16 August 2016

Sea otters beyond utter cuteness

On the left are sea otters from ©Finding Dory and opposite is its real-life counterpart, Enhydra lutris (photo by Michael Gore).

Sea otters or Enhydra lutris are nearshore marine mammals, strongly associated with rocky coastal areas near kelp beds where they forage. Other than for food, they also use these kelp to sometimes entangle themselves with, keeping them afloat [1]. Most of time they are seen in groups called rafts [8], lying on their backs with such a laid-back pose [2], holding on to each other to make sure no one drifts away in their sleep [9]. They currently inhabit the coasts of Japan, Russia, Canada, North America and Mexico [1], but the majority reside in Alaskan waters [4].

True to being so adorable and a favorite in Finding Dory, sea otters are rarely seen fighting or being aggressive with their kin. In fact, they are weakly territorial, where only adult males form turfs [1]. 

Beyond being fuzzballs, what sets them apart from other marine mammals is their unique capacity to use tools. Using their forearms to grab a stone and prey from the ocean floor, they resurface to set a prey, for example, a mussel or clam on its chest, pries it open or smashes it against a stone [2]. Known as voracious feeders, sea otters even have pouches of loose skin under each forearm, where they could easily stash their prey [5]. They also feast on a variety of organisms such as sea urchins, crabs, squids, bony fish [3] and octopuses [6].

Unlike other marine mammals, they don’t have a thick layer of blubber to keep them warm. To compensate for this, they don the thickest and densest of furs, where a square inch of its skin can grow a million hair! [4]. To further keep the warmth, they spend hours grooming their coats until they are covered with natural oils [5]. They also eat to their tummy’s content (approximately 25% of their body weight), and spend most of their time resting afloat [4]. 

Below is a video of an Alaskan sea otter pup floating on its own [7].

It might not be obvious with how sea otters behave and handle themselves, but they are, most importantly, keystone species. That means their existence or absence has a greater effect in the ecosystem relative to other species. That is, sea otters help keep sea urchin population in check, and in turn maintain a healthy kelp forest [4].

Sea otters have been considered endangered since 2000 [1]. Today there are only about 100,000 to 150,000 individuals [2].

To know more about Enhydra lutris and other characters from Finding Dory, visit SeaLifeBase.

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[1] Doroff, A. & Burdin, A. 2015. Enhydra lutris. The IUCN Red List of Threatened Species 2015: e.T7750A21939518. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T7750A21939518.en. Downloaded on 26 July 2016.
[2] National Geographic (2016). Sea otter - Enhydra lutris. Retrieved from http://animals.nationalgeographic.com/animals/mammals/sea-otter/
[3] Gaichas, S. K. (2006). Development and application of ecosystem models to support fishery sustainability: A case study for the Gulf of Alaska. Retrieved from Proquest Dissertations and Theses database.
[4] Defenders of Wildlife (2016). Basic facts about sea otters. Retrieved from http://www.defenders.org/sea-otter/basic-facts
[5] Monterey Bay Aquarium (2016). Southern sea otter. Retrieved from https://www.montereybayaquarium.org/animal-guide/marine-mammals/southern-sea-otter
[6] Vincent, T. L. S., Scheel, D., & Hough, K. R. (1998). Some aspects of diet and foraging behavior of Octopus dofleini (W├╝lker, 1910) in its Northernmost Range. Retrieved from http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0485.1998.tb00450.x/abstract
[7] BBC (2015, January 28). Sea otter pup left to float alone - Alaska: Earth's frozen kingdom: episode 1 preview - BBC two [Video file]. Retrieved from https://www.youtube.com/watch?v=sWJXG2SS6AA
[8] World Wildlife Fund (2016). Ten facts about sea otters. Retrieved from http://www.worldwildlife.org/blogs/good-nature-travel/posts/ten-facts-about-sea-otters
[9] Schweig, S. V. (2016, April 13). Sea otters hold hands while they're sleeping. The Dodo. Retrieved from https://www.thedodo.com/sea-otters-hold-hands-1727255897.html

11 July 2016

Meet Hank, the east Pacific red octopus

Left photo is is ©Finding Dory's red octopus Hank (Source: movie.disney.co.uk)  and on the right is its real-life counterpart, Octopus rubescens (Photo by Ken Phenicie Jr.).

