Bivalvia

Literature Review of Class Bivalves 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 order of Heterodonta subclasses. The last bivalve subclass was Anomalodesmata which has only one order, Pholadomyoida. This subclass was much modified and it might be burrowing or boring form. The shells is aragonitic and desmodont detition (Clarkson, 2009). 3. Ecological importance 3.1.…

Protests about saving the earth is all over the internet if searched, and recycling is most often always reinforced in public school across America as well as the idea of wasting the things we’re ever so blessed to obtain. However, within the big picture of what could result from global warming, ocean acidification, and all other world-polluting occurrences, the measurement and discovery about what has already resulted is not as publicized… at least not in regards to the backbone of all…

classes of Brachiopoda, Inarticulata and Articulata, are differentiated by their hinges. Inarticulata, the more primitive of Brachiopoda, possess a simple, smooth hinged while the Articulata class have a complex, teethed hinge. Despite their differences in hinges, all Brachiopods have a mantle, a trait which is shared with the phylum Mollusca. Mollusca can be differentiated from the rest of the supergroup Unikonta by the presence of a foot. The foot, a modified appendage which offers anchorage…

1987. The unionid mussels (Mollusca, Bivalvia) of the Belgian upper River Meuse: an assessment of the impact of hydraulic works on the river water self-purification. Biological Conservation 42: 115-132. Ligon, F.K., Dietrich, W.E., and W.J. Trush. 1995. Downstream ecological effects of dams. BioScience 45: 183-192. Loar, J.M., Dye, L.L., Turner, R.R., and S.G. Hildebrand. 1980. Analysis of environmental issues related to small-scale hydroelectric development. I. Dredging. Unpublished report, Oak…