Posts filed under News

Soil Nematodes of the Antarctic Dry Valleys

Although many people are not familiar with nematodes’ existence, they are more common than one may think. They are very successful roundworms that are found all over the Earth. Due to their small size, one may not take the time to notice them. However, they are worthy of our attention for a couple reasons. First, particular species of nematodes are gaining attention as a fish larvae food. Secondly, they are very hardy creatures that have adapted to unusual and extreme environments. Surprisingly, many readily grow on banana tree roots and unpasteurized vinegar. Some even dwell in one of the coldest environments, such as the Antarctic Dry Valleys. While considering these factors, one may wonder why such a simple creature can survive in such various conditions. Unlike their simple body, the factors that lead to their survival and success are not simple. This is especially true for the soil nematodes that dwell in the Antarctic Dry Valleys.

While the reasons that lead to their success is quite complicated, it is very obvious that they have obtained the secret to survive in such harsh conditions. Treonis and Wall (2005) explains by stating the fact that “soil nematodes are capable of employing an anhydrobiotic survival strategy in response to adverse environmental conditions” (Pp. 741-750). As the name suggests, the Antarctic Dry Valley is very dry. For example Treonis and Wall (2005) states that, “the McMurdo Dry Valleys of Antarctica are the coldest and driest terrestrial ecosystem on Earth” (Pp. 741-750). Thus, the anhydrobiotic survival strategy of the soil nematode came in very handy while trying to survive in such harsh conditions.

Although the anatomy and physiology of soil nematodes and humans are extremely different, the concept of homeostasis is very similar. When a person is cold, he or she will try to retain heat by decreasing heat loss. This commonly results in cuddling or curling action in order to decrease the surface area of the skin, which is where the heat is lost from. This same effect was observed in the soil nematodes in dry areas. The soil nematodes tried to retain the water by decreasing the surface area of its cuticle. Treonis and Wall (2005) explains this concept by stating that “coiling reduces the surface area of the nematode cuticle that is exposed to the environment and slows drying” (Pp. 741-750). When the soil nematode coils itself, the overlapped part of the cuticle is able to retain its moisture better than the exposed part of the cuticle. These very simple mechanisms seen in both soil nematodes and humans are very interesting. For soil nematodes, the research reported by Treonis and Wall (2005) suggests that “coiling confers survival benefits” (Pp. 741-750). From these results, it makes one notice the importance of the homeostatic mechanisms that can easily be taken for granted. Similarly to the soil nematodes, these mechanisms are what enable us to survive under various conditions.

References

Treonis, A., Wall, D. (4-8 Jan. 2005). Soil Nematodes and Desiccation Survival in the Extreme Arid Environment of the Antarctic Dry Valleys. Integrative and Comparative Biology. Oxford Journal, Volume 5, Pp. 741-750.

Posted on August 16, 2014 and filed under News.

The World of Fishkeeping

The vast underwater world of fish is truly amazing. Fish are known to have colonized almost every aquatic environment on this planet Earth. From the freezing depths of the Arctic Ocean to the shallow pools of the Sahara desert, the finfish have permeated far reaches well beyond any man-made borders. At the same time, the geographical separations have created an abundance of variation among these fish. Today, we can see the product of over 400 million years of population fragmentation and natural selection. Many new species have been created as species of fish have become too different to interbreed after a long period of separation. In fact, this process has lead to 25,000 different species of fish known today, and many more are being discovered each year. This makes fish the most diverse group of the major vertebrae groups.

The Japanese must have realized the beauty of the finfish when they started selectively breeding the wild carp 2000 years ago to develop domesticated koi and goldfish as strictly ornamental fish. In fact, records of fishkeeping can be traced back to as far as the ancient Sumerians. Fishkeeping is still practiced by many people thousands of years later as they are fascinated by the underwater world of the finfish. Due to advancement in technology of today, it is possible to bring a piece of private underwater world into one’s home or office with ease. A well maintained aquarium can bring life to a space and become a comforting centerpiece of the entire room. An aquarium is appreciated by people of any age and can provide endless hours of entertainment. Gazing into the beautiful shoal of fish swimming against the gentle current of water is exceptionally therapeutic. It is no wonder that they appear so often in waiting rooms to calm the frustrated minds. In order to enjoy your aquarium however, understanding basic fish keeping practices and species specific requirements are vital. Welcome to the world’s greatest hobby of fishkeeping.

