This Thursday, the Anchorage-based North Pacific Fishery Management Council[1] approved an unprecedented plan to ban commercial fishing in the Arctic Ocean, as a part of their Arctic Fishery Management Plan. The council voted 11-0 in favour of the plan, which essentially bans all commercial fishing from the Canadian border down to the Bering Strait, and it is now up to the U.S. Commerce secretary to approve or reject the ban.

Before approving the ban, the North Pacific Fishery Management Council spent two years developing an Arctic Fishery Management Plan in response to global warming and the retreat of sea ice along Alaska’s northern coast. As of today, fishing is not carried out on any major scale in the Arctic Ocean, but commercially interesting species like crab and pollock may expand in this part of the sea and this could make the area attractive for fishing fleets. The council therefore decided to develop a plan in advance to be prepared for any future developments.

Environmentalists and fishing industry groups alike have praised the Arctic Plan, since both parties recognize the need to enforce strong management control over the Arctic Ocean. We still know very little about life in this remote part of the world and the few fish stock surveys that has been carried out in these waters has not managed to find any larger fish populations. The area could be opened up for regulated commercial fishing in the future, if more thorough research of the Arctic Ocean would show that sustainable fishing could be carried out without injuring the ecosystem.

“Climate change is having a significant effect on the Arctic, opening previously ice-covered waters and drawing cold-water species farther north,” says Dave Benton of the Alaskan Marine Conservation Alliance[2]. “The council’s action to close these waters as a precautionary measure gives us the opportunity to conduct the scientific review necessary to develop a plan for how sustainable fisheries might be conducted in the Arctic in the future.“

A new species of catfish belonging to the genus Lithogenes has been described by ichthyologists Scott Schaefer and Francisco Provenzano in a recent issue of the journal American Museum Novitates[1].

The new fish has been given the name Lithogenes wahari, after Ruá-Wahari, the Piaroapeople’s God of Creation[2]. The species is known from the Cuao River, a part of the Orinoco River drainage, where it inhabits clear and swift forest streams with exposed bedrock substratum. It was actually collected over 20 years ago by anthropologist Stanford Zent, but it would take until 2001 before the fish was found again by Scott Schaefer and Francisco Provenzano.

Lithogenes wahari is the third scientifically described member of the small genus Lithogenes and can be distinguished from its two close relatives by the absence of odontodes on the proximal portion of the ventral surface of the first pelvic-fin ray, the lack of accessory premaxillary teeth, the extensive ridges present on the thickened skin of the pelvic pad, and the intense pigment band that runs along the base of the anal fin. There is also a diffuse spot located midlength on the anal fin rays.

Interestingly enough, the new information on this Lithogenes member has led ichthyologists to suggest that the common ancestor of the Loricariidae and Astroblepidae was a fish capable of climbing rocks by grasping them with its mouth and pelvic fins.

Picture here

The cichlid genus Crenicichla now has two new described members: Crenicichla tesay and Crenicichla mandelburgeri.

Crenicichla tesay

Crenicichla tesay lives in the Paraná River drainage and was described by Argentinian ichthyologists Jorge Casciotta and Adriana Almirón. The fish was caught in the Iguazú River upstream of Iguazú falls in Argentina, an environment characterized by falls and pools with clear and rapidly flowing water. The bottom in this habitat consists of stones, mud and sand.

The name Crenicichla tesay is derived from the Guaraní word for tears; the fish displays a tear-shaped suborbital stripe. You can distinguish Crenicichla tesay from its close relatives by the existence of a serrated posterior preopercle border, the number of scales on the E1 row, the length of the snout, and the colour pattern which consists of a suborbital stripe, 4–6 dark blotches and numerous irregularly scattered dots on the sides of the body.

The description has been published in the journal Revue Suisse de Zoologie[1]. For more information, see the paper: Casciotta, J and A Almirón (2008) Crenicichla tesay, a new species of cichlid (Perciformes: Labroidei) from the río Iguazú basin in Argentina. Revue Suisse de Zoologie 115, pp. 651–660.

Crenicichla mandelburgeri

Just like Crenicichla tesay, this newly described cichlid hails from the Paraná River drainage. It was described by Swedish ichthyologist Sven Kullander and named Crenicichla mandelburgeri in honour of Paraguayan ichthyologist Darío Mandelburger.

