Hydrobiologia 455: 41–53, 2001. © 2001 Kluwer Academic Publishers. Printed in the Netherlands. 41 Frequency of occurrence of mangrove fungi from the east coast of India V. Venkateswara Sarma1,3 , K. D. Hyde2 & B. P. R. Vittal1 1 Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai-600 025, India for Research in Fungal Diversity, Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong 3 Present address: Centre for Research in Fungal Diversity, Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong 2 Centre Received 11 May 2000; in revised form 18 March 2001; accepted 19 March 2001 Key words: manglicolous fungi, marine fungi, frequency of occurrence, tropical fungi Abstract This paper describes the frequency of occurrence and biodiversity of fungi from mangroves of the Godavari and Krishna deltas, on the east coast of India. Seventy three species were identified from Godavari and 67 from the Krishna mangroves. Fifty five species were common to both sites, 18 were found only at Godavari and 12 at Krishna mangroves. Verruculina enalia was found to be very frequent at both sites with a higher frequency of occurrence at Godavari. Eutypa bathurstensis was very frequent at Godavari but only frequent at Krishna. Cirrenalia pygmea and Cryptosphaeria mangrovei were frequent at the Godavari mangrove, but were recorded occasionally at Krishna. Decaying samples of Rhizophora and Avicennia were studied in detail. Forty three species were common to both hosts, while 22 species were recorded only from Avicennia and 20 only from Rhizophora. Verruculina enalia was the only very frequent fungus recorded on both hosts with a lower percentage occurrence (14.8%) on R. apiculata as compared to Avicennia spp. (24.3%). Eutypa bathurstensis was the next most frequent fungus on Avicennia, while Rhizophila marina was next most frequent on Rhizophora. Dactylospora haliotrepha which was recorded frequently on Rhizophora was infrequent on Avicennia. Introduction Mangroves are one of the richest and most productive of habitats and litter from mangrove trees form the base of food chains in tropical estuarine environments. They are considered important to commercial fisheries since they act as breeding and nursery grounds (Jones & Alias, 1997). Furthermore, they are the store houses to various fauna which are dependent on products of microbial degradation of mangrove litter. Marine fungi play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter (Fell & Master, 1980). Early workers have collected marine fungi on drift wood, shoreline plants and soil. Cribb & Cribb (1955) reported for the first time marine fungi from mangrove plants. Since then, a great deal of work has been carried out on manglicolous fungi (Hyde & Lee, 1995; Jones & Alias, 1997) Many workers have investigated the mycota of mangrove soils in India (Pawar & Thirumalachar, 1966; Pawar et al., 1967; Rai et al., 1969; Matondkar et al., 1980 a,b), but studies on marine fungi colonizing dead and decomposing mangrove substrates in India were reported for the first time by Raghukumar (1973). All the above workers recorded ubiquitous soil fungi in their investigations. An extensive survey of marine fungi from the west coast of India, particularly the Maharashtra coast, was made by Patil and his colleagues (Patil & Borse, 1983, 1985; Borse, 1988; Borse et al., 1988). Many interesting fungi recorded by these workers were published under the series ‘Marine fungi from India’ and ‘Marine fungi from Maharashtra’. Chinnaraj (1992, 1993a) and Chinnaraj & Untawale (1992) recently published several reports on mangrove fungi including marine fungi from the Lakshadweep islands and other areas on the west coast of India. 42 Although mangrove fungi of the west coast of India have been well studied, there have been few studies on the east coast (Bay of Bengal), despite the fact that its mangroves are more extensive compared to the west coast (Untawale, 1987). Ravikumar (1991) initiated the systematic studies on fungi of the Pichavaram mangroves in the Cauvery River Basin along the east coast of India. Ravikumar & Vittal (1996), reported 48 species belonging to 37 genera on Rhizophora apiculata at Pichavarm. However, vast tracts along the east coast are still unexplored. For example, there are no reports of marine fungi from Godavari, Krishna, Mahanadi and the Ganges (Sunderbans) delta mangroves. Chinnaraj (1993b) had earlier reported 63 species of higher marine fungi from the Andaman and Nicobar Islands which are approximately 1000 km away from the mainland on the east coast. Much of the current literature on mangrove fungi is taxonomic in nature with descriptions of new taxa and new host records, but information