Chinese Soft-Shelled Turtle

I feed Rufus the Chinese Softshelled Turtle.

In the back rooms of the London Aquarium, many animals deemed to aggressive to go into the display tanks live in their on private biomes. One such animal is Rufus, the Chinese Soft-Shelled Turtle. As a rule, these strange turtles are angry and short-sighted, which makes them likely candidates for biting the fingers of children who leave them trailing in the open pools around the aquarium, so as you might imagine he is kept safely away. Rufus was donated to the aquarium by a pet owner who no longer had the resources to feed him, or simply got bored of him. While is was better to donate Rufus than to abandon him in a local pond, far too many people donate their pets each year, and this can cause problems for the aquarium, who can only house so many. It’s far better to keep your turtle, or sell them to a local pet shop where they can have a new owner.

The Soft-Shelled Turtle, or Pelodiscus Sinensis, despite its name has a shell no softer than that of any other turtle, instead owing its name to the lack of sharp ridges that cover the shells of most turtles and the flexible edges that their shells have. The centre of the shell (or carapace) is made of bone and as hard as any other species. In general, Chinese Soft-Shelled Turtles are a dark khaki colour across their shell and on their limbs, like Rufus, but some have a more mottled, blotchy colouration. Several darker lines can often be seen around the head area, but they are difficult to spot on Rufus, since he seldom stops moving when people are near. The strange shape of the nostrils, that resemble long tubes, are used as snorkels to breath below the water. They are also useful as they are able to release waste products from that area, which means they don’t lose much water from urinating. This is useful because these turtles live in areas where salt water and freshwater mix, meaning the slightly salty water is often bad to drink.

Chinese Soft-Shelled Turtles eat mainly invertebrates, crustaceans like shrimp and small fish in the wild, which are plentiful in their habitats. However, these turtles are rather opportunistic and have been known to eat plant life, and in captivity, pet food and small vertebrates like mice and young frogs. Be warned though, they don’t make for good ratters. I fed Rufus with a few frozen prawns, which he swam up to the surface to receive. Keeping my fingers out of the way, I waved the food in the water until he smelt it and came to me, and then I released it in front of him so that he could take it away. Unfortunately, Rufus has fairly poor eyesight, and at one point did not see me release the food, where upon it sank to the bottom, with Rufus looking at me angrily and expectantly. He found it eventually, but not after a few malicious looks at my fingers.

In China, people eat soft shelled turtles fairly regularly, even to the point where they are farmed, with many millions being eaten nationally. They are often made into a sort of turtle soup, or stewed with vegetables, and are fairly nutritious. In Japan these turtles are considered a delicacy, and can be eaten in a variety of ways. In the West, they are mainly kept as pets, like Rufus before he came to the aquarium, and you can find them in larger pet shops across the country. Luckily, these turtles are in plentiful supply, and are unlikely to ever be in danger of extinction.

After feeding Rufus his fill of frozen prawns, I waved goodbye to him and went on to feed some of the larger, flatter denizens of the aquarium.

Moon Jelly

Young moon jellyfish at the London Aquarium.

The moon jelly, or Aurelia Aurita, is one of the most widely distributed jellyfish in the world, ranging from equatorial tropics, to more northerly seas around Europe and in the Atlantic. On my ‘Marine Biologist Day’ at the London Aquarium, I saw a tank of young moon jellies being raised until they were ready to go on display in one of the larger Kreisel Tanks. Jellies of the Aurelia genus are very distinctive from other jellyfish, by their large disc shaped bodies, which are roughly 10 – 20 cm in diameter. Unfortunately, it is virtually impossible to identify individual species in the genus without the use of genetic sampling. Like many other species, moon jellies are capable of free swimming, although they often move with the currents which makes them seem as though they are drifting with the current. In reality, most jellyfish swim by undulating their bodies, and one of the only free drifting jellyfish, is not really a jellyfish at all. The Portuguese Man O War is in fact a colony of four separate organisms, working symbiotically as a single siphonophore.