Posted on August 10, 2014 and filed under News.

Snakehead - Invasively Beautiful

Snakehead Facts:

  • Snakeheads on land can survive for 4 days.

  • Snakeheads are considered invasive species in American waters.

  • Northern Snakehead population throughout North America is unknown.

The Snakehead Fish

The snakehead fish is an air-breathing freshwater fish that is native to certain areas in Asia and Africa. Unfortunately it is an invasive species in American waters and has been found in freshwater sources across many different U.S. states. The reason it’s called a snakehead is because of the enlarged scales that can be found on its head. It’s also very long and shaped like a cylinder. When you’re looking at it head on you can see it has a protruding lower jaw with a row of sharp teeth. The snakehead fish varies in color and size but will typically match the color of the freshwater environment it’s living in.

Considered an unusual fish, the snakehead is a top-level predator and is highly capable of destroying populations of fish in the body of water it’s residing in. This makes these fish much more dangerous when it’s placed in non-native areas as it will completely decimate any native fish populations. The fact that it’s a top-level predator means that it has no natural enemies in its environment and the population of these fish can continue to grow unharmed. The majority of a snakeheads diet is fish, crustaceans, and insects. In rare cases they will eat plants depending on the availability of prey or the season.

Snakehead on land

Snakehead on land

The snakehead prefers muddy and vegetated waters where it can blend in and hide well. Ponds, swamps, and slow moving streams are where this fish can typically be found and it’s able to survive in temperatures between 0 and 30 degrees Celsius.  What sets this fish apart from other predatory fish is the fact that the snakehead can survive out of water. It can breathe air easily and can travel on land for a period of up to 4 days without having to enter another body of water. If they burrow in mud they can survive for an even longer period of time.

They travel on the surface similar to a way a snake would by wriggling their bodies along while searching for mud or water. The reason this is possible is that they have evolved over time in areas of seasonal water availability and when their current water source dries up they have been forced to find somewhere new. Snakehead fish do not need to consume as much oxygen in the water as typical fish. There is a space above their heads where oxygen is passed through and then added to the blood vessels. This enables the snakehead to live effectively both in and out of water. With how aggressive this fish is and how capable it is at moving around, the transportation and sale of snakehead fish is illegal in many parts of the world.

While the snakehead fish has not currently fully established itself in North American water supplies, if it does happen to do so the consequences would be disastrous. Even in Northern state climates the snakehead is capable of surviving a cold winter and can even breed successfully throughout the season. The fact that they can travel over land to new bodies of water makes them that much more deadly and is the reason why people are worried. The snakehead grows quite large, up to 4 feet in some cases, and is highly aggressive. Smaller local fish populations are at stake of becoming wiped out whenever this fish is introduced into their habitat.

Snakehead fish can also reproduce effectively in any environment. A female snakehead in optimal conditions can produce over 10,000 young in a single year. This ensures that large populations of snakehead can establish themselves quickly and start devouring local native fish populations. Many freshwater ecosystems are very fragile and highly susceptible to the damage caused by a growing population of snakeheads. Foreign and exotic fish are not welcome in many freshwater bodies around the world and a lot of work has been done to ensure that these fish do not cause any more harm to ecosystems they’re currently in. While they’re fun to fish for and look at, scientists around the world are continuing to develop ways of removing them from water systems they have invaded.

In its natural habitat the snakehead fish is a beautiful specimen. However the problems people have with them are when they’re moved from areas in Asia and Africa to locations in Western Europe and North America. As a fearsome and vicious predator the snakehead has established a name for itself as one of the most dangerous and invasive freshwater fish on the planet. Besides the dangers involving this fish there are many interesting facts about it when it comes to its diet, how it can survive out of the water, and why it’s such a strong and effective predator. The snakehead will be studied for years to come regarding the impact that invasive species have and how the sale and transport of illegal fish impacts local economies. What is going to happen to this fish in the future, especially in freshwater bodies where it’s not wanted, is unknown. However, the snakehead fish will continue to dominate and live at the top of the food chain in the areas where it belongs.

Posted on August 10, 2014 and filed under Freshwater Fish, News.

