Coprophilous Ascomycetes

Coprophilous Ascomycetes Michael RICHARDSON Abstract: The relative frequency of occurrence of ascomycetes that grow on herbivore dung is recorded and discussed, based on over 12000 records from more than 1300 herbivore dung samples that were collected and examined during incubation in damp chambers, between 1965 and 2019. individual samples can produce from 0–21 ascomycete species, with an average of seven/sample. some interesting associations are discussed — parasitic species, restricted substrate preferences, and the use of dung fungus spores as in- Ascomycete.org, 11 (6) : 205–209 dicators in palaeoecological studies. Mise en ligne le 24/12/2019 Keywords: Ascomycota, coprophils, distribution, diversity, palaeoecology, parasitism. 10.25664/ART-0275 Introduction ments are often present, which can protect the genetic material from harmful radiation, since a spore may be exposed on the vegetation for some time before it is eaten. Good sources of information, Faeces, especially those of herbivore animals, have long been a especially ecological and taxonomic, are Brummelen (1967), WeBsTer source of material for mycologists. They are easily collected, and in- (1970), lundqvisT (1972), doveri (2004) and Bell (2005). cubation in damp chambers allows the spore inoculum that has since 1965 i have collected and incubated samples of herbivore been ingested by the animals to grow and develop to maturity. Co- dung, from various countries (Figure 1) and habitats, and recorded prophilous fungi have various adaptations that allow their spores the fungi that grew when they were incubated in damp chambers to be dispersed so that they are likely to be ingested by herbivorous — a total of 1376 samples, and 9666 ascomycete records. The results animals, since their germination is facilitated by passage through of these studies have been reported in several publications (inter an animal’s gut. To get into the airstream, spores are often dis- alia riChArdson, 2001; riChArdson, 2015). The first was a synthesis of charged explosively from the asci; by aiming at the sun and dis- data from 425 samples collected between 1994 and 2000, which charging at midday the chance of getting into the airstream is showed that such studies can be used to estimate diversity in differ- increased; mucilaginous sheaths or appendages encourage aggre- ent locations and habitats (dung type), and to demonstrate that the gation of the spore group on dispersal, or spores may be aggregated decrease in species richness from equatorial to polar regions known into a group, which improves the ballistics of the propagule; mu- to occur in other groups of biota (e.g. rosenzWeiG, 1995; BroWn & lo- cilaginous sheaths or appendages also assist the adhesion of spores molino, 1998) holds good for the fungi as well. The second was a data to any vegetation they land on; and purple or dark exospore pig- paper containing the 12326 records of coprophilous fungi obtained Fig. 1 – Approximate locations from where samples were collected 205 from incubating 1354 samples, pdf copies of observational notes, samples were scanned with a dissecting microscope (× 7–45 mag- and pdfs of 20 papers reporting the findings. since then 21 more nification); apothecia/perithecia/ pseudothecia/cleistothecia were samples have been examined, which provided 148 additional removed with a needle, mounted in water (with melzer’s iodine records. This paper takes those additional observations into account added later if required) and examined with a compound microscope and explores some aspects of the ecology and occurrence of the at ×100, ×400 and, rarely, ×1000 magnification. measurements were fungi. made with a calibrated eyepiece micrometer scale. Material and methods Results samples were collected opportunistically from the wild, during of the 12474 records obtained from 1376 samples, 9666 were of travels, or specifically for mycological inventories of places of inter- ascomycetes (77.5%) and, subdivided into major taxonomic groups, est. They were collected into paper bags or envelopes, or small con- their relative occurrences are listed in Table 1. These accounted for tainers, and either incubated in a moist chamber as soon as possible 99% of all ascomycete records. The mean number of ascomycete after collection or gently dried until they could be rehydrated and species recorded from a sample was 7, but the number for individual incubated. samples were examined when set to incubate, and then samples ranged from 0 to 21. The ten most frequent genera, ac- at intervals until no more new records of species were observed. The counting for 78% of all ascomycete records were: Sporormiella ellis Table 1 – The relative frequency of coprophilous ascomycete genera appearing on herbivore dung when incubated in a damp chamber Total no. of % of % of all Type Genera Records