Chinese Sturgeon ( Acipenser sinensis )

Chinese Sturgeon (Acipenser sinensis) is a member of family acipenseridae and one species anodromous great. Anodromous mean adult fish live in the ocean and return to rivers to spawn. They belong to one of 27 species of sturgeon that still exist in the world. Chinese sturgeon has existed on earth since 140 million years ago and is one of the vertebrate oldest who has lived from the time between chondrichthian and bony fish.

Taxonomy

Kingdom   : Animalia
phylum      : chordates
Class         : Actinopterygii
order         : Acipenseriformes
Family       : Acipenseridae
genus        : Acipenser
species      : Acipenser sinensis

 
Due to the long period of his life that this fish is often referred to as a living fossil. Once the fish are scattered in some point in East Asia such as Korea, Japan and western Kyushu in the Yellow River, Yangtze, Pear, Mingjiang and Qingtang in China, but now impossible to find these fish in that place except in the waters of the Yangtze River below the Gezhouba Dam China. Chinese sturgeon is classified as endangered animals in China's first level equal status Panda Bear. The fish population is estimated at about 10,000 birds in the 1970s and lived 203-257 tail in 2005-2007. These data showed a decrease in population of approximately 97.5% over 37 years. Status of the fish is also listed in the IUCN Red List status with categories "Critical Endangered". Fish are considered by the Chinese as a national treasure begin preserved. China alone has built Chinese Sturgeon Museum is located on the island in the river Xiaoxita Huangbo. This museum is a government institution to protect these fish and also as a place of learning including fish breeding techniques. Beginning in 1983-2007 has been released around 9 million baby fish into Yangtze River to increase the population.

 According to experts, the transition between the sturgeon is a species of cartilaginous fish with a true bony fish. This suspicion arises because the fish that have appeared in the Cretaceous era. Chinese sturgeon has a fairly large body size even regarded as the king of freshwater fish in the biggest and longest lifespan. Adult fish can reach a length of 4 meters with a weight of 500 kg and age may exceed 14 years. This fish has the physical characteristics of the conical head shape, body colored silver-black, the mouth of which is located under the jaw and had barbells. There is a set of bones that stand out like thorns that became known as Osteones well in the center of the head and the stomach lining from the tip of his nose. The fish's body is covered with at least five osteones line. Info about engineering maintenance on the tank has not been found, given that the threatened status of this fish and have a declining population trend.

As with Salmon, Chinese Sturgeon is a fish that migrate in groups of oceans to rivers to spawn or known as Anodromous. Adult fish will reach the downstream Yangtze River during the month of June-July and they will not eat when it's in the river. They will only reach the middle of the river when september-october. Total distance they traveled ranged 2500-3300 km. After reaching the destination with the condition of benthic nurseries rippling water with rocks and steep ravines, they will begin to release eggs. Fertilization occurs externally fertilized eggs and the percentage of success is less than one percent. This fish has a poor reproductive capacity, they will only spawn three or four times during his life and female fish carrying around a million eggs in a single pregnancy. Eggs are large enough and then sunk into the ground until they hatch. After hatching, they will go down to the sea coast to the downstream or until they grow large enough. In this environment the baby fish are the main food zoobenthos and other basic aquatic invertebrates. Chinese young sturgeon are carnivores with the main meals are all water animals, but as adults they tend to prey on the larvae, insects and humic substrates. Chinese sturgeon is known to use at the end of the upper lip kemosensor to detect food. Maintenance as pets fish still should not be done because its status is still conserved. In addition, the behavior of fish that also live in the sea and migrators will also troublesome during maintenance.

There are several factors that led to a drastic decline in population of Chinese sturgeon, among others:

1. The construction of hydropower projects on the Yangtze river downstream Gezhouba Dam, this causes loss of fish migration path to reproduce

2. Contamination that occurred in the Yangtze River by hazardous chemicals. Research conducted Jianying Hu et al, mentioned that in the liver chinese sturgeon found Triphenyltin compounds (TPT) approximately 31-128 ng / g. TPT is a pesticide compounds that can cause malformations in larval fish.

3. In addition to the construction of Gezhouba Dam, the construction of about 106 bridges and sluice gates on the Yangtze river also automatically cut off the fish migration.

4. Amount of water transportation vehicles and overfishing directly reduce the number of population.
Conditions endangered Chinese sturgeon were so forbidden to catch or keep the fish in order to maintain its population in the wild.