According to a new research report released by Canadian scientists, American lobsters use jet propulsion to gain extra speed as the walk across the ocean floor. The lobster can produce 27 to 54mN of thrust, which is comparable to that produced by the pectoral fins of proficient swimmers like the Bluegill sunfish (Lepomis macrochirus) and Surfperch (Embiotoca jacksoni).

On the abdomen, the American lobster has tiny paddle-like structures, formally known as pleopods, which it can fan to create a wake that propels it forward. To understand why the lobster fans its “paddles”, graduate student Jeanette Lim and Professor Edwin DeMont of St Francis Xavier University in Antigonish built a mechanical model which replicates the moving parts of the lobster belly.

“No one had actually measured how much force the American lobster’s pleopods could produce,” says Lim. “We just took the abdomen of a lobster, emptied out the tissues, and hooked up eight mini servomotors bought from a robotic toy company in California to the pleopods.”

To image and measure how the plepods affected the surrounding water, the researchers used a technique called particle image velocimetry.

“Once we saw the flow visualisations, we were surprised with how large the wake was,” says Lim, now studying for her PhD at Harvard University in Boston, US. “The pleopods on American lobsters (Homarus americanus) are relatively broad and paddle-shaped compared to pleopods on crayfish, for example. But they are still fairly diminutive and rather flimsy appendages when you consider the size and toughness of the rest of the body. So we were surprised their beating produced a sizable wake with thrust that was on par with forces produced by the fins of some swimming fish.”

The results have been published in the Journal of Experimental Biology.

300,000 pounds of rock has been stolen from the bottom of the ocean near Alligator Light and Islamorada off the coast of Florida.

The Florida Fish and Wildlife Conservation Commission and the Monroe County Sheriff’s Office wish to hear from anyone who may have seen a boat harvesting the material from the site. If you have any information about this case, please contact FWC, the

Sheriff’s Office or call the Crime Stoppers of the Florida Keys at (800) 346-TIPS. You can also leave an anonymous tip at https://www.tipsubmit.com/.

The stolen rocks belong to Neal Novak, 51, a Miami aquarist who leases the quarter-acre site inshore of Alligator Reef from the federal government to cultivate live rock for the aquarium trade. Unfortunately, Novak hasn’t visited his farm in a year so it is hard to know when the theft took place.

Live rock consists of dead coral rock or quarried rock colonized by a profusion of marine species. Anything from tiny bacteria to large sponges can find a home in and on this type of “living” rock, and rocks covered in colourful coralline algae are especially coveted. Saltwater aquarists use live rock to make their aquariums look more beautiful, make the ecosystem more balanced, and help keep the water quality up in the tank. Live rocks are often colonized by scavenging species that will take care of any left-over food in the aquarium before it gets a chance to foul the water. According to Novak, the wholesale price for quality live rock in Florida is about $3 per pound.

Since the harvest of live rock from the wild can hurt marine environments, Florida banned it in the 1990s and state and federal governments decided to lease barren sea-bottom sites to people interested in aqua-culturing live rock for the aquarium trade.

Novak created his live rock farm by purchasing rock from quarries in south Miami-Dade County and ferrying them to his farm where the rocks have been resting in roughly 20 feet (6 metre) of water until someone took them. The rock pile, which was designated by GPS coordinates, has most likely not been moved by natural forces, because no hurricanes have been reported from the area since 2005 and a second stone pile with immature live rock was left largely intact.

With a wholesale price of $3 per pound, 300,000 pounds of rock can naturally give a tidy little profit for unscrupulous boulder thieves.

“They stole my livelihood,” Novak said. “This is devastating to my whole family. It cost me almost $150,000 to put the rock down and start the business. I spent my life savings to make this work. We could be looking at bankruptcy.”

The remains of a 15 meter[1] long sea living predator has been found in Svalbard, an archipelago located about midway between mainland Norway and the North Pole. The animal, a species of pliosaur dubbed Predator X by the group of scientists who discovered it, lived in the ocean 147 million years ago during the Jurassic period.

Predator X hunting (Photo: Atlantic Productions)

The skull of Predator X is twice as big as the skull of a Tyrannosaurus Rex and researchers believe the jaws of this hunter could exert a pressure of 15 tonnes[2]. The weight of the live animal is estimated to be around 45 tonnes[3].

