In the present investigation
In the present investigation, “Studies on aquatic fungal biodiversity in Maharashtra,” an account of aquatic fungi have been undertaken both from fresh and marine aquatic bodies. Aquatic fungi are those, who grow in organic materials in waters of streams, rivers, lakes, waterfalls, seashore, seawaters on dead and living plant parts, algae, insect bodies viz., ants, cockroaches, honey bees, feather, nails, exoskeleton etc. The Edaphic and climatic factors play, an important role on the diversity and availability of these fungi. All these plant materials (allochthonous) of forest litter, provide an essential source of energy to aquatic fungi as well as other organisms, habiting in various marine and freshwater ecosystems, present in the forests. (Webster et al. 1981; Barlocher, 1992).
Aquatic habitats are characterised by a unique balance of allochthonous (external) and autochthonous (internal) organic matter supply, which is controlled largely by watershed characteristics, surface area and location etc. For example, headwater streams and small ponds, receive most of their organic matter from terrestrial riparian vegetation, whereas large lakes are mainly supplied with organic matter internally from algal primary producers, (Wruzbacher Christian et. al. 2011). In different seasons, different types of fungi colonise the leaves, stems, etc in water. Their growth is favoured by different climatic conditions. The evergreen and semi evergreen forests of the Sahyadri ranges provide the foliage and ultimately the source of energy throughout the year. Therefore, the present work has undertaken to investigate the floristic study of different aquatic mycoflora of the leaves, stem pieces of the plants, in water, near water, seawater, in lakes, which will also help to understand the ecological and taxonomical features of the fungi.
Out of many groups of fungi aquatic hyphomycetes are important drivers of leaf litter decomposition in streams, a fundamental ecosystem process in forested catchments (Barlocher and Kendrick 1974, Suberkropp and Klug 1976, Gessner and Chauvet 1994, Hieber and Gessner 2002, Pascoal and Cassio 2004). Colonization of leaves and other substrates by aquatic hyphomycetes, may occur through three pathways: by direct contact as a result of hyphal outgrowth from a colonized leaf touching another leaf or piece of wood; secondly by either detached hyphal fragments (Park 1974, Knudsen and Stack 1991) or asexual spores called conidia, (Read et. al. 1992), that land on a leaf surface. And thirdly, the typical mechanism appears to be the predominant one to colonize distant leaf patches (Sridhar and Barlocher 1992).
Due to their peculiar existence in water they have been neglected from their study. Very few people have worked on aquatic fungi (Ingold, 1942, 1975; Dayal 1961; Ingold and Webster, 1973;Manoharachary and Rao, 1981; Subramanian and Bhat, 1981 and Khulbe, 2001) in our country and abroad. In Maharashtra, there are very few people, studied aquatic fungi Marine fungi, aquatic hyphomycetes and aquatic phycomycetous fungi. Keeping in mind, this topic has been selected and study is carried forward. Eminent mycologists from Maharashtra have reported, a large number of fungi from different regions of Maharashtra, but the aquatic fungi from South -West region is remain unexplored. So the present topic on aquatic fungi has been selected and work has been carried out.
Maharashtra is geographically third largest state in India with an area of 308 lakh hectares of land. It lies in North Latitude 15°40′ and 22°00′ and East Longitudes 72°30′ and 80°30′. It is bordered by the states of Madhya Pradesh to the North, Chhattisgarh to the East, Andhra Pradesh to the South East, Karnataka to the South, and Goa to the South West. The state of Gujarat lies to the North West, with the Union territory of Dadra and Nagar- Haveli sandwiched in between. The Maharashtra state is divided geographically into five regions i.e., Konkan, Khandesh or Northern Maharashtra region, Western Maharashtra or Desh, Marathwada, and Vidarbha. (Arunachalam 1967, Deshpande1972)The Arabian Sea makes up West land limitation of Maharashtra. The Western Ghats or Sahyadri ranges run parallel to the coast, at an average elevation is of 1,200 metres (4,000 ft.). To the West of these hills, lie the Konkan coastal plains of about 50 to 80 kilometres in width and to the East of the Ghats, lie the flat Deccan Plateau.
