Crunch Time

It’s getting to crunch time for my PhD – just over three months before my funding dries up, so a fairly busy time for me. There doesn’t seem to be enough hours in the day to get everything done at the moment, so I’m having to prioritise my time, and unfortunately blogging is pretty much at the bottom of the pile for quite a while. New posts are going to be a scarce commodity for a while until I get my thesis bashed into shape or I feel that I have some time I can afford to waste on something other than my PhD.

Marine Critter Thursday – Giant Isopod

Take the humble woodlouse (or pillbug or  slater or whatever you want to call them), that common inhabitant of gardens and damp houses that is pretty inoffensive and rolls up into a ball when poked. Imagine scaling the little guy up to the size where it is about as long as your forearm, and you’ve pretty much got a giant isopod (Bathynomus giganteus). I first came across a giant isopod during a zoology practical as a first year undergrad, and the pickled specimen that looked like a woodlouse who’d taken rather too many steroids left a lasting memory.

 Giant isopods are another denizen of the deep sea, found on the sea floor from depths of 170 m down to around 2,000 m. Physically, they look remarkably like the terrestrial woodlouse, and even have the same ability to roll up into a ball for protection, but can reach lengths of up to 15 inches, compared to the 5 cm of the garden woodlouse. As the deep sea is a very food poor environment, giant isopods make do with whatever they can find to consume. They are carnivorous, primarily acting as scavengers on dead whales, fish and squid, although they may also be active predators of slow moving creatures such as sea cucumbers and worms. Giant isopods can survive long periods without food, whilst they are also known to gorge themselves completely when food is abundant, eating so much food to the extent that their ability to walk is inhibited. Just in case I haven’t got the scale of the beastie rammed home by now, check the photo below, and then imagine finding a couple of those in your damp bathroom.

Enthralled by Life

Last night heralded the start of Sir David Attenborough’s new TV series, Life, which looks at the extraordinary lengths that plants and animals go in order to survive. I’ve found all of  Sir Attenborough ’s nature programme to date simply amazing, and I’ve been eagerly anticipating Life. The photography was stunning, capturing some absolutely breathtaking moments. Highlights for me included footage of cheetahs hunting an ostritch, and some male hippos smashing into each other in slow mo. If the first episode is anything to go by, the rest of the ten part series should be equally enthralling.

Knitted Sea Creatures

Came across some pictures of brilliantly knitted sea creatures from Cast & Bindwhilst looking for some Dumbo octopus images, which I’ve included below. There’s a jellyfish, a Dumbo octopus, and my favourite, a blue ringed octopus.

Marine Critter Thursday – Dumbo Octopus

Many strange looking creatures inhabit the deeps of the world’s oceans. Take for example the Dumbo octopus.

The common name of the Dumbo octopus comes from the resemblance between the animal and Walt Disney’s flying elephant, with the pair of large fins on the octopus’ head looking like large ears. There are several different species, which were initially all grouped under the genus Grimpoteuthis, but have now been spread over a number of different genus. Not much known is about the Dumbo octopus. Although they have a global distribution, they are typically found at depths between 100 – 5,000 m, with one specimen recorded from 7,000 m deep. The depth at which the octopus lives makes it hard to study in its natural environment. Dumbo octopuses are usually found on or near the sea floor, hovering around looking for food. They feed on small crustaceans, worms and bivalves found at the bottom of the oceans. Dumbos usually swallow their prey whole, which is unusual behaviour amongst octopuses. Dumbos swim by flapping their ’ears’ and by the expansion/contraction of their webbed arms. They move around very gracefully in the water, and have a surprising turn of speed when necessary. Check this video to see a Dumbo octopus swimming around.

Marine Critter Thursday – Barnacles

I was feeling slightly uninspired about what marine animal to post about today. Since I’ve just got back from Wales where I was teaching rocky shore ecology to undergrads, I thought I’d write a brief article on something a saw every day there – barnacles. You might take some convincing that barnacles are interesting, but they are a very unique and diverse group of animals. Charles Darwin spent 8 years studying and classifying barnacles after returning home from his voyage on the Beagle, after following the suggestion by a friend that he needed to throughly understand at least one group of species before making generalisations in his theory of evolution by natural selection.

Barnacles are crustaceans from the class Cirripedia. This can catch some people out. The hard shell and sessile lifestyle of barnacles put people in mind of molluscs, not crabs or lobsters. There are several different types of barnacles, including the stalked barnacles, which have a long stalk (naturally), and parasitic barnacles that bear little resemblance to other barnacles except at the larval level. The most commonly found barnacle is the acorn barnacle, which I’ll describe in a little more detail.

Acorn barnacles have a free swimming larval stage. When the larvae is ready to settle they cement themselves by their head to a suitable surface, and calcareous plates form around the body. The plates act as a layer of protection for the barnacle, with an operclum at the apex, from which the legs of the barnacle can flick out. Barnacle legs are known as cirri. They are very long and feathery and function in suspension feeding, gathering particles from the water. The photo to the right shows what a barnacle looks like when feeding, with its cirri extended out from its operculum. The most commonly known fact about barnacles is the extremely large length of their penises in comparison to their body size. Barnacles possess the largest penis size to body length ratio in the entire animal kingdom. If barnacles were approximately human in size, it would equate to having something the height of the Empire State Building in your trousers. Why so long? Barnacles are completely sessile and unable to leave their shells, so the penis needs to be extremely long in order to fertilise other nearby individuals.

