Essays >> Fungi in the Ramioul Cave

FUNGI IN THE RAMIOUL CAVE

By

David Malloch, New Brunswick Museum

The Ramioul Cave, "La Grotte de Ramioul", is a cavern near the village of Ramioul in the commune of Flémalle, province of Liège, Belgium. It was discovered by Les Chercheurs de la Wallonie in 1911 but the extensive system of lower galleries was not explored until 1956. It is a site of great prehistorical and biological interest, well interpreted by the museum just outside its entrance.

The Ramioul Cave has been threatened several times by quarrying activities and has been preserved mainly through the tireless efforts of Mr. Jean-Marie Hubart. Mr. Hubart has spent much of his life studying the cave and has established a small laboratory within it for speleological research.

In 1985 Mr. Hubart sent some small spherical objects found in the cave to David Malloch. These originally were discovered covering a small piece of meat inadvertently left in the cave by a previous visitor. Subsequent experiments revealed that if a small piece of meat were left in the cave for about a month it always became covered with the spheres. The dense black masses of spheres resembled caviar, leading to the nickname "Le Caviar de Ramioul". The spheres turned out to be perithecia of an unnamed species of Microascus, described by Malloch and Hubart in 1987 (Can. J. Bot. 65: 2384-2388) as Microascus caviariformis.

In April of 1986 Malloch had the opportunity to visit the Ramioul Cave and examine the caviar in its natural habitat. This involved an arduous climb and near free-fall to the lower levels of the cave in the company of Mr. Hubart and Dr. Jean-Pierre Discry. In the largest room of the lower level, "La Grande Salle", Hubart and Discry pointed out structures remarkably similar to the Microascus embedded in thin layers of limestone in the cave wall. Later examinations showed these to be fossilized sclerotia of Cenococcum geophilum, a fungus forming mycorrhizal relationships with the roots of a variety of trees. Studies by Malloch and his students in Ontario had shown sclerotia of Cenococcum geophilum to be waterborne and exceedingly abundant in spring runoff water. Malloch, Grenville and Hubart (Can. J. Bot. 65: 1281-1283. 1987) published their findings on the fossil sclerotia and suggested that these had been trapped on the walls of the Grande Salle when spring runoff water receded 2750 to 7500 years ago.

Many insects occur on the walls of the Ramioul Cave near its two entrances. These are mostly flies in the genera Amoebaleria, Eccoptomera andHeleomyza (all Heleomyzidae - kindly identified by Dr. J.R Vockeroth, Agriculture Canada). Fungal infections are common among these insects and can take on spectacular forms. Hirsutella guignardii forms long white synnemata hanging down from dead flies attached to the ceiling of the cave (illustration above right).

In addition to those fungi causing disease in cave insects there are a variety using insects to transport their spores. Malloch spent a few weeks studying these fungi in 1991, both in the Ramioul Cave and at the Mycotheque de l'Université Catholique de Louvain-la-Neuve (MUCL). Many of the fungi isolated from heleomyzid flies and from beetles of the genus Speonomus belonged to the genus Mortierella. These and other insect-borne forms are still under investigation.

PUBLICATIONS ON FUNGI FROM THE RAMIOUL CAVE

Malloch, D., D. Grenille and J.-M. Hubart. 1986. Presence exceptionnelle de sclerotes de champignons fossiles dans la Grotte de Ramioul. Bulletin des Chercheurs de Wallonie 27: 89-96.

Malloch, D. and J.-M. Hubart. 1986. Decouverte d'une nouvelle espèce de Microascaceae dans la Grotte de Ramioul. Bulletin des Chercheurs de Wallonie 27: 97-100.

Malloch, D., D. Grenville and J.-M. Hubart. 1987. An unusual subterranean occurrence of fossil fungal sclerotia. Canad. J. Bot. 65: 1281-1283.

Malloch, D. and J.-M. Hubart. 1987. An undescribed species of Microascus from the Cave of Ramioul. Canad. J. Bot. 65: 2384-2388.

Malloch, D. and R.S. Khan. 1988. Three fungal records from the Cave of Ramioul. Bulletin des Chercheurs de Wallonie 28: 189-197.