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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
ikenbot CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
“Ice Fish” Bleeds Clear Blood:
The deep oceans have yielded many mysteries that have puzzled people for centuries, from the giant squid to huge jellyfish that look like UFOs. To that list add a fish with totally transparent blood.
The Ocellated Ice Fish lives in the freezing waters of the Antarctic Ocean, where it manages to keep its body doing all the things that other fish do, but with blood that is absolutely clear, researchers said.
The reason, say experts at Tokyo Sea Life Park, is that the Ocellated Ice Fish has no hemoglobin, making it unique among vertebrates the world over.
Hemoglobin is the protein found in every other animal with bones. It is what makes blood red and is the agent that carries oxygen around the body.
The fish, which has no scales, is a prize catch for the aquarium, the only place on the planet that has the curious specimen in captivity.
Satoshi Tada, an education specialist at the center, said very little is known about the fish, which was brought back to Japan by krill fishermen.
“Luckily, we have a male and a female, and they spawned in January,” he said, adding that having more examples to study might help scientists unlock some of the fish’s secrets.
Researchers believe the fish can live without hemoglobin because it has a large heart and uses blood plasma to circulate oxygen throughout its body.
Its skin is also thought to be able to absorb oxygen from the rich waters of the Antarctic, where it is found at depths of up to a kilometer(3,300 feet).
But the evolutionary mechanism that left this creature with clear blood running through its veins is a mystery.
“Why is it the fish lost hemoglobin? More studies are needed on the question,” Tada said.
abluegirlIs that really red snapper on your plate?
A recent survey done by Oceana says that fish found at the market are not always correctly labeled. So, scientists are working on a genetic sequence technique called fish barcoding that can positively identify fish species.
Marine biologist Ron Burton of the UCSD’s Scripps Institution of Oceanography says it’s important for the public to make sure they’re getting what they think they’re getting:
“In a market like red snapper, we can be seeing red snapper at many fish markets and that would lead somebody to believe that the fish is very common, when in fact what’s being sold is a diversity of species - some of which are common, some of which aren’t. And so it can lead to a false impression about the abundance of species to the public.”
Read more on Science Today →
ucresearchPresence of certain fins and the morphologies of each are determined by the lifestyle of each fish. I use the largemouth bass to present fin structure because it has most of fin structures of fishes.
(Picture of a largemouth bass (Micropterus salmoides) from here)
Caudal fin - used for forward propulsion of the fish.
Soft dorsal fin - may be used for forward propulsion and as a rutter to change direction.
Spiny dorsal fin - used as a keel to maintain fish balance. Can be lowered to increase streamlining of fish (increase swimming speed)
Pectoral fin - used for braking and turning while swimming and may be used for forward propulsion.
Pelvic fin - prevents fish from floating upward when fish brakes (with pectoral fins)
Anal fin - acts as a rudder for turning, may be used for forward propulsion.
(Tail of bigeye tuna (Thunnus obesus). Picture from here)
Finlets - increase speed of swimming of fish by reducing drag.
(Picture of rainbow trout (Oncorhynchus mykiss) from here)
Adipose fin - function unknown. Current though is that it does nothing, but new studies suggest that it may have sensory functions.
via The Scientist:
Image of the Day: Limber Seahorse
CT scans of a seahorse show its bony plates, which slide past each other as the animal bends, allowing it to be hard and yet flexible.
Jacobs School of Engineering
Landmarks on the Dorsal fin of a shark.
These features can be used to identify different shark species. The inability to ID shark species via their fins has been an argument used to exemplify that the trade in shark fins can’t be regulated by species.
Dr. Demian Chapman and the Pew Environment Trust show us that that simply is not an excuse anymore, and have made a guide to prove just that. An just in time for CITES, where three types of shark are up for listing.
1. Porbeagle
2. Oceanic White Tip
3. Hammerhead Sharks ( I say this because if one of the three species are listed, the other two will be by proxy because their fins look too similar to distinguish)
Fins from 14 large-bodied shark species make up roughly 40% of the global fin trade. The oceanic whitetip and three hammerheads in this guide are included in this group and were estimated to constituted 7-9% of traded fins in 2000. Shark fin traders in Asia visually sort fins from these species into specific trade categories using the shape and color of the fin.
[…]
This guide is intended to help enforcement and customs personnel in the provisional identification of the first dorsal fins of these five shark species. In law enforcement situations, this could provide probable cause to hold questionable fins, so that expert opinion could be sought or genetic testing could be conducted to confirm the field identification.
Check out the online ID guide here.
These sharks are proposed for listing in CITES Appendix II. This means trade would still be allowed, but under tighter regulation that should ensure the products are coming from a sustainable source. Therefore it is vital to be able to identify their fins.Science might not always mean Conservation, but Conservation is built on good science.