on the ecology of mangrove fungi is sparse (Hyde & Jones, 1988). The present investigation was, therefore, initiated and directed towards the ecological studies of manglicolous fungi, with emphasis on fungal diversity (Sarma & Vittal, 2001); frequency of occurrence; variation with respect to different substrata such as wood, pneumatophores, roots, prop roots and seedlings (Sarma & Vittal, 2000); and to seasons; and the vertical distribution of fungi. In this paper, the frequency of occurrence of manglicolous fungi on mangroves of the Godavari and Krishna deltas are reported. range of 19–27 ◦ C in the night and 29–39 ◦ C during the day. The Indian coast is influenced by the south west and north east monsoons. Major precipitation is experienced between September to December. The area receives monsoon rains from July to September and cyclonic rains from October to November. As a general rule, the latter coincides with the depressions in the sea (Bay of Bengal) which blow over the coasts. Cyclones are frequent in the Bay of Bengal and often hit the east coast. The number of rainy days in a year vary from 53 to 64 days. A detailed description of the collection sites is given below. Materials and methods Krishna delta The mangroves of Krishna delta cover an area of about 5120 hectares (Sidhu, 1963), and fall within latitudes 15◦ 50′ , 15◦ 55′ N and longitude 80◦ 45′ , 80◦ 50′ E. During the period of study, the monthly mean minimum and maximum temperature ranged between 17.5 and 38 ◦ C. The average annual rainfall ranged between 1039 and 1091 mm. Humidity was high throughout, ranging between 60 and 95%. The surface water temperature during day time was between 25 and 33 ◦ C. Salinity was between 4 and 37¡ and pH between 7.3 and 8. The mangroves occurred along mud flats, tidal channels and tidal creeks which at high tides were covered in sea water or brackish water. The soil was river borne alluvial silt and formed extensive mud flats. The Kothapalem area with its luxuriant mangrove vegetation was selected for collecting samples. The general laboratory techniques adopted were similar to the procedures outlined by Kohlmeyer & Kohlmeyer (1979), Jones & Hyde (1988) and Hyde & Pointing (2000). Description of sites studied The mangroves of the Godavari and Krishna delta regions on the east coast of India in the state of Andhra Pradesh were selected for the present investigation. Owing to their geographical proximity, these 2 regions show certain similarities in climatic conditions. Both regions enjoy a humid tropical climate with a mean annual temperature of 28 ◦ C and a dry season extending for 5 – 6 months from December to May. The air temperature fluctuates throughout the year with a Godavari delta The mangroves of the Godavari delta cover an area of about 13 304 ha (Sidhu, 1963), and fall within latitudes 16◦ 31′ , 16◦ 45′ N and longitude 82◦ 14′ , 82◦ 20′ E. During the study period, the monthly minimum and maximum air temperature ranged between 20 and 38 ◦ C. The average annual rainfall was 1080 – 1535 mm. Humidity was high throughout the year, with the mean monthly relative humidity ranging between 71 and 85%. The average surface water temperature during day time ranged between 25 and 32.5 ◦ C. Salinity ranged between 3 and 33¡ and pH between 7.5 and 8. The soil was entirely river borne alluvial silt and extremely fine mud which formed extensive muddy flats. Mangrove materials were collected from two of the three vegetation zones. These were Coringa to the north and Balusutippa to the south of the Godavari River. Pandi to the south was not sampled. 43 Materials examined Results Twelve regular bimonthly collections were made from the Godavari and Krishna deltas between January 1994 and November 1995. Substrata such as decaying wood, roots, pneumatophores, seedlings, prop roots and leaf litter belonging to Avicennia marina (Forsk.) Vierh., A. officinalis L. (Avicenniaceae) and Rhizophora apiculata Blume (Rhizophoraceae) were collected and examined for ecological studies. Samples were examined immediately after they were brought to the laboratory as well as after incubation in moist chambers, for up to 1 month. Fungal diversity on mangroves of the Godavari delta Presentation of data The term ‘percentage occurrence’ is used to denote the number of samples on which a particular fungus was found, as against the total number of samples (supporting sporulation) examined in each bimonthly collection and is calculated according to the formula outlined by Hyde (1986) and Hyde & Jones (1989). Percentage Occurrence = Number of samples on which a particular fungus is recorded × 100 Total number of samples examined supporting sporulating fungi