Moon jellies and other jellyfish have no internal systems, such as the nervous, endocrine, respiratory or excretory systems. The transfer of chemicals, oxygen and nutrients throughout the body, as well as the removal of waste products, are dealt with by diffusion, simply allowing the substances to move throughout the thin cell walls of the body, rendering the need for the latter three systems void. Nobody quite understands how the jellyfish is capable of operating without any kind of nervous system, however it is known that jellyfish can detect the direction of current, and respond to it.

Moon jellies normally feed on a diet of plankton, larvae, fish eggs and small molluscs, which they catch with their trailing tentacles and then pull into their stomach. The tentacles contain cnidoblasts, small exploding cells, that deliver the venom to the prey when they burst. Moon jellies are mainly predated by Leatherback Turtles, Sunfish, and various tiny parasites.

I only saw these moon jellies in passing at the London Aquarium, but I find these animals strangely beautiful and alien, and their lack of brain fascinates me. I hope that I will get more chances to interact with Moon Jellyfish in the future.

London Aquarium Non-Display Tanks

A juvenile Thornback Ray in a tank in the London Aquarium tanks.

On my ‘Marine Biologist for a Day’ trip at London Aquarium, one of the first things that the staff showed me were the tanks where all of the animals not on display are kept, including the juveniles, like the Thornback Ray above. Any animal that was not out in the aquarium for the people to see, are kept in smaller tanks around the back of the site. Animals that are stressed, ill, too aggressive or just to young to be with the other animals are brought here until they are ready to be seen.

Every year the aquarium receives dozens of donations of tropical fish and aquatic reptiles, sent in from pet owners who have found they can no longer take care of the animals themselves. Red-Ear Terrapins are one example of animals that the aquarium is offered on a regular basis, and they are now at the stage that they cannot take on any more. This is also where breeding of the animals takes place, with new seahorses and jellyfish being born here, as well as Fire Eels, rays and corals.Some of the corals the aquarium grows for their tanks.

The corals from the aquarium are grown to be used in tank exhibits around the tropical reef sections of the aquarium. Again, most of the coral that the aquarium owns is donated by tank owners who no longer have use for their tanks. There is a common misconception that most of the coral is taken from people trying to smuggle it in and out of the country as ornamental pieces. In fact, there is very little of this occurring, since protection of reefs is so strong that the profit is normally not worth the potential punishment for the smugglers. Some of the corals that are kept in this part of the aquarium are Hammer Coral, which is a hard coral found in Indonesia and Australia, and Mushroom Coral, which originates in the Indian Ocean.Seahorses kept for breeding.Jellyfish kept in the iconic circular tanks.

These jellyfish are called Japanese Sea Nettles, and they are small juveniles kept here until they grow large enough for the exhibit. Jellyfish are always kept in these strange circular tanks, because they require currents to move them around, and in a normal square or oblong tank, the movement of the water will push them into the corners, causing them to get stuck and potentially damaging or killing the jellyfish. Luckily, the jellyfish seem quite beautiful spiralling in their round tanks.

The starfish and crabs that live in the rockpool section are kept on a rotation, since having people touch them can cause them quite a bit of stress. To prevent this from becoming unhealthy, every 2-3 hours the rockpool in changed, moving in new animals through the use of a bucket of cold water. There are about six tanks, meaning a full rotation lasts around 2 days, more than enough time for the starfish to recover. I was allowed to change the animals part way through the day, and had to remove the starfish from the tank by gently stroking their sides, until they let go of the rocks they held on to. Despite harassment from an over animated crab, I changed around the starfish without any trouble.

It was very interesting to see all of the processes that went behind running the aquarium, which I had only every seen from one side of the exhibits. Getting to help was one of the best experiences of my life.

Work Experience with Matt

Matt hunts down an interesting bee he has spotted.

