A team of scientists at the Michigan State University has found a new, more efficient method for cloning zebra fish.

“After the mouse, it is the most commonly used vertebrate in genetic studies,” said Jose Cibelli, an MSU professor of animal science and one of the paper’s co-authors. “It is used in cancer research and cardiovascular research because they have many of the same genes we have.”

Zebra fish is also used by scientists researching normal development and birth defects, as well as various human diseases and the functions of cell populations within organs.

Up until now, zebra fish cloning has had a low success rate, but the new Michigan method has changed this. The new method uses ovarian fluid from a Chinook salmon to keep the unfertilized egg alive.

“This worked well, because it kept the egg inactive for some time”, Cibelli explained. It gave us two or three hours to work with.

During the next step of the process, the Michigan researchers used a laser to remove DNA from the egg; a method borrowed from human in vitro fertilization. Next, the team devised a new, more efficient way of inserting the donor cells into the egg.

“The tricky part was finding a way to get into the egg,” Cibelli said. “We used the same entrance that sperm uses. There was only one spot on the egg, and we had to find it.”

You can find more information in the most recent issue of the journal Nature Methods.

The main author of the article “Novel Somatic Cell Nuclear Transfer Method in Zebra Fish,” is Kannika Siripattarapravat, a doctoral student in Cibelli’s Cellular Reprogramming Laboratory. Other authors include Patrick Venta, an associate professor of microbiology and molecular genetics, and C.C. Chang, a professor of pediatrics and human development.

The Floridian town of Wellington used to spend nearly 7,000 USD a month of taxpayer funds to keep the stagnant pools of foreclosed homes sanitary. Not anymore however, since they have enlisted the aid of some very unusual pool boys – algae eating catfish.

At a typical home, officials now drop 15 catfish in the pool instead of using chemicals to keep the water clear.

“Some of us got clever and decided to try the algae eating fish,” code enforcement officer Debra Mitchell told NBC affiliate WPTV-5.

Mitchell hopes that cleaner and more sanitary pools, combined with the lower fees for upkeep, will make the foreclosed Wellington houses more attractive to buyers.

The mysterious deaths among dogs visiting the beaches of Auckland have now been solved; they were caused by tropical pufferfish.

Tropical pufferfish contains a highly potent toxin known as tetrodotoxin. They are considered a delicacy in Japan, but will be a deadly indulgence unless prepared by an expert pufferfish chef. Even just touching a pufferfish can be lethal.

Tests done by the Cawthron Institute found tetrodotoxin in the vomit of one of the dogs that died after visiting Narrow Neck beach, and the toxin was also present in a sea slug sample taken from the same beach. How the toxin got into the sea slug remains unknown.

If members of the public find unusually large numbers of fish and other dead animals they should report these to the MAF Biosecurity New Zealand emergency pest and disease hotline 0800-809-966.

First of let me say that I am sorry for the lack of post these last weeks. Internet problems. Will hopefully be back to normal soon. Now to the story

Hearing impairment caused by damage to hail cells in the inner ear is by far the most common cause of hearing loss, but research carried out on Zebrafish might be able to show us how these hair cells can be re-grown.

Scientists involved in the experiments say there could be therapeutic trials to prevent hearing loss using drugs within a decade, while finding a cure for hearing loss using hair-cell regeneration is probably at least 20 years away.

Hair cells in the inner ear can be damaged by a long row of factors, such as noise, drugs, disease and ordinary aging. Once a hair cell dies, mammals – including us humans – aren’t able to replace that hair cell with a new one. Until the mid-1980’s, researchers thought that this was true for all warm-blooded vertebrates, but we now know that birds are able to grow new hair cells and that this hair-cell regeneration can result in improved hearing.

Among the so called cold-blooded animals, aquatic creatures like the zebrafish are equipped with clusters of hair cells running along the outside of the body to help the animal sense vibrations in the water. Just like the birds, zebrafish are capable of regenerating these hair cells if there’re damaged and this has attracted the attention of U.S. researchers looking for a cure for hearing loss.

Why some animals can regenerate hair cells while other can’t, and why some animals – even within the same species – are more vulnerable to hair-cell death, remains a mystery.

“I literally walked around for years wondering about this variability,” says Ed Rubel, a professor of hearing sciences who leads part of a University of Washington research effort in Seattle.

The Seattle research teams are currently using zebrafish to gain a better understanding of hair cell generation in hope of figuring out how to protect human hair cells from becoming damaged and how to stimulate the cells to regenerate. The project is focused on understanding the molecules and genetics involved with hair cell regeneration, and how to mimic this process in animals that don’t spontaneously regenerate hair cells.

