Pilobolus species found on herbivore dung from the São Paulo Zoological Park, Brazil

Espécies de Pilobolus encontradas em fezes de herbívoros do Parque Zoológico de São Paulo, Brasil

Pilobolus species found on herbivore dung from the São Paulo Zoological Park, Brazil

Espécies de Pilobolus encontradas em fezes de herbívoros do Parque Zoológico de São Paulo, Brasil

Aírton Viriato

Hospital Infantil Cândido Fontoura, Secretaria de Estado da Saúde, Rua Siqueira Bueno 1757, 03173-010 São Paulo, SP, Brasil ([e-mail])

ABSTRACT

A study of Pilobolus species from 168 dung samples of various herbivoresous animals, collected in the São Paulo Zoological Park, was carried out. Ten species were found, illustrated, described, and a key for their identification is provided.

Key words: coprophilous fungi, Mucorales, Zygomycota

RESUMO

Para o estudo de espécies de Pilobolus, foram coletadas 168 amostras de fezes de animais herbívoros no Parque Zoológico da cidade de São Paulo. Dez espécies foram verificadas, ilustradas e descritas e uma chave de identificação é apresentada.

Palavras-chave: fungos coprófilos, Mucorales, Zygomycota

Introduction

Pilobolus is a saprotrophic genus belonging to the Mucorales (Zygomycota), frequently found in herbivorous animals feces (Alexopoulos et al. 1996). The genus is characterized by coprophilous habit, positive phototropism and method of spore dispersal. In the dispersal process, the mature sporangium is thrown more than 2 meters by dehiscence of the mucilage found at the junction of the columella-with the sporangium, caused by the rupture of the subsporangial vesicle. This is why it is called "sporegun" dispersal (Ingold 1971). The group was studied and its taxonomy revised by Grove (1934). Since then there have been few works on the taxonomy of the group (Nand & Mehrotra 1968; Tandon 1968; Zycha et al. 1969). In Brazil, Pilobolus species have been recorded by Trufem (1984), Viriato & Trufem (1985) and Richardson (2001). The species of Pilobolus are attached to the substrate by an absorptive structure, the swollen trophocyst, semi-immersed in the substrate at the base of the sporangiophore. Generally the trophocysts are ovoid to globose, with a long-cylindrical, rhizoidal extension. The sporangiophores are straight, never branched, positively phototropic, with two rings of orange pigment, one at the base and the other at the base of the subsporangial vesicle. The orange carotenoid pigments act as light sensors which are lined up with each other by the expanded subsporangial vesicle acting as a lens, so that the sporangium is always aimed at the brightest light. The sporangia are black, sub-hemispherical and have resistant walls. The columellae are generally smooth and long-elliptical, and sometimes mammiform. The spores are spherical to ellipsoid, and generally smooth walled, hyaline or with carotenoid pigments. The diagnostic structure of the Zygomycota is the zygosporangium, containing the zygospore, formed by the conjugation and fusion of two gametangia. No zygospores were observed during the study. The objective of this research is to contribute to the knowledge of the biodiversity of this group of fungi and to learn about their distribution on herbivorous dung from different species of mammals.

Material and methods

One hundred and sixty-eight samples of animal feces [camel (Camelus bactrianus L.), horse (Equus caballus L.), "cotia" (Dasyprocta fuliginosa L.), "guanaco" (Lama guanacoe Muller), "orix" (Orix gazela L.), "veado-catingueiro" (Mazama gouazoubira Fischer), "veado-nobre" (Cervus elaphus L.), zebra (Equus burchelli Gray)] were collected monthly (from September 1994 to July 1995) from the Fundação Parque Zoológico de São Paulo by the breeder in the morning, using wooden spatulas, being careful to keep the samples intact. The samples were incubated in moist chambers, sterilized Petri-dishes, in a laboratory with ambient light and temperature conditions, for four or five days, when the observations were made. The morphology of each Pilobolus species was studied, measured with an eyepiece micrometer coupled to the optical microscope, and drawn with a drawing attachment/camera lucida. As Pilobolus specimens do not develop well in culture, they were removed end immediately examined.

