A Greater Weever (Trachinus draco) has been found in a stretch of the Thames estuary in Great Britain. The species, which is native to the Eastern Atlantic, the Mediterranean, and the Black Sea, is one of many signs of the improving health of the Thames estuary.

The weever was found after a two-year investigation carried out by the Environment Agency and Zoological Society of London and is the 60th new species found in the Thames since 2006. “The diversity and abundance of fish is an excellent indicator of the estuary’s health”, says Environment Agency Fishery Officer Emma Barton.

Flowing through London and several other urban areas, the Thames has a long history of being heavily polluted. In the so called ‘Great Stink’ of 1858, pollution in the river was so severe that sittings at the House of Commons at Westminister had to be abandoned.

So, should we fear this semi-new addition to the Thames estuary? No, there is no need to panic. This fish can deliver a very painful sting and should be handled with care, but the sting is rarely dangerous to humans – especially not if you seek medical attention.

The Greater Weever has venom glands attached to both of the spines on its first dorsal fin, and to the spines of the gill cover. The spines are equipped with grooves through which venom is driven up if the spines are pressed. A person that receives a sting from a Greater Weever can develop localized pain and swelling, and the result has – in a few rare cases – been fatal. Fortunately, there are several things you can do to make the situation less dangerous for a stung victim.

· If the wound bleeds, allow the wound to bleed freely (within reason of course) to expel as much venom as possible.

· Soak the affected limb in warm water because the toxin produced by the Greater Weever is sensitive to heat. There is no need use extremely hot water it and risk scalding the skin, because the toxin will deteriorate at a temperature of 40° C / 104° F.

· Seek medical attention.

The pain is normally at its most intense during the first two hours after being stung and even without treatment, the severe pain normally goes away within 24 hours. It is however possible for some pain to last for up to two weeks, and it is also possible for the spine to break off and get stuck inside the stung limb where it can continue to cause problems until it is removed.

In May this year, hundreds of Asian swamp eels were discovered in and around Silver Lake in historic Gibbsboro, New Jersey. This was the first finding in New Jersey, Asian swamp eelbut not the first finding in the United States. Unlike Florida, Georgia, and Hawaii – the three other U.S. states where this species have been discovered – New Jersey is however subjected to harsh winters and a breeding population of Asian swamp eels in New Jersey confirms the suspicion that this Asian invader has no problem adjusting to the
chilly climate of northern North America.

The Asian swamp eels were found by a local college student checking on frogs and turtles in the Silver Lake. As he spotted snake-like heads peeking from the water, he decided to photograph them and post the pictures online. This lead to the “snakes” being identified as Asian swamp eels, Monopterus albus, and prompted a call to the local authorities.

In its native environment in Asia and Australia, the swamp eel Monopterus albus inhabits gentle hill streams, estuaries and lowland wetlands, and it is a common species in rice paddies. It has developed a long row of traits that makes it an apt survivor in many different kinds of environments. Unfortunately, these traits also make it the “perfect” invasive species and biologists fear that the Asian swamp eel may wreck havoc with existing North American ecosystems, especially if the predatory species of these systems prefer to target familiar prey rather than catching the newcomers.

– The Asian swamp eel can survive long periods of drought by burrowing in moist earth, and can therefore take advantage of seasonally appearing, short-lived bodies of water.

– If its home becomes unsuitable, e.g. because of drought, this eel simply crawls ashore and make its way to a more suitable home by slithering over land, just like a snake. This makes it hard to eradicate from bodies of water using poison or similar; there is always the risk of at least two specimens getting away over land and forming a new breeding colony in nearby waters.

– The Asian swamp eel can tolerate a wide range of oxygen levels in the water since it is capable of absorbing oxygen from the air above the surface through its skin. This skill doesn’t only come in handy in oxygen depleted waters; it is also what makes it possible for the fish to travel impressive distances over land.

– This eel prefers freshwater habitats, but can tolerate brackish and saline conditions, which increases its chances of always finding a suitable home.

– It eats all sorts of prey, not only fish, crustaceans, amphibians, and other aquatic animals, but detritus (decaying organic matter) as well. Highly specialized feeders have a much harder time adjusting to new habitats and are therefore less likely to become problematic invasive species.

– This eel is a protandrous hermaphrodite, which means that it can change its sex. All specimens are born male, but can turn into females if necessary. This means that if an aquarist releases two male specimens into a lake, one of them can turn into a female to make reproduction possible.