In collaboration with Dr. David Raible, another University of Washington scientist, Professor Rubel has already identified chemicals that seem to protect hair cells from damage. Those chemicals are now being tested on mice and rats to see if they will have an affect on warm blooded mammals and not just on zebrafish. The goal is to develop a medicine that can be administered to patients receiving drugs known to kill hair cells, e.g. chemotherapeutic agents.

Dr. Rubel’s and Dr. Raible’s teams also are studying the genetics of zebrafish to identify markers that confer hair-cell protection. The teams are also working on a separate group of studies regarding the genes and other molecules that make the regeneration of hair cells possible in zebrafish, birds and mice. In 2008, the teams jointly indentified several genetic mutations and drug-like compounds that seemed to protect hair cells from death, publishing their findings in the journal PLoS Genetics.

In addition to this, Dr. Rubel’s lab is investigating the role of the so called support cells; cells that surround the hair cells and are capable of both turning into hair cells and generate new hair cells. “If we understand the template of genes that are expressed by the cells we would want to divide, then we could tap into that template to mimic regeneration efforts in mammals”, Dr. Rubel explains.

How do hair cells work?

Hair cells are called hair cells since they look like cells with little hairs growing out of them when you look at them through a microscope. Hair cells are found in our inner ears and damage to these cells is a major cause of irreversible hearing loss. The filament hairs, also known as cilia, bend as sound waves enter the ear, prompting the hair cell to send an electrical signal to the auditory nerve from which it continues to the brain.

A Japanese team of scientists are now announcing that they are close to completing genome sequencing of the Bluefin tuna. Once they have reached this goal, their next project will be to use their knowledge to create a tuna breeding program for a new type of tuna specially designed for aquacultures.

The wild tuna populations have become severely depleted due to overfishing and the WWF has warned that the Atlantic Bluefin tuna will be eradicated within three years unless radical measures are taken to safeguard remaining specimens.

“We have already completed two computer sequencing runs and have around 60 per cent of the tuna genome,” says Dr. Kazumasa Ikuta, director of research at the Yokohama-based Fisheries Research Agency. “We expect to have the entire sequence in the next couple of months. We plan to use the sequence to establish a breeding programme for bluefin tuna as most aquaculture farmers presently use wild juveniles. We want to establish a complete aquaculture system that will produce fish that have good strength, are resistant to disease, grow quickly and taste delicious.”

The genome sequencing is the result of the collaborative efforts of scientists from Japan’s Fisheries Research Agency, Kyushu University, and The University of Tokyo.

Specimens of the invasive Blue catfish (Ictalurus furcatus) have now grown large enough to reach the top of the food chain in James River, Virginia. A catfish weighing 102 lbs (46 kg) was caught from the river not long ago; the largest caught freshwater fish ever to be reported from Virginian waters.

30 years ago, Blue catfish was deliberately introduced to this U.S. river as a game fish. During recent years, the catfish population has grown explosively while many other fish species have decreased. An eight year old Blue catfish normally weigh a mere 4 lbs (1.8 kg), but as soon as it gets large enough to start catching other fish and devouring fully grown crabs, it begins putting on weight at a rapid pace and can gain as much as 10 lbs (4.5 kg) a year.

Blue Catfish – Ictalurus furcatus. Copyright www.jjphoto.dk

According to Bob Greenlee, a biologist with the state Department of Game and Inland Fisheries, scientists doing sampling used to get around 1,500 catfish in an hour in this river in the 1990s. Today, this number has increased to 6,000. “We have an invasive species that is taking over the ecosystem,” says Rob Latour, a marine biologist with the Virginia Institute of Marine Science at the College of William and Mary.

The world’s first public aquarium specialising in clownfish has now opened its door for visitors. The aquarium, which is located in Taitung County in Taiwan, will eventually house 1500 clown fish from 18 different species.

The aim of the clownfish aquarium is to educate the public about clownfish life-cycles and captive breeding techniques, and specimens will be sent to the aquarium by breeders such as the Eastern Marine Biology Research Center in Taitung.

“By meeting market needs we are helping to ease the crisis of clownfish species being endangered”, says researcher and museum planner Ho Yuan-hsing. “Due to the increasing number of artificially-bred clown fish, the fishing of clownfish is no longer seen in Taiwan’s coastal areas because it is unnecessary.”

AC comment:

The movie “Finding Nemo” made a lot of people interested in getting their own “Nemo”, but few were willing to learn how to properly maintain a saltwater aquarium. Before you decide to get a clownfish, please keep in mind that these are marine fishes. Simply adding some salt to your freshwater aquarium will not make is a suitable home for marine fish; not even for the sturdy clownfish. Even though the worst Nemo-craze seems to have cooled off now, a lot of “Nemos” still face an early death in the hands of uninformed fish keepers; deaths that could have been easily prevented.