Precipitation: The time period or duration of rainfall activities over Maharashtra region are slowly confining in the monsoon months only, which may have impact in the agricultural activities over the region. The state enjoys a tropical monsoon climate; the hot scorching summer from March onwards yields to the rainy monsoon in early June. The seasonal rains from the Western sea-clouds are very heavy and the rainfall is over 400 cm, on the Sahyadrian crests. The Konkan on the windward side is also endowed with heavy rainfall, declining Northwards. East of the Sahyadri, the rainfall diminishes to a meager or scanty 70 cm in the Western plateau districts, with Solapur-Ahmednagar lying in the heart of the dry zone. The rains increase slightly, later in the season, Eastwards in the Marathwada and Vidarbha regions.
The highly variable rainfall in Maharashtra, varies from 400 to 6000mm in four month period between, June to September with the number of rainy days varying between 40 and 100. The estimated average-annual availability of water resources consist of 164 km3 of surface water and 20.5 km3 of subsurface water. (Source: www.mwrra.org.)
The Western Ghats is one of the three important watersheds of India, from which many rivers originate, viz., Godavari, Bhima, Koyana and Krishna. The cultivable area of Maharashtra is 225 lakh hectors of land. Out of this, 40% of the area is drought prone, and about 7% of the area is flood prone. In Maharashtra, of the 5 river basin systems, 55% of the dependable yield is available from the four river basins (Krishna, Godavari, Tapi and Narmada) East of the Western Ghats, these four river basins comprise 92% of the cultivable land and more than 60% of the population in rural area depends on them. The Maharashtra state has more than 11 important West-ward flowing rivers including Damanganga, Surya, Vaitarna, Ulhas, Savitri, Kundalika, Patalganga, Vashisti, Shastri, Karli, and Terekhol. There are also numerous smaller rivers, joining the creeks. The 45% of state’s water resources are from West-ward flowing rivers, which are mainly monsoon specific, emanating from the Ghats and pouring into the Arabian sea. Also there are about 1821 notable smaller or larger dams have been constructed in Maharashtra state viz., Jayakwadi, Bhandardara chas, Khadkwasala, Dhom, Kanher, Koyananagar, Koradi, Pawana, Radhanagari, Sina, Yeralwadi etc.There are nearly around 180 lakes are situated in Maharashtra viz., Ambazhari, Kas, Lonar, Mushi, Pashan and Pimpri, Rankala, Venna lake etc. Some water is gathered in ponds, ditches, puddles etc. which remain full of water throughout the year while some vanish in summer.
The Maharashtra Sea coast, which stretches between Bordi/Dahanu in the North and Redi/Terekhol in the South, is about 720 km long and 30-50 km wide i.e., Konkan. The shoreline is indented by numerous Westward flowing river mouths, estuaries, bays, headlands, promontories and cliffs. There are about 18 prominent creeks/estuaries along the coast and many of which harbour important mangrove vegetation. Dahanu (coastal/creek), Tarapur (coastal/creek), Bassein/Ulhas River (coastal/estuary), Manori/ Gorai (creek), Versova (creek), Mahim (creek), Bandra Outfall (coastal), Worli Outfall (coastal), Thane/Mumbai Harbour (coastal/creek), Patalganga (estuary), Amba Estuary, Thal RCF, D. P. (coastal), Alibag (coastal), Kundalika (coastal/estuary), Murud/Rajpuri (coastal/creek), Savitri (coastal/estuary), Dabhol/Vashishti (coastal/estuary), Enron Developmental program (coastal), Jaigad/Shastri (estuary), Ratnagiri/Mirya harbour (coastal/bay), Bhatye (Bhatye River), Pawas (creek), Vijaydurg/Waghotan (coastal/estuary), Deogad (coastal/estuary), Malvan (coastal/harbour), Vengurla (coastal), Redi (coastal).
All these rivers, streams, lakes, ponds, dams, estuaries, bays, provide cool and moist atmosphere to the vegetation outside and inside the water reservoirs throughout the year and so also, the aquatic vegetation including fungi nich and grow on them. Arunachalam 1967, Deshpande1972 Source: www.mwrra.org.
Still major portion of the state is semi-arid type. There are large variations in the quantity of rainfall within different parts of the state. Ghats and coastal parts receive an annual rainfall of 2000 mm but most part of the state lies in the rain shadow belt. Such localities where some kind of fungi occur in a peculiar period.