Away to Wales

I’m off to Wales for a week tomorrow to help teach undergrads about rocky and sandy shore biology/ecology. Although I’m getting paid pittance for my time, I’m quite looking forward to escaping from the office and doing something fairly hands on and completely unrelated to my PhD. Hopefully the weather will be sunny and I’ll have a glorious week sitting around on beaches. However, internet access is pretty limited where I’m going, so unfortunately I doubt I’ll be posting anything new or doing anything blog related whilst I’m in Wales.

Marine Critter Thursday – Walrus

After a brief absence whilst I was away in Liverpool last week, Marine Critter Thursday returns in the unmistakable shape of the walrus. With its large pronounced tusks, whiskered snout and large bulk, the walrus must rank as one of the most recognisable marine creatures around.

The name walrus is thought to have several possible origins. The first is a combination of two Dutch words, either walvis (‘whale’) and ros (‘horse’) or wal (’shore’) and reus (‘giant’). However, the most likely origin of the name walrus comes from Old Norse, from the word hrossvalr (‘horse-whale’), which was passed in a juxtaposed form to Dutch and North-German dialects as walros and Walross. The species name for walrus is Odobenus rosmarus, with the genus name derived from the Greek odous (‘tooth’) and baino (‘walk’), based on observations of walruses using their tusks to haul themselves out of the water.

Walruses are distributed around the Arctic Ocean and sub-Arctic seas in the Northern Hemisphere. They can be found around shallow shelf sea regions, spending a large part of their life on sea ice, from which they dive down to the ocean floor to find bottom dwelling molluscs to eat. There are three subspecies of walrus, the Atlantic walrus, the Pacific walrus and the Laptev walrus, found (unsurprisingly) in the Atlantic, Pacific and Laptev Sea respectively. Walruses are big – an adult male can weigh up to 2,000 kg, although most are weigh in somewhere between 800 – 1810 kg. Females are typical about two thirds the size of males. Out of the other pinnipeds (finned mammals including seals, sealions etc), only the elephant seal is larger than the walrus.

The tusks of the walrus are actually elongated canines, and can grow up to a meter in length. Both sexes have tusks, although they are slightly longer and thicker in males than females. Male walruses use their tusks in dominance displays and fighting. Those males with the most impressive tusks tend to dominate social groups. Tusks were once thought to be used to dig out prey items, but studies have shown that the upper lip is actually used to dig whilst the tusks are just dragged through the sediment. Tusks are also used to enlarge holes in the pack ice, and to help walruses to pull themselves out of the water. The tusks are surrounded by an array of stiff bristly whiskers known as vibrissae. A walrus can have between 400-700 vibrissae on its snout, and they function as a highly sensitive touch organ. As the walrus digs for food on the sea floor, visibility is extremely reduced by clouds of sediment they kick up, and the vibrissae are used to feel out prey. Walruses feed on a variety of different organisms, but they have a great preference for bivalve molluscs, especially clams. Once a clam has been found, the walrus seals its lips around it and sucks the flesh out by creating a vacuum by piston movements of the tongue. The suction is so powerful that captive walruses have been known to suck holes in plywood and strip the paint off walls. A grown walrus can consume an incredible 3,000-6,000 clams in one sitting, and they consume around 4-6% of their body weight per day. Considering how much a walrus weighs, this is a tremendous amount of food. The walrus also possess an air sac under its throat, which acts as a flotation device and allows them bob vertically at the surface of the water and sleep there.

Due to its huge size and formidable nature, the walrus has only two natural predators, the polar bear and the orca (killer whale). Polar bears rarely lauch direct attacks on walruses, only preying on injured or juvenile walruses. However, walruses have a long history of human exploitation, especially throughout the 18th and 19th centuries. Pretty much none of the animal went to waste. The tusks represented a valuable ivory commodity, whilst the blubber was rendered down for oil. Even the guts and intestines were used to create waterproof clothing. Although the commercial hunting of walruses is now banned, the potential impact of global climate change on walrus populations is of great concern.

Glass Viral Sculptures

I found some very interesting photos of some glass sculptures depicting different viruses and bacteria in an article on the Telegraph website. The artist Luke Jerram worked closely with virologists to accurately represent various bacteria and viruses to challenge public perceptions about what these vectors for human illnesses actual look like. I love when people blend science and art together, and I think the sculptures look amazing. I’ve included a couple below - SARS and E-Coli. The sculptures can be seen in London’s Smithfield Gallery between 21st September – 3rd October. More details can be found on the artists webpage – www.lukejerram.com

Back From Liverpool

I just got back from my week away in Liverpool this weekend. Had a pretty great time, absolutely exhausted by end the Friday thou, and spent most of Saturday and Sunday catching up on my sleep. The conference was good, if a bit gloomy in tone. Lots of the presentations highlighted the current mess that the oceans are in and the impact of climate change on marine life, with some bleak outlooks to the future. Not exactly new news to me, but being repeatedly told the same depressing story, albeit with varying slants, roughly ten times a day for a week slowly grinds you down. Luckily the city of Liverpool provided a much interesting and uplifting backdrop to elevate the conference gloom. I’d never been to Liverpool before, and apart from knowing that Liverpool had once been the European City of Culture, I really didn’t know what to expect, and was pleasantly surprised. I didn’t get as much time to look around the city as I would have liked, but what I did see (including a tour on the Yellow Duckmarine – see picture) really impressed, and I’ll definately have to head back at some stage to take in more of the city.