For my work experience this year, I have been lucky enough to have Matt Smith, a freelance consultant ecologist and expert on bees, take me under his wing for a couple of days of pond and reptile surveys. I went with him to learn about that kind of work that somebody in an ecological mindset could find, and I was not disappointed. Over our time together, we thrashed ponds to find what kind of invertebrate life we could find, discovering dragonflies, water spiders, pondweeds and even newts. Its really amazing finding out what kind of animals live in the little bodies of water so close to home, and the breadth and depth of Matt’s knowledge on the subject was astounding. We tramped through heathland after elusive lizards, instead finding birds and beetles, and we peeked under carpets in search of slowworms and snakes. It was one of the most exciting experiences of my life, and it gave me a great insight into the sort of work that may be available to me in the future. I’m deeply thankful to Matt for giving me this wonderful experience.

Ground Nesting Birds

The speckled brown eggs of a ground nesting bird.

While performing a reptile survey in Snelsmore Common, Matt and I saw many signs warning us about the presence on ground nesting birds on the site, and the dangers of disturbing or damaging their nests. We had been walking around the Common, hunting lizards, and spotting spiders for several hours, and we were starting to suspect that there were no ground nesting birds here at all. However, as we approached the end of our day, and were making a last trip around the north of the Common, a small brown bird squawked under my feet and flew into the air. The bird and it’s nest had been camouflaged so perfectly, neither of us spotted it until we were almost on top of it.

The nests of ground nesting birds are set into the earth, where there is lots of grass and leaves to cover them, in order to hide them from predators. Typical eaters of eggs like these, include Crows, Red Foxes and the American Mink. They can also be trampled by larger grazing animals such as horses and cows, who don’t notice the nests until they are crushed. Due to the decline in heath areas where birds like this can hide their nests, which are cut away to make cattle land and crop fields, it is important to protect these birds wherever possible, and several laws have been passed preventing people from disturbing these nests.

The eggs of ground nesting birds are often brown and speckled, whereas it is much more common for high nesting birds to have bright blue or white eggs. This is because high nesting birds rely on the safety of the tree for protection from predators, while the ground eggs need any extra camouflage they can have. Judging from the number and size of the eggs in the nest, these are likely Chaffinch, which live in the area. Unfortunately, I am not an expert in Oology (the study of birds eggs) and I can not be sure of this. There is a huge variety of such birds in Britain.

After the bird had flown off, and Matt and I had recovered from the shock of it’s unexpected squawk, we made sure nearby horses weren’t going to trample it, and moved away. The parent bird would return as soon as it was sure we had left.

Labyrinth Spider

The peculiar web of a labyrinth spider.

Dotted around Snelsmore Common you can find tubular spider webs, about 2cm in diameter, with wide sheets of spider silk around their entrance. This is not the home of the famous and feared Sydney Funnel-Web Spider, native to Australia, but the web of a Labyrinth Spider, that are common across Central Europe. The Labyrinth Spider, or Agelena Labyrinthica, is a species of funnel-web spider measuring at 10mm in males and 12mm in females with a broad beige cephalothorax, and a dark brown abdomen with a pale band down the middle.

These spiders will wait for prey to stray to close to their maze-like webs and send vibrations through the air as they struggle in the silk threads, alerting the spider to the prey’s presence. The spiders can feel these air vibrations through the use of trichobothria, small hairs on their legs, which are shaken by even the tiniest air movement. They will then exit their web and drag the prey back into their den. Typically, they will feed on small insects, such as grasshoppers and lacewings, since these creatures live in the tall grass they make their webs in. These spiders lay roughly 100 eggs, which are stored in an eggsack at the perimeter of the web, disguised with grass and leaf cover. They young remain in the web through winter, until they are ready to leave.

While the bites of Labyrinth Spider are harmless, their webs look very similar to those of the Cellar Spider, Segestria Florentina, who have a particularly painful bite. These spiders come to Britain on boats from Europe, and make their funnelled webs in cracks in buildings. To tell the difference, the Cellar Spider is black, with a distinctive green shine on the fangs, and will be living in urban, often costal areas. In addition, these spiders have five or six distinct lines leading from their homes, while the Labyrinth Spider has a single sheet. Try to avoid the Cellar Spiders, as their venom contains several painful neurotoxins.

