Hagfish

Hagfish, an elongated scavenger found on the bottom of the sea, is truly a weird and wonderful creature. A single fossil of hagfish shows that is has undergone little evolutionary change in the last 300 million years, and the hagfish is believed to the be oldest living connection to the first vertebrate. Its the Hagfish, an elongated scavenger found on the bottom of the sea, is truly a weird and wonderful creature. A single fossil of hagfish shows that is has undergone little evolutionary change in the last 300 million years, and the hagfish is believed to the be oldest living connection to the first vertebrate. Its eyespots can detect light but lacks both lens and extrinsic musculature, and is therefore believed to show a significant step in the evolution of more complex eyes. The hagfish is also famous for exuding vast amounts of a gel-like slime when threatened. An adult hagfish can secrete enough slime to turn a 20 litre (5 gallon) bucket of water into slime in a matter of minutes. When captured, e.g. by a human or predatory fish, it will tie itself in an overhand knot which gradually works its way from the head to the tail of the hagfish, scraping off the slime as it goes, thus freeing the hagfish from its captor and from the slime in one swift movement.

Hagfish eat dead and injured sea creatures and will borrow into the body cavity of a dead (or dying!) animal to devour it from within. Once its full, it can go several months without feeding again.

Now, a new study on hagfish caught near Vancouver Island in Canada has unveiled yet another remarkable fact about the hagfish – it seems as though this fish is actually able to eat with its skin and gills, i.e. absorb nutrients through its skin and gills instead of using its mouth.

A research team* headed by Chris Glover of the University of Canterbury in New Zealand and Bamfield Marine Sciences Center took skin and gill tissue from hagfish and tested the tissues’ absorption of two different amino acids.

“We wanted to start with a simple dissolved organic nutrient, and given the fact that the food source is a large decaying pile of protein, an amino acid seemed to be the best place to start,” says Glover.

When a hagfish has managed to burrow its way into a carcass, it will feed surrounded by a high concentration of dissolved nutrients, so being able to absorb food through more than just its mouth could come in handy.

The results of the study carried out by Glover and his colleges indicate that specific molecular mechanisms exist within the hagfish tissues to move the two tested amino acids into the body of the fish. When researchers increased the concentration of amino acids the tissue increased its absorption – but only up to a certain level.

“A quick and simple calculation suggests that the skin in particular may be capable of absorbing nutrients at levels equivalent to that of the digestive tract!”, says Glover.

There are quite a few invertebrates, including many mollusks and worms, that can absorb nutrients through their skin. But up until now, no vertebrates have been known to have this capacity. The hagfish may represent a transition between the feeding habits of aquatic invertebrates like mollusks and the more specialized digestive systems found in vertebrates. While some organisms exchange nutrients with the water around them in order to maintain their body fluid salt concentrations, the hagfish is – according to Glover – likely to transport amino acid molecules through its skin and gills exclusively to feed itself.

The paper “Adaptations to in situ feeding: novel nutrient acquisition pathways in an ancient vertebrate” has been published in the most recent issue of journal Proceedings of the Royal Society B: Biological Sciences.

* Chris N. Glover (http://www.biol.canterbury.ac.nz/people/glover.shtml) School of Biological Sciences, University of Canterbury, Christchurch, New Zealand Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada

Carol Bucking (no bio page available) Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada Department of Zoology, University of British Columbia, British Columbia, Canada

Chris M. Wood (http://www.biology.mcmaster.ca/faculty/wood/wood.htm) Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada Department of Biology, McMaster University, Ontario, Canada

An international consortium has been formed to study the potential effects of adding iron to the ocean to promote the growth of phytoplankton. Phytoplankton use carbon dioxide from the atmosphere and ocean fertilization might therefore be a way of mitigating the effects of global warming. When phytoplankton die, organic carbon sinks to the seafloor where it may remain for decades, centuries or even longer – we still do not now much about the time-line.

Iron fertilization of the ocean is far from uncontroversial, since it is very difficult to foresee the long term effects of such a project. The international consortium, which has been named In-Situ Iron Studies (ISIS) consortium , will carry out iron fertilization experiments in the open ocean in an effort in to answer some of the questions regarding how iron affects the ocean’s capacity for dragging carbon dioxide from the air and into the water. All experiments will adhere to the London Convention/London Protocol regarding ocean iron fertilization research.

