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.