The Labyrinth Spider webs could be found all over Snelsmore, around shin level in the grassy heather, but Matt and I did not see any of the spiders themselves, since we did not have time to wait and watch the webs.

Snelsmore Reptile Survey

This map of Snelsmore Common shows all of the points where Matt and I saw common lizards. Notice that there are not many in the south, where scrubland is rarer.

This map of Snelsmore Common shows all of the points where Matt and I saw common lizards. Notice that there are not many in the south, where scrubland is rarer.

On the second day of my work experience with Matt, we went to Snelsmore Common in order to survey the reptiles that were supposedly living there. There had been previous reports of Common Lizards, Slowworms, Grass Snakes and even Adders living around the common, and Matt and I needed to find out where each species was living, and how many of them there were. The only way to perform a reptile survey like this is to walk around the area that you are surveying for several hours, slowly looking to see what you can find, and noting down it’s position. After a quick look at the map, Matt broke up the Common into three sections: the flat southern section, covered in gauze bushes and deforested land, the west and centre area, filled with various heathers, and the rougher northern section, with longer, uncut heathers. We ignored the forests, since reptiles tend not to live in wooded areas like that, preferring the low bracken where they can get a lot of heat from the sun, while still staying close to cover.

The typical heather enviroment, Matt and I were searching.Stick piles like this are perfect for adders to hide in.

In the southerly section of the Common, there where very few reptiles could be found, except for the occasional lizard, there was very little heath for reptiles to hide in, since the whole area had recently been deforested. In order to control deforestation in this protected area, different sections are cut down for different harvests, meaning that the rest of the woodland has time to recover before more wood is needed. Another way in which this protected land is being sustainably used is grazing of Highland Cows. These cows are much closer to the pre-domestication wild cattle than the black and white cows we have today. As a result, they are far less picky with what they eat, munching on bracken and fern as easily as grass. This means that cattle can be raised in this area for human benefit, without cutting down the land for grazing space.

In the north and western areas, there was plenty of scrub for lizards and snakes to hide in, but the lizards that we did spot were to fast to photograph, leaving me sadly without any images of them. The heathers were taller here, and large piles of twigs were dotted about the landscape, the perfect places for adders to be hiding. The diamond crisscross camouflage on the adders back, helps to break up the outline of the adder, when it is amongst bracken. While still, it is very difficult to see a hidden adder, and so you must watch your step while in areas adders might live. Unfortunately, we did not see any adders, although I thought I saw the tail end of a large, brownish snake disappearing into the bushes. Since adders often remain in the same territories, we staked the bush out for several minutes, but the mystery snake did not return. We noted down where it was so that Matt could return another time.

In the day we had 16 lizards siting across Snelsdon Common, and one possible adder. This days was mainly about finding out what the Common was like, and where the reptiles where living. Matt will return to the Common several more times before he concludes this Reptile Survey.

Maidenhead Reptile Survey

A piece of roofing felt placed to attract reptiles.

On the second day of my work experience with Matt, we went to do a reptile survey near Maidenhead. The area was due to be turn into a bowling green, but before the developers could begin construction, they needed to have a reptile survey done in order to determine how many reptiles were living there and whether or not they needed to be relocated first. There had already been reports of Slowworms in this part of Maidenhead, and so it was Matt’s job to find out what was living here and how many. Matt had already placed out pieces of roofing felt, like the one above, in order to attract reptiles that needed cover and a place to warm their bodies.

We went on Matt’s fourth trip to the site, hoping to find around 8 – 12 slowworms hiding in the grass, as well as the (somewhat legendary) silver grey slowworm Eric, a large male with fairly rare blue specks, named by Matt. At first, the only thing that was hiding under the roofing felt were colonies of ants, which crawled onto our arms, and left us with little irritating bites. However, on the fourth piece of tarp, we found a small female, whose gender we could identify by the brown stripe running down her sides. Overall we found 10 of the legless lizards, including a beige juvenile and a large dark brown male, pictured below.A male slowworm caught under a piece of tarp.