On the basis of percentage occurrence, the following frequency groupings were made: Very Frequent – occurring in more than 10% of samples Frequent – above 5% – below 10% Infrequent – above 1% – below 5% Rare – below 1% Similarity Index (S.I.) is calculated according to the following formula: S = 2c/a + b, where a is the Total number of species in site/host a, b is the Total number of species in site/host b, c is the Number of species common to both sites/hosts. Similarity is expressed with values between 0 (no similarity) and 1 (absolute similarity). Fifty species belonging to 39 genera were identified from 1706 samples of R. apiculata (Table 1). These included 33 species of ascomycetes, 1 basidiomycete and 16 mitosporic fungi (12 species of hyphomycetes and 4 species of coelomycetes). Verruculina enalia (17%), Cirrenalia pygmea (11%) and Rhizophila marina (10%) were the very frequent fungi. Among the three, V. enalia was more abundant and occurred in a large proportion of samples. Cryptosphaeria mangrovei (9%) and Saccardoella rhizophorae (6%) were frequently recorded. Among the species classified as ‘infrequent’ Lophiostoma mangrovei (4%), Lulworthia sp. (4%), Phomopsis mangrovei (4%) and Halocyphina villosa (3.7%) showed relatively high percentage occurrences. The percentage occurrence of 30 species was less than 1% each and these are considered ‘rare’. Examination of 1294 decaying samples of Avicennia spp. resulted in the identification of 54 species belonging to 42 genera. These included 41 ascomycetes, 1 basidiomycete and 12 mitosporic fungi (including 3 coelomycetes and 9 hyphomycetes) (Table 1). Verruculina enalia (25%) was very frequent followed by Eutypa bathurstensis (23%) and Lophiostoma mangrovei (10%). Hypoxylon sp. (5%) was frequent. Among the 14 species categorized as infrequent; Halorosellinia oceanica (3.6%), Lulworthia sp. (3%), Halocyphina villosa (2.6%) and Savoryella lignicola (2%) showed relatively high percentage occurrences. The percentage occurrence of 36 species was less than 1% each and are regarded as rare. The total number of species recorded on Avicennia spp. (54) was slightly greater than on Rhizophora apiculata (50). There were also differences in the composition of fungi between the hosts. While ascomycetes were more abundant on Avicennia spp., the mitosporic taxa were relatively more common on Rhizophora apiculata. Thirty-one species were common to both hosts. Nineteen were recorded only from R. apiculata and 23 from Avicennia spp. The Similarity Index between the hosts was 0.59. Although many fungi were common to both hosts their percentage and frequency of occurrence were not the same. Verruculina enalia was very frequent on both hosts, but its percentage occurrence was very high on Avicennia spp. Cirrenalia pygmea and Rhizophila marina were very frequent on Rhizophora, while 44 Table 1. Percentage occurrence of manglicolous fungi at the Godavari delta Name of the species Ascomycetes Aigialus grandis Kohlm. and S. Schatz A. mangrovei Borse A. parvus S. Schatz and Kohlm. Aniptodera chesapeakensis Shearer and M.A. Mill. A. haispora Vrijmoed, K.D. Hyde and E.B.G. Jones A. mangrovei K.D. Hyde Anthostomella sp. Bathyascus avicenniae Kohlm. Chaetomastia typhicola (P. Karst.) Barr Cryptosphaeria mangrovei K.D. Hyde Cryptovalsa sp. Dactylospora haliotrepha (Kohlm. and E. Kohlm.) Hafellner Eutypa bathurstensis K.D. Hyde and Rappaz Gnomonia sp.-like Halorosellinia oceanica Whalley, E.B.G. Jones, K.D. Hyde and Laessøe Halosarpheia abonnis Kohlm. H. marina (Cribb and J.W. Cribb) Kohlm. H. minuta W.F. Leong H. ratnagiriensis S.D. Patil and Borse Hypoxylon sp. Hysterium sp. Julella avicenniae (Borse) K.D. Hyde Kallichroma tethys (Kohlm. and E. Kohlm.) Kohlm. and Volkm.-Kohlm. Kirschsteiniothelia maritima -like Lautospora gigantea K.D. Hyde and E.B.G. Jones Lecanidion atratum (Hedw.) Endl. Leptosphaeria australiensis (Cribb and J.W. Cribb) G.C. Hughes L. peruviana Speg. Leptosphaeria sp. Lignincola laevis Höhnk L. longirostris (Cribb and J.W. Cribb) Kohlm. L. tropica Kohlm. Lophiostroma mangrovei Kohlm. and Vittal Lulworthia grandispora Meyers Lulworthia sp. Marinosphaera mangrovei K.D. Hyde Massarina thalassiae Kohlm., Volkm.