“It is the largest sea dwelling animal ever found and as far as we know it is an entirely new species”, says palaeontologist Espen Madsen Knutsen[4] from the Olso University in Norway to Swedish newspaper Dagens Nyheter.

Knutsen is a part of the research team who dug out the skull and backbone of the creature during a two week long research expedition to Svalbard in June 2008. The remains were first discovered by Professor Jörn Hurum[5] from the Natural History Museum at Oslo University in 2007. Hurum noticed a piece of bone sticking up from the permafrost, but since it was the last day of the 2007 expedition the group was forced to leave the bone behind without any further investigation after having jotted down its GPS position.

Parts of the head and backbone was dug out during the abovementioned June 2008 expedition and together with an earlier find of a smaller specimen of the same species located just a few kilometres away, scientists have now managed to map together a good picture of what the live animal once looked like.

“We haven’t unearthed a high number of parts yet, but the parts that we do have are important ones and this has made it possible for us to create an image of what Predator X once looked like”, says Knutsen.

The digg site (Photo: Atlantic Productions)

In the excavated area, palaeontologist have found roughly 20,000 bone fragments – the remains of at least 40 different sea dwelling Jurassic animals. Once you’ve started digging in this region, it is fairly easy to spot the bones since their pale colour contrasts sharply against the black earth of the Svalbard tundra. The main difficulty is instead the short dig period and the fact that much time is spent restoring the excavated area after each dig.

“Each time we leave a dig site we have to restore the area. There can be no traces of our activities. This forces us to use half of our time digging up the same spot all over again when we return”, Kutsen explains.

Svalbard lies far north of the Arctic Circle and the average summer temperature is no more than 5°C (41°F), while the average winter temperature is a freezing −12 °C (10 °F). In Longyearbyen, the largest Svalbard settlement, the polar night lasts from October 26 to February 15. From November 12 to the end of January there is civil polar night, a continuous period without any twilight bright enough to permit outdoor activities without artificial light.

The team plans to return to Svalbard this summer to carry out more digging. They hope to find another specimen in order to make the skeleton more complete, and they also wish to unearth the remains of other animals that inhabited Svalbard at the same time as Predator X.

If you wish to learn more, you can look forward to the documentary shot by Atlantic Productions during the Svalbard excavations. The name of the documentary will be Predator X and the animal is actually named after the film, not the other way around. The film will be screened on History in the USA in May, Britain, Norway and across Europe later this year and distributed by BBC Worldwide.

Pliosaur crushing down on Plesiosaur with 33,000lb bite force (Ill.: Atlantic Productions)

All the scientific results will be published in a full scientific paper later this year.

You can find more Predator X information (in English) at the Natural History Museum, University of Oslo: http://www.nhm.uio.no/pliosaurus/english/

A study published in the online scientific journal PLoS Biology on October 27 with the provocative headline “Dams make no damn difference to salmon survival”[1] is now being questioned by a number of scientists, including several co-authors of the study.

According to the study, young fish running the gantlet of dams on the Snake and Columbia rivers did just as well as youngsters in an undammed river. Dams are widely regarded as one of the main reasons behind the sharp decline of salmon in North America’s western rivers and a study claiming that dams make no damn difference for salmon survival is therefore destined to receive a lot of attention from dam proponents and dam critics alike.

While a number of scientists, including several co-authors, are questioning the results and cautioning about what conclusions can really be drawn from them, lead-author David Welch stands by his report. “We’re not saying that the dams have never had an effect,” says Welch. “What we all have to ask ourselves is, if survival is up to the level of a river that doesn’t have dams, then what’s causing survival problems?”

Welch has already warned against overstating what the study proves, and continues to do so. According to Welch, the results of the study do however suggest that dams might not play such a big role in the fate of endangered Columbia River salmon today, and that the situation in the ocean – where the salmon live until it migrates upstream to spawn – is of higher importance than river conditions.

Michele DeHart, manager of the Fish Passage Center[2], strongly disagree with the conclusions drawn from the study. “There’s a huge mass of scientific literature that documents the impacts of dams. It’s just huge,” says DeHart. “It’s like saying, ‘Gosh, I just did this comparison and smoking does not cause cancer.’ Would you change your mind?”

