Systematics and Evolution, Part A The Mycota

1. Mitospores

a) Sporangiospores
The primary mode of asexual reproduction in
zygomycotan fungi is the unicelled sporan-
giospore. In multispored sporangia, sporan-
giola, and some merosporangia (Mucorales),
spores are delimited from the cytoplasm by
cleavage vesicle fusion.In other merosporangia

(Zoopagales), spores are formed as a result of

the fusion of the invaginating plasmalemma.

Sporangiospores are unicelled, uni-, bi-, or

multinucleate, and often are smooth-walled,

although some taxa have external spines,

warts, or striations, and many members of the

Kickxellales have spines embedded in their

walls. The majority of species produce a hyaline

spore, but a few fungi have pigmented spores.

Fig. 8.2Representatives of all four orders of Kickxel-
lomycotina. 15 , 16. Asellariales.Asellaria ligiae 15.
Portion of thallus showing footcell (f) and arthros-
pores (a). 16. Arthrospores. 17 , 18. Harpellales. 17.
Capniomyces stellatusshowing zygospore (z) and sev-
eral trichospores (t). 18 .Harpella melusinaeshowing
large, curved trichospore (t). 19 , 20. Dimargaritales.
19 .FertileheadofDimargaris aridashowing two-

spored merosporangia (m). 20. Zygospore ofDimar-

garis bacillispora. 21 , 22. Kickxellales. 21 .Twozygos-

pores ofCoemansia pectinata. 22. Fertile head of

Martensiomyces pterosporusshowing sporocladia (s),

pseudophialindes (p), and merosporangia (m). 15 , 18.

Bar 100 mm. 16 , 17 .Bar 20 mm. 19 .Bar 50 mm.20–22.

Bar 25 mm

Zygomycetous Fungi: Phylum Entomophthoromycota and Subphyla Kickxellomycotina,... 225