''Meristacrum'' is a fungal
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
in the monotypic
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Meristacraceae, of the order
Entomophthorales
The Entomophthorales are an order (biology), order of fungi that were previously classified in the class Zygomycetes. A new subdivision, Entomophthoromycotina, has recently been circumscription (taxonomy), circumscribed for them.
Most species of ...
.
They are parasites of soil invertebrates, they typically infect
nematodes
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...
,
and
tardigrades
Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them Kleiner Wasserbär ...
.
[P. F. Cannon and P. M. Kirk (Editors) ][David J. McLaughlin and Joseph W. Spatafora (Editors) ]
Fungi strains such as ''Meristacrum asterospermum'' and ''
Zygnemomyces echinulatus'' have been identified as potential sources of
biological control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
against parasitic nematodes.
[ Although, they have yet to be raised within laboratory or ]Axenic
In biology, axenic (, ) describes the state of a culture in which only a single species, variety, or strain of organism is present and entirely free of all other contaminating organisms. The earliest axenic cultures were of bacteria or unicellul ...
conditions.[
]
History
The family Meristacraceae was specifically erected to hold the genus ''Meristacrum'' in 1940.[
The genus ''Meristacrum'' gets its name from the ]Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
word ''meristos'' which means 'divided'.[
Three genera that were formerly included in ]Ancylistaceae
The ''Ancylistaceae'' are a family of fungi in the order Entomophthorales. The family currently contains 3 genera: '' Ancylistes'', '' Macrobiotophthora'', '' Conidiobolus''. '' Capillidium'' was added in 2020, it was once thought to be a sub-gen ...
family; '' Ballocephala'', ''Meristacrum'', and '' Zygnemomyces'', were transferred to Meristacraceae by American mycologist Richard A. Humber in 1989, because these fungi all produce a simple, upright conidiophore
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an Asexual reproduction, asexual, non-motility, motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are al ...
bearing several conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...
.
Genera ''Ballocephala'' and ''Zygnemomyces'' were later then transferred to subdivision Kickxellomycotina
Kickxellomycotina is a fungus grouping. In the subkingdom of Zoopagomyceta .
The name was changed from "Harpellomycotina", because "Kickxellomycotina" had an older stem. It came from the genus '' Kickxella'', named after Jean Kickx.
Orders in ...
, based on the bifurcate, plugged septa in their vegetative hyphae, this was also confirmed by Humber (in 2012).
Life cycle
In general, the various fungal species of Meristacraceae, find a host using a germ hyphae produced by adhesive spores that were actively (ballistically) discharged and airborne.[Carl A. Batt and Pradip Patel (Editors) ] They use conidial propulsion, or by 'papillar eversion', which is by fluid discharge by a swollen subtending cell, or passively released from a short pedicel.
Conidia then adhere to the integument
In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, shell, germ or rind.
Etymology
The term is derived from ''integumentum'', which is Latin for "a covering". In a transferred, or ...
(skin) of a live nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
, then either penetrate directly by a germ tube or germinate externally and produce secondary conidia. Resting spores germinate and produce a single erect conidiophore similar to those produced by thallodic segments
The fungus then invades the abdomen of the host and a systemic infection develops. Once the host has died,