Topography and Soil:
The whole Deccan plateau is formed of basalt. The ground rises Westwards through a series of low hills to the high peak and the plateaus of the Sahyadri. The slope Eastward is rather gentle, about a meter per kilometre. The Deccan trap influences, the landscape over a major portion of the area, has an average height of 500 meters above sea level. Sahyadri’s scrap forming the most prominent feature along its Western boundary. The plateau is greatly dissected Eastwards by flowing rivers eg., Godawari, Bhima and Krishna and their tributaries. A 300 meter contour line may be taken as its Northern and Eastern boundry. The plateau falls in height to less than 300m both towards North and East. Northern areas are flanked by Satpura to its North and Deccan plateau to its South, is an alluvium filled valley, drained by Westward flowing Tapi and its tributaries. In Eastern region is also anterior alluvium lowland drained by Wardha, Wainganga and Pranhita rivers. Along with extreme Eastern boundary of the state (Chanda distt.), there are destached hills of about 500m elevation.
The Western Ghats carry huge plateau on their top and are almost flat. The Mahabaleshwar (1430m), Harischandra gad (1424m), Kalsubai (1646m) and Salhar (1567m) are the highest peaks. Eastwards, there are three main ridges which branched off within the limits of the state. They are Mahadeo ranges, Balaghat ranges and Ajanta ranges. The Ajanta range divide into two spurs as Nirmal ranges and Satmala ranges. They carry Buldhana and Malegaon plateau on their tops. Extending from Daman in the North to the Terekhol in South for a Distance of about 350 Kms. to the West of Sahyadri, is the Konkan coastal lowland. The Ghats, that present their steep scars to the Konkan, limit the width of the coast lands to 20-40 Kilometers.
The hill ranges and valleys have characteristic “Lava” topography consisting of flat tops and staff escrapments or flanks, which carry several Terraces and steps. The soil varies from tract to tract. A variety of soil, from rich loam to poor thin ‘murmad’ is met with. The soils are mainly derived from trap, except the forest covered with laterite soils. In the valleys the soil are of mixed characters and varies from brownish and reddish. In the Eastern side, deep soils are formed due to the undulating nature, while the ridges are covered with shallow soils, more or less partially eroded. The Lava, due to weathering forms the black cotton soil or ragur soil, where crops are grown successfully. Sandy, marshy or khar or alkaline soil met in the coastal Konkan. Red soil occurs in the uplands and hills and also at Wainganga and Wardha valleys.
Minerals: The state is fairly well endowed with industrial and fuel minerals like Iron ore, Manganese, coal and fossil oil, baurite, lime-stone, fairly rich depositer of Chromite, Itmenite, Dolomite, and industrial clays. It is also rich with building stones and raod metals as basault and laterite. Numerous other minerals as Silicon, Mica, Sand, Wolframite, quartzs occur in small quantities.On concentration basis of minerals the state is divided into two zones:
(1) Eastern Vidarbha or Wardha- Wainganga basin mainly of the districts of Chanda, Bhandara and Nagpur
(2) Extreme Southern parts of the state in S. Ratnagiri and Konkan.
The Mumbai high of the Arabian sea is rich with natural oil and gas in fairly large extent.
The heavy concentrated area containing minerals are as follows:
Coal:-Vidarbha, Wardha and Wainganga valleys.
Manganese:-Nagpur and Bhadara districts.
Iron ore:-Chanda and S. Ratanagiri districts.
Lime stone:-Chanda districts.
Bauxite:-Kolhapur, Ratanagiri and Raigad Districts.
Chromite:-Bhandara and Ratnagiri districts.
Temperature: The temperatures vary throughout the year, season to season and also day and night. In the summer (Hot weather season) the maximum temperature recorded was 410C in Konkan and 460C and 480C in the Northern and Eastern parts of the state. The mean daily maximum temperature ranges from 350C to 400Cin the month of April while the temperatures decline with the burst of the monsoon as low as 240C-260C. During the post monsoon period i.e., from mid-September to mid-December, temperatures begin to riseupto 310C. In the cold weather season the days and nights are cool. The mean daily temperatures are 210C – 220C or even less. The relative humidity also show drastic variation throughout the year. In the summer or hot weather season it is 15% to 20% or even less than 10% in Deccan. It rises with the increase in the South West monsoon as high as 60% to 80% in the interior. It is highest in the months of July and August and declines every month from September upto 25% in the morning and 50% in the evening.