In Georgia, the first specimens of Asian swamp eel was discovered in 1994, and three years later eels were found in Florida as well. The Hawaiian history of combating swamp eels is much longer as the first specimens are believed to have been released in Hawaiian waters about 100 years ago. In Georgia and New Jersey, biologists blame aquarists of having caused the situation by releasing their pets into the wild. In Florida and Hawaii however, Asian food markets and fish-farmers are considered more likely sources. Asian swamp eels are typically sold fresh in food markets and can be kept alive for long periods of time as long as their skin is kept moist.

New Jersey authorities are now focusing on containing the creatures while trying to figure out a way of annihilating them. “We’re not panicking yet,” says Lisa Barno, chief of the New Jersey Bureau of Freshwater Fisheries. “It’s more that it’s just an invasive species we’d rather not have. We’re still documenting the true extent of the problem, but right now it seems to be fairly contained.” One of the immediate goals is to prevent an expansion downstream to the Cooper River and a watershed leading to the Delaware River. Since May, only one Asian swamp eel has been discovered outside the Silver Lake.

In addition to the recently proposed areas in the Pacific Ocean, (See this and this) president Bush now says he wants to find even more regions of the Pacific Ocean to protect.

This Friday, Bush made public that he has asked the secretaries of the Interior, Commerce and Defense to identify additional areas of the Pacific Ocean that could be eligible for conservation. He also revealed that the Monterey Bay National Marine Sanctuary will be expanded by 585 square nautical miles and come to include the Davidson Seamount. Davidson Seamount is a 42 km long underwater mountain located roughly 120 km southwest of Monterey, California. The seamount rises 2400 meters off the ocean floor, but its highest point is still more than a kilometre below the surface.

In a new study on Tanganyika cichlids, three scientists[1] [2] [3] from Uppsala University in Sweden have shown that intricate rearing behaviour varies with brain size in females. The only previously published study showing similar patterns concerned predatory animals.

Tropheus moori – one of the species used in the study. – Picture www.jjphoto.dk

How the vertebrate brain has developed throughout the course of evolution is still not clear, and we are still not certain if brain functions in a specific species develop to match a demanding environment. One way of learning more about this is to compare brain size and structure in closely related species living under dissimilar circumstances.

“It is important to look at differences between males and females since females often distinguish themselves from males, both in behaviour and appearance”, says Niclas Kolm, lead-author of the study.

The study looked for correlations between brain size and ecological factors in a large number of specimens from 39 different species of Tanganyika cichlid. Lake Tanganyika is especially suitable for this type of study since it is inhabited by cichlid groups exhibiting significant dissimilarities in both brain structure and ecology, and whose ancestry is well known. Tanganyika cichlids varies dramatically from species to species when it comes to factors such as body size, diet, habitat, parental care, partner selection, dissimilarities between the sexes, mating behaviour, and brain structure.

The result of the study showed a correlation between brain size and the two factors diet and parental care behaviour. Species where only the female fish cares for egg and fry turned out to have bigger brains than species where both parents engage in parental care. The brain was however only larger in females; there was no difference in brain size between males of the two groups.

The largest brains of all were found in algae-eating cichlids. These fishes live in environments characterized by a high level of social interaction. “This indicates that social environment have played a role in brain development”, says Kolm.

The study was published in the web version of “Proceedings of the Royal Society of London Series B” on September 17. You can find it here (http://journals.royalsociety.org/content/j114062824820l76/).

As you probably know already, many sea living creatures are capable of emitting their own fluorescent light. Turning yourself into a living light bulb comes in handy when you live at depths where no sunlight or only very little sun light is capable of reaching you, and the glow can for instance be used for communication, as camouflage, or to lure in prey.

Up until now, most fish experts have assumed that marine fish living below a depth of 10 metres (30 feet) could not be red since the type of sunlight necessary for the colour red to be visible to the eye isn’t capable of travelling so far down into the ocean, and why would an animal develop a red pigmentation that nobody could see in its natural habitat?

New light has now been shed on the situation and – according to a study published on September 15 by researchers at the University of Tubingen in Germany – fish living at these depths have managed to circumvent the problem of light scarcity by emitting their own red fluorescent light instead of relying on sun beams to display their colours. According to the study, a lot of marine species are capable of emitting a fluorescent red light which can be seen even at depths below 10 meters.

“The general consensus, which dominated fish literature for 20 or 30 years, was that fish don’t see red very well or at all,” says Nico Michiels, one of the researchers behind the study. “We have been blinded, literally, by the blue-green light that is available on reefs in the daytime.”