The octopus is considered as one of the most elusive and intelligent of sea creatures [1]. We sure were fascinated with Hank, the animated counterpart of Octopus rubescens, more commonly known as the east Pacific red octopus. This species is known to inhabit the waters of Bering Strait, Alaska down to Baja California, from low intertidal to a depth of 210 m.  It can reach a total length of 45 cm [2] and lives up to two years [9]. It has a neutral color of red or reddish brown [3]. In the movie Hank wishes to live in captivity permanently, away from all the dangers of the wild. In reality though, juveniles are found among kelps [9] while adults settle on rock and soft bottoms [2]. It is a voracious predator of crabs [4] and also feeds on bony fish [4], mollusks, and euphausiids [6]. It can even drill holes on shells of the bivalve Venerupis philippinarum [5].

What makes them so interesting is beyond what we have encountered in the movie. Sure, they can change into a kaleidoscope of colors before and after capturing a prey. Based on one study, it displayed various colors before detection of a crab, turned light orange to gray during a free-swimming attack, colorless and almost transparent on landing, spotted or mottled upon grabbing the crab, and back to various colors. This series of color change may be associated with locomotor acts and postural adjustments [7]. Below is a video of O. rubescens feeding on a crab [8].

Because of its soft flexible body and small papilla (projections on its skin), O. rubescens can morph into different shapes and textures, an ability that is very useful against predation. At the point of detection, it can rapidly change color, shape or even texture, confusing and alarming its predator altogether [9].

Much like Hank’s crafty moves in Finding Dory, O. rubescens is truly capable of escaping captivity and surviving on land. According to Monterey Bay Aquarium, a juvenile O. rubescens sneaked into an aquarium using a sponge as a cover, and was only caught red handed (after a year in an exhibit) while walking in the middle of the night. Workers also noticed that the crabs in the exhibit were decimated [10].

And yes, this species has three hearts as other octopuses do: one pumps blood through the body, specifically for the organs, while the other two exclusively pump blood through the gills [1]. No doubt Hank, in the end, had the heart (or hearts?) to return and help Dory and her friends go back to their true home, the ocean.

To know more about O. rubsecens and other characters from Finding Dory, visit SeaLifeBase.

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[1] Nuwer, R. (2013, October 31). Ten curious facts about octopuses. Retrieved from http://www.smithsonianmag.com/science-nature/ten-curious-facts-about-octopuses-7625828/?no-ist
[2] Gotshall, D. W. (2005). Guide to marine invertebrates: Alaska to Baja California (2nd ed. revised). Sea Challengers.
[3] Biodiversity of the Central Coast (2014). Pacific red octopus – Octopus rubescens. Retrieved from http://www.centralcoastbiodiversity.org/pacific-red-octopus-bull-octopus-rubescens.html
[4] Boletzky, S. V., & Hanlon, R. T. (1983). A review of the laboratory maintenance, rearing and culture of cephalopod molluscs. Memoirs of the National Museum Victoria, 44, 147-187. Retrieved from https://www.researchgate.net/profile/Roger_Hanlon/publication/279192347_A_review_of_laboratory_maintenance_rearing_and_culture_of_cephalopod_molluscs/links/56b13e1008ae5ec4ed48808c.pdf
[5] Anderson, R. C., Sinn, D. L., & Mather, J. A. (2008). Drilling localization on bivalve prey by Octopus rubescens Bery, 1953 (Cephalopoda: Octopodidae). The Veliger, 50(4), 326-328. Retrieved from http://eprints.utas.edu.au/8464/
[6] Laidig, T. E., Adams, P. B., Baxter, C. H., & Butler, J. L. (1995).  Feeding on euphausiids by Octopus rubescens. California Fish and Game, 81, 77-79. Retrieved from
[7] Warren, L. R., Scheier, M. F., & Riley, D. A. (1974). Colour changes of Octopus rubescens during attacks on unconditioned and conditioned stimuli. Animal Behaviour, 22(1), 211-219. Retrieved from http://www.sciencedirect.com/science/article/pii/S0003347274800710
[8] NgomaMom (2014, May 21). East Pacific red octopus in the mood for food [Video file]. Retrieved from https://www.youtube.com/watch?v=_Wkl3exDmys
[9] Orwick, S. (2005). Crypsis, substrate preference and prey detection in the red octopus, Octopus rubescens (Berry, 1952). Retrieved from Oregon Institute of Marine Biology https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/8072/Orwick%2005.pdf?sequence=1&isAllowed=y
[10] Monterey Bay Aquarium (2016). Red octopus.  Retrieved from  https://www.montereybayaquarium.org/animal-guide/octopuses-and-kin/red-octopus

