crab

Velvet Swimming Crab

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While surveying the Pacific Oyster population on Batten Bay, Jack lifted several smaller rocks that littered the coastline, giving us a glimpse of the wildlife that was hiding under the seaweed forests that covered the lower shore. At first glance, most animals on the rocky landscape seemed stationary and with little diversity. Limpets and oysters dominated the rocky areas and on the sandy beaches tiny common crabs scuttled, giving the only sign of movement. The Plymouth coastline, however, is one of the most diverse habitats in Britain. Hidden beneath the sand, there is a wide range of snails, tiny nudibranchs, sea spiders and most noticeably, this creature:

A Velvet Swimming Crab, raising its claws in absolute fury.

The Velvet Swimming Crab is one of the largest crabs that can be found on the British coast, preferring areas of sheltered shore, such as the crannies of the large slate formations across Batten Bay. Commonly found across Europe in the North Atlantic and Mediterranean, easily identifiable by the blue and red stripes around the eyes and carapace, and the tiny hairs across the back that give it the ‘velvet’ part of its name. It’s paddle like back legs allow it to swim in high tides, rather than being forced to scuttle on the sea floor. Extremely aggressive for a crab of its size, it is little wonder that these crabs are sometimes called Devil Crabs, and even as I held it firmly from the back, I could feel it trying to turn and assault my fingers. This is an example of some of the larger creatures that make up the Plymouth aquaculture, but there are many other species hiding under rocks, just out off sight.

The AES Annual Exhibition and Trade Fair

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Once every year, the Amateur Entomologist Society holds a large meeting at Kempton Racetrack, where enthusiasts and traders can come and show off their invertebrates and trade them. It is the largest event of its type in Britain, and several hundred entomologist turn up each year to attend. I go to this event most years, since I have a sizable interest in entomology (keeping a colony of white-spotted assassin bugs myself) and I enjoy wandering about the stands looking at the different exhibits.

On the ground floor of the Kempton Racetrack building, there is a large trade centre, where breeders from across the country gather to display and sell the various invertebrates that they have in stock. Phasmids, cockroaches, mantis and any number of pinned butterflies. Tarantulas are a particular favourite, with a wide variety, including Red Rump, Salmon Pink, Ornamental Indian and Greenbottle Blue Tarantulas available as spiderlings, as well as many more. Tarantulas are incredibly large ambush spiders, meaning that rather than build elaborate webs to catch flying prey, like the garden spiders we are used to seeing, they prefer to lie in wait, watching for invertebrates and small mammals that stray to close them. People are often terrified of the Tarantula’s giant fangs, which can seem extremely intimidating. While there bite is painful, it is not fatal; the real threat that Tarantulas pose are in their bristles. These tiny barbed hairs can be released into the air, where they get into the eyes and nose and irritate the skin.A Red Rump Tarantula in a box at the Trade Fair.

On the floor above, while there are still many traders about, the various societies, such as the Phasmid Study Group, who deal in stick and leaf insects, and the Bug Club, for minors who are interested in the basics of entomology. This year there was even a small unattended stand proclaiming the importance of earthworms on soil health, naming four separate kinds of worm and a largely inactive worm enclosure. Why a worm would need such a secure enclosure is beyond me, and there was no one around to ask. I saw a number of crabs, which while they are not actually to do with entomology are invertebrate, and therefore fair game. My father even decided to bring home three of those Hermit Crabs to keep in a tank. I shall see how they progress.A group of Rusty Millipede on hisplay at the exhibition.

Also attending the Exhibition, was Matt Smith, who took me on my work experience thrashing ponds and surveying reptiles a few months ago. As a professional entomologist and ecologist, he always attends the Trade Fair, and sometimes sells the extra beetle grubs from his vast collection of colourful invertebrates.

I enjoy the AES Annual Exhibition greatly, and it is one of the highlights of my year. I hope to attend again next year, if my exam schedule permits me to. The people there are almost as interesting as the insects.

Feeding the Ray Pool

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I feed the juvenile tank in the aquarium ray pool.

On my day as a helper at the London Aquarium, one of the interesting activities I participated in was feeding the ray pools, which are the open pools near the start of the aquarium containing all manner of flatfish, crabs and rays. Taking a delectable tray of calamari, raw fish, freeze dried prawns and other seafood goodies, the staff, Monica (my guide for the day), and I went about the pools making sure all of the animals were fed. Under the direction of the staff I selected the correct creatures and gave them food with the use of a long stick and some well timed throws.

Above I am feeding the juvenile tank, where the adolescent rays are kept after they are old enough to come out of the private tanks in the back of the aquarium. There are a selection of Undulated and Thornback Rays in the ray pools, and we used smaller pieces of fish and squid for these younger ones. In the wild they would act the same way any adult ray did, but for the sake of safety the aquarium places them separate to the larger crabs of the adult pool. The more confident rays came to the surface to receive their food, and would often snatch food away from the shyer animals, meaning I had to make sure those rays got food while the others weren’t looking. It was difficult to time, since they did not always eat the food immediately, but between myself and the staff, every ray got some food.The aquarium staff feed the various denizens of the ray pool.

In the larger ray pool, there were some animals other than rays to feed, such as the aptly named Herbert, who was a Turbot, and a large slow moving Edible Crab. Turbots camouflage is perfect for the sandy sea bed, a mixture of pale yellows and white, only identifiable by the twin eyes poking out from under the sand. Flatfishes eyes start on different sides of their heads when they are born, but as they develop, the eye on the bottom side rise through the head to the other side, since they do not see on the face down side. The crab was slow to move, and I had to dangle the squid and prawns in front of his face before he would try to eat them. Fighting back other hungry rays, I would hold it in front of him, waiting for his soporific claw to close around the food.

It was incredible fun to feed these animals, and I was amazed to be working so closely with such  incredible creatures. I hope to work with animals like this again in the future, and recommend it utterly to all who are considering such opportunities.