The scuba diving research team made their discovery when looking through a filter that blocked out the brighter green and blue light waves. While using the filter – which leaves only red light waves – the scientists realised that their dive spot was inhabited by a long row if different marine creatures capable of emitting their own red light. In addition to fish, they saw fluorescent red coral, algae and other small organisms.

Further investigation revealed that the red glowing organisms use guanine crystals to produce their light. Guanine is one of the five main nucleobases found in DNA and RNA and guanine crystals are commonly used by the cosmetics industry to give products such as shampoo, eye shadows and nail polish a shimmering lustre. As early as 1656, a Parisian rosary maker named François Jaquin extracted crystalline guanine forming G-quadruplexes from fish scales – so called pearl essence. Guanine crystals are rhombic platelets composed of multiple transparent layers and the pearly lustre appears when light is partially reflected and transmitted from layer to layer.

The red fluorescent light emitted by the organisms studied by Michiels and his colleagues is only visible at a close distance, at least to us humans. More research is now needed to investigate why so many sea dwellers have developed this capacity and how the red colour benefits them in their daily life.

The sturgeon on the picture is not the sturgeon in the story
Photo by NOAA

A four year old boy got his arm broken by a jumping sturgeon on the Suwannee River on September 7. At the same time, the boy’s father was cut by the fish. According to the Fish and Wildlife Conservation Commission, witnesses observed the family’s boat moving through the water at about 30 miles per hour when a three to four foot long sturgeon jumped up from the water in front of the craft. The sturgeon shattered the boat’s windshield and cut 32-year old Christopher Howard before smashing into his four year old son Chandler Howard. The impact was severe enough to break the arm of the young boy.

The Suwannee River is home to a major sturgeon population. According to state biologists, about 6,500-7,000 specimens spend up to 9 months per year in the river. Since their average weight is 40 lbs (18 kg) and the largest specimens caught in the Suwannee weigh about 200 lbs (90 kg), these sturgeons can cause serious injury to humans when jumping up from the water at high speed.

A conservation group named Bush Heritage Australia will spend $3.5 millions on the purchase and ongoing management of 8100 hectares in Central Queensland. The main reason for the purchase is to safeguard the rare Redfin blue-eye fish.

The property, Edgbaston Station, is connected to a network of more than 50 artesian springs that provides Edgbaston pools with spring water from the Great Artesian Basin. The spring-fed pools are surrounded by arid landscape and the isolation has given numerous endemic species a chance to develop, including several species of fish, snails, plants and a crustacean. The entire known population of Redfin blue-eye resides in five spring-fed pools at Edgbaston. In addition to arid grass lands and spring-fed pools, the property also contains woodlands and wetlands and is an important region for migratory birds. The rare Redfin blue-eye fish is therefore not the only species that will benefit from the purchase.

A substantial part of the money used to finance the acquisition of Edgbaston Station – $1.324 millions – comes from the Australian Government’s “Maintaining Australia’s Biodiversity Hotspots” program­. The two departments “Qld Department of Natural Resources and Water” and “Qld Department for Sustainability, Climate Change and Innovation” have also assisted, together with Bush Heritage Australia volunteers and donors.

Edgbaston Station is located within the traditional country of the Iningai people and Bush Heritage Australia plans to work together with them to understand and protect the cultural values of the property.

“Edgbaston has exceptional biodiversity value and Bush Heritage is proud to own, manage and protect such an important Australian landscape,” says Doug Humann, CEO of Bush Heritage Australia. “This purchase will allow us to closely manage the health of Edgbaston’s incredible artesian springs, which support a variety of life forms unique to the region.”

Bush Heritage Australia currently owns and manages 31 reserves throughout Australia. You can find more information on their site: http://www.bushheritage.org.au.

1 Australian dollar = 0.8 U.S. dollars

Facts about the Red-finned Blue-eye

The Red-finned Blue-eye (Scaturiginichthys vermeilipinnis) lives in spring fed pools in Queensland and the species has only been encountered in a handful of pools. None of the pools are very large and the average water depth is just a few centimetres. The pools are located in a very arid part of Australia and there is hardly any surrounding vegetation that can shadow the shallow water. During the hot season, the air temperature can reach 50 degrees C (122 degrees F) during the day and the water in the pools can become almost as warm as the surrounding air. The Red-finned Blue-eye is however not only capable of handling a high water temperatures; it is also very tolerant to rapid changes in water temperature since the shallow pools where it lives change temperature rapidly as the surrounding air temperature fluctuates. During the cold season, the water temperature can be as cold as 3 degrees C (37 degrees F).