“A great deal remains to be learned about ocean iron fertilization and how effective it could be in storing carbon dioxide in the oceans, and the formation of this consortium is an important first step,” says Lewis Rothstein, professor of oceanography at the University of Rhode Island. “This is not a call for climate engineering; on the contrary this is a research consortium. It is premature to advocate for large-scale ocean iron fertilization, but it is time to conduct a focused research experiment that will examine the concept as comprehensively as we can. We want to make sure that it doesn’t generate harmful side effects that might negatively affect the marine ecosystem.”

The twelve ISIS-members are the following:
University of Rhode Island, USA
University of Hawaii, USA
University of Illinois at Urbana-Champaign, USA
University of Maine, USA
University of Massachusetts Boston, USA
University of Plymouth, UK
Xiamen University, Fujian, China
The Antarctic Climate and Ecosystems Cooperative Research Centre, Australia
Netherlands Institute for Sea Research, The Netherlands
The National Oceanography Centre, UK
Moss Landing Marine Laboratories, California, USA
Woods Hole Oceanographic Institution, Massachusetts, USA

African Wolf aka Egyptian Jackal

This is not really fish related but cool enough to warrant a post here anyway. Scientists have discovered a new species of Wolf in Egypt. A team a researchers from Oxford University’s Wildlife Conservation Research Unit (WildCRU), the University of Oslo, and Addis Ababa University, with funding from the University of Oslo, shows that Gray wolves reached Africa around 3 million years ago before spreading throughout the northern hemisphere. The new wolf is a relative of the Holarctic grey wolf, the Indian wolf and the Himalayan wolf.

The Egyptian jackal (Canis aureus lupaster) is an importan part of the Egyptian mythology and has until now been considered a subspecies of the Golden jackal (Canis aureus) but this new research show that the egyptian jackal is infact a species of wolf. This new species is not closely related to the rare Ethiopian wolves. Ethiopian wolves are a relatively recent of spring from the gray wolf complex while this new species, ”African wolf” (suggested name by Professor Sillero), likely arrived in Africa much earlier.

Professor David Macdonald says: “A wolf in Africa is not only important conservation news, but raises fascinating biological questions about how the new African wolf evolved and lived alongside not only the real golden jackals but also the vanishingly rare Ethiopian wolf, which is a very different species with which the new discovery should not be confused.”

The jackal is important in Egyptian Mythology

The team also found genetically very similar specimens to this new wolf in the highlands of Ethiopia, 2,500 km from Egypt, suggesting that the new species might have a large distrobution and that it is not just found in Egypt.

The conservational status of this new species is not known.

Professor Sillero says: “It seems as if the Egyptian jackal is urgently set for a name-change, and its unique status as the only member of the grey wolf complex in Africa suggests that it should be re-named ‘the African wolf’.”

WildCRU is part of Oxford University’s Department of Zoology.

If you want to read the entire paper (direct link) you can do so at PlosOne:

Photo by: L. Brian Stauffer.

‘A species of giant crayfish native to Tennessee in the United States has been scientifically described and given the name Barbicambarus simmonis.

Barbicambarus simmonis can reach a size of at least 5 inches (12,5 cm) which is twice the size of an average North American crayfish.

The researchers behind the paper in which Barbicambarus simmonis was described are Christopher Taylor from University of Illinois at Champaign-Urbana and Guenter Schuster from Eastern Kentucky University.

The first specimen was found by Tennessee Valley Authority scientist Jeffrey Simmons in 2010, and that is why the species bears his name. This specimen, as well as the specimen encountered by Taylor and Schuster, lived in Shoal Creek, a stream in southern Tennessee that ultimately drains into the Tennessee River. The creek has attracted the attention of researchers for at least half a century, which makes it reasonable to assume that Barbicambarus simmonis is either rare or very difficult to find.

You can find out more about Barbicambarus simmonis in the paper “Monotypic no more, a description of a new crayfish of the genus Barbicambarus Hobbs, 1969 (Decapoda: Cambaridae) from the Tennessee River drainage using morphology and molecules”  published in the journal Proceedings of the Biological Society of Washington.