Results

The following key is for the species we observed.

Key for the identification of Pilobolus species

1. Spores spherical ..................................................................................... 2 1. Spores not spherical ................................................................................ 7 2. Spores with twin walls ............................................... 8. Pilobolus oedipus 2. Spores with single walls ........................................................................ 3 3. Spores 10-20 μm diam ....................................................................... 4 3. Spores < 10 μm diam ........................................................................ 5 4. Sporangiophores 0.4-0.5 mm high ................................ 1. P. borzianus 4. Sporangiophores 4-6 mm high ............................ 10. P. sphaerosporus 5. Sporangiophores 1-3 mm high .................................. 5. P. longipes 5. Sporangiophores smaller ............................................................ 6 6. Spores yellow, 5-7 μm diam .................................... 6. P. morinii 6. Spores hyaline, 3.5-4 μm diam ................................. 7. P. nanus 7. Spores variously shaped ........................... 3. P. heterosporus 7. Spores ellipsoid to short-cylindrical ..................................... 8 8. Sporangiophores 0.8-0.95 mm high; spores hyaline, short elliptical ....................................................... 9. P. pullus 8. Sporangiophores > 1.5 mm high; spores yellow, elliptical to short cylindrical .......................................................... 9 9. Columellae conical; trophocysts 500-700 μm long ............. .............................................................. 4. P. kleinii 9. Columellae mammiform; trophocysts 350-400 μm long ....... ...................................................... 2. P. crystallinus

1. Pilobolus borzianus Morini, Mem. Accad. Sci Inst. Bolgna ser. 6, 3: 126. 1906.

Fig. 1-8

 

Trophocysts ovoid to globose, 250-300×150-250 μm; rhizoidal extensions up to 150 μm, little orange pigmentation; sporangiophores long-cylindrical, 400-500×90-110 μm; sporangia black, globose, 250-290×180-200 μm; columellae smooth, long-elliptical, 130-150×100-120 μm; subsporangial vesicles smooth, ovoid, 270-370×200-250 μm; spores smooth, yellow, with grainy contents, spherical, 10-20 μm diam. Collected from dung of horse (Oct., Nov., 1994, Jan., May, 1995), "guanaco" (Sep., 1994), "orix" (Sep., Dec.,1994, June, July, 1995), "veado-catingueiro" (October/1994), "veado-nobre" (February/1995, June/1995, July/1995), zebra (October/1994, May/1995). The observed material corresponds well with to the descriptions of Grove (1958), Naumov (1939) and Nand and Mehrota (1968). Pilobolus borzianus was recorded in the State state of São Paulo by Viriato and Trufem (1985) and the current material corresponds well with to their description. P. borzianus differs from the other species of the genus with spherical spores because of the spore size, which can reach 20 μm diam. As regards to the sporangiophore height, only P. morinii approaches that of P. borzianus, but its spores are much smaller (up to 7 μm diam.), and its columellae are semi elliptical, while those of P. borzianus are long-elliptical.

