Fauna and habitat of aquatic arthropods of Kashan in 2010

Aquatic arthropods are the group of animals which live in the lotic and lentic water as a stage of its lives. Some of them live near waters and somehow depend on it. Arthropods live in different aquatic habitats, except marine and oceans. These arthropods can be frequently found near the vast aquatic environments, seas and rivers. Most of the aquatic ecosystems are suitable environment for special species of arthropods. These arthropods enrich the area in terms of biological view1. Aquatic arthropods play an important role in nutritional chain of other animals such as Fish and Vertebrates. Some of them such as insects, orders Trichoptera(Insects) and Ostracoda (Crustacean) has been considered as index for quality of water. Also some immature stages of them has been evaluated in Toxicological studies2,3. Huge parts of fresh water around the world as habitats for aquatic arthropods have been changed because of


Introduction
Aquatic arthropods are the group of animals which live in the lotic and lentic water as a stage of its lives.Some of them live near waters and somehow depend on it.Arthropods live in different aquatic habitats, except marine and oceans.These arthropods can be frequently found near the vast aquatic environments, seas and rivers.Most of the aquatic ecosystems are suitable environment for special species of arthropods.These arthropods enrich the area in terms of biological view 1 .Aquatic arthropods play an important role in nutritional chain of other animals such as Fish and Vertebrates.Some of them such as insects, orders Trichoptera(Insects) and Ostracoda (Crustacean) has been considered as index for quality of water.Also some immature stages of them has been evaluated in Toxicological studies 2,3 .Huge parts of fresh water around the world as habitats for aquatic arthropods have been changed because of malapropos humanistic actions 4 .Biological diversity of these arthropods in fresh water is totally important in studies related to them.Ongoing studies about these arthropods and doing any change in to destroying species and reducing their population is symptom of inappropriate situation 5 .Aquatic Arthropods play an important role in aquatic's nutrition including Fish.Among farmed aquatics, Salmon is the most popular one, but the way of nutrition and farming it, is an important factor in keeping its taste.One of the most crucial factors in its meat's taste is its nutrition.Arthropod Gammarus from Amphipod is it's the natural nutrition which affects the meat's color and taste.Studying Gammarus , its dispersal and gain the ways of farming and reproduction, can help whom try to farm Salmon and meet some needs of human's protein 6 .
Apart from biological importance of aquatic arthropods in medical view, since understanding their role in transmission of diseases, they have been studied frequently.From the medical view Culicidae family of mosquitoes are the most important insects that include Anopheles, Culex and Aedes.There are more than 2800 species of these mosquitoes around the world 7 .Since these mosquitoes' important role on transmission of Malaria, Filariasis, Encephalitis, and other types of diseases due to Arbovirus and pain caused by their bite, they have been introduced as the main group of arthropods in medicine and health care studies.At present problem of diseases transmitted by this family, is the most considerable health issue in different areas including developing countries and South Africa.These diseases polluted more than 500 million people and caused to death of 1-3 million people annually around the world 8 .Aquatic arthropods live in different aquatic habitats except seas and oceans.These arthropods occupy great part of fresh water.Since Iran has different hemispheres ,natural and artificial floats, it is a proper place for farming these arthropods which some of them play important role in transmitting main diseases and some of them must be considered as biological national wealth.Widely Studies has been done about larvae of Culicidae family including city of Kashan 9 .Kashan is considered as a tropical area of Iran, which different areas of it especially in south part have temporarily and seasonal aquatic floats.These floats are the substantial habitats for aquatic arthropods.Since some stages or whole life of these animals is in aquatic environment, so proper situa-tion of water can be an important factor in their reproduction 10 .Given the importance of habitat in farming of aquatic arthropods, this investigation has been done in order to reach the mentioned goal in the year of 2010.