Nemo flashes a smile. Snapped in the Philippines, this clownfish living amid the stinging tentacles of a huge sea anemone was photographed by Steve De Neef.
ikenbot
cantsuppressthejess Asks:
scinerds Said:
No such things as dumb questions here. Always look at your curiosity towards things as a gift. Not all species get to ask the same questions we can. Think of it as a lovely privilege.
Most all fish spend time in an energy-saving state that can be called “rest”, and we might even call their behavior “sleep”, though it is probably different than “sleep” in most land animals. Many fish, like Bass and perch, rest on or under logs at night. Coral reef fish active in the day, hide and rest in crevices and cracks in the reef to avoid being eaten at night. The resting behavior of fish is very different from their behavior the rest of the day. Many minnows, for example, which are very active in schools during the day, scatter and remain motionless in shallow water at night. Many fish “rest” or “sleep” during the day and are active at night instead, but almost all fish sleep. There are some animals that never stop swimming, like many species of shark, however, they HAVE to keep moving to push water through their mouths in order to breathe, and they may still sleep while moving. [**]
But are they capable of REM (rapid eye movement) sleep in the way humans and other land animals can? Very unlikely for various reasons. Their brain’s are not developed like ours nor are they structured to process information like ours so they don’t need REM sleep the way we do. They get into a semi-conscious state that allows them to still keep alert and responsive to outside factors like predators and other ocean life dangers as they rest their brains and bodies for their waking period. So it’s not exactly what one would call a full night’s sleep. There’s still a lot to learn about the way fishes sleep and process memory as these variables change depending on the type of fish you refer to.
And again, no such thing as a dumb question. Keep curious!
Parrotfish Sheilds
presence of mucus cocoons in parrotfish
several species of parrotfish are known to secrete a protective mucus cocoon around themselves before they go to sleep. This cocoon provides several benefits for the fish as it hides its scent from predators, and acts as an early warning system giving the fish a few precious seconds to escape from a preadator. This membrane also keeps the fish clean as parasites and UV light cannot penetrate the membrane. The skin of the membrane may have antioxidant properites in it which could help the fish repair any damage done to it.
What? Okay, but… why did you do this again?
Genetically engineered angelfish (Pterophyllum sp.) glow in a tank during a news conference before the 2012 Taiwan International Aquarium Expo in Taipei, on November 7, 2012. The fish, which are the world’s first pink fluorescent angelfish and can be viewed without blacklight, were created by a joint project between Taiwan’s Academia Sinica, National Taiwan Ocean University and Jy Lin, a private biotechnology company, according to the organizer.
(via: The Atlantic) (photo: Reuters/Pichi Chuang)
The Amphibious Mudskipper
The mudskipper is quite active out of water, using their pectoral fins to ‘walk’ on land. Like amphibians, mudskippers can breathe through their skin in a process known as cutaneous breathing.
Klaus Stiefel on Flickr
At up to 36ft in length, the oarfish is the largest bony fish known to science and is thought to be responsible for many sea serpent legends. Although it lives in tropical and temperate waters worldwide, the oarfish is rarely caught or seen alive. Little is known about its behavior.
The embryo of a guppy fish at 40-times magnification.
Image by Shmuel Silberman.
THIS WEEK’S QUESTION!
Every Sunday, a question will be asked about one of the images from this past week. Be the first to answer correctly, and your blog will be promoted on Monday’s image post and Biocanvas’s main site!
Some flowering plants have evolved ways to inhibit self-fertilization in order to increase the genetic variability of the population.
What is one specific mechanism employed by plants to prevent a flower from using its own pollen to fertilize itself?
(via ikenbot)
Seagulls Remove Parasites on Sunfish - National Geographic
Being the largest bony fish in the world brings with it problems of the parasitic kind. Unable to remove the parasites itself, the sunfish (Mola mola) seeks the help of smaller fish to remove them directly from the skin. However, some parasites call for the help of a more specialist species - seagulls.
© NATIONAL GEOGRAPHIC
Amazing underwater ‘crop circles’ spun by Japanese puffer fish
The intricate patterns are beautiful, but these gorgeous surprises also serve a purpose.
Help scientists identify seafloor types and living species in this engaging, citizen dependent project. The hope is to identify species, map populations, and get a better idea of the makeup of the northeastern continental shelf of the U.S.
Despite just being released, over 200,000 images have been mapped and possibly even a new species. How reliable those mappings are remains to be seen, but with such a great amount of input the results should even out.
A fantastic project that really takes advantage of the huge citizen workforce that is available on the web. I’m looking forward to see what results Seafloor Explorer can give us, and whether any similar projects pop up.