2. Pilobolus crystallinus (Wiggers) Tode, Schriften Naturforschenden Froukleich Berlin 5: 96. 1784.

Fig. 9-15

Trophocysts ovoid to globose, 350-400×250-300 μm, with rhizoidal extensions up to 400 μm long, little orange pigmentation; sporangiophores long cylindrical, 1.5-5.0 mm×115-150 μm, black sporangia, hemispherical to ovoid, 250-350×240-340 μm, resistant and smooth walled; smooth columellae, mammiform, 180-200×160-175 μm, subsporangial vesicles with smooth walls, without pigmentation, ovoid to globose 500-700×400-600 μm, yellow spores, homogeneous content, smooth, short-cylindrical, 8.0-10×7.0-9.0 μm. Collected from dung of horse (December/1994, June/1995), "guanaco" (October/1994), "orix" (December/1994), "veado-catingueiro" (November, December/1994, May/1995), zebra (September/1994, October/1994, December/1994, January/1995, April/1995). The characteristics of the material well with the descriptions of Naumov (1939), Boedjin (1958), Grove (1958), Tandon (1968), and Richardson & Watling (1969). Pilobolus crystallinus was also mentioned by Viriato and Trufem (1985) in the of São Paulo. It differs from the other species of the genus due to the short-cylindrical spores, up to 10 μm long. The only species with similar characteristics is Pilobolus pullus, but it differs in sporangiophore height, because P. crystallinus is about 1,0 mm larger. P. pullus spores are short-elliptical and can reach up to 12 μm long, bigger than in P. crystallinus.

2. Pilobolus heterosporus Palla, Zur Kenntniss der Pilobolus Arten, Österreichische Botanische Zeitschrift 50: 349. 1900.

Fig. 16-22

Trophocysts ovoid to globose, short-ellipsoid, 300-400×250-300 μm, with rhizoidal extensions up to 150 μm long, little yellow pigmentation; sporangiophores long-cylindrical, 2.0-3.0 mm×100-120 μm, black sporangia, hemispherical and ovoid, 350-400×250-350 μm, resistant wall; conical columellae, 140-150×120-135 μm, little pigmented subsporangial vesicles, ovoid and ellipsoid, 450-550×350-400 μm; smooth spores, soft yellowish grainy pigmentation, globose, oval, piriform to irregular, (8.5)10.0-18.0(20.0)×(5.0)7.0-9.0(11.0) μm. Collected from zebra's dung (October/1994). The observed material shows similarities with the descriptions of Naumov (1939), Grove (1958), Tandon (1968), and Nand & Mehrotra (1968). Pilobolus heterosporus was cited by Viriato & Trufem (1985) in the State of São Paulo. The referred taxon differs from the other species of the genus due to its irregular spores with grainy contents.

4. Pilobolus kleinii van Tieghem, Trois. Mém. Annales des Sciences Naturalles, ser 6. 4: 337-338. 1876.

Fig. 23-29

Trophocysts ovoid to globose, with yellow pigments, globose to elliptical, 550-700×300-450 μm, with rhizoidal extensions up to 250 μm; sporangiophores long-cylindrical 3.0-5.0 mm× 100-135 μm; black sporangium, hemispherical to lowered, 350-400×150-300 μm diam., smooth and resistant wall, smooth columellae, conical, 200-205×150-190 μm; smooth subsporangial vesicles, hyaline, ovoid to subellipsoid, 500-700×450-550 μm; yellow spores, refringent and with slightly grainy contents, smooth, ellipsoid, 11-9.0×8.0-5.0 μm. Collected from dung of camel (April/1995), horse (November/1994, February/1995, March/1995, May/1995), and zebra (September/1994, January/1995, February/1995, March/1995, June/1995). The characters of the are similar to the descriptions of Nand and Mehrotra (1968), Richardson and Watling (1969), and Liu and Yang (1973). For the state of São Paulo, the species was described and illustrated by Trufem (1984) and Viriato and Trufem (1985), and both descriptions correspond to the current material.

5. Pilobolus longipes van Tieghem, Trois. Mém. Annales des Sciences Naturalles, ser. 6. 4: 338-340. 1876.

Fig. 30-36

 

Trophocysts ovoid to globose, long-cylindrical, 400-750×200-300 μm, with rhizoidal extensions up to 950 μm, with a soft yellow pigmentation; sporangiophores 1.0-3.0 cm×90-110 μm; black sporangium, globose, ovoid to slightly levelled, 300-350×250-200 μm, resistant wall, with up to 1.0 μm high thorns, smooth, conical columellae, 155-170×140-150 μm; subsporangial vesicles with smooth walls, little pigmentation, ovoid, 650-700×500-600 μm; yellow spores, grainy content, smooth, spherical, 6.0-15 μm diam. Isolated from horse (July/1995), and zebra (February/1995, June/1995, August/1995). The characters of the are similar to the descriptions of Grove (1958), Nand & Mehrotra (1968), and Tandon (1968). Spores of Pilobolus sphaerosporus and P. oedipus are almost the same size as those of P. longipes, but those of the former are lightly pigmented and reaches 14 μm diam., while the latter has spores with twin walls, which was not seen in the material being discussed.