On the basis of agro-climatic conditions, the state is divided into following zones: (Table No.1) Source/ Ref.: www.mwrra.org.
Sr.No. Agro-climatic zone Characters of the Zone Climatic conditions Avg. Annual
rainfall Soil Type
1 South Konkan Coastal Zone Very high rainfall, with laterite soils Daily temp. Above 200C. throughout the year. 3105 mm in 101 days Laterite.
PH-5.5-6.5 acidic,poor in Phosphorous, rich in Nitrogen and Potassium
2 North Konkan Coastal Zone Very high rainfall with non-lateritic soils Average daily temp 22 to 300C. Mini. temp. 17 to 270 C. Humidity 98%in rainy season & winter-60% 2607 mm in 87 days. Coarse &shallow. PH 5.5to 6.5, acidic, Rich in Nitrogen, poor in Phosphorus & Potash.
3 Western Ghats Western Ghat Zone/Ghat zone
Maximum temp. ranges from 29-390 C. Minimum temp ranges from 13-200 C.
3000 to 6000 mm. rainfall recorded in different places of the zone viz. Igatpuri, Lonawala, Mahabaleshwar, & Radhanagari.
Warkas’ i.e. light laterite ; reddish brown. Distinctly acidic, poor fertility, low Phosphorous ; Potash content.
4 Transition Zone-1
Sub Montane Zone/ Transition Zone 1
Average Maxi. Temp. / is between 28-350 C and minimum 14-190 C
mm rains received mostly from S.W. monsoon.
Soils are reddish brown to black tending to lateritic. PH 6-7.Well supplied in Nitrogen but low in Phosphorous ; Potash
5 Transition Zone-2 Western Maharashtra Plain Zone /Transition-2 Water availability ranges from 120-150 days. Maximum temp. / 400 C ; minimum 50 C. Well distributed rainfall, 700 to 1200 mm. Topography is plain. Soils greyish black moderately alkaline, PH 7.4- 8.4, lowest layer is ‘Murum’ strata. Fair in NPK content. Well drained ; good for irrigation.
6 Scarcity Zone Western Maharashtra Scarcity Zone/ Scarcity Zone Suffers from very low rainfall with uncertainty ; ill-distribution. Maximum temp. 410 C minimum temp. -14-150 C Less than 750mm in 45 days. Two peaks of rainfall. 1) June/ July2) September. Bimodal pattern of rainfall. General topography is having slope between 1-2%. Infiltration rate is 6-7 mm/hr. The soils are vertisol. Soils have Montmorilonite clay. Poor in Nitrogen, low to medium in Phosphate ; well supplied in Potash.
7 Assured Rainfall Zone Central Maharashtra Plateau Zone /Assured Rainfall Zone Maximum temp. 410 C
Minimum temp. 210 C 700 to 900 mm, 75 % rains received in all districts of the zone. Soil colour ranges from black to red. Type- 1) vertisols 2) entisols ; 3) inceptisols PH 7-7.5
8 Moderate Rainfall Zone Central Vidarbha Zone /Zone of Moderate Rainfall Maximum temp. 33-380C Minimum temp. 16-260 C Average daily humidity 72 % in rainy season, 53 % in winter ; 35% in summer. 1130 mm./annum Black soils derived from basalt rock. Medium to heavy in texture, alkaline in reaction. Low lying areas are rich and fertile.
9 Eastern Vidarbha Zone Eastern Vidarbha Zone/ High Rainfall
Zone with Soils derived from parent material of different crops. There are four subzone based on climate, soils and crop pattern
Mean Maximum temp. varies from 32 to 370 C.
Minimum temp. 15 to 240 C. Daily humidity 73% for rainy season 62% winter ; 35% in summer
950 to 1250 mm on Western side. 1700 mm on
Extreme East side No of rainy days 59.
