird and Toonen, 2011).  Sea cucumbers like many other species are also the target of artisanal or commercial fishing activities. Stocks of sea cucumbers are being continually depleted, with the more valuable species being depleted first (Skillings et al., 2011). Studies have shown the loss of sea cucumbers from an ecosystem can result in the hardening of sands around reefs, which can lead to the loss of soft bottom species, increased growth of micro and macro algae and reduced nutrient processing (Skillings et al., 2014).

Black sea cucumber. Image Hawai'i Institute of Marine Biology
Why is removing them such a problem? Little is known about the growth rate, longevity, or sexual maturity of these animals. The few studies of wild populations of sea cucumbers suggest that these are very long-lived animals with slow growth and reproductive rates.  These are characteristics that make a species very sensitive to overharvest (Skillings et al.,2014).  Studies conducted on species of sea cucumber that are harvested for consumption, primarily Holothuria whitmaei and Holothuria (Microthele) nobilis, suggest that it can take one sea cucumber 10-35 years to reach sexual maturity (Shiell and Uthicke, 2005). Sea cucumbers show no visible sings of ageing and theoretically in perfect conditions they could live forever. However in a wild population the likelihood of this happening is very rare. It is estimated that that the average life span of a sea cucumber is approximately 40-60 years (Shiell and Uthicke, 2005). 

Black sea cucumber. Image Hawai'i Institute of Marine Biology
Why has the harvesting of sea cucumber become such a problem? Sea cucumbers have been harvested for consumption for over 1000 years in China and India (James and James, 1994).  These traditional practices only harvested a small amount of sea cucumber for consumption. This was not a problem because they were not depleting the stocks to a point that they could not recover (Friedman, 2010). The commercialization of the sea cucumber, primarily as ‘beche-de-mer’ the dried form, in the Asia-Pacific region saw a spike in the amount of sea cucumbers being harvested. As this industry was unregulated, sea cucumbers were being harvested in huge number in the early 1800's but the trade declined by the early 20th century as the populations were reduced to a point that there were insufficient numbers to support a trade or to replenish the stock numbers (Ward, 1972; Moore, 2003). 

Over a hundred years later, in the 1980's, another boom in the harvesting of sea cucumbers occurred, as there was a spike in the demand from the Chinese communities around the world (Friedman, 2010).  Today, the demand from the Chinese communities around the world is still increasing. Even with the introduction of an aquaculture industry, the demand for sea cucumber greatly outweighs the supply. One kilogram of sea cucumber has been recorded selling for US $2,950. This has caused sea cucumbers to be harvested from wild populations in numbers that have not been seen before (Friedman, 2010).  If this trend is to continue, irreversible damage will be done to the sea cucumber populations resulting in the extinction of many species (Purcell, 2010).

Written by Jardine Gunn

Department of Land and Natural Resources, (2015). 06/26/15 - Sea Cucumber Harvesting Banned For 120 Days in Hawaii. [online] Available at: [Accessed 7 Jul. 2015].

Friedman, K., Eriksson, H., Tardy, E. and Pakoa, K. (2010). Management of sea cucumber stocks: patterns of vulnerability and recovery of sea cucumber stocks impacted by fishing. Fish and Fisheries, 12(1), pp.75-93.

James, D.B., and James, P.S.B.R. (1994).  A hand book on Indian sea-cucumbers. CMFRI Special Publications, 59, pp. 47

Moore, C. (2003). New Guinea: Crossing Boundaries and History. University of Hawaii Press, Honolulu.

Purcell, S., Lovatelli, A., Vasconcellos, M. and Ye, Y. (2010). Managing sea cucumber fisheries with an ecosystem approach. Rome: Food and Agriculture Organization of the United Nations.

Shiell, G. and Uthicke, S. (2005). Reproduction of the commercial sea cucumber Holothuria whitmaei [Holothuroidea: Aspidochirotida] in the Indian and Pacific Ocean regions of Australia. Marine Biology, 148(5), pp.973-986.

Skillings, D., Bird, C. and Toonen, R. (2011). Gateways to Hawai 'i: genetic population structure of the tropical sea cucumber Holothuria atra. Journal of Marine Biology, pp.1-16.

Skillings, D., Bird, C. and Toonen, R. (2014). Comparative population structure of two edible Indo-Pacific coral reef sea cucumbers (Echinodermata: Holothuroidea). Bulletin of Marine Science, 90(1), pp. 359-378.

Ward, R. (1972). The Pacific Beche-de-mer trade with specific reference to Fiji. In: Man in the Pacific: Essays on Geographical Change in Pacific Islands (ed. R. Ward). Oxford,  Clarendon Press. pp. 91-123


Clayton Wakida, K. (2015). Sea cucumber harvesting banned for 4 months in Hawaii. [online] KITV. Available at: [Accessed 10 Jul. 2015].

Friday, July 10, 2015

Make-A-Wish Visit - Camron island

Aloha everyone,

On Tuesday, CEP had the pleasure of hosting a Make-A-Wish child, Camron.  The Make-A-Wish Foundation is dedicated to granting the wishes of children with life-threatening diseases.  The HIMB faculty, staff and students were excited to contribute to making her wish of undertaking a genuine marine biology experience with the University of Hawaii come true.  In her honor, we renamed the island for the day!
Camron with CEP's coordinator, Mark Heckman, on their way to Moku o Lo'e. 
Photo taken by Jose Magno, UH Admissions Office

Camron and her family with HIMB's Community Education Program and the Make-A-Wish Foundation Staff
Photo taken by Lee Nakamoto, UH Admissions Office
Her visit consisted of a shark feeding with the Holland Lab and coral breakage surveys with CEP.  Over the past 4 months, we've monitored specific breaks in rice coral, Montipora capitata, and tracked their regrowth over time.  Camron assisted with the photo-taking for the day's monitoring.