6. Pilobolus morinii Saccardo, Sylloge Fungorum 17: 505. 1905.

Fig. 37-43

Trophocysts ovoid to globose, with little yellowish pigmentation, spherical to ovoid, 250-300×150-250 μm, rhizoidal extensions up to 150 μm; sporangiophore long-cylindrical, 400-800×80-110 μm; black sporangium, smooth and resistant walls, globose to hemispherical, 150-200×100-150 μm; columellae with smooth wall, hyaline, half-elliptic, 110-140×70-100 μm; hyaline subsporangial vesicles, smooth wall, oval, 250-550× 200-300 μm; yellow spores, smooth, little grainy content, globose, 5.0-7.0 μm diam. Isolated from zebra (September/1994). The observed material corresponds to that described by Naumov (1939). The descriptions provided by Boedjin (1958) and Tandon (1968) differ in sporangiophore height, mentioned as up to 3.0 mm. The taxon differs from the other species of the genus, with spherical spores, because of spore size that can reach 7.0 μm diam., and also due to the half-elliptical columella form which is seen only in this species.

7. Pilobolus nanus van Tieghem, Trois. Mém. In Annales des Sciences Naturalles, ser 6 4: 340-342. 1876.

Fig. 44-50

Trophocysts ovoid to globose, elliptical, 200-250×155-195 μm, with rhizoidal extension up to 120 μm, little yellowish pigmentation; sporangiophores long-cylindrical, 0.5-1.0 mm×55-65 μm; black sporangia, resistant wall, hemispherical to ovoid, 170-200×130-150 μm; columellae with smooth walls, convex, 75-95×120-140 μm; subsporangial vesicles with smooth wall, hyaline, little pigmentation, slightly ovoid, 290-310×270-290 μm; hyaline spores, smooth, globose, 3.5-4.0 μm diam. Collected from dung of horse (October/1994). The isolated material corresponds well with the description of Grove (1958), except for columella format. There have been no previous reports from Brazil. P. nanus differs from the other species of the genus with spherical spores because its spores are smaller, up to 5.5 μm diam. Additionally, it has convex columellae, which do not occur in any other species of the genus.

8. Pilobolus oedipus Montagne, Ann. Soc. Linn. de Lyon p. 1-7. 1828.

Fig. 51-57

Trophocysts ovoid to globose, globose to subglobose, 200-250×145-190 μm, with rhizoidal extension up to 300 μm, little yellowish pigmentation; sporangiophores long-cylindrical, 1.5-2.0 mm×100-110 μm; black sporangia, wall with cuticle, resistant, spherical to hemispherical, 350-450×240-300 μm; columellae smooth walled, 200-250×130-150 μm; subsporangial vesicle smooth walled, little pigmentation, ovoid to elliptical, 550-650×450-500 μm; yellow spores, grainy content, smooth wall, twin, globose, 9.0-16 μm diam. Collected from dung of horse (January/1995), and zebra (November/1994, March/1995, June/1995). The observed material corresponds well to the description of Nand & Mehrotra (1968). Pilobolus oedipus was registered in the state of São Paulo by Viriato & Trufem (1985). It differs from the other species of the genus with spherical spores because of the specific twin wall of the spores.