24 June 2016

Finding Dory: insights from getting lost and being found

Photo from movies.disney.com.au
Warning: spoiler alert!

Disney-Pixar's sequel to 2003's Finding Nemo, is quite a treat for people of all ages who dearly love the ocean, and after watching this movie, those who don't, will soon do. Finding Dory showcases the beauty of the marine environment, from the towering kelps and serene seagrasses, the myriad of majestic corals, cryptic crabs and worms, a fast jetting squid and an agile octopus, to sunbathing Californian sea lionshard-to-resist sea otters, thunderous spotted eagle rays, an adventurous common loon and green sea turtles. As if these marine creatures aren’t fantastic enough, the film delivers an incredibly funny, very poignant story that will tug at everyone’s hearts.

The Pacific regal blue tang, Dory, charmed the audience, chunks of humor aside and her whale-talking-prowess, with a genuine portrayal of what it is like to have an anterograde amnesia, of its limits and quite surprisingly, the strength that it brings forth. We can learn a lot from Dory by looking at the brighter side and asking ourselves the question: “What would Dory do?” instead of saying: “Don’t be such a Dory!”.

Who wouldn’t be in awe with Hank the east Pacific red octopus as he skillfully turns to a house plant, and moments later to a baby feeding on his bottle? Octopuses are probably the most intelligent sea creatures, utilizing every imaginable human litter on the ocean floor to blend in, and yes, even break out from captivity.  Hank was the epitome of such cleverness. More importantly, with Hank getting into trouble inch by inch with Dory, who can match such loyalty? Indeed, when you ask for help, the world conspires in helping you achieve it.

Destiny, the whale shark, although near-sighted and bumps her head all the time, was able to rise above her insecurity (literally and figuratively) and help her pipepal Dory as she launches a rescue operation. Her friend beluga, Bailey was able to regain his ability to echolocate - a ton of help, not to mention super fun - as he and Destiny helped Dory find her way through the pipes. What Dory said was true: “Best things happen by chance.” She happens to have a pipepal who also happens to have the coolest partner. And of course, the world is a better place with people living to their potential and helping each other out.

Our old friends, the orange clownfish Nemo and his father Marlin, resonate a story so familiar – of being lost and then reunited. Marlin knew very well how empty it felt to have lost Nemo and didn't want to go through it all again, that’s why he was hesitant to help Dory, but he was reminded that it was because of Dory and her sometimes thoughtless acts, that helped both Nemo and Marlin muster courage when they needed it most. Sometimes fear can paralyze us, but Dory and many of the characters prove otherwise, and that we won't realize what we’re capable of until we try. So let’s battle against the tempest and just keep swimming!

Join us in the next few weeks as we get to know more about the amazing animals we've met in this story.

Visit SeaLifeBase and FishBase, respectively, or click the designated links.

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