The Crenicichla mandelburgeri specimens were collected from two different environments. Some lived in the rapids of a large stream (5-10 meters wide and up to 1 meter deep) with turbid, brownish water. Others lived in a much smaller stream (up to 3 meters wide) with shallower brown water where both velocity and transparency fluctuated. In this environment, the bottom consisted of stones and sand and was generally without any plants.

Young Crenicichla mandelburgeri cichlids feature numerous narrow vertical bars along the side, which changes into an irregular dark horizontal band as the fish matures. You can also distinguish Crenicichla mandelburgeri from other crenicichlas by the distinct caudal blotch, the number of scales in the lateral row and in the E1 row, the lower jaw (which is longer than the upper), and the serrated preopercular margin.

For more information, see the paper: Kullander, SO (2009) Crenicichla mandelburgeri, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná river drainage in Paraguay. You can find it in Zootaxa 2006: 41–50.[2]

Crenicichla

Crenicichla is the cichlid genus where you can find the largest number of described species, about 75 species. They live on the South American continent where they inhabit freshwater rivers, streams, pools and lakes. The richest variation of species is encountered in the Amazon region, but you can find Crenicichla cichlids as far north as Guyana, Venezuela and Colombia and as far south as Uruguay and central Argentina where the water can become fairly cold in the winter.

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

The Indian government’s Marine Products Export Development Authority (MPEDA) is now launching a breeding program for the threatened Red line torpedo barb (Puntius denisonii).

Torpedo barb – Picture by brookfish

Puntius denisonii, commonly known as Red line torpedo barb, Roseline shark, or Denison barb, is native to the fast-flowing hill streams and rivers in Kerala, at state located in the southern part of India. It is highly sought after in the aquarium trade.

After several years of research, the MPEDA has now managed to successfully breed Red line torpedo barb using two different techniques: one that relies on hormone treatment to trigger spawning and one where the natural breeding conditions of this barb is recreated in captivity.

MPEDA hopes to be starting commercial production shortly.

Picture by brookfish

Lake Victoria, the world’s second largest lake and the world’s largest tropical lake, has long been plighted by environmental problems caused by pollution and exotic species being introduced to the lake. On of the most well know of these problems was the introduction of Nile perch to the lake; a large predatory fish that all but wiped out the lakes wide variety of native, endemic species.

Moses Kabuusu, Member of Parliament for Kyamuswa country in Kalangala district, has now expressed concerns about another problem developing in the area. According to him the amount of fish in the lake has now become so low that crocodiles are increasingly looking at humans as food. The number of croc attacks on humans has indeed increased in Kalangala, but it is hard to tell whether this is due to less fish being present or if there are other reasons that have increased the number of attacks on humans.

Kabuusu warns people about spending time in the water due to the rampant problem of humans being eaten by crocodiles and adds that it is mostly people swimming in the lake and women getting water in the lake that are being hunted by crocodiles.

He has requested help by the Uganda Wild Authority.

Lake victoria beach.

The oceans of the world absorb a large part of the carbon dioxide released into the atmosphere by us burning fossil fuels, burning forests to make room for fields, etc. This have helped slow down global warming, but new studies shows that it might have a devastating effects on certain fish species such as clown fish. Tests performed on clown fish larvae have shown that increased levels of carbon dioxide can make them disoriented an unable to find a suitable home and avoid predators. The pH level in the ocean has dropped 0.1 since pre-industrial times due to the absorption of carbon dioxide and researchers believe that it will fall another 0.3-0.4 before the end of this century.

This increased acidicy of the water can cause serious problems for clown fish larvae, since clownfish larvae lose the ability to sense vital odours in more acidic waters – probably owing to the damage caused to their olfactory systems. Kjell Døving (Oslo University), co-author of the rapport that was published in US journal Proceedings of the National Academy of Sciences, says “They can’t distinguish between their own parents and other fish, and they become attracted to substances they previously avoided. It means the larvae will have less opportunity to find the right habitat, which could be devastating for their populations.“

The research indicates that other species might be affected in a similar way and might have a hard time finding their way to suitable habitats if carbon dioxide levels raises in the oceans.

About the study

The study was executed in such a way that the researchers checked how well clownfish larvae could detect smells in normal sea water (pH 8.15) and how well they could detect odours in more acidic water (at levels predicted to be a reality around the year 2100 and later). The test showed that at pH 7.8 the larvae stopped following scent trails released by reefs and anemones and started following sent trails they would normally avoid; scents that are associated with environments not suitable for clown fish. The larvae also lost the ability to use smell to distinguish between their parents and other fish. At pH 7.6 the larvae were unable to follow any kind of odour in the water, and instead swam in random directions.