Unfortunately, the illustrious Eric did not turn up today, but we did find another unexpected visitor underneath the tarp. As I reached down to scoop up a lizard for a better look, Matt waved me away. He had spotted the dark form of a snake underneath the grass, and for a scary moment had thought it an adder, waiting to lash out at my unsuspecting fingers. Upon closer inspection we found that it was a young grass snake, only just turned mature. It’s skin had turned almost completely black and it’s eyes where milky instead of clear, because it was ready to moult its old skin. The black scales would soon fall away to reveal new brown-white scales. The two large scales kept over it’s eyes to protect them had begun to lift away, causing them to fog up with the cloudy colours. It was fantastic to see.A near moulting grass snake, ready to drop it's skin.

We returned all of the roofing felt to it’s original place, and moved on to the next part of our day. Matt would have to return to this site another three times before his survey was complete, and then pass on the results to another ecologist for assessment and relocation.

Silt Pond Thrashing

A very silty pond.

Matt and I needed to thrash this churned up pond during my work experience with him, and we found a wealth of interesting life hiding in the rising silt of the pond. Grazing animals such as cows and sheep often come into ponds like this to bath and drink, and as a result a lot of grit and animal faeces are stirred up and reveal some interesting life near the pond floor. We located two major habitats within the pond that we needed to thrash, one of which was the clear bank nearest to us, where we could see pond skaters and whirligigs Whirligig beetles are small predatory beetles that skim on the surface of water, and use a collection of air bubbles they carry around with them, in order to dive and catch small invertebrates. They get their peculiar name from the unmistakable circling pattern they make when moving on the surface of the water, which is reminiscent of the spinning tops that they are named after.

On the left and right sides of the pond, where there was more aquatic vegetation, we found smaller water beetles. The water was murky from the silt, making it hard to see anything below the surface, and Matt had to wade in quite deep to find any of the dragonfly or mayfly larvae, or to pick leeches off the surface of the sedge and pondweed. Thrashing this area was harder than the first, since we could not properly see where the weeds were below the surface, and they dragged into our nets. Despite this, we found a number of beetles we had not seen in any pond that day, and collected them to be dissected to identify their exact species.

An emperor dragonfly larvae we found in the pond.Silt from the pond. After thoroughly thrashing the pond for about an hour, Matt and I found water boatmen, water skaters, whirligigs, a nasal leech, emperor dragonfly larvae, mayfly larvae, caddisfly larvae cases, many small water beetles and bloodworms. The pond can be considered fairly productive, with a healthy foodweb, although it is likely that grazing animals wallowing in it has had a large effect on the ponds diversity.

Palmate Newt

An adult palmate newt.

While thrashing a pond full of newts on my work experience with Matt, we found an adult Palmate Newt hiding in the pondweeds nearby some common frogs. It is the smallest newt in Britain, 6 or 7cm smaller than the enormous Great Crested Newt, is common throughout West Europe, although it is actually extremely rare in Belgium and Holland. Palmate Newts are normally brown or pink in colour, with a slightly darker banded stripe across their eyes. They can have dark spots on their backs, but never as many as a Smooth Newt, and not as dark as those of a Great Crested Newt. Males possess webbed back feet, as well as a slight, smooth crest that will develop during mating season, which is around April.

These newts will eat most invertebrates smaller than them, crustaceans like freshwater shrimp, water fleas, frog or toad tadpoles, and occasionally, they will eat each other, making them the only cannibalistic newt in the UK. Palmate Newts only hunt at night, when the air is full of water, or the ground is particularly damp, spending the day and unsuitable nights underwater or beneath moist logs and stones. During the breeding season, the newts will also become active during the day, since they need to attract a mate and hunt.

The newt Matt and I found was a young female, and in relatively good health. We noted that Palmate Newts were present in the pond, and then moved away from where we found her, so that we wouldn’t disturb her and the other newts in the area again.