Round+Goby+-+Tirzi

=Round Goby (//Neogobius melanostomus//)=

=__General Information__= The Round Goby is a freshwater fish that is native to Eurasia; more specifically the Black and Caspian Seas. This small fish has large, protruding eyes, and is characterized by a black dot on its first dorsal fin. They can grow to anywhere from 4 to 10 inches, and weight in between .176 to 2.816 ounces as a mature adult (1).

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=__Detailed Description__= = =

__A. Reproduction__
Male gobies are responsible for taking care of their offspring. During mating season, the males more from deep water to shallower breeding grounds. Naturally territorial, they can very successfully guard the areas of rock that the newly hatched eggs call home. With a 95% survival rate, and an egg clutch population of 5,000 eggs, the number of round gobies is steadily increasing (1).

__B. Diet__
The round goby's diet ranges from larval flies to zebra mussels, which may actually be a good thing (since the zebra mussel is another vicious invasive species) (2). Fish eggs, worms, and insect larvae also dominate this nocturnal eater's diet (1).

__C.Success as an Invasive Species__
This species was accidentally brought to the Great Lakes via cargo ships. First discovered in the St. Clair River in 1990, the gobies are native to the Caspian and Black Sea regions of Europe (1). Gobies are quite aggressive and are renowned for eating other fish. Both their high reproductive rates and the their ability to adapt to different kinds of waters has helped the goby population grow into an intimidating invasive species (2).

=__Habitat and Distribution__= Round Gobies have spread from their original dump site, the Great Lakes, to the surrounding areas. Since they are salt tolerant, they are able to move between several different locations without being affected. Since they're bottom dwelling fish, they tend to inhabit areas with lots of loose gravel which will work to their advantage during mating season (1).

=__Impacts__= While there has been a small number of positive impacts upon the ecosystem, like the consumption of other invasive species, the round gobies have not attributed much else worthy of praise. Their voracious appetites for fish eggs have depleted some species in the Great Lakes of their young, and may soon pose as a threat to humans. Mussels pick up and store toxins from the water. The round gobies that eat these mussels then have the potential of passing on the toxins to larger, predatory fish. Since the toxins are continuously transferred along the food train, they may eventually pass on to humans (3).

=__Control measures__= To control the ever-growing goby population, people have begun to use electrical barriers and pesticides to inhibit any further spreading or migration. The prohibition of transporting live gobies for bait has also helped cut down on their growth. While there's no quick way to limit the species, these small actions surely help (4). = =

=__Works Cited__= 1. "Round goby." __Wikipedia:The Free Encyclopedia__. Wikipedia. 12 Nov. 2008 . 2. Springer, Craig. "Goby roundup: the round goby is a bottom-dwelling fish native to the Caspian and Black Seas. It was carried to the great lakes in the ballast water of translantic ships." //New York State Conservationist.// 59. 6 (June 2005): 22(3). //Student Resource Center - Gold//. Gale. Stroudsburg High School. 13 Nov. 2008 <[|http://find.galegroup.com/srcx/infomark.do? &contentSet=IAC-Documents &type=retrieve &tabID=T003 &prodId=SRC-1 &docId=A133009782 &source=gale &srcprod=SRCG &userGroupName=stro53037 &version=1.0]>. 3.Raloff, J. "Invading Gobies Conquer Great Lakes.(round goby fishes from the Black Sea area have moved into the Great Lakes and is in the process of becoming a dominant presence." Science News (1999): 68. Gale Student Resource Center. 19 Nov. 2008 . 4."Round Goby." ANS Task Force. United States Federal Aquatic Nuisance Species Task Force. 19 Nov. 2008 .