This story might be a few days old but is still of interest and as I haven’t been able to get to it sooner I decided to post about it today.

Indonesia will allow trawling in selected areas for the first time in 30 years, maritime ministry official Bambang Sutejo announced on January 15. Trawling will be allowed off four areas of Indonesia East Kalimantan province, despite concerns about overfishing.

“There will not be overfishing this time as we’re only allowing small boats to trawl, and it’s not allowed in other parts of Indonesia,” says Sutejo, adding that legalising trawling would help fight illegal trawlers.

According to Chalid Muhammad of the independent Green Institute, trawling has a destructive impact on the marine environment and will intensify the problem with overfishing in Indonesian waters. “The total amount of fish caught is getting smaller each day while their imports are getting bigger,” says Muhammad.

Muhammad also feels a legalization of trawling will embarrass Indonesia as it prepares to host the World Ocean Conference. “If the government allows this, Indonesia will have a weak standing during the World Ocean Conference as sustainable management of marine resources will be discussed,” Muhammad said. The World Ocean Conference is an international gathering of policymakers and scientists held in May 2009.

Kalimantan is the Indonesian portion of the island Borneo, the third largest island in the world, and is divided into four provinces: East Kalimantan, West Kalimantan, South Kalimantan, and Central Kalimantan.

What is trawling?

Trawling is a fishing practise where fishing boats tow long nets behind them. These nets do not only scoop up commercially valuable fish, but all sorts of marine life. Trawling is divided into bottom trawling and midwater trawling, depending on where in the water column the trawling takes place. Bottom trawling is especially harmful to marine environments since it can cause severe incidental damage to the sea bottoms and deep water coral reefs.

New research has revealed that the tapetail, bignose and whalefish are in fact all the same fish.

For decades, three different names have been used for three very different looking underwater creatures: the Tapetail, the Bignose and the Whalefish. A team of seven scientists*, including Smithsonian curator Dr Dave Johnson, has now discovered that these three fishes are in fact part of the same family.

After studying the body structures of the tapetails (Mirapinnidae), bignose fish (Megalomycteridae) and whalefish (Cetomimidae) and taking advantage of modern DNA-analysis, the team realized that the three are actually the larvae, male and female, respectively, of a single fish family – Cetomimidae (also known as Flabby whalefish).

“This is an incredibly significant and exciting finding,” says Johnson. “For decades scientists have wondered why all tapetails were sexually immature, all bignose fishes were males and all whalefishes were females and had no known larval stages. The answer to part of that question was right under our noses all along—the specimens of tapetails and bignose fishes that were used to describe their original families included transitional forms—we just needed to study them more carefully.”

If you wish to find out more, the article “Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families” has been published in the journal Biology Letters by the Royal Society, London.

http://publishing.royalsociety.org/

http://journals.royalsociety.org/content/g06648352k5m1562/

* The seven scientists behind the discovery are:

G.David Johnson, Division of Fishes, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA

John R. Paxton, Ichthyology, Australian Museum, Sydney, New South Wales 2010, Australia

Tracey T. Sutton, Virginia Institute of Marine Science, Gloucester Point, VA 23062, USA

Takashi P. Satoh, Marine Bioscience, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639, Japan

Tetsuya Sado, Zoology, Natural History Museum and Institute, Chuo-ku, Chiba 266-8682, Japan

Mutsumi Nishida, Marine Bioscience, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639, Japan

Masaki Miya, Zoology, Natural History Museum and Institute, Chuo-ku, Chiba 266-8682, Japan

The Suffolk Police has decided to call off their investigation into the mysterious disappearance of 27 koi and seven goldfish, since the culprit turned out to be a hungry heron.

When the expensive fish disappeared from their home in Carlton Colville, UK, the police suspected human thieves and promptly issued a witness appeal which asked if locals had seen “anything suspicious” or if they had been offered similar fish. The appeal was however recalled soon, as the police found out the true identity of the perpetrator.

A further statement issued by police explained: “This incident is now being attributed to a large heron.”
“We take all incidents very seriously and we were worried that someone might have made off with fish worth thousands of pounds”, a police spokesman explains. “Thankfully, on this occasion an arrest wasn’t necessary.”