The results of a few of our monitored breaks are demonstrated in the pictures below:

The photos on the left show clean breaks marked on February 9, 2015.
The photos on the right display their regrowth as of July 7, 2015.

While some of our breaks have recovered successfully, it's apparent that algae competitors are the main factors in preventing regrowth of coral tissue.  CEP is working to develop this program further in order to more closely observe coral breakage recovery steadily over longer time periods.  Camron's assistance with these photo surveys was a welcome contribution to our coral breakage study. Working with Camron and the Make-A-Wish foundation was positive reinforcement for our continued development and maintenance of citizen science programs.

Photo taken by Lee Nakamoto, UH Admissions Officer
It was our pleasure to host Camron at Moku o Lo'e for the Day.  The Community Education Program hopes to have many more Make A Wish collaborations in the near future.

Casey and Leon

Friday, June 19, 2015

Peter Yarrow of Peter, Paul, and Mary playing at UHM June 26th

HIMB's Community Education Program is collaborating with Ocean Matters to put on a concert at UH Campus Center featuring Peter Yarrow, a member of the popular folk-trio Peter, Paul, and Mary.  The group has created hits such as "Puff (the magic dragon)", "Leaving on a jet plane", and "If I had a hammer". 

Peter Yarrow is now a director of Ocean Matters, an organization dedicated to providing programs centered around marine conservation for youth and educators.  As a long-time advocate for marine conservation and education, he has donated his performance so all proceeds may go towards an Ocean Matters/HIMB scholarship fund allowing local students to participate in Ocean Matters' future expeditions to HIMB.

The event will take place on Friday, June 26th at 7:00pm in the Campus Center Ballroom.  Doors will open at 6:30pm. 

You may purchase tickets at the Campus Center Ticket Office or on eventbrite at the following link: Peter Yarrow Concert - Eventbrite
Adults are $32.50 and Students with ID are $20
You may buy a VIP ticket for $75.00 which includes a Meet & Greet reception with light refreshments following the event.
Please see the attached poster below for additional details! 

Peter Yarrow was interviewed yesterday on NPR.  You may listen to the show at the following link.  It starts around 16 minutes in:

Sunday, June 7, 2015

The unnatural history of Kane'ohe Bay: coral reef resilience in the face of centuries of anthropogenic impacts

Fresh off the press is a new publication titled "The unnatural history of Kane'ohe Bay: coral reef resilience in the face of centuries of anthropogenic impacts" authored by graduate student Keisha Bahr, and HIMB faculty members Paul Jokiel (Point Lab) and Rob Toonen (ToBo Lab/New Pauley Lab).  This research paper examines how the estuarine reef ecosystem of Kane'ohe Bay has been impacted by anthropogenic (man-made) activities as well as natural stressors.  Human impact was measured in terms of sedimentation, introduction of invasive species, over fishing/harvesting, dredging and filling, urbanization of the surrounding area, sewage discharge, and increases in global temperatures due to anthropogenic fossil fuel emissions.  Natural stressors occurring in Kane'ohe Bay include exposure during very low tides, freshwater killing of coral due to storm floods, as well as greater temperature variation, sedimentation, and lower pH levels than more oceanic reefs.  Drawing from over 100 sources, the authors track the state of the reef in Kane'ohe Bay from the Polynesian Era (1250-1778) to the Western Era (1778-2015), and provide multiple projections of reef health in the Future Era (2015-2040).
Indigenous: Striped Mullet (Mugil cephalus, 'ama'ama).  Picture by Randall, J.E.
One of the most interesting aspects of the Polynesian Era was the higher percentage of coral cover despite a greater human population residing in Kane'ohe than the nearly 35,000 people here today. This was due, in part, to the practice of sustainable agriculture and aquaculture.  The practice of aquaculture was so abundant in Kane'ohe Bay that by the 19th-century 30 fish ponds comprised 30% of the bay's shoreline.

Invasive: Kanda (Valamugil engeli, syn. Moolgarda engeli). Picture by Randall, J.E.

While examining the major impacts during the Western Era, the authors discuss the introduction of invasive species, which currently account for approximately 14.5% of the bay's total biota.  One example of an invasive Kane'ohe Bay resident is the kanda (Valamugil engeli, syn. Moolgarda engeli), a species of mullet which is thought to compete with the native striped mullet (Mugil cephalus, 'ama'ama).  While the a mature striped mullet grows to three times the size of the kanda, as juveniles they are almost impossible to differentiate in situ (Randal, J.E., 2007).

Indiginous: Bandtail Goatfish (Upeneus arge, weke pueo). Picture by Randall, J.E.

Also thought to be in competition with the striped mullet is the stripped goatfish (Upeneus vittatus), which looks very similar to the native bandtail goatfish (Upeneus arge, weke pueo).  In 1974, it was discovered that the original U. vittatus type specimen had been lost and replaced with a similar goatfish species (Randal, J.E., 2007).

Invasive: Stripped Goatfish (Upeneus vittatus). Picture by Randall, J.E.

In the Future Era segment of this article there is a figure plotting the amount of coral cover in Kane'ohe Bay from 1250 AD up to 2040 AD.  From 2015 onward to 2040 there are two projections predicting future coral cover.  The label of the grim projection swooping downward toward 0% coral cover left me dumbfounded; "business as usual."  It seemed that "worse case scenario" would have been more accurate description, and that "business as usual" felt unscientific and indifferent.  The authors, however, explained the reasoning for said label masterfully, and I hope you take the time to read it for yourself at

Leon Weaver

Other work cited:
Randall, J. (2007). Reef and shore fishes of the Hawaiian Islands. Honolulu: Sea Grant College Program, University of HawaiĘ»i.