-Kohlm. and O.E. Erikss. M. velatospora K.D. Hyde and Borse Rhizophora apiculata No. of % occuroccurrences rence Avicennia spp. No. of % occuroccurrences rence Total no. of occurrences Total % occurrence 18 – 1 1 1 22 – – 2 152 – 20 1.1 – 0.05 0.05 0.05 1.3 – – 0.1 8.9 – 1.2 – 7 – 13 5 4 1 7 – – 2 14 – 0.54 – 1 0.38 0.3 0.07 0.54 – – 0.15 1.08 18 7 1 14 6 26 1 7 2 152 2 34 0.6 0.23 0.03 0.46 0.2 0.86 0.03 0.23 0.06 5.1 0.06 1.13 – 5 48 – 0.3 2.8 302 11 46 23.33 0.85 3.5 302 16 94 10.1 0.53 3.1 3 – – 15 8 10 – 2 0.17 – – 0.87 0.46 0.58 – 0.11 – 9 3 5 77 6 3 – – 0.69 0.23 0.38 5.95 0.46 0.23 – 3 9 3 20 85 16 3 2 0.03 0.3 0.1 0.66 2.8 0.53 0.1 0.06 1 – 7 13 0.05 – 0.41 0.76 – 1 4 25 – 0.07 0.3 1.93 1 1 11 38 0.03 0.03 0.36 1.26 16 – – – 1 69 23 69 – 7 0.93 – – – 0.05 4 1.3 4 – 0.4 2 2 1 14 3 127 20 39 2 – 0.15 0.15 0.07 1.08 0.23 9.81 1.5 3.01 0.15 – 18 2 1 14 4 196 43 108 2 7 0.6 0.06 0.03 0.46 0.13 6.53 1.44 3.6 0.06 0.23 15 0.9 2 0.15 17 0.56 Continued on p. 45 45 Table 1. contd. Name of the species Massarina sp. Mycosphaerella pneumatophorae Kohlm. Nais glitra J.L. Crane and Shearer Ophiodeira monosemeia Kohlm. and Volkm.-Kohlm. Pedumispora rhizophorae K.D. Hyde and E.B.G. Jones Rhizophila marina K.D. Hyde and E.B.G. Jones Saccardoella marinospora K.D. Hyde S. rhizophorae K.D. Hyde Savoryella lignicola E.B.G. Jones and R.A. Eaton Splanchnonema brtizelmayriana-like Tubeufia setosa Sivan. and W.H. Hsieh Verruculina enalia (Kohlm.) Kohlm. and Volkm.-Kohlm. Zopfiella latipes (N. Lundq.) Malloch and Cain Z. marina Furuya and Udagawa Zopfiella sp Ascomycete 1 Basidiomycetes Halocyphina villosa Kohlm. Mitosporic taxa Alveophoma sp. Bactrodesmium linderii (Crane and Shearer) M.E. Palm and E.L. Stewart Camarosporium roumeguerii Sacc. Cirrenalia basiminuta Raghuk. and Zainal C. pygmea Kohlm. C. tropicalis Kohlm. Dictyosporium sp. Ellisembia vagum (C.G. and T.F.L.) Subram. Epicoccum purpurascens Ehrenb.:Schlecht. Monodictys sp. Periconia prolifica Anastasiou Phoma sp. Phomopsis mangrovei K.D. Hyde Phomopsis sp. Trichocladium achrasporum (Meyers and R.T. Moore) Dixon T. alopallonellum (Meyerss and R.T. Moore) Kohlm. and Volkm.-Kohlm. Trimmatostroma sp. Zalerion varium Anastasiou Total = 72 species Rhizophora apiculata No. of % occuroccurrences rence Avicennia spp. No. of % occuroccurrences rence Total no. of occurrences Total % occurrence 32 – – – 1 177 – 105 10 7 6 292 – – – – 1.9 – – – 0.05 10.4 – 6.1 0.6 0.4 0.35 17.1 – – – – 3 3 2 1 – – 2 – 27 – – 325 11 6 9 1 0.23 0.23 0.15 0.07 – – 0.15 – 2.1 – – 25.1 0.85 0.46 0.69 0.07 35 3 2 1 1 177 2 105 37 7 6 617 11 6 9 1 1.16 0.1 0.06 0.03 0.03 5.9 0.06 3.5 1.23 0.23 0.2 20.56 0.36 0.2 0.3 0.03 64 3.8 30 2.35 94 3.1 6 10 0.35 0.6 – – – – 6 10 0.2 0.33 – 4 189 1 – 12 17 7 28 23 69 7 57 – 0.23 11.1 0.05 – 0.7 0.99 0.4 1.6 1.3 4 0.4 3.3 17 – – 2 4 2 9 13 15 11 – 13 12 1.3 – – 0.15 0.31 0.15 0.69 1 1.15 0.85 – 1 0.92 17 4 189 3 4 14 26 20 43 34 69 20 69 0.56 0.13 6.3 0.09 0.13 0.46 0.86 0.66 1.4 1.13 2.3 0.66 2.3 7 0.4 13 1 20 0.66 18 28 1.1 1.6 6 – 0.46 – 24 28 0.8 0.93 1706 1294 3000 46 Eutypa bathurstensis was very frequent on Avicennia. These fungi are specific to the respective hosts. The species which were frequent on the two hosts also differed. Cryptosphaeria mangrovei and Saccardoella rhizophorae were frequent on R. apiculata (specific to the host), while Lophiostoma mangrovei and Hypoxylon sp. were frequent on Avicennia spp. Lophiostoma mangrovei was infrequent on Rhizophora apiculata and its percentage occurrence was only half that on Avicennia spp. Similar differences were noticed in the percentage occurrence of several species common to both hosts. For example, the percentage occurrence of Hypoxylon sp., Leptosphaeria australiensis, L. mangrovei, Lulworthia sp., Halorosellinia oceanica, Savoryella lignicola and V. enalia were higher on Avicennia spp. than on R. apiculata. The contrary was true in the case of Halocyphina villosa which showed a higher percentage of occurrence on R. apiculata. Fungal diversity on mangroves at the Krishna delta Fifty-three species belonging to 42 genera were identified from 1283 decomposing substrates of R. apiculata (Table 2). These included 37 species of ascomycetes, 1 basidiomycete and 15 mitosporic fungi (including 12 hyphomycetes and 3 ceolomycetes). The percentage occurrence of Verruculina enalia (11.6%) and Dactylospora haliotrepha (11.3%) was high. Rhizophila marina (5.9%), Halosarpheia abonnis (6.2%) and Lulworthia sp. (5.5%) were recorded frequently. Eighteen species were recorded infrequently of which Epicoccum purpurascens (4.9%), Saccardoella rhizophorae (4.8%), Leptosphaeria australiensis (3.5%), Cirrenalia pygmea (3.4%), Phoma sp. (3.4%), Hysterium sp. (3%), Halocyphina villosa (2.9%) and Trimmatostroma sp. (2.7%) had relatively high percentage occurrences. Thirty-one species representing 58.4% of the total were rare. Forty-four species belonging to 35 genera were identified from 710 decaying materials of Avicennia spp. Of these, 34 species belonged to ascomycetes, one to the basidiomycetes, and 9 species were mitosporic taxa (3 species of coelomycetes and 6 species of hyphomycetes) (Table 2). Verruculina