The Red-finned Blue-eye is listed as “Critically Endangered” on the IUCN Red List of Threatened Species.

In an earlier post, we wrote about President Bush’s proposal to create the largest protected marine area in the world in the Pacific Ocean.

A group of scientists, environmental groups, and former members of Australia’s navy are now calling for the creation of another reserve that would ban fishing in a whopping 400,000 square mile area off Australia’s northeast coast.

Coral at the Great barrier reef, Australia

It will sure be interesting to see if these two suggestions will become a reality, and if so, which of the protected areas that will ultimately become the largest protected marine area in the world. When discussing protected areas it is also important to keep in mind that the term “protected” can mean very different things.

The proposed protected area off of Australia’s northeast coast is known as the Coral Sea. It is a so called marginal sea, which means that it is a part of an ocean partially enclosed by land, e.g. by archipelagos and peninsulas. The Coral Sea is bordered by the east coast of Queensland to the west, by the Vanuatu archipelago and New Caledonia to the east, and by the Solomon Islands to the north.

The Coral Sea Basin is believed to have been formed between 58 and 48 million years ago when the Queensland continental shelf was lifted up by tectonic forces. The sea is not only famous for its rich biodiversity; it is of cultural significance as well and was for instance the location of a famous battle during World War II.

The effort to create a no-take marine park in the Coral Sea is headed by the Pew Environment Group. You can find more information about the initiative on their site.

Two new species of fish has been scientifically described and named: Glyptothorax filicatus and Glyptothorax strabonis. The genus Glyptothorax is a part of the family Sisoridae in the catfish order Siluriformes, and the most species-rich and widely distributed genus of the entire family.

The new species both hail from Vietnam and were described by Heok Hee Ng[1] and Jörg Freyhof[2]. Glyptothorax species typically live in fast flowing hillstreams or faster-flowing stretches of larger rivers, and the two new species are no exceptions – they have both been described from the rivers draining the Annam Cordilleras in central Vietnam.

Glyptothorax filicatus can be distinguished from its close relatives in Indochina on the diverging pattern of striae that runs along the edges of the central depression in the thoracic adhesive apparatus, while Glyptothorax strabonis is recognized on its very small eyes.

As an adaptation to a life in fast moving waters, members of the Glyptothorax all have an adhesive apparatus on the body, commonly known as a “sucker”. An adhesive apparatus comes in handy when you live in fast flowing waters since it makes it possible to “suck” yourself to a surface, e.g. a rock, and avoid being swept away by the current. Members of the genus Glyptothorax are equipped with an adhesive apparatus on the thorax with grooves parallel or oblique to the longitudinal axis of the body. This separates them from the other genera in the family since those fishes have no thoracic adhesive apparatus at all or a thoracic adhesive apparatus with grooves that runs transverse to the longitudinal axis of body.

During the last week of August, Gary Owen, a Charles County sheriff’s corporal, discovered 167 snakeheads swimming in two puddles off Sharpersville Road near Mattawoman Creek in Maryland. Mattawoman Creek is a tidal tributary of the Potomac River located in Prince George’s and Charles Counties. The sheriff’s corporal was not actually on the look-out for invasive species when he did his unexpected discovery; he was leading a news crew to a location where a homicide victim was found almost 30 years ago.

The group of 167 snakeheads, who inhabited two puddles under a tree stump, consisted of two adult fish and 165 youngsters. The two adults were a male and a pregnant female. When the finding was reported to the Maryland Department of Natural Resources, they decided to kill all fishes and take them to their laboratory for further examination.

Mattawoman Creek is considered one of the best creeks for bass fishing on the East Coasts and anglers now worry that snakeheads might cause injury to the bass populations by competing for the same prey or by preying on smaller bass.

Snakeheads are not a natural part of the Maryland fauna; they hail from Africa and South East Asia, and conversationalists fear that these skilled predators could disrupt native ecosystems if there were allowed to establish themselves in the U.S. Snakeheads became the centre of quite a media frenzy when they were discovered in Maryland in 2002 as the first known examples of a breeding population of wild snakeheads in the U.S. You can read more about it in our article “Environmental effects of Snakeheads”. You can see how widespread sakeheads have become in parts of the Potomac river in this video.

Since 2003, it is illegal to import snakeheads to the United States.