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Dragonet is a common name of certain fishes of the Goby family. The gemmeous dragonet (Callionymus Lyra) is found in the British seas.
 Research Dragonet
Fish (Pisces) are an aquatic class of vertebrates, the lowest class of vertebrates. Fish may be briefly described as vertebrate animals living in water and respiring the air therein contained by means of gills or branchiae, having cold red blood, and a heart consisting of one auricle and one ventricle; and having those organs which take the form of limbs in the higher vertebrata represented by fins.
There are more kinds of fish than all other kinds of aquatic and terrestrial vertebrates put together. The smallest fish is the Trimmaton nanus, a goby of the Indian Ocean, which grows to about one centimetre long. The largest fish is the whale shark, which may grow more than 12 metres long and weigh over 14 metric tons. It feeds on plankton and is completely harmless to most other fish and to human beings. The most dangerous fish weigh only a few kilograms. They include the deadly stonefish, whose poisonous spines can kill a human being in minutes.
Fish live almost anywhere there is water. They are found in the near- freezing waters of the Arctic and in the steaming waters of tropical jungles. They live in roaring mountain streams and in quiet underground rivers. Some fish make long journeys across the ocean. Others spend most of their life buried in sand on the bottom of the ocean. Most fish never leave water. Yet some fish are able to survive for months in dried-up riverbeds.
Fish have enormous importance to human beings. They provide food for millions of people. Fishing enthusiasts catch them for sport, and people keep them as pets. In addition, fish are important in the balance of nature. They eat plants and animals and, in turn, become food for plants and animals.
Fish thus help keep in balance the total number of plants and animals on the earth. All fish have two main features in common. (1) They have a backbone, and so they are vertebrates. (2) They breathe mainly by means of gills. Nearly all fish are also cold-blooded animals - that is, they cannot regulate their body temperature, which changes with the temperature of their surroundings. In addition, almost all fish have fins, which they use for swimming. All other water animals differ from fish in at least one of these ways. Dolphins, porpoises, and whales look like fish and have a backbone and fins, but they are mammals. Mammals breathe with lungs rather than gills. They are also warm-blooded - their body temperature remains about the same when the air or water temperature changes. Some water animals are called fish, but they do not have a backbone and so are not fish. These animals include jellyfish and starfish. Clams, crabs, lobsters, oysters, scallops, and shrimps are called shellfish. But they also lack a backbone.
The first fish appeared on the earth about 500 million years ago. They were the first animals to have a backbone. Most scientists believe that these early fish became the ancestors of all other vertebrates.
Research Fish
Goby is the popular name of a family of acanthopterous fish (Gobiidae) characterized as having two dorsal fins nearly united into one, the anterior fin having flexible rays, not spinous. The ventral fins are thoracic and united more or less by their bases. the body is scaly and the head unarmed. there are about 400 species of goby.
Research Goby
The mudskipper is a fish of the goby family, genus Periophthalmus, found in brackish water and shores in the tropics, except for the Americas. It can walk or climb over mudflats, using its strong pectoral fins as legs, and has eyes set close together on top of the head. It grows up to 30cm long.
Research Mudskipper
The Remora is a genus of fish included in the Goby family. They have on top of their head a peculiar sucking-disc which they use to attach themselves to the bottom of other fish or ships.
Research Remora
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The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
©1993 - 2009 The Probert Encyclopaedia
Southampton, United Kingdom
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