Barbicambarus simmonsi

Barbicambarus is a genus of freshwater crayfish that up until now had only one member: Barbicambarus cornutus. Barbicambarus cornutus is known only from the Barren River and Green River systems of Tennessee. The largest known specimens are 23 cm (9 inches) long, so this crayfish is even larger than Barbicambarus simmonis and one of the largest species of crayfish in North America*. It was scientifically described in 1884, but not seen again by scientists until the 1960s.

North America is rich in crayfish and also a comparatively well explored part of the world. Of the roughly 600 scientifically described species of crayfish, roughly 50% are native to North America. However, even though North America is such a well surveyed part of the world, new species are regularly described by scientists. The Pearl Map Turtle, Graptemys pearlensis, was for instance described in the summer of 2010. Just like Barbicambarus simmonis, this turtle is native to the southern part of the U.S. It lives in the Pearl River in Louisiana and Mississippi.

bluntnose sixgill shark

The Cape Eleuthera Institute, located in the sunny Bahamas, has just begun a new study this past week, which aims to figure out the numbers and diveristy of deep ocean sharks living in the calm waters of the all too popular tourist destination.

The scientists behind this new study include: Lucy Howey-Jordan, of Microwave Telemetry Incorprated; Dr. Demian Chapman, of Stony Brook University; and Dr. Dean Grubbs, of Florida State University. This group of savvy researchers has traveled to the Cape Eleuthera Institute to help get the project on its feet, and have had some great success.

During three days, performing six different surveys, the group managed to reel in six different species of deep water sharks. The sharks reeled in included some 13 foot bluntnose sixgill sharks, and even an 18 inch, which is still fully grown, sawtail catshark.

We don’t really know a whole lot about the myriad of species which dwell in the depths of our oceans and this is no less true when we talk about deep ocean sharks. Of all the current species of sharks known to man, fifty-six percent of them dwell below 600 feet of water. Of these fifty-six percent, only five of the species encompassed have life history, and only three species have movement patterns mapped out.

This study aims to change all that, and they are off to a good start. It hasn’t been at all harmful to the local tourism industry either. While the teams are buying goods and provisions locally, tourists are also being drawn to the research as well.

Thermal Vent

Well, just when you are comfortable knowing that what you know is accurate, the world comes along and throws you another curve ball. We used to know there were 9 planets, now there are 8, we used to know the earth was the center of the solar system, now we know better.. Now, just when you thought you pretty much knew your basic zoology, an amazing new discovery has been made that is basically going to force some poor guy to rewrite the molluscan, larval ecology and invertebrate text books.

Between the 1850’s and the 1870’s supposedly all known forms of snail were discovered. However, thanks to modern technology, and some persistent researchers, we now know that we were mistaken, and that the forms of snail are really much more diverse than originally thought.

This new snail larval form is really turning heads, and here’s why. This larval form discovered is the first of its kind to be found to be a free-swimming pre-veliger larva. This is rather interesting because normally they don’t swim freely. Not only that but it appears these new little guys can actually turn hydrogen sulfide, and methane as an energy source.. Imagine, a snail which subsists on farts…

Credited with this astounding discovery are Anders Waren, a Swedish Naturalist from the Royal Museum of Natural History in Stockholm, and collegue Philippe Bouchet.

They have been working on this project since the 1980s, and have finally made their marks on history. These are a pair to watch folks, who knows what they might discover next?

Old drawing of dragonfish

The conundrum of why a particular group of deep sea fish have a gap between their skull and spinal columns has finally been solved by a crack team of researchers, which include representatives from the Natural History Museum.

It appears that the Barbeled Dragonfish also have a number of bones missing which would normally connect their skulls to their spine, and this has been puzzling researcher for quite some time.

There are a total of 28 genera of these fish, which represent over 270 species, and all of them have this same gap. However, are these missing bones always the cause?

An international group of scientists including Dr. Nalani Schnell, of the University of Tubingen; Dr Ralf Britz, of the Natural History Museum; and Dr. David Johnson, of the smithsonian Institution in Washington DC.

Together they performed the most in depth and comprehensive study for this group.

