The catfish L239 has finally been described by science and given a proper name: Baryancistrus beggini. Ichthyologists Lujan, Arce and Armbruster described the species in a paper[1] published in the journal Copeia[2].

Baryancistrus beggini lives in Venezuela and Colombia; in Rio Guaviare and at the confluence of Rio Ventuari and Rio Orinoco. The researchers found the fish in crevices amongst boulders. By analysing stomach contents, they were able to learn that this catfish feeds on periphyton and associated microfauna growing on rocks. (Periphyton is a mixture of algae, heterotrophic microbes, cyanobacteria, and detritus that can be found attached to submerged surfaces, e.g. stones, in most underwater ecosystems.)

In the aquarium trade, L239 is known as Blue panaque or Blue-fin panaque. The name beggini was given by Lujan and his colleagues in honour of Chris Beggin, the owner of an aquarium fish store in Nashville, USA who funded the research. The species has been placed in the genus Baryancistrus, but this might have to be corrected in the future as we learn more about the tribe Ancistrini.

Baryancistrus beggini sports a uniformly dark black to brown base colour with a blue sheen and the abdomen is naked. Along each side of the body you can see a distinctive keel above the pectoral finns; a keel formed by the strongly bent first three to five plates of the midventral series. The body also features two to three symmetrical and ordered predorsal plate rows and the last dorsal-fin ray is connected to the adipose fin.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Loricariidae
Subfamily: Hypostominae
Tribe: Ancistrini
Genus: Baryancistrus

New species: Baryancistrus beggini

The hydrothermal vents that line the mid-ocean ridges are a major source of iron for the creatures living in the sea. Humans are not the only ones who suffer when iron becomes scarce; creatures such as phytoplankton are known to grow listless in waters low in iron, even if they are drifting around in an environment rich in many other types of nutrients.

Earlier, scientists assumed that the iron exuded from hydrothermal vents immediately formed mineralized particles as soon as it came in contact with the salty water – a form of iron that is hard to utilize for living creatures.

New research has however unveiled that some of the iron spewed out from these vents actually remain in a form that is easy to absorb for oceanic beings. According to researcher Brandy Toner, a surprising interaction between iron and carbon in hydrothermal vents serves to stop the corrosion.

“Iron doesn’t behave as we had expected in hydrothermal plumes. Part of the iron from the hydrothermal fluid sticks to particulate organic matter and seems to be protected from oxidation processes,” Toner explains.

The research was carried out on hydrothermal vent particles collected by the team from the Tica vent in the Eastern Pacific Rise. With the help of the Advanced Light Source synchrotron at the Lawrence Berkeley National Laboratory, Toner was able to analyze the particles using focused X-ray beams.

Iron is a key player in this newly discovered process in the ocean, but the exact mechanisms remains unknown.

“So the question becomes, what are those organic compounds? Are they organic compounds like in oils and tars or is it actually the stuff of life?”, says Chris German, co-author of the paper. “Brandy’s work doesn’t mean that these [carbon-iron] complexes are definitely alive. But, this is a possible smoking gun. This paper opens up a whole new line of research and asks a new set of questions that people didn’t know they should be worrying about until now. A bit of work on a tiny nanometer scale can force you to ask questions of global significance.

Perhaps hydrothermal venting, a process traditionally believed to be a completely inorganic process, actually is a part of the organic carbon cycle on our planet.

The paper “Preservation of iron (II) by carbon-rich matrices in a hydrothermal plume” by Brandy Toner and her colleagues[1] has been published in Nature Geoscience[2].

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Aquarium Toplist function added

Reef building corals rely on herbivore animals to continuously remove unwanted algae growth from them, since algae compete with the corals for both sunlight and nutrients. Without regular cleaning, corals eventually die and the reef becomes overgrown by various types of algae. A report scheduled to be published this week in the early edition of the journal Proceedings of the National Academy of Sciences now suggests that having herbivore animals present on the reef isn’t enough; there must also be a proper balance between the various species. This conclusion results from a long-term study on coral reef recovery and seaweed[1] carried out by Dr. Mark Hay, the Harry and Linda Teasley Professor of Biology at the Georgia Institute of Technology, and his co-author Dr. Deron Burkepile who is now Assistant Professor at the Florida International University’s Marine Science Program.

Different fish feed on different algae and maintaining a proper balance may therefore be critical. “Of the many different fish that are part of coral ecosystems, there may be a small number of species that are really critical for keeping big seaweeds from over-growing and killing corals,” says Hay. “Our study shows that in addition to having enough herbivores, coral ecosystems also need the right mix of species to overcome the different defensive tactics of the seaweeds. This could offer one more approach to resource managers. If ecosystems were managed for critical mixes of herbivorous species, we might see more rapid recovery of the reefs.”

Coral reef

The 10 month long study was carried out 18 metres (60 feet) below the surface off the coast of Florida, where Hay and Burkepile placed 32 cages on a coral reef in November 2003. At this point, the coral reef area chosen by the researchers had only four to five percent live coral coverage. Each cage was roughly two metres square and one metre tall (1 metre = 3.3 feet) and the mesh was fine enough to prevent large fish from entering or leaving the cage. The scientists then carefully selected the number and type of fish to place in each cage, using the four following combinations:

· Two fish capable of eating hard, calcified plants

· Two fish capable of eating eat soft plants that defends themselves chemically

· Both types of fish.

