DISCUSSION
Studies conducted on the egg morphology of Gomphidae species have
revealed a filament coil structure in the posterior poles of the eggs ofIctinogomphus ferox , Ictinogomphus rapax ,Ictinogomphus australis , and Lestinogomphus africanusspecies (Trueman, 1990; Gambles, 1956; Gambles & Gardner, 1960; Andrew
& Tembhare, 1992; Corbet, 1983). This study has identified similar
morphology and filament coils in the eggs of Lindenia
tetraphylla .
While the L. tetraphylla egg shares a general morphology with theLestinogomphus africanus egg, there are some differences. No
light microscope or SEM photographs were taken of the L.
africanus egg. Corbet (1983) provides only a drawing, referencing
Gambles & Gardner (1960). Comparison with this picture and literature
information has revealed that the L. africanus egg has a single
filament in the posterior pole (Gambles & Gardner, 1960), whereas theL. tetraphylla egg has 55-65 filaments. Additionally, according
to Gambles & Gardner (1960), L. africanus has a protruding
structure at the micropyle pole, formed by rods resembling a stick
handle. These rods appear to number eight, and the micropyle orifice
likely extends between them, although this has not been proven. TheL. tetraphylla egg, on the other hand, does not have a long
stick-like micropylar area at the micropyle and has 7 micropylar
orifices. L. africanus eggs display hexagonal patterns on their
surfaces, while L. tetraphylla eggs show polygonal patterns,
predominantly hexagonal ones. Comparing their sizes, their lengths are
almost the same, while the L. tetraphylla egg is wider.
When comparing L.tetraphylla eggs to those of I.ferox ,I.rapax , and I.australis , significant differences are
observed, particularly in their surface patterns and filament coil.
Trueman (1990) states that I. australis has a truncated cone
structure comprised of 12-15 filaments. In terms of surface patterns and
filament numbers, I. australis eggs, which are similar in size toL. tetraphylla , differ from them (Trueman, 1990). Additionally,
the micropylar structure of I .australis eggs, which also have 5
micropylar orifices, differs from that of L. tetraphylla . TheI. rapax egg, which has 6 micropylar orifices, contains 50-60
filaments that are 8 mm long and 2 µm thick (Andrew & Tembhare, 1992).
In contrast, the L. tetraphylla egg, which is similar in size,
has filaments of the same thickness but shorter length, measuring about
3 mm.
According to Gambles & Gardner (1960), filaments in the eggs of other
insects with aquatic larvae are typically seen as an adaptation for
spawning in flowing water. However, the presence of these filaments inIctinogomphus , which breeds in muddy ponds and lakes, suggests
the influence of rheophilic ancestors. Gambles (1956) theorized that
these filaments adapted to life in fast-flowing waters and served as an
anchor. This suggests that these filaments may be present in many
different genera of the family Gomphidae. Corbet (1983) filaments may be
evidence of fast-flowing water-adapted ancestors of species currently
living in stagnant and muddy environments.
The filament found in the egg is not a structure unique to gomphids.
Similar structures can also be found in species of Tipulidae from the
order Diptera. According to Candan et al. (2005), the egg surface ofTipula latifurca was smooth and lacked chorion protrusions.
However, the anterior end of the egg does have a disc-shaped structure
that consists of a spiral terminal filament.
Gambles and Gardner (1960) suggested that reticulation in L.
africanus may serve to provide footholds for emerging larvae. This
issue needs to be investigated, and it should be determined if
reticulation has functions other than providing strength to the chorion.
According to Ivey et al. (1988), Gomphidae eggs have chorions that are
relatively thicker and more ornamented compared to those of libellulids.
The author also suggests that ootaxonomic characters can be helpful in
identifying higher taxa of odonates and may also be useful in
distinguishing genera and species within the Gomphidae family.
According to Andrew & Tembhare (1992), the fine structure of the egg
chorion, micropyle stalk, and cone filaments indicated that L.
rapax was more closely related to I. australis than to I.
ferox . Although the morphology of L. tetraphylla eggs and those
of I. rapax appear to be closely related, much more comprehensive
studies are needed to discuss the phylogenetics of these two different
genera living in very distant zoogeographies.