They stained the fish so that their bones and nerves would show up in different colors, so they could discern them properly.

The researchers discovered that the bones were one missing in 2 of the different genera of barbeled dragonshish, Chauliodus, and Eustomias and in the Leptostomias gladiator as well. The loss of these bones occurred naturally as they evolved.
Dr Britz explains, ‘In stomiids [barbeled dragonfishes are in the Family Stomiidae], vertebrae develop in an unusual fashion from back to front, which facilitated the loss of front vertebrae. They have failed to form in development leaving a gap between the skull and backbone.

However, the gap in the spine of the other barbeled dragonfish is caused by a lengthening of the notochord.

There you have it… Mystery solved.

Sea otter. Credit: Mike Baird

After 10 years of a steady recovery, the southern sea otter – a species on the federal list as being threatened – populations are declining for the second year running, so says a population survey conducted by researchers with the U.S. Geological Survey.

“We have seen a decrease in sea otter numbers throughout most of their range, particularly in those areas where most of their reproduction occurs, while pup counts have dropped to 2003 levels,” explains the head researcher for the yearly survey, Tim Tinker of the USGS Western Ecological Research Center. “A number of human and natural factors may be influencing this trend, and we are working to better understand what those are.”

The estimates of the population are calculated as three year averages of the yearly results of the surveys, which make allowances for variables which arise during different times of observation and give researchers a better picture of the trends in abundance. The estimate this year – averaging out the results from surveys from 2008, 2009 and 2010 – is a mere 2,711 otters. This signifies a 3.6 percent drop in the population overall, and an 11 percent drop in the number of otter offspring, compared to the estimates of 2009.

“Remember, sea otter health can tell us a lot about the health of the coastal waters that humans also enjoy,” Tinker reiterates. “So, we’re eager to learn more.”

Well, if that’s an indication.. Our world might just be in a heap of trouble.. Let’s hope they get to the bottom of it quickly.

Leatherback Turtle

Well, they say turtles are slow, but this particular beauty made a surprise comeback to a Malaysian beach after an astonishing 32 years. A report issued Friday hailed this return as a “miracle” by conservationists and rekindling hope that the endangered species is not quite gone yet.

The leatherbacks, the biggest of all the sea turtle species, were at one time the stars of the show at Rantau Abang beach in the northern state of Terengganu. However, overfishing, poaching, and pollution have caused the population of these turtles to take a nose dive over the years, to the point of being critically endangered.

This turtle, aptly named “Puteri Rantau Abang” or Rantau Abang Princess, and identified by some special markings, had returned last month to finally end the long period of time that turtle sightings were rare, which began in Terengganu in the 1980’s.

“It is a miracle that leatherback turtles are making a comeback to this area,” commented, Ahamad Sabki Mahmood, the Malaysian Fisheries Department director-general.

He went on to explain that the return of this turtle proves that Rantau Abang is once again being made a nesting ground for turtles, he is hoping that the next possible nesting period between the 15th of August and 20th of August that more turtles will make an appearance.

This just goes to show you that old habits die hard, and that mother nature triumphs over all. Hopefully the future turtles which land at the beach will receive as warm a welcome.

pond skater

And you think this sort of thing only happens in people society… Apparently the male pond skaters play on the fears of females to coerce them into having sexual intercourse. The fear that they tap into is the fear of predators.

This rather surprising sexual behavior was discovered by Professors Chang Han and Piotr Jablonski of Seoul National University in South Korea.

Female pond skaters appear to have the upper hand when it comes to when and if they engage in sexual intercourse because they have a “chastity belt” type covering over their genitals. This means that a male pond skater can only get some action if and when the female decides to let them in.

However, Professors Han and Jablonski have found that males will cause ripples in the surface of the water during courtship rituals, and these ripples attract fish from down below.

The male will keep making these ripples in the water, until the female consents to have sexual intercourse with him, much like a child will stamp his feet to get his way. However, this obviously has more severe implications for the pond skater than the child, as the child won’t be eaten by something if they don’t stop.

What makes this all the more interesting, is that the females were more likely to give in to the male’s desire to engage in sexual activity if she had experienced a predator attack in the past.

However, there was no conclusive link to see if a male was less persistent if the same had happened to him…