A new technique to monitor conidia of aquatic hyphomycetes in streams using latex-coated slides

Abstract

We examined the pattern of adherence of aquatic hyphomycetes conidia on six latex-coated slides (Artocarpus heterophyllus, A. hirsutus, Calotropis gigantea, Ficus benghalensis, Manilkara zapota and Plumeria rubra) with plain slides (control) exposed up to 18 h in a tropical coastal stream. Conidia of 21 species were trapped on latex-coated slides against seven on control slides. The total conidia adhered on latex-coated slides was higher than control slides. Latex-coated slides showed the highest diversity of aquatic hyphomycetes than control slides (1.805) and water (0.729). The top five species of aquatic hyphomycetes in latex-coated slides and drift conidia were comparable. Sørensen’s similarity of species in control slides against latex-coated slides ranged from 25% (P. rubra) to 62.5% (C. gigantea) indicating superiority of latex-coated slides in conidial trapping. Among the latex-coated slides, similarity varied between 13.3% (A. hirsutus vs. P. rubra) and 89.6% (F. benghalensis vs. M. zapota). One-way ANOVA showed significant difference in richness of species (P < 0.001) and conidia (P < 0.05) between control and latex-coated slides by F. benghalensis. Based on the trapping efficiency of species and conidia, the latex of F. benghalensis ranked first and serves as an inexpensive technique to monitor aquatic hyphomycetes in streams.

Diurnal periodicity of conidia of aquatic hyphomycetes in water and entrapment on latex-coated slides in two South Indian streams

“…There is a notion that buoyancy as well as trapping efficiency of stauroid conidia in air bubbles (in foam) is better than that found for ovoid and scolecoid conidia (Iqbal and Webster 1973b). On the contrary, observations made in this study as well as in an earlier study (Ghate and Sridhar 2015) showed that water filtration, adhesion on plain slides and latex-coated slides are not biased towards conidial shape (Sridhar and Sudheep 2010; Ghate and Sridhar 2015). In this study, top five species in all methods encompass scolecoid as well as stauroid conidia; moreover, they were also top in frequency of occurrence based on annual or biannual observations in Konaje and Sampaje streams (with an exception of Trifurcospora irregularis in Konaje stream).…”

“…Considering adhesion property of conidia, a variety of techniques have been designed for assessment of aquatic hyphomycetes (e.g. cellophane, collodion-coated glass rods, latex-coated slides, plexiglass and rosin-coated slides) (Webster 1959; Lindsey and Glover 1976; Müller-Haeckel and Marvanová 1976; Bärlocher et al 1977; Ghate and Sridhar 2015). …”

“…Some of the important conventional methods employed to study them in streams include: (i) Enumeration of drift conidia in water (microscopic observation and membrane filtration) (Iqbal and Webster 1973a; Müller-Haeckel and Marvanová 1979; Sridhar and Sudheep 2010); (ii) Conidial assessment in foam or scum (microscopic observation) (Ingold 1975); (iii) Conidial adhesion on artificial or natural traps (e.g. cellophane, plexiglass and rosin-coated slides and latex-coated slides) and microscopic assessment (Lindsey and Glover 1976; Müller-Haeckel and Marvanová 1976; Bärlocher et al 1977; Ghate and Sridhar 2015); (iv) Direct microscopic examination of fungal growth and sporulation in substrata (incubation of segments of leaf detritus in distilled water in Petri plates) (Ingold 1942). Rosin-coated or latex-coated slides can also be employed as methods of choice as they efficiently trap conidia of aquatic hyphomycetes in streams (Bärlocher et al 1977; Ghate and Sridhar 2015).…”

“…cellophane, plexiglass and rosin-coated slides and latex-coated slides) and microscopic assessment (Lindsey and Glover 1976; Müller-Haeckel and Marvanová 1976; Bärlocher et al 1977; Ghate and Sridhar 2015); (iv) Direct microscopic examination of fungal growth and sporulation in substrata (incubation of segments of leaf detritus in distilled water in Petri plates) (Ingold 1942). Rosin-coated or latex-coated slides can also be employed as methods of choice as they efficiently trap conidia of aquatic hyphomycetes in streams (Bärlocher et al 1977; Ghate and Sridhar 2015). …”

“…Although dynamics of aquatic hyphomycetes have been investigated based on drift conidia in different parts of the world (Müller-Haeckel and Marvanová 1979; Shearer and Lane 1983; Aimer and Segedin 1985; Shearer and Webster 1985; Thomas et al 1989; Fabre 1998; Gönczöl and Révay 1999; Gönczöl et al 2001), studies on diurnal fluctuations of drift conidia in streams seem to be scanty (Thomas et al 1991, 1992; Sridhar and Sudheep 2010; Ghate and Sridhar 2015). Among the six latexes tested, latex derived from banyan tree species ( Ficus benghalensis ) proved excellent in adhesion of conidia (Ghate and Sridhar 2015). In this follow-up study we compared the pattern of diurnal fluctuation of conidia of aquatic hyphomycetes by using three methodologies: (i) under drift in water, (ii) adhesion on plain glass slides and (iii) adhesion on banyan latex-coated glass slides in typical coastal and Western Ghat streams.…”