Soils derive from parent rock granite, gneisses, and schists. Brown to
Red in colour. PH 6 to 7
Climate and Vegetation: The monsoonal rhythm dominates the climatic characteristics of the state. The close proximity of the Sahyadri to Arabian sea is a predominating factor determining the climate. The climate of Konkan strip stands sharp contrast to the interior climate. Four climatic seasons are recognised in the state viz., the cold weather season are recognised in the season from mid-December to February, hot weather period from March to May; South -West Monsoon period from June to September and post monsoon period from October to Mid-December.
The Vegetation depends upon the distribution of the climatic elements over the region, edaphic and soil conditions, topography, natural drainage conditions, biotic factors and the extent of human interference. Among these, temperature and rainfall are most important. It is the precipitation factor that determines and distinguishes the vegetation regime. Most of the localities visited during these studies are nearby forests of Maharashtra. The forests are the major sources of aquatic fungi. The inoculum flows in water throughout the year and settle in water bodies. The forest areas are the major source of energy and inoculum of aquatic fungi. Two categories of the vegetation are grouped in Maharashtra as:
A. Humid types- consisting of tropical and sub-tropical evergreen, semi-evergreen types of forest found in Konkan Ghats, Satpuda, Chanda receiving the rainfall less than 100 mm per year giving rise to scruby and thorny jungles found in entire plateau and slopes. The major vegetation types are as follows:
I). Tropical evergreen forests: this type has occupied large tract at the foot of the Ghats and are dense evergreen forests, receiving more than 2000mm rainfall per annum. They extend upto Mahabaleshwar and Bamnoli ranges. At further east are semi-evergreen and mixed deciduous forests of west zone are luxuriantly developed. The plants growing are shade loving ones include Mangifera indica L. Memecyclon umbellatum Burm., members of the family Annonaceae, Bamboos, ferns, orchids etc.,
II). Tropical semi- evergreen forests: they receive rainfall less than 2000mm per annum. Such forests occur at margiales of evergreen and moist deciduous forests. They also occur at more windy sections, crests of Ghats. The plant show stunted growth. Terminalia peniculata Roth. is representative member along with other deciduous species and Bamboos.
III). Tropical monsoon forests or moist deciduous forests: They receive annual rainfall of about 1200mm to 1600mm per annum. As moisture is not adequate, the deciduous trees, shed their leaves to check the transpiration. The forests are developed at the slopes of Ghats, North, Konkan hills, Gawilgad hills, Western sides of Mahadeo, Harishchandragad and Satmala ranges. The trees grow to heights of 30m – 40m develop dense forests. The major vegetation is of Terminalia tomentosa W. and T. chebula Retz., T. paniculata Roth., Dalbergia latifolia Roxb., Anogeissus latifolia Wall., Albizzia procera Benth. etc.
IV). Sub-tropical evergreen forests: these forests are found at high plateau (1000m) as Mahabaleshwar and Pachgani or on peaks of Ghats, receiving heavy rains and with cool temperature. Species of Magnolia, Eugenia and Memecylon umbellatum Burm. are major species.
B. I). Dry deciduous forests: the areas which received 800-1200mm rainfall annually are found in lower foot hills of Ghats, Deccan and Satpuda etc. the forests appear evergreen during rainy season otherwise are leafless trees. The dominant plants are Tectona grandis L., Terminalia arjuna W. and A., Hardwickia binate Roxb. etc.
II). Scrub jungles or Thorny forests: Receiving precarious rainfall of less than 800 milimeter. Deccan plateau, east of Ghats are covered by these jungles. The stunted trees, long grasses and bushes as Acacia catachue Wild., A. Arabica Wild., different species of Euphorbia and Zizyphus are common.
Coastal Vegetation: On the coastal line, near sea-shore there is a peculiar mangrove vegetation with Avicincia sp., Sonneratia sp., Rhizhophora sp., which are growing in muddy coastal line, creeks, mouth of rivers and help a lot to check the erosion of coast, checking the interior salinity, conservation of minerals and adapted so well to much a situation to act as ‘screen plants’.