Sea Lamprey spawning sites have been discovered in the River Wear at Chester-le-Street, County Durham, by local anglers. After being alerted by the fishermen, the Environment Agency found no less than 12 spawning sites, known as redds, measuring up to a metre across.

“We were thrilled to discover lampreys back in the River Wear as these rare blood-suckers show us that the water quality in the river is very high“, says Environment Agency fisheries officer Paul Frear. “Lampreys are extremely selective with their spawning sites and will only nest where the water quality is optimal. Today, only three species of this blood-sucking creature remain in Britain and their habitats are protected by an EC directive.”

The lamprey feeds by attaching itself to another animal with its suction-cup like mouth and, once in place, gradually rasps away tissue from its host. The largest specimens are roughly 100 cm long, but most lampreys are smaller than this.

If you see a lamprey or a lamprey redd (nest) in the UK, please report the sighting directly to Paul Frear by e-mailing him at paul.frear@environment-agency.gov.uk.

As reported earlier, invasive sea lampreys have caused serious problems in North America where they lack natural enemies.

Picture is from North America where the lamprey have caused serious problems.

Up to 50 lungfish, some of them up to on metre long, was killed when tonnes of water was released from an Australian dam this week.

The water was released from the North Pine Dam in southeast Queensland between Monday morning and Tuesday night as heavy rains were threatening to overfill the dam.

According to SEQWater, who manages the North Pine Dam, up to 100 native fish went with the release, including roughly a dozen lungfish. SEQWater spokesman Mike Foster said staff were on the scene at every dam release to check for “fish kills” and that they had rescued a handful of lungfish from pools. He also stated that staff would return on Thursday [today] to see if more could be done.

In May, when the North Pine Dam opened its gates for the first time in many years, up to 150 lungfish were rescued.

Roger Currie, spokesman for the Wide Bay Burnett Conservation Council, said conservationists on the scene during the most recent water release had found up to 50 lungfish that had been killed or mutilated as a result of the release.

“Some were found caught in trees yesterday and last night,” Currie said. “They’ve just been pummelled by the sheer force of it.”

The Wide Bay Burnett Conservation Council is pushing for a study to find out how large the North Pine Dam lungfish population is, and the council is also calling for measures to protect fish during water releases.

Lungfish of the species Neoceratodus forsteri.
Copyright www.jjphoto.dk

What’s so special about the Australian lungfish?
The Queensland lungfish, Neoceratodus forsteri, is the only now living member of the family Ceratodontidae and order Ceratodontiformes. Also known as Australian lungfish or Barramunda, Neoceratodus forsteri is native only to the Mary and Burnett river systems in south-eastern Queensland. It has however been introduced to several other Australian rivers south of this area during the past century.

Fossil records of the lungfish group date back 380 million years to a period when the higher vertebrate classes were at the starting point of their development. Prehistoric fossils unearthed in New South Wales are almost identical to the now living Qeensland lungfish, indicating that this species hardly has evolved at all during the last 100 million years. Lungfishes flourished during the Devonian period (c. 413-365 million years ago) but only six species of freshwater lungfish remain today; one in Australia, one in South America, and four in Africa.

The Queensland lungfish can survive for several days out of water, but only if kept moist. It can breathe oxygen directly from the air using its lung-like swim bladder. This species is remarkably long-lived compared to most other fish species and will usually attain an age of at least 20-25 years if it manages to survive into adulthood. Granddad, a Queensland lungfish living at the Shedd Aquarium in Chicago, is at least 80 years old. He has been housed at the aquarium since 1933 and seen many generations of zoo keepers come and go. The largest

Rocky, a snakehead living with its keeper Chris Deverso in New York State, might get a new lease on life.

Snakeheads are Asian predatory fishes capable of breathing oxygen from the air and move over land. They have been banned in the USA since they might wreck havoc with North American ecosystems if introduced to the wild.

Channa marulius caught by fisherman.
Copyright www.jjphoto.dk

Due to this regulation, the Department of Environmental Conservation wanted to euthanize the pet snakehead, but Deverso – who has owned the fish since before the ban was put into action in 2004 – refused to give up his pet and has therefore been back and forth to court and fined for owning the illegal fish.

The Department of Environmental Conservation has now offered a compromise; they will grant Deverso an educational permit, provided that he fulfils the educational permit requirements. He must:

– Install a lock on the top of the aquarium.

– Holds an open house or lecture in his home for groups interested in learning about snakehead fish.

– Pay an annual permit fee of $500.

“I never went to college; I never made much. I’m just an average guy who stood up for what I believed in and hopefully in time I’ll be granted the permit and it’ll all be worth it,” said Deverso. “I’ve taken care of him for 11 years, it’s my family pet; $500 is a lot of money but if it saves his life, it’s worth it.”