Healy, J.M. and Jamieson, B.G.M.
Euspermatozoa, paraspermatozoa and spermatozeugmata of Littoraria
(Palustorina) articulata (Prosobranchia:
Caenogastropoda) with special reference to the Pseudotrich. Acta
Zoologica (Stockholm) 74, 321-330.
Paraspermatozoa and euspermatozoa of the
littorinid gastropod Littoraria
(Palustorina) articulala are examined
transmission electron microscopy and light microscopy. In the seminal
both sperm types occur, either as free cells or organized into
spermatozeugmata. It is shown that the elongate (120-140 mu-m),
component of the paraspermatozoon is in fact a tubular extension of the
membrane which encloses granular material but no axonemes or
structure. here termed the pseudotrich, shows no evidence of motility
function remains obscure. The main body region of the paraspermatozoon
32-36 mu-m) contains numerous spherical vesicles, scattered
mitochondria, one or
two large, rod-shaped bodies (length 20-24 mu-m) and a fusiform,
(containing DNA; probably a modified nucleus). The rod-shaped bodies,
body and surrounding matrix are contained by a common membrane, and are
therefore separated from other contents of the paraspermatozoon. In
spermatozeugma, euspermatozoa are attached via the tips of their
the paraspermatozoan body at the opposite end to the pseudotrich.
exhibit a conical acrosomal complex (with axial rod and basal plate), a
nucleus sheathing the axoneme, a midpiece (5-6 helical mitochondrial
sheathing the axoneme), an annulus (with two rings), a glycogen piece
end piece (total sperm length 268-272 mu-m). The euspermatozoa of L.
are similar to those of most littorinids and many other
presence of a pseudotrich in the paraspermatozoon appears to be
the subgenus Palustorina.