- Kickxellomycotina
The members of Kickellomycotina (Fig.8.2)
are characterized by the formation of regularly
septate hyphae. The septa produce a lenticular
cavity that contains a single plug that is more
or less lens-shaped.The members of Dimargar-
itales form plugs with two protuberances, one
on each side, that protrude into the cytoplasm
of the adjoining hyphal cells. The septal plugs
formed by the remaining orders lack protuber-
ances. Asexual reproduction is by arthrospores
[Fig.8.2(16)], one- or two-spored merosporan-
gia [Fig.8.2(19, 22)], or trichospores [Fig.8.2
(17, 18)]. The zygospores are globose, broadly
fusiform, hemifusiform, or long-cylindrical and
coiled. These fungi are terrestrial parasites or
saprobes, or symbionts in the mid- or hindgut
of insects or isopods. Taxa of Asellariales and
Harpellales can be found on the trichomycetes
Web site (http://www.nhm.ku.edu/~fungi/).
Humber (2012b) transferredBallocephala
and Zynemomyces from Entomophthoromy-
cota to Kickxellomycotina as taxa of unknown
affinities because a member of both taxa pro-
duces a septum and septal plug characteristic of
this subphylum (Saikawa 1989 ; Saikawa et al.
1997 ). Tretter et al. ( 2013 ) report thatBarbatos-
pora,Orphella(Harpellales),Ramicandelaber,
andSpiromyces (Kickxellales) may represent
unique clades in Kickxellomycotina.
a) Asellariales
The members of Asellariales [Fig.8.2(15, 16)]
produce branched, multicelled thalli attached to
the hindgut of their host by a cellular or noncel-
lular holdfast [Fig.8.2(15)]. Asexual reproduc-
tion is by arthrospore [Fig.8.2(16)] formation.
Sexual reproduction has been reportedinAsel-
laria jatibonicuaL.G. Valle & Cafaro (Valle and
Cafaro 2008 ). InAsellaria ligiaeTuzet & Manier
ex Manier, arthrospore development is similar to
trichospore formation in some members of Har-
pellales, especiallyCarouxella(Lichtwardt et al.
2001 ). Lichtwardt ( 1986 ) recognized two genera,
Asellaria and Orchesellaria (Degawa 2009 ; Valle
and Cafaro 2008 ). One monotypic genus,Balto-
myces (Oman and White 2011 ), has been
described that may belong in Asellariales, but
its final disposition will depend on further
study. Several genes have been sequenced for
A. ligiae(E. Tretter, pers. comm.); it appears to
be a member of Kickxellomycotina.b) Dimargaritales
All members of Dimargaritales [Fig.8.2(19,
20)] are haustorial parasites of other fungi,
especially Mucorales, but someDispiraspp.
are parasitic on Chaetomium (Ascomycota;
Benjamin 1959 , 1965 , 1966 , 1979 ). Subaerial
hyphae and sporophores are regularly septate
and simple or branched.The septa are incom-
plete and have a lenticular cavity containing a
single plug with polar protuberances. The
plugs dissolve in 2–3 % KOH(Benjamin 1959 ,
1966 , 1979 ).Asexual reproduction is by two-
spored merosporangia [Fig. 8.2(19)] formed
directly on a fertile vesicle (Spinalia) (Benjamin
1959 ) or on simple or branched sporiferous
branchlets that arise from inflated or unmo-
difled sporophore apices (Dimargaris,Dispira,
Tieghemiomyces) (Benjamin 1959 , 1965 ). All
species of Dispira and Tieghemiomyces and
two species of Dimargarisare dry-spored at
maturity; all otherDimargarisspecies are wet-
spored (Benjamin 1959 , 1965 ). Merosporan-
giosporogenesis is successive in most Dimar-
garitales but simultaneous in twoDimargaris
spp. (Benjamin 1959 , 1965 ).Sexual reproduc-
tion is by hyaline, smooth, or ornamentated
zygospores formed in the substrate on undif-
ferentiated sexual hyphae [Fig.8.2(20)](Benja-
min 1966 ). Zygospores are similar in all
Dimargaritales members, and their formation
is enhanced when a culture is grown on non-
slanted YpSs agar (Benny 2008 ) medium in a
test tube.
The haustorial parasites in Dimargaritales,
Dimargaris,Dispira, andTieghemiomycescan
grown on a medium containing glycerol as a
carbon source (Barnett 1970 ), but growth is
extremely slow and most taxa do not sporulate.
Benjamin ( 1959 ) reported thatTieghemiomyces
californicusR.K. Benj. grows and sporulates
normally without a host on malt extract–yeast
extract agar (Benny 2008 ). A few Dimargaris
species have been isolated from soil, but most
members of Dimargaritales are found on dung,
especially of small rodents (Benjamin 1959 ,
1965 ). Several species may have a global distri-
bution but are seldom recognized or cultured.
Spinalia radiansVuill. is a member of Dimar-230 G.L. Benny et al.