The Aquatic Fungi are growing in various water bodies. They occur in streams and rivers and become a part of lotic ecosystem and also occur in ponds, ditches, pools and lakes within lentic ecosystem. They are also found at the margins, as well as strictly terrestrial habitats. The aquatic fungal population in freshwater and marine water mainly consists of representatives of Mastigomycotina, Deuteromycotina, Ascomycotina and Basidiomycotina (Sparrow, 1968). These fungi have, either saprophytic or parasitic mode of nutrition. The saprophytic members growing on a variety of substrata, viz., plants and animal remains, snake skin, insect bodies, on aquatic bodies and animals, hair and feathers in water. It is believed that, increase in occurrence of aquatic fungi is mainly due to increase or addition in organic matter, domestic and agricultural wastes in water bodies, disturbances in mud and scum and the water bodies with more industrial influents, etc. These fungi occur on a wide variety of substrates of fresh and marine waters.
Kohlmeyer (1974), defined those fungi as “marine” which grow and reproduce in marine habitats. He further divided marine fungi into ‘obligate’ and ‘facultative’ marine fungi. Facultative marine fungi, are able to grow in marine environment. The obligate marine fungi are those, which grow and sporulate exclusively in marine habitats. “Marine fungi” is not a natural taxonomic group, but consists of a heterogenous assemblage of species growing in marine habitats.
Aquatic fungi are filamentous and mostly moniliaceous, conidia forming fungi (Bhatt, 1998). Their conidia are characteristically shaped, either tetra-radiate, sigmoid, coiled, appendaged or branched. (Ingold, 1942).
De Wildeman (1893), recognized the spores of fungi, found in water. Ingold (1942-75), carried out an outstanding work on microfungi, found in running streams and rivers. Descals and Webster (1980), later on fondly referred, this unique group as an ‘Ingoldian Fungi’. In freshwater habitats, they are represented by 2 major groups, namely Saprolegniales (water moulds) and aquatic Fungi – Imperfecti (Hyphomycetes), number of other Mastigomycetes (zoosporic fungi) and few Basidiomycetous members too.
Aquatic hyphomycetes are mitosporic states of Ascomycetes (Phylum Ascomycota) and Basidiomycetes (Phylum Basidiomycota). Hawksworth et al.(1995). They occur most commonly on deciduous leaves that have fallen into streams, and perform a vital role conditioning this plant detritus for consumption by stream invertebrates
The aquatic fungi which typically decompose leaf litter and wood with a hyphal network are the polyphyletic group known as “aquatic hyphomycetes”. Aquatic hyphomycetes are most common in clean, well oxygenated, flowing waters (Ingold, 1975; Bärlocher, 1992.
Table No. :-2 Fungi from aquatic habitats around the world : (Shearer, et. al. 2007)
Sr. No. Taxonomic group Number of species
2 Freshwater meiosporic ascomycetes 450
3 Mangrove meiosporic ascomycetes 612
4 Marine meiosporic and mitosporic
5 Ingoldian mitosporic fungi 290
6 Aeroaquatic mitosporic fungi 90
7 Miscellaneous mitosporic fungi 405
8 Saprolegniales 138
9 Basidiomycetes from freshwater habitats 11
10 Basidiomycetes from brackish and
Total Number of Taxa 3047
Aquatic fungi are divided into following groups, based on their biology as follows:
Ingoldian fungi : Ingold (1975), confirmed, spectacular flora of “Saprophytic microfungi” which grow in submerged decaying leaves and twigs in flowing streams and rivers in a classical documentation entitled, “An illustrated Guide to Aquatic and Waterborne Hyphomycetes (Fungi Imperfecti) ” with notes on biology of the fungi. The Ingoldian fungi are found growing on submerged leaves, stems, woods and twigs, in well-aerated bodies of water. The conidia are produced under water and when are freed, become trapped in surface foam, produced by water action.
Lower aquatic fungi: The group of eukaryotic micro-organisms, traditionally termed the “Lower Fungi” is a heterogenous group, which basically comprises species with a coenocytic hyphal system. This includes the Myxomycetes, Zygomycetes and Zoosporic fungi. The group has also been formly called the “Phycomycetes” a term which is now absolete and can only be used as general term. (Hawksworth et. al., 1995)
Aero-aquatic fungi: Aero-aquatic fungi survive, in water and mud of low oxygen level and colonise on new substrates. They are formed at the air – water interface, where they are produced. Ecologically, it is defined both by inhabiting plant litter periodically submerged in stagnant to slow flowing water bodies, and produce dispersal units only on substrata exposed to air. These multicellular dispersal units are morphologically diverse, but all have one feature in common, they entrap air between in their cells and therefore, float on air water interface (Webster and Descals, 1981; Goh and Hyde, 1996a).
