Fig.1b. Variation in shapes of spermatophores
a. Podura aquatica (Poduridae) b. Monobella grassei (Neanuridae) c. Deutonura monticola (Neanuridae) d. Isotoma viridis (Isotomidae) e. Dicyrtomina minuta (Dicyrtomidae)
Fig.1a. Spermatophore
Podura aquatica After Schaller 2001.
Collembola have separate sexes (see fig.Gf and Gm)
and reproduce by means of indirect sperm transfer
(modified from Hopkin 1997:134).
In general, spermatophores are produced every other inter-moulting period
(Joosse & Veltkamp, 1970).
Males may produce up to 200 spermatophores during such a reproductive instar
phase.
Fig.Pa. Podura aquatica Spermatophore anterior aspect
After Schliwa in Cassagnau, P. 1971 Fig.1G
In Podura aquatica
(family Poduridae),
the spermatophore is fixed at the substrate through a base from which a
stalk rises of about 60 micron long.
(after Cassagnau 1971:609).
Fig.Bg. Bilobella grassei from France
Spermatophore anterior aspect
After Cassagnau, P. 1971 Fig.1D
In Bilobella grassei
(family Neanuridae),
the spermatophore is fixed at the substrate through a base from which a short
stalk rises (15-25 micron long and 5-10 micron in diameter).
Stalks up to 70 micron are found occasionally.
The subspheric spermdrop is about 30-35 micron in diameter.
Composite spermatophores of 2 to 3 have been found.
(after Cassagnau 1971:610-612).
Fig.Bg. Bilobella aurantiaca from France
Spermatophore anterior aspect
C. composite spermatophore
D. detail apical button dorsal aspect
E. detail apical button lateral aspect
After Cassagnau, P. 1971 Fig.1E,2C,D,E
In Bilobella aurantiaca
(family Neanuridae),
the spermatophore is fixed at the substrate through a rhizoid base from which a
stalk rises (40 micron long and 3-5 micron in diameter).
The ovoid spermdrop is about 20 micron wide and 30 micron high.
The spermdrop lacks any superficiel nerves.
Composite spermatophores of 3 to 6 have been observed.
(after Cassagnau 1971:612-614).
Fig.Bm. Bilobella matsakisi from France
F. Spermatophore anterior aspect
A. Spermdrop in profile aspect after release of sperm
B. Spermdrop in apical pole aspect after release of sperm
After Cassagnau, P. 1971 Fig.1F,2A,B
In Bilobella matsakisi
(family Neanuridae),
the spermatophore is fixed at the substrate through a rhizoid base from which a
stalk rises of variable length. Medium length is 70-80 micron,
but extremes of 50 micron and 150 micron have been observed.
The diameter of the stalk ranges from 8 to 12 micron.
The ovoid spermdrop is about 30 micron wide and 40-45 micron high.
The spermdrop has nerves that form two windows from which the sperm is released
(fig BmB).
Composite spermatophores of 3 to 7 have been observed.
(after Cassagnau 1971:614).
Fig.Lm. Lathriopyga monticola from France:
A. spermatophore anterior aspect
B. spermatophore head posterior aspect
C. spermatophore head lateral aspect
F. composite spermatophore
After Cassagnau, P. 1971 Fig.1A,B,C,2F
In Deutonura monticola previously designated Lathriopyga monticola
(family Neanuridae), the spermatophore comprises a stalk
of about 100 micron high, 7 to 10 micron in diameter, and a spherical spermdrop
of 40 to 45 micron diameter. The spermdrop is encapsulated in a membrane hold in
shape by 2 nerves, doubled at their base, and united at the opposite distal pole
into a button in the shape of a spiral (fig.LmA,B,C).
The spermdrop opens by the rupture of the membrane between the fork of nerves
(see arrows in fig.LmA,C).
Spermatophores are occasionally deposited on eachother forming a composite
spermatophore (fig.Lm2F).
This composite spermatophore is one of the most evolved spermatophores
among the Poduromorpha.
(after Cassagnau 1971:614).
In Isotominae, the stalk of the spermatophore penetrates the
sperm drop at the basis and creates at the top of the drop a local nipple-like
projection of the drop surface (fig.1d, fig.Kb).
Spermataphores of Isotoma viridis consist of a stalk which is 235um long,
which is attached to the substrate by a large basal plate.
The tip of the stalk ends in a fine hook, from which the sperm drop of 100um
diameter hangs. The terminal hook is located in an apical protuberance
of the sperm drop (Poinsot-Balaguer, 1970; Betsch-Pinot, 1974).
The sperm in the spermdrop of spermatophores may survive 2 days.
The original glass transparent spermdrop then becomes opale translucent.
In Orchesellinae, where the males guard their freshly deposited spermatophores,
the spermathophores are inspected regularly and aged spermatophores are eaten
and replaced by new ones.
Spermatophores are deposited by the males on the substrate
(Christiansen in Dindal, 1990:968),
or placed directly on the female genital opening (Hopkin 1997:134),
and subsequently picked up by the female.
In Deuterosminthurus bicinctus the male deposits a spermdrop in front of
the female. The female then immediately picks up the spermatophore. Male and
female continue then in a kind of 'post-mating' ritual.
In Dicyrtomina, the stalk of the spermatophore penetrates the sperm drop
at the basis and continues out of the drop at the top (fig.1e, fig.Ds).
When the sperm drop has been picked-up by the female, the
stalk remains empty (fig.Do).