Material and Methods
Descriptive study and sampling at 13 locations and over 39 times in 2303 on the number of larvae, nymphs, Pupa and adults were collected.Collecting instruments were Hand lens, Small sieve, pond net, blunt forceps, fine brush, dropper, vial and jar.These samples, based on their type of habitat and activity, were collected in diverse techniques.Arthropods, order Ephemeroptera, order Odenata and samples of Crustacea, larvae and pupas of Aedes and Culex were collected by small sieve in different parts of stream.Tabanids larvae from the inside of plants and aquatic Algae were collected by pond net and blunt forceps.Plecoptera larvae and Ephemeroptera nymph by extracting the stones in water, Simulium larvae by extracting aquatic plants, stones and woods pieces in water were collected in fairly quickly speed.Aquatic insects which swim quickly and mostly live in Lentic water, were collected by pond net .Samples collected after the transfer to the laboratory using a stereo microscope and identified using morphological keys 11-15 used were identified (Results, based on order and family of aquatic arthropods, illustrated in table and compared.The study was approved by the local ethical committee.
Samples of Plecoptera Orders, Ephemeroptera, Fauna and habitat of aquatic arthropods Tricoptera and Odonata from Lentic waters and other Orders were collected from Lotic waters.Samples of Diptera were collected in both Lentic and Lotic waters.From Order of Diptera, Culicidae families with 639 samples (49.7%),Simulidae with 436 samples (33.9%)Chironomidae with 112 samples (8.7%), Ceratopogonidae with 90 samples (7%), Eryphidae with 4 samples (0.3%), Tabanidae with 3 samples (0.2%), were identified.Naragh was the richest area at the point of diversity in order of Diptera families view with 20% of total Diptera.Poorest area was Abyaneh with 2 families in this order.(Table 2)

Discussion
This study showed, there are 7 orders of aquatic insects and three orders of Crustacea in Lentic and Lotic waters of Kashan.This evaluation shows that this city with a tropical and dry weather is totally rich in fauna arthropods.Compared with other areas, it has the most frequent Orders and Families.Regarding to other studies , which have been done in colder weathers with more resources of Lotic and Lentic waters , it seems despite the fact that Kashan has less resources of water, reducing the average temperature of environment causes enrichment in orders and families of aquatic arthropods.On the other hand, since this area divides into two mountainous and desert climates, arthropods of both cli-mates could be found in their own habitats.Order of Diptera with more than 55% amount, was the most frequent Orders of aquatic insects.Study of this Order has been considered in priority, because of its importance in medical studies.Results are consistent with the previous studies' results 9,10 .Study showed that in city of Kashan , Amphipoda(Scud) and Ostracoda (Seed shrimp) are the most populated ones and live in Lotic and Lentic waters.Existence of these Crastacea in this area is the fact which is reported for the first time.These arthropods are very important and they can be used as quality index 3 , therefore more studies on description, ecology, biology and environmental needs of these animals is recommended.6.9 percent of collected samples belong to Tricoptera Order which is consistent with Dehghani's study in 2005.In contrary to studies about arthropods around the world, there is no report or study about descriptive status, diversity and biological situation of insects in Iran 9 .It seems importance of these insects have been ignored.It might be ignored because of agricultural and health pest's importance by authorities.About 6.7% samples of this study were Ephemeroptera Order.Hojjat

Conclusion
As the results show, Amphipoda and Ostracoda Orders of Crustacean and Eryphidae, Dixidae and Ceratopogonidae families of Diptera are reported in city of Kashan.It is inferred from this study, great amount of these arthropods is very crucial in the natural balance of environment and its key role in healthy function of natural habitats and provide the nutrition of aquatics.It is recommended entomologists and biologists study more on these insects and their effect on environment's health in Order to signify biological values of these arthropods and signify their damages in case.
Fauna and habitat of aquatic arthropods

Dispersal of aquatic arthropods of Kashan based on Place
and Dehghani et al. mentioned the existence of two families of them 9,15 .In this study we collected about 2.6% of Odonata.Tirgari and