records group ascomycetes Ascobolus 994 29.4 10.3 Thelebolus/Ryparobius 787 23.3 8.1 Saccobolus 535 15.8 5.5 Iodophanus 294 8.7 3.0 Coprotus 266 7.9 2.8 Lasiobolus 256 7.6 2.6 operculate ‘discomycetes’ 3380 Cheilymenia 74 2.2 0.8 Ascozonus 67 2.0 0.7 Trichobolus 34 1.0 0.4 Thecotheus 26 0.8 0.3 Pseudombrophila 25 0.7 0.3 Peziza 17 0.5 0.2 non-operculate ‘discomycetes’ 42 Unguiculella 32 78.0 0.3 laboulbeniomycetes 27 Pyxidiophora 27 100 0.3 Schizothecium 1325 31.8 13.7 Podospora 944 22.7 9.8 Coniochaeta 537 12.9 5.6 Sordaria 423 10.2 4.4 Arnium 186 4.5 1.9 Sphaeronaemella 157 3.8 1.6 Hypocopra 133 3.2 1.4 Perithecial spp. 4160 Podosordaria 114 2.7 1.2 Phomatospora 86 2.1 0.9 Melanospora/Sphaerodes 66 1.6 0.7 Cercophora 53 1.3 0.5 Anopodium 51 1.2 0.5 Selinia 20 0.5 0.2 Zygopleurage+Zygospermella 19 0.5 0.2 Bombardioidea 11 0.3 0.1 Sporormiella 1501 80.2 15.5 Trichodelitschia 193 10.3 2.0 Pseudothecial spp. 1874 Delitschia 142 7.6 1.5 Preussia 17 0.9 0.2 Sporormia 16 0.9 0.2 Chaetomium 102 55.7 1.1 Cleistothecial spp. 183 Onygenales 50 27.3 0.5 206 Ascomycete.org & everh., Schizothecium Corda, Ascobolus Pers., Podospora Ces., of coprophilous fungi, of which ascomycetes comprise a large pro- Thelebolus Tode/Ryparobius Boud., Coniochaeta (sacc.) Cooke, Sac- portion. The data presented here give some indication of the abun- cobolus Boud., Sordaria Ces. & de not., Iodophanus Korf. and Copro- dance and diversity of ascomycetes to be recorded when herbivore tus Korf & Kimbr. The 12 most frequent species are listed in Table 2 dung is simply incubated in a damp chamber and observed over a and comprised nearly half (46%) of all records. marsupial samples period, which can be as long as several months, since the break- were the most species rich, but that observation is from only a small down of some of the more complex polysaccharides and other com- number of samples and was not significantly different from those pounds in dung can be protracted. of the six other ‘large’ mammals (Figure 2 and Table 3). small mammal and bird samples provide a much smaller resource, and the Associations birds have a very different metabolism. Although they were overall A few of the fungi observed on dung are not coprophiles per se, less species rich than the other seven mammal dung types studied, but there because they are parasitic on the dung fungi. The numbers and significantly fewer species were recorded per sample, these lat- recorded were relatively low, so full statistical analysis to see if there ter two substrates have their own distinctive mycota, with species was any difference due to dung type was not practical. Based on χ2 that are more likely to be encountered on them than on the other tests of contingency tables, however, some differences appeared to dung types. Ascobolus brantophilus dissing and Saccobolus be significant and are pointed out. Two species and species of three quadrisporus massee & e.s. salmon have only been recorded on genera recorded in this study were: goose dung from high latitudes, and Ascobolus carletonii Boud. Sphaeronaemella fimicola marchal (155 records). There were sig- mainly from droppings of tetraonid birds (e.g. Grouse, Ptarmigan). nificantly more occurrences on rabbit and deer than would be ex- Ascobolus brassicae P. Crouan & h. Crouan was four times more likely pected from a random distribution (×1.8), as many on sheep, and to be recorded from small mammal dung than the other dung types fewer on bird, hare, and cattle of the six types that allowed a valid sampled. χ2 test (P<0.05). In vitro, many coprophilous fungi stimulated perithecial production of S. fimicola, particularly species of Co- Table 2 – The most frequent ascomycete species recorded niochaeta, Ryparobius, Thelebolus and Trichobolus (sacc.) Kimbr. & No. of Cain, and were parasitized by intrahyphal growth of S. fimicola Species % records (WeBer & WeBsTer, 1998). Melanospora Corda and Sphaerodes Clem. spp. (64 records). Thelebolus stercoreus agg. 608 6.3 There were significantly more occurrences of these genera on rabbit Schizothecium vesticola (Berk. & Broome) n. lundq. 482 5.0 than would be expected from a random distribution, as many on Sporormiella intermedia (Auersw.) s.i. Ahmed & Cain 464 4.8 bird and sheep, and fewer on deer and hare of the five types that Schizothecium tetrasporum (G. Winter) n. lundq. 404 4.2 allowed a valid χ2 test (P<0.05). These fungi are mycoparasitic on many hosts, including ascomycetes and their anamorphs (GAms et Sporormiella australis (speg.) s.i. Ahmed & Cain 378 3.9 al.., 2004). Podospora decipiens (G. Winter ex Fuckel) niessl 366 3.8 Unguiculella tityri (velen.) huhtinen & spooner (31 records). Saccobolus versicolor (P. Karst.) P. Karst. 336 3.5 There were significantly more occurrences of this small, white Ascobolus albidus P.

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