Spinellus fusiger

Description

Spinellus fusiger is a species of fungus in the Zygomycota phylum. It is a pin mold that is characterized by erect sporangiophores (specialized hyphae that bear a sporangium) that are simple in structure, brown or yellowish-brown in color, and with branched aerial filaments that bear the zygospores.

It grows as a parasitic mold on mushrooms, including several species from the genera Mycena, including M. haematopus, M. pura, M. epipterygia, M. leptocephala, and various Collybia species, such as C. alkalivirens, C. luteifolia, C. dryophila, and C. butyracea. It has also been found growing on agaric species in Amanita, Gymnopus, and Hygrophorus.

Common names: Bonnet Mold.

Mushroom Identification

During the reproductive phase of its life cycle, Spinellus fusiger grows throughout the cap of the mushroom host, eventually breaking through to produce radiating reproductive stalks (sporangiophores) bearing minute, spherical, terminal spore-containing structures called sporangia.

Ultimately, the spores in the sporangia are released after the breakdown of the outer sporangial wall, becoming passively dispersed to new locations via wind, water, and insects. The sporangia contain non-motile mitospores known as aplanospores.

Like other Spinellus species, S. fusiger is homothallic, and sexual spores known as zygospores are produced following the union of branches called gametangia, that arise from the same mycelium.

History

This fungus species was described scientifically in 1824 by German naturalist Johann Heinrich Friedrich Link (1767 - 1850), who gave it the binomial scientific name Mucor fusiger. In 1875 French mycologist Phillippe Édouard Léon van Tieghem (1839 - 1914) redescribed this species, transferring it to Spinellus, a new genus that was circumscribed by Tieghen at that same time.

Synonyms of Spinellus fusiger include Mucor fusiger Link, Mucor macrocarpus Corda, and Spinellus macrocarpus (Corda) P. Karst.

The generic name Spinellus means little spike or thorn, while the specific epithet fusiger means 'like a spindl'e.

Photo sources:

Photo 1 - Author: KostasGiannakis (CC BY-SA 4.0)

Photo 2 - Author: Aorg1961 (CC BY 3.0)

Photo 3 - Author: Dan Molter (shroomydan) (CC BY-SA 3.0)

Photo 4 - Author: Holger Krisp (CC BY 3.0)