SUMMARY

During the summer of 2021, thirty-one sanguivorous leeches were collected in two localities in Erbil city, Hassan Bag Mountain, and Debaga Township. Two different species were identified and their feeding organs including; jaws, teeth and salivary glands were aimed of the current study.

Morphological features of the triple jaw, denticles, and salivary gland cells of two blood-sucking leeches Hirudo orientalis (Utevsky and trontelj 2005) and Limnatis paluda (Tannet 1959), were studied using a stereomicroscope (SM), light microscopy, and scanning electron microscopy (SEM).

The results of the current study showed that H