enalia (22.6%) and Eutypa bathurstensis (22.3%) were very frequent. Halocyphina villosa (8.8%) and Lulworthia sp. (8.5%) were recorded frequently, while P. prolifica (4.6%), Cryptovalsa sp. (4.1%), H. abonnis (3.9%) D. haliotrepha (3.9%) and Halosarpheia sp. (2.4%) had a relatively high percentage occurrence. Twenty-nine species constituting 66% were rare. The total number of fungi recorded on Rhizophora apiculata (53) were considerably greater when compared with Avicennia spp. (44). Furthermore, the number of ascomycetes and mitosporic fungi recorded on R. apiculata was greater than on Avicennia spp. Thirty species were commonly recorded on both the hosts, while 23 species were recorded only from R. apiculata, and 14 were recorded only from Avicennia spp. The similarity index between the hosts was 0.62. The frequency of occurrence of common fungi recorded on both hosts also varied. Although Verruculina enalia was very frequent on both hosts its percentage occurrence was significantly higher on Avicennia spp. (22.7%) as compared to R. apiculata (11.6%) (Table 2). Eutypa bathurstensis (22.3%) (host specific) was the next most frequent fungus on Avicennia spp., while Dactylospora haliotrepha (11.3%) was the next most frequent fungus on R. apiculata. The latter fungus was infrequent on Avicennia spp. (3.9%). Similarily, Halocyphina villosa (8.9%) was third in the order of dominance on Avicennia spp. whereas it was Rhizophila marina (9.7%) on R. apiculata. H. villosa was infrequent on R. apiculata (2.9%). Lulworthia sp. although frequently recorded on both hosts, had a higher percentage occurrence on Avicennia spp. (8.5%) than on R. apiculata (5.5%). Such differences in percentage occurrence were observed with regard to several other species common to both hosts. Thus, the percentage occurrence of D. haliotrepha, H. villosa, L. australiensis and Epicoccum purpurascens were relatively higher on R. apiculata than on Avicennia spp. In contrast to this, Lulworthia sp., V. enalia, H. villosa and Periconia prolifica showed a high percentage of occurrence on Avicennia spp. (Table 2). Discussion Prior to the 1980s, there was scant information on the frequency of occurrence of fungi or their role in the degradation of organic matter in the mangrove ecosystem. Early studies had concentrated on the taxonomy and geographical distribution of marine fungi. There is an interest in the ecology of these organisms, and a better understanding of their role and function is now emerging (Alias et al., 1995). A range of fungi occur in the mangrove ecosystem although these differ as to their location and some fungi occur more frequently than others (Hyde & Jones, 1988). The percentage 47 Table 2. Percentage occurrence of manglicolous fungi at the Krishna delta Name of the species Ascomycetes Aigialus grandis Kohlm. and S. Schatz A. mangrovei Borse A. parvus S. Schatz and Kohlm. Aniptodera chesapeakensis Shearer and M.A. Mill. A. mangrovei K.D. Hyde Anthostomella sp. Ascocratera manglicola Kohlm. Bathyascus avicenniae Kohlm. Chaetomastia typhicola (P. Karst.) Barr Corollospora pulchella Kohlm., I. Schmidt and N.B. Nair Cryptosphaeria mangrovei K.D. Hyde Cryptovalsa sp. Dactylospora haliotrepha (Kohlm. and E. Kohlm.) Hafellener Eutypa bathurstensis K.D. Hyde and Rappaz Halorosellinia oceanica (Whalley, E.B.G. Jones, K.D. Hyde and Laessøe Halosarpheia abonnis Kohlm. H. marina (Cribb and J.W. Cribb) Kohlm. H.minuta W.F. Leong H. ratnagiriensis S.D. Patil and Borse H. viscosa (I. Schmidt) Shearer and J.L. Crane Halosarpheia sp. Hapsidascus sp.-like Heleococcum japonense Tubaki Hypocrea sp. Hypoxylon sp. Hysterium sp. Julella avicenniae (Borse) K.D. Hyde Kallichroma tethys (Kohlm. and E. Kohlm.) Kohlm. and Volkm.-Kohlm. Lecanidion atratum (Hedw.) Endl. Leptosphaeria australiensis (Cribb and J.W. Cribb) G.C. Hughes L. peruviana Speg. Leptosphaeria sp. L. longirostris (Cribb and J.W. Cribb) Kohlm. L. tropica Kohlm. Lineolata rhizophorae (Kohlm. and E. Kohlm.) Kohlm. Lophiostroma mangrovei Kohlm. and Vittal Lulworthia grandispora Meyers Rhizophora apiculata No. of % occuroccurrences rence Avicennia spp. No. of % occuroccurrences rence 25 1 3 5 2 2 2 3 1 4 17 29 174 158 17 1.25 0.05 0.15 0.25 0.1 0.1 0.1 0.15 0.05 0.2 0.85 1.45 8.7 7.9 0.85 1.9 – – 0.07 0.15 – 0.07 – 0.07 0.3 1.3 – 11.4 – 0.7 80 1 – 28 – 16 – 9 4 4 38 – 6 6.2 0.07 – 2.2 – 1.2 – 0.7 0.3 0.3 3 – 0.5 28 – 1 9 2 17 2 14 – 3 1 8 1 3.9 – 0.14 1.3 0.3 2.4 0.3 2 – 0.4 0.14 1.1 0.14 108 1 1 37 2 33 2 23 4 7 39 8 7 5.4 0.05 0.05 1.8 0.1 1.65 0.1 1.15 0.2 0.35 1.95 0.4 0.35 4 45 0.3 3.5 – 4 – 0.5 4 49 0.2 2.45 12 1 1 – 21 10 14 0.9 0.07 0.07 – 1.6 0.8 1.1 – 1 4 2 – 10 8 – 0.14 0.6 0.3 – 1.4 1.2 12 2 5 2 21 20 22 0.6 0.1 0.25 0.1 1.1 1 1.1 – – 29 28 158 8 0.14 0.14 0.42 0.56 Total % occurrence 24 – – 1 2 – 1 – 1 4 17 – 146 – 9 – 1 1 3 4 – 2 1 3 Total no. of occurrences 0.3 0.14 0.4 – – 4.1 3.9 22.3 1.1 Continued on p. 48 48 Table 2. contd. Name of the species Lulworthia sp. Marinosphaera mangrovei K.D. Hyde Massarina thalassiae Kohlm. and Volkm.