In the study, the survival rate of young salmon and steelhead heading for the ocean (so called smolts) was measured in the rivers Columbia and Snake, which are heavily dammed, and in Fraser River, which has no dams at all. To the researchers’ surprise, the recorded survival rate was around 25 percent for all smolts, regardless of whether they travelled in dammed or undammed waters. If you take into account that smolt in the Columbia River actually have to travel a longer distance, it even looks as if smolt traversing dammed waters are doing better than their counterparts in the undammed Fraser.

Environmental groups are now claiming that comparing the different rivers with each other is like comparing apples and oranges, and co-author Carl Schreck, head of the Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University, warns that the study could have failed to account for fish that die in the ocean due to the stress they have been subjected to while traversing dams in Columbia and Snake.

Ed Bowles, biologist and head of fisheries for the Oregon Department of Fish and Wildlife, says that it would be better to compare how similar fish, e.g. spring Chinook, do when they spawn in the same river – some above dams and some below.

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.

This August, a turtle decided to take a stroll through a cannabis garden in a secluded part of one of America’s public parklands. This wouldn’t have been a problem for the resourceful horticulturist responsible for the plantation if it hadn’t been for the fact that this particular turtle was fitted with a GPS tracking device and followed by a park ranger. When the park ranger realised that the turtle had led him to an outdoor hydroponics lab, he contacted the police who stalked out the patch and eventually arrested its illicit gardener.

Florida Box Turtle. Picture by: Jonathan Zander

“He felt like he had a layer of security, but he probably never counted on a turtle with a tracking device leading us to that location and finding the field,” says Sergeant Robert Lachance of the U.S. Park Police. On a personal note I must humbly admit that I likely would have made the same misstake and been caught by Sergeant Robert Lachance as well. But after this I will make sure to consider the risk of turtlea with GPS tracking devices if I ever decide to get into the drug trade. (Just joking!)

The park in question was the Rock Creek Park, a large urban natural area with public park facilities that bisects Washington, D.C. The parklands follow the course of Rock Creek across the border between D.C. and Maryland and connect with the Rock Creek Stream Valley Park and the Rock Creek Regional Park in Montgomery County.

According to Christian Agrillo, an experimental psychologist at the University of Padua in Italy, the North American mosquito fish can count up to four. This rudimentary mathematical ability makes it possible for the North American mosquito fish to count how many other fish that are nearby – but only up to four. Similar counting abilities have already been observed in dolphins, but until now researchers only new that fish could tell big shoals from small ones, not that they were able to actually count.

In earlier research, Agrillo and his colleagues found that a female specimen of the North American mosquito fish will swim to the largest nearby shoal to protect herself from a harassing male. In order to do so, she must of course be able to somehow tell the difference between a larger shoal and a smaller one.

To establish exactly how advanced the counting ability of the North American mosquito fish was, Agrillo et al continued their research by testing if a lone specimen would prefer to join a shoal consisting of 2, 3 or 4 other fish. The study showed that female fish could tell the difference between two shoals even when the shoal size differed by only one specimen. Females would significantly more often prefer to join a shoal consisting of four others rather than three, and would also favour shoals comprised of three fish rather than of two.

When a new series of experiments were conducted using even larger shoals, researchers found that the female North American mosquito fish were unable to directly count over four. If two shoals differed in size by a ratio of 2:1 she would go for the larger one, but if the difference was smaller she seemed to conclude that they were “both big”. She would for instance not favour a shoal consisting of 12 fish over a shoal of 8, but could clearly tell a shoal of 16 from a shoal of 8. The female North American mosquito fish therefore seems to have the ability to estimate larger numbers, but not very exactly.

The results of the study can be found on BBC’s site Loveearth.com

(photo provided by: NOAA Photo Library)

Thirty-four cownose stingrays died in a 24 hour period at the new $250,000 dollar exhibit in the Calgary Zoo. Veterinarians are stating that it must be a water problem for so many animals to die so quickly. The nine surviving stingrays are remaining under close observation while the cause is determined and the exhibit remains closed. In just three hours, on Sunday, 26 of the 43 stingrays had died. The following morning the other eight had passed as well.

Further information on the findings of the cause of death will be posted once provided.

to read the entire article visit: http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20080512/stingray_deaths_080512/20080512?hub=TopStories

(photo is of a Southern Ray not a CowNose Stingray)