· No fish at all

The two species used for the experiement where the Redband parrotfish (Sparisoma aurofrenatum) and the Ocean surgeonfish (Acanthurus bahianus).

As suspected, the type of fish turned out to play a key role in the growth of algae and seaweed on the reef.

“For the cages in which we mixed the two species of herbivores, the fish were able to remove much more of the upright seaweeds, and the corals in those areas increased in cover by more than 20 percent during ten months,” says Hay. “That is a dramatic rate of increase for a Caribbean reef.”

Areas with only one type of fish or no fish at all lost as much as 30 percent of their live coral coverage during the research, while areas with two species of fish increased their live coral coverage from four to five percent to six to seven percent.

“Species diversity is critically important, but we are losing critical components of the Earth’s ecosystem at an alarming rate,” says Hay. “There has been little work on the role of diversity among consumers and the effect that has on communities. This study will help add to our knowledge in this critical area.”

After the initial 10-month experiment, Hay and Burkepile launched a second study where the Ocean surgeonfish (Acanthurus bahianus) was substituted with Princess parrotfish (Scarus taeniopterus). Unfortunately, the cages only stayed on the reef for seven months before being wiped away by Hurricane Dennis in July 2005.

The research was conducted at the National Undersea Research Center in Key Largo, Florida and supported by the National Oceanic and Atmospheric Administration, the National Science Foundation and the Teasley Endowment at Georgia Tech.

You can read more about Hay’s and Burkepile’s work at

http://www.biology.gatech.edu/faculty/mark-hay/ http://www.biology.gatech.edu/faculty/mark-hay/lab.php
http://www.fiu.edu/~dburkepi/front.htm
http://www.fiu.edu/~dburkepi/research.htm

The release of sediment and algae-boosting fertilizers into Lake Victoria can cause cichlid species to interbreed in the murky water, according to Ole Seehausen, evolutionary biologist at the University of Bern in Switzerland and the Swiss Federal Institute of Aquatic Science and Technology in Kastanienbaum.

In a recent article published in Nature, Seehausen and his colleagues are shedding some light on the question of how closely related species of cichlids living adjacent to each other in Lake Victoria manages to avoid interbreeding. According to Seehausen et al, species may develop and stay distinct because of how the members of each species see colours.

Seehausen and his research team have studied closely related species of Lake Victoria cichlids where the males are either blue or red. It has since long been known that females of these species prefer to mate with the male displaying the brightest colours, but the new research suggests that both sexes have evolved to preferentially see only red or blue. This means that if a brightly coloured red male swims by a blue-seeing female, she will not be able to appreciate his sexy brightness since see can not see the colour red.

“Reds and blues live in the exact same spot,” says Seehausen,. “Colour is very important in mate choice.”

In order to fully understand the role of vision in underwater evolution, we must be aware of how light acts when it penetrates the water. Blue colours shine much brighter than red ones in the shallows, while red pigmentation trumps blue as we proceed farther down. As you probably have guessed already, red cichlid species tend to be found near the surface in Lake Victoria, while the blue ones inhabit greater depths.

To learn more about what happens to cichlids in the transition between red and blue zones in the lake, Seehausen and his team studied species inhabiting the shores of five different islands. The cloudiness of the surrounding waters varies from island to island due to variations in sedimentation, giving the researchers a great opportunity to study the effects of varying water clearness.

In comparatively clear waters, the colour that appears brighter slowly and gradually changes from red to blue with depth. This makes each species stay within its own zone and prevents interbreeding. In more clouded waters, the change from red to blue occurs much more suddenly, causing a higher prevalence of interbreeding between closely related species of fish.

Further testing in laboratory aquariums showed that hybrid females, like the ones living in cloudy waters, did not favour red males over blue ones or the other way around. This distinguished them from non-hybrid females, since females belonging to a species with red-sensing eyes picked red males in the laboratory tanks while the blue-sensing females opted for blue beaus.

Seehausen is now worried that the unchecked release of sediment and algae-promoting fertilizers into Lake Victoria will cause more and more fish to interbreed, thereby greatly reducing the number of species in a lake famous for its astonishing biological diversity and degree of endemic species. “Species diversity in this lake has imploded in the last 30 years,” Seehausen says. “It is the largest human-witnessed mass extinction of vertebrates.“

You can read more in the article “Speciation through sensory drive in cichlid fish” by Seehausen et al. http://www.nature.com/nature/journal/v455/n7213/abs/nature07285.html

Researchers at Arizona State University have received a $3 million grant to further develop their aviation fuel derived from algae. The development of algae jet fuel is already progressed quit far and researchers have already moved past the laboratory stage and are working on a pilot project to scale the process. They hope to be able to create large quantities of economically competitive jet fuel as soon as possible. The research team says that cost reduction benefits are greater than with kerosene produced from petroleum.

The breakthrough in the research to create algae jet fuel came when the researchers identified algae strains that can convert pieces of their cellular mass into oil containing high concentrations of medium chain fatty acids. The hydrocarbon chains that are created when the oil is deoxygenated are very similar to those created when regular kerosene goes through the same process.

Researchers hope that this type of jet fuel might end up being cheaper than regular kerosene based jet fuel as an expensive process (thermal cracking) isn’t necessary to make jet fuel from algae oil.

The new fuel can be used in most jet planes when mixed with a small amount of fuel additives.

I will post a more complete introduction to algae oil before the end of this week. (I Hope)