-Kohlm. M. velatospora K.D. Hyde and Borse Massarina sp Ophiodeira monosemeia Kohlm. and Volkm.-Kohlm. Passeriniella obiones (H. Crouan and P. Crouan) K.D. Hyde and Mouzouras Pedumispora rhizophorae K.D. Hyde and E.B.G. Jones Quintaria lignicola (Kohlm.) Kohlm. and Volkm.-Kohlm. Rhizophila marina K.D. Hyde and E.B.G. Jones S. rhizophorae K.D. Hyde Savoryella lignicola E.B.G. Jones and R.A. Eaton Verrruculina enalia (Kohlm.) Kohlm. and Volkm.-Kohlm. Basidiomycetes Halocyphina villosa Kohlm. Mitosporic taxa Bactrodesmium linderii (Crane and Shearer) M.E. Palm and E.L. Stewart Camarosporium roumeguerii Sacc. Cirrenalia basiminuta Raghuk. and Zainal C. macrocephala (Kohlm.) Meyers and R.T. Moore C. pygmea Kohlm. Cytospora rhizophorae Kohlm. and E. Kohlm. Ellisembia vagum (C.G. and T.F.L.) Subram. Epicoccum purpurascens Ehrenb.:Schlecht Monodictys sp. Periconia prolifica Anastasiou Phoma sp. Phomopsis sp. Trichocladium achrasporum (Meyers and R.T. Moore) Dixon T. alopallonellum (Meyers and R.T. Moore) Kohlm. and Volkm.-Kohlm. Trimmatostroma sp. Zalerion varium Anastasiou Total = 67 species occurrence is an expression of the frequency of collections of fungi and gives an indication of the more common fungi in the mangrove ecosystem (Hyde & Jones, 1988). Recent investigations on the intertidal Rhizophora apiculata No. of % occuroccurrences rence Avicennia No. of occurrences spp. % occurrence Total % occurrence 131 2 7 7 32 4 4 6.6 0.1 0.35 0.35 1.6 0.2 0.2 0.05 0.05 6.2 3.1 0.2 15.5 71 – 7 7 31 – 3 5.5 – 0.5 0.5 2.4 – 0.23 60 2 – – 1 4 1 1 1 124 61 4 149 0.07 0.07 9.7 4.8 0.3 11.6 – – – – – 161 – – – – – 22.7 1 1 124 61 4 310 37 2.9 63 8.9 100 12 0.9 – – 12 0.6 – 1 4 43 6 2 63 8 14 43 12 25 10 – 0.07 0.3 3.4 0.46 0.15 4.9 0.6 1.1 3.4 0.9 1.9 0.8 2 1 33 4 7 2 – 0.8 – – – – – 0.3 0.14 4.6 0.6 0.98 0.3 – 6 1 4 43 6 2 65 9 47 47 19 27 10 0.3 0.05 0.2 2.2 0.3 0.1 3.15 0.45 2.35 2.35 0.95 1.35 0.5 35 10 2.7 0.77 6 4 0.8 0.56 41 14 2.1 0.7 1283 6 – – – – – 710 8.5 0.3 – – 0.14 0.56 0.14 Total no. of occurrences 5 1993 mangrove fungi have provided information on the frequency of occurrence, host distribution, succession and distribution with depth of the substrate (Hyde 1988a,b, 1989a, 1990; Hyde & Jones 1988; Leong et 49 al., 1991; Alias et al., 1995; Poonyth et al., 1999). In this paper, frequency of occurrence of mangrove fungi on decaying substrates of Rhizophora apiculata and Avicennia spp. in both the Godavari and Krishna delta systems are discussed. Fungal diversity and frequency of occurrence There were fewer fungi collected from Krishna (67) as compared to Godavari (72) although the difference is not significant. The dominant species at the two deltas, however, varied. The similarity index between the sites was significant (0.78). Although Verruculina enalia was very frequent at both the sites, its percentage occurrence was more at Godavari (20.6%) than at Krishna (15.6%). Eutypa bathurstensis which was very frequent at Godavari delta (10%) was only frequent at Krishna (7.9%). On the contrary, Dactylospora haliotrepha which was frequent at Krishna (8.7%) was infrequent at Godavari (1.1%). While Lophiostoma mangrovei, Cirrenalia pygmea, Rhizophila marina and Cryptosphaeria mangrovei were the frequently recorded species at Godavari delta, Dactylospora haliotrepha, Lulworthia sp., Halosarpheia abonnis and Halocyphina villosa were the frequently recorded species at Krishna (Table 3). Similar variations in species composition among different mangrove stands were reported in Malaysia (Alias et al., 1995), Mauritius (Poonyth et al., 1999) and Seychelles (Hyde & Jones, 1988). While studying the fungi in three mangrove sites viz., Morib, Kuala Selangor and Port Dickson in Malaysia, Alias et al. (1995) found Halocypina villosa and Leptosphaeria australiensis to be very frequent at both Morib and Kuala Selangor in contrast to Halorosellinia oceanica (= Hypoxylon oceanicum) and Massarina ramunculicola at Port Dickson. Alhough Lulworthia sp. was reported to be very frequent at all the 5 sites studied in Mauritius, the other frequent fungi were different from one site to another (Poonyth et al., 1999). Swampomyces triseptatus and Verruculina enalia were frequent at Poudre d’Or & Beau Rivage respectively, but were less frequent at other sites (Beau Champ, Ile d’ Ambre & Macond’e). Hyde & Jones (1988) reported