Lee, M.S.Y. and Jamieson, B.G.M.
1993a. The
ultrastructure of the spermatozoa of bufonid and hylid frogs (Anura,
Amphibia): implications for phylogeny and fertilization biology. Zoologica
Scripta 22, 309-323.
Comparison of the spermatozoa of Bufo
marinus, six Australian species of the family Hylidae, and the
myobatrachine
Adelotus brevis, with those of
41 other species of frogs, in a total of
12
investigated families allows the following phylogenetic inferences: the
bufonoids (myobatrachids, leptodactylids, hylids, and bufonids) form a
monophyletic assemblage with a single synapomorphy: the presence of a
conical
subacrosomal perforatorium. This structure is analogous to, rather than
homologous with, the perforatorium in archaeobatrachians, which differs
notably
in being an endonuclear structure. The hylid-leptodactylid-bufonid
assemblage
is the sister-group of the Myobatrachidae (Australian 'leptodactylids).
Myobatrachids are distinguished by two, albeit weak, synapomorphies,
the
presence of well-defined pericentriolar material, and the extension of
the
axial rod up the centriolar fossa, the latter condition approached in
the
bufonid Nectophrynoides. The
bufonid, leptodactylid (sensu strictu),
and hylid
families are united, and separated from myobatrachids, by a single
synapomorphy:
a thick collar-like cytoplasmic sheath that emanates from the
centriolar
region, is separated from the flagellum by a cytoplasmic canal. and
contains
the mitochondria. Litoria fallax,
L. gracilenta, and L. lesueuri are
associated
by a unique synapomorphy, hypermorphosis of the minor fibre
(juxta-axonemal
fibre), though this is approached in Bufo
bufo. However, there is no
spermatological evidence supporting the recognition of Australian
hylids
(pelodryadids) as a group distinct from the remaining eubufonoids and,
specifically, from the Hylidae. Evidence is presented in support of the
tentative proposal that the Lissamphibia were primitively internally
fertilizing.