9. Pilobolus pullus Massee, Kew Bulletin p. 160. 1901.

Fig. 58-64

 

Trophocysts ovoid to globose, hyaline, globose to ovoid, 110-155×60-100 μm, with rhizoidal extension up to 300 μm; isolated sporangiophores long-cylindrical, 800-950×80-100 μm; black sporangia, with resistant wall, hemispherical to lowered, 200-300×170-210 μm; smooth columellae, mammiform, 150-200×120-140 μm; subsporangial vesicle with smooth wall, no pigmentation, ovoid to globose, 550-650×350-4500 μm; hyaline spores, smooth, short elliptical, 8.5-12×6.5-7.5 μm. Isolated from dung of horse (November/1994) and "guanaco" (September/1994). The isolated material has characters that agree with the description of Naumov (1939). Pilobolus pullus was recorded in the state of São Paulo by Viriato & Trufem (1985). It differs from the other species of the genus because it has short-elliptical spores, up to 12 μm. The columellae are typically mammiform. Pilobolus crystallinus is the only species whose characteristics come close to P. pullus, but the sporangiophores of P. crystallinus are larger, reaching 1.9 mm high.

10. Pilobolus sphaerosporus Palla, Oesterr. Bot. Zeitschr. 50: 400. 1900.

Fig. 65-71

Trophocysts ovoid to globose, long-ovoid, 550-700×250-275 μm, with rhizoidal extension up to 600 μm, with little pigmentation; sporangiophores long-cylindrical, 4.0-6.0 mm×130-150 μm; black sporangia, with resistant wall, hemispherical to ovoid, 185-270×295-400 μm; smooth columellae, mammiform, 95-200×65-150 μm; subsporangial vesicles smooth walled, no pigmentation, ovoid to globose, 650-800× 625-695 μm; yellow spores, smooth, grainy content, globose, 10-20 μm diam. Observed on dung of horse (October/1994, November/1994, March/1995, July/1995), "guanaco" (November/1994, December/1994, January/1995), and zebra (October/1994, December/1994). The studied material is similar to the descriptions of Naumov (1939), Grove (1958) and Nand & Mehrotra (1968). Pilobolus sphaerosporus was isolated and described in the state of São Paulo by Viriato & Trufem (1985). It differs from the other species of the genus due to sporangiophores height, up to 4-6 mm high.

Acknowledgments

We would like to thank to Dr. Mike J. Richardson, for suggestions; Dr. Faiçal Simon (in memorian) and Dr. Mario Borges da Rocha, for making possible the collection of the feces from the herbivorous mammals in the Parque Zoológico de São Paulo.

Received: May 2, 2007. Accepted: September 4, 2007

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• Boedijn, K. B. 1958. Notes on the Mucorales of Indonesia. Sydowia, Annales Mycologicy 12: 321-362.
• Grove, W.B. 1934. A systematic account and arrangement of the Pilobolidae. Pp.190-224. In: A.H.R. Buller. Researches on fungi v.6. New York, Hafner Publishing.
• Ingold, C.T. 1971. Fungal spores: their liberation and dispersal London, Oxford University Press.
• Liu, C. & Yang, B. 1973. Studies on certain species of Taiwan Mucorales. Taiwania 18: 73-82.
• Nand, K. & Mehrotra, B.S. 1968. Species of Pilobolus and Pilaira from India. Sydowia, Annales Mycologici, ser. II. 22: 299-306.
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• Richardson, M.J. 2001. Coprophilous Fungi from Brazil. Brazilian Archives of Biology and Technology 44: 283-289.
• Tandon, R.N. 1968. Mucorales of India. New Delhi: Indian Council of Agricultural Research
• Trufem, S.F.B. 1984. Mucorales do Estado de São Paulo: 4. Espécies Coprófilas. Rickia 11: 53-64.
• Viriato, A. & Trufem, S.F.B. 1985a. Mucorales do Estado de São Paulo: 5. Pilobolaceae. Rickia 12: 77-88.
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Publication Dates

• Publication in this collection
  11 Nov 2008
• Date of issue
  Sept 2008

History

• Accepted
  04 Sept 2007
• Received
  02 May 2007