(A) Oocyte (o) located in the distal part of the vitellarium, further developed oocyte surrounded by follicular epithelium (fe) showing germinal vesicle (gv), peritoneal sheath (sh), trachea (tr), tracheoles (trl); (B) Gradual maturation of follicles (fo) with yolk (yo) and germinal vesicle (gv); (C) Mature follicle located in the proximal part of the vitellarium with yolk (yo).
N1: without follicles, no clear differentiation between germarium and vitellarium; N2: ovarioles begin to differentiate (germarium and vitellarium), follicles begin to form but not yet mature; N3: ovarioles completely differentiated, proximal follicle mature and ready to be ovulated, no follicular relics present; PA: follicles in oviducts; PB: presence of follicular relics.
Caption: FIGURE 5: Effect of host age (at oviposition) and female age on the mature egg (individual egg chambers located in the vitellarium
who displayed an ovoid form and had a slender tapering stalk at their posterior end (in black striped color in Figure 1)) load in Therophilus javanus.
Melanin or melanin components such as tyrosine were detected very strongly in the vitellarium using the FF stain (Figure 2(d)).
Ferro-ferricyanide stained the inner necrotic mass, necrotic tegument remnants, and cytoplasm green, while the vitellarium stained intensely green (Figure 3(d)).
Tyrosine is found in the vitellarium, as this organ produces not only yolk but also egg shell precursors which contain tyrosine as trematode egg shells are produced by quinone tanning .
No identifiable organs or cells except for evidence of an atrophied vitellarium were observed within the necrotic trematode.
niloticus from Sudan, in having similar body size, the ovary being irregularly lobed, uterine coils that seldom cross the intestinal caeca laterally and the ovary lies posterior to the vitellarium. It differs in that the caeca does not terminate a distance from the posterior margin and the intestinal bifurcation being closer to the oral sucker in this species.
gariepinus from the Bangu River, Transvaal (presently Gauteng), in having the same body size and shape, the ovary being round to weakly trilobed and the vitellarium also being weakly lobed.
Ovary lies to right of median line in six specimens; to left in other six specimens, but always in front of testes and posterior to vitellarium. Ovary irregularly round or lobed mass (Fig.
The histochemistry and fine structure of the vitellarium
in Atta (Formicidae, Myrmicinae).
a) N1--Note the lack of differentiation in the vitellarium
(v) and large size of the germarium (g) in comparison to the vitellarium