that Halocyphina villosa was the very frequent species in Brillant mangroves, Seychelles, followed by Lulworthia grandispora, Rhizophila marina and Antennospora quadricornuta. On the other hand, Halosarpheia marina followed by Halocyphina villosa were very frequent at Anse Boileau. The reasons attributed to these differences were different mangrove trees dominant at each site (Hyde & Jones, 1988) and the age of the drift materials on the mangrove floor (age of submersion of substrata) (Leong et al., 1991). In the present study, since host plants were the same in both sites and the colonization pattern was not followed or age of the sample was not recorded, subtle local environmental factors may account for the differences in the percentage occurrence of the fungi. However, caution should be taken for this interpretation as the exact factors are not known. Verruculina enalia seems to be the most prevalent fungus on the east coast of India (Ravikumar, 1991; Chinnaraj, 1993b; Ravikumar & Vittal, 1996 and this study). This fungus was also recorded frequently from atolls in the Maldives (Chinnaraj, 1993a), Mauritius (Poonyth et al., 1999), Thailand (Hyde et al., 1990) and Malaysia (Alias et al., 1995). The very frequent fungus from other mangroves sites in the Indian ocean differed. Halocyphina villosa was frequent in the Seychelles (Hyde & Jones, 1988), Lulworthia sp. in Mauritius (Poonyth et al., 1999), Savoryella lignicola in Thailand (Hyde et al., 1990), Halosarpheia marina in Singapore and North Sumatra (Hyde, 1989b; Tan & Leong, 1992), and Leptosphaeria australiensis and Halocypina villosa in Malaysia (Alias et al., 1995). The other very frequently recorded mangrove fungi from east coast of India are Eutypa bathurstensis, Dactylospora haliotrepha, Lophiostoma mangrovei, Halocypina villosa and Cirrenalia pygmea. Some of these fungi are also dominant on the west coast of India and other mangrove sites in the Indian Ocean (Chinnaraj, 1993a – Maldives; Steinke, 1995 – South African coast; Chinnaraj, 1992 – Lakshadweep islands). Borse (1988) reported Massarina velatospora (8.5%) to be the most common fungus from Maharashtra coast followed by Halocyphina villosa (7.7%), Verruculina enalia (6.8%) and Aigialus grandis (6.8%). Jones et al. (1988) reported Massarina velatospora, Halosarpheia marina and Rosellinia sp. as common manglicolous fungi in the Philippines. However, with the exception of V. enalia, the other fungi mentioned above were infrequently recorded on the east coast of India. Many factors such as salinity, temperature, availability and diversity of substrata, quantity of propagules in the water, the nutrient status of the water and host specificity appear to have an effect on species occurrence (Jones & Alias, 1997). Based on their study and other works, Alias et al. (1995) reported that more than 60 fungal species can be regarded as common to mangrove ecosystems of the West Indo Pacific region. They concurred with 50 Table 3. Comparison of frequent fungi from different mangroves sites in the Indian Ocean Place Very Frequent > 10% Frequent 5-10% INDIA East coast of India a. Godavari (Present study) Verruculina enalia (20.6) Eutypa bathurstensis (10.1) Lophiostoma mangrovei (6.5) Cirrenalia pygmea (6.3) Rhizophila marina (5.9) Cryptosphaeria mangrovei (5.1) b. Krishna (Present study) Verruculina enalia (15.6) Dactylospora haliotrepha (8.7) Eutypa bathurstensis (7.9) Lulworthia sp. (6.5) Halosarpheia abonnis (5.4) Halocyphina villosa (5) Pichavaram mangroves Ravikumar (1991) Verruculina enalia (27.8) Lophiostoma mangrovei (11.8) Dactylospora haliotrepha (7.9) Leptosphaeria australiensis (6.7) Aigialus grandis (5.5) West coast of India Maharastra Borse (1988) -Nil- Massarina velatospora (8.5) Halocyphina villosa (7.7) Verruculina enalia (6.8) Aigialus grandis (6.8) Lulworthia sp. (6.0) Dactylospora haliotrepha (5.1) Andaman & Nicobar islands Chinnaraj (1993) Verruculina enalia (12) Halocyphina villosa (10.2) Lophiostoma mangrovei (9.9) Halorosellinia oceanica (9.6) Lulworthia grandispora (9.2) Ascocratera manglicola (7.7) Trichocladium achrasporum (6.9) Dactylospora haliotrepha (6.7) Biatriospora marina (5.1) Atolls of Maldives Chinnaraj (1993) Lophiostoma mangrovei (20.7) Verruculina enalia (14.7) Dactylospora haliotrepha (9) Massarina thalassiae 7.6) Lineolata rhizophorae (6.9) Mauritius (Poudre d’Or) (Poonyth et al., 1999) Lulworthia sp. (22.2) Swampomyces triseptatus (15.7) Marinosphaera mangrovei (11.1) Lineolata rhizophorae (10.2) Leptosphaeria australiensis (8.3) Halosarpheia fibrosa (5.6) Singapore (Tan & Leong, 1992) Halosarpheia marina (21.6) Lulworthia sp. (16.7) Lignincola laevis (11.8) Halosarpheia retorquens (10.8) Cirrenalia basiminuta (9.8) Bathyascus sp. (8.8) Aniptodera chesapeakensis (7.8) Antennospora quadricornuta (7.8) Mycosphaerella pneumatophorae (5.9) Continued on p. 50 51 Table 3. contd. Place Very Frequent > 10% Frequent 5-10% Malaysia (Alias et al., 1995) Kuala Selangor Halocyphina villosa (25.3) Leptosphaeria australiensis (17) Kallichroma tethys (17) Lulworthia grandispora (14.8) Marinosphaera mangrovei (12.2) Eutypa sp. Dactylospora haliotrepha (7.9) Lignincola longirostris (5.2) Ascocratera manglicola (6.9) Morib Leptosphaeria australiensis (20.5) Halocyphina villosa (16.4) Kallichroma tethys (15.7) Halorosellinia oceanica (14.9) Lulworthia grandispora (7.9) Julella avicenniae (7.1) Eutypa sp. (5.2) Port Dickson Leptosphaeria australiensis (16.8) Halorosellinia oceanica (15.2) Massarina ramunculicola (15.2) Kallichroma tethys (13.6) Halosarpheia ratnagiriensis (12.4) Lulworthia grandispora (7.2) Marinosphaera mangrovei (7.2) Dactylospora haliotrepha (6.8) Massarina velatospora (5.6) Lignincola longirostris (5.2) North Sumatra (Hyde, 1988) Halosarpheia marina (22) Rhizophila marina (18.7) Phoma sp. (15.3) Lulworthia sp.1 (12.7) Dactylospora haliotrepha (12) Lignincola laevis (11.3) Cirrenalia pygmea (10.7) Aniptodera chesapeakensis (9.3) Lulworthia sp.2 (8.7) L. grandispora (6.7) Aigialus grandis (6.7) Halosarpheia ratnagiriensis (6.0) Massarina velatospora (6) Halocyphina villosa (5.3) Thailand (Hyde et al., 1990) Savoryella longispora (14) Aigialus grandis (9.6) Lulworthia grandispora (8.5) Phialophorophoma litoralis (8.2) Verruculina enalia (7.6) Kallichroma tethys (7.6) Leptosphaeria australiensis (7.1) Halocyphina villosa (7.1) Seychelles (Hyde & Jones, 1988) a. > Brillant Mangrove Halocyphina villosa (27.3) Lulworthia grandispora (22.7) Rhizophila marina (15.5) Antennospora quadricornuta (12.4) Halosarpheia marina (19.3) Halocyphina villosa (13.3) Dactylospora haliotrepha (7.2) Aniptodera mangrovei (6.7) Caryosporella rhizophorae (6.7) b. Anse Boileau Hyde (1990) that although there are differences in the common species at these study sites, a ‘core’ group of fungi occurring in the mangrove ecosystem can be recognized. Antennospora quadricornuta (5.9) Cirrenalia tropicalis (5.9) Trichocladium alopallonellum (5.9) Variation of fungal diversity between the hosts and sites It is interesting to note from the present study that different plants harboured different mycota although growing in the same community. A comparison of the 52 mycota isolated from Avicennia and Rhizophora revealed that in addition to species common to both host plants there were some fungi found only on a single host plant. Although significant similarity was found in the composition of the fungi between the 2 hosts, many species were recorded on any one host only. Thus, 20 species were recorded from only Avicennia and 22 from only Rhizophora. Furthermore, each had its own very frequent, frequent and infrequent species. Even when recorded on both hosts, their percentage occurrence was not the same. For example, at the Godavari delta, Verruculina enalia, Cirrenalia pygmea and Rhizophila marina were very frequent on R. apiculata, V. enalia and Eutypa bathurstensis were very frequent on Avicennia spp. At the Krishna delta, while V. enalia and Dactylospora haliotrepha were very frequent on R. apiculata, V. enalia and Eutypa bathurstensis were very frequent on Avicennia spp. Similar observations were made by earlier workers. While few species are host specific, some show a more common occurrence or ‘recurrence’ for a certain substrate. Hyde (1990) found that Coronopapilla mangrovei was more common on Xylocarpus sp., while Aigialus parvus and Eutypa sp. were more common on Avicennia sp. Tan et al. (1989) and Leong et al. (1991) found that Halocyphina villosa was infrequent on Bruguiera cylindrica and Rhizophora apiculata, but was common on Avicennia spp. Several fungi have now been shown to be unique to Rhizophora spp. or having a greater ‘recurrence’ on this host genus. These include Capillataspora corticola, Caryosporella rhizophorae, Etheirophora blepharospora, Hypophloeda rhizospora and Rhizophila marina (Hyde, 1990). While the question of host specificity is still unresolved, dominance of certain fungi seems to differ from one host to another. To conclude, there is an overlap of frequently occuring fungi in both the sites although there are differences in their percentage occurrence. This could be attributable to the geographical proximity and similar climatic factors prevailing in both the delta systems. However, minor differences could be due to subtle local environmental factors. 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