Submerged aquatic hyphomycetes: The term submerged aquatic fungi were coined by Ingold (1975), growing on submerged decaying plant material. These are the mostly dematiacious conidiophores and conidia. Mostly these fungi which grow in submerged conditions and on submerged plant debris, wood pieces etc.
Terrestrial aquatic hyphomycetes: These are ecologically diffferent group of hyphomycetes. These fungi were collected from raindrops associated with interact terrestrial plant parts, such as leaf surfaces or rainwater draining from intact tree trunks (Ando, 1992a ; b).
Marine fungi: Kohlmeyer (1974), defined those fungi as “marine” which grow and reproduce in marine habitats. He further divided marine fungi into ‘obligate’ and ‘facultative’ marine fungi. Facultative marine fungi, are able to grow in marine environment. The obligate marine fungi are those, which grow and sporulate exclusively in marine habitats. “Marine fungi” is not a natural taxonomic group, but consists of a heterogenous assemblage of species growing in marine habitats. As, pointed by Raghukumar (1996), the marine system is as complex as its terrestrial counterpart and incorporates the deep sea coral reefs, mangroves, and intertidal beaches. In addition the estuarine habitats like rivermouths, lagoons and back waters containin brackish water also frequently support the growth of these habitats which display a fascinating gradient of saline conditions where obligate marine fungi, facultative marine fungi and purely terrestrial fungi co-exist. (Borse et. al. 2012)
Algicolous fungi: Algal inhabiting fungi are known as algicolous fungi and they represent taxonomically diverse group aquatic fungal biodiversity viz. mutualists, endosymbionts, parasites, pathogens and saprobes.The aquatic fungi, grows on algae both marine and freshwater algae. They include parasites, saprophytes and endophytes of seaweeds and planktonic taxa.
Along these taxonomic studies, efforts will also made to study of Mycoherbicides. Mycoherbicides are highly concentrated inoculums of aquatic fungal pathogen that can be used against aquatic weeds in a similar manner to chemical herbicides (Biocontrol) (Hasan 1988).
Ecology of aquatic fungi: There is clear cut evidence that, the water chemistry and species richness of aquatic hyphomycetes from mountain, mid-altitude, foot hill and coastal streams (Sridhar et al. 1992, Raviraja et al. 1998). Natural calamities and human interference (e.g. severe monsoon, forest fire, agricultural practices, mining and input of organic matter) may influence the water chemistry and in turn the structure and functions of aquatic hyphomycetes.
The aquatic fungi play important role, as in the productivity of an aquatic ecosystem considering the heterotrophic nature of fungi. It seems that, their key role in aquatic environment is concerned in the utilization and transformation of organic matter. The fungi, most commonly observed on decaying leaves in streams are typical aquatic hyphomycetes. They are important in the breakdown of the organic matter. There is a seasonal occurrence of an aquatic fungi, in the rainy season and autumn at various temperature and humidity. The rain water flows and remains in all water bodies. The fallen leaves are carried with the water. It is in autumn, when the streams receive a great supply of tree leaves, the aquatic fungi are dominant at least in the early stages of decay. (Barlocher, 1992)
The irregularity of rain may also cause direct occurrence and predominance or scarcity of aquatic fungi. The season variability may directly affect the growth or availability of aquatic fungi. Several studies have indicated that, during the May, June and July months, the water samples are with less spores or conidia. This is because of less inoculum due to less leaf litter. While, in August, colonization of leaves is increase, as the inoculum level increases. The occurrence of conidia were found to be extremely abundant in winter and spring, and their percentage of occurrence gradually less and less in summer.
Taking into the view of the special nature of aquatic fungi and their requirement, habit, ecology and adjustment with environment, the group has been selected for our study. Very few people have studied this group due to peculiar condition of occurrence and so this has remained as a neglected one or less considered. Attempts will made to bring many features to lime- light along with taxonomical characteristics of aquatic fungi.