1. Introduction
Freshwater and marine bivalves
Taxonomy, ecological value, economical value, current Issues, current threats
2. Taxonomy
According to Treatise on Invertebrate Paleontology, the Bivalves class was divided into six subclasses which cover 13 orders. The first subclass, Palaeotaxodonta, have characteristics such as small body, taxodont, protobranch, infaunal and aragonitic shells. This subclass has only one order, Nuculoida. In the second subclass Cryptodonta, there are two orders, Solemyoida and Praecardoida. The main feature of this subclass same with previous subclasses except the absence of tooth (dysodont). Subclass Pteriomorpha includes order Arcoida, Mytiloida and Pterioida which is heterogeneous. The shell made from calcites or aragonite. Paleoheterodonta as the fourth subclasses have mostly aragonitic basic shells includes order Modiomorphoida, Unioidia, and Trigonoida. Order Unioidia is known as freshwater bivalves. The fifth subclass, Heterodonta, mostly has a shells made of aragonites. The crossed-lamellar shells feature in these subclasses is a morphology adaptation as filter feeder. Veneroida, Myoida, and Hipputitoida are the …show more content…
Human health and natural resources are threatened by these problems. The chemical compound in the coastal environment has to be regularly monitored to protect both human and ecosystem in the coastal area. The environment pollution monitoring using mussels was established in North America coastline and estuarine. It’s followed by other countries like Australia, Japan, France, Taiwan, India, and Mediterranean (Goldberg, 1975) in (Widdows and Donkin, 1992). The environmental tolerance ability, abundance, population stability, contaminant metabolism ability and living behavior are the advantages of using mussels in pollution monitoring (Widdows and Donkin,