Koi Hanako - Longest Living Fish Ever

koi_hanako

At 226 years old, koi Hanako was the longest living fish ever recorded. Koi Hanako was a beautiful scarlet coloured female fish in Japan. Her name Hanako is translated “flower girl” in Japanese. Hanako died in July 7, 1977 at a grand old age of 226. Born in 1751, Hanako was born in the first year of Horeki, in the middle of the Tokugawa Era. This makes Hanako older than the United States of America!

In May 25 1966, Dr. Komei Koshihara, the last owner of koi Hanako, made a broadcast to the whole Japanese nation through Nippon Hoso Kyokai radio station about the story of koi Hanako. At this time, Hanako was 215 years old weighing 7.5 kilograms and 70 centimeters long. He explained that the koi was passed down from his grandmother on his maternal side, who had inherited the fish from “olden times.” Dr. Koshihara described Hanako as his dearest friend.

Hanako’s actual age was verified by analyzing the rings on her scales. Much like how dendrologists determine the age of trees by counting the number of rings of growth on wood, the rings of growth on the scale of Hanako was counted using a light microscope. The growth rings on the scale shows a pattern of wide growth followed by a narrower growth. The differences in the width of the rings reflect the seasonal change of summer and winter. During the summer, fish eat more and grow more resulting in a wider growth ring pattern. The narrower growth represents the slower metabolism during the cold icy weather. In order to analyze the exact age of Hanako, she was extracted from the pond in the deep mountains of Mino Province. Two scales from different parts of her body were taken off with tweezers. The individual annual ring on the scale was painstakingly analyzed over a period of two months in Laboratory of Animal Science, Nagoya Women’s College by professor Masayoshi Hiro. Both Dr. Koshihara and Professor Hiro were delightfully surprised when Hanako was discovered to be 215 years old at the time. Following this discovery, the remaining five koi carp in the same pond was examined as well. After a yearlong analysis, the results showed that they were all over 100 years old as well.

While nobody knows the exact reason for her amazingly long lifespan, perhaps the crystal clear waters of the Japanese mountains in addition to the great love and care of her owners was the key. Koi carp is generally a long-lived fish with a lifespan of approximately 50 years. However, there are many carp that lives over a century. This is one of the reasons why the koi carp have gained so much admiration in Japan and the rest of the world as well. Koi Hanako, is a great example of the how long living koi carps truly are. Next to whales, turtoises, and tuataras, koi are one of the longest living vertebrae on Earth.

Posted on August 1, 2014 and filed under News.

Aquaculture in the U.S.

Seafood is a great food source for protein, vitamins, and minerals. This nutrient rich food source can provide us with essential omega-3 fatty acids not found in other foods. In fact, health experts are suggesting that we double our consumption of seafood for health benefits alone. Currently however, 85% of the seafood consumed in the U.S. is being imported from other countries. With the growth in global population, now reaching over 7 billion people, the demand for seafood continues to increase. In the meantime, wild harvest fisheries in many oceans worldwide are reaching a maximum sustainable yield. Thus, it is not difficult to predict a need for an efficient food production method such as aquaculture. With proper technique and sustainability in mind, aquaculture can be a very efficient and environmentally friendly means of producing quality food source.  Not surprisingly, aquaculture food production is in fact increasing at a steady rate in many countries. In Thailand, governmental and industrial outreach program have aided aquaculture to greatly succeed. However, in the U.S. the aquaculture industry have remained relatively stagnant with posed limitation on the industry in many states. While the U.S. exports the technology and equipment for aquaculture, local production remains scarce.

Posted on March 31, 2013 and filed under News, Journal.

What is the Plural Form of Fish?

plural_of_fish.jpg

What is the plural form of fish? Some believe that the plural of fish is “fish,” while others claim that the plural of fish is “fishes.” In fact, they are both correct. However, while both “fish” and “fishes” can refer to the plural form of fish, they must be used appropriately. “Fish” can be used when referring to many fish of one species. For example, if a person is pointing at 10 goldfish he would say, “Look at those fish in the pond!” On the other hand, “fishes” is used when referring to many fish of multiple species. For example, if a person is pointing at 10 goldfish and 10 koi fish, he would say, “Look at those fishes in the pond!” So there you have it! The plural form of fish is “fish” AND “fishes.”

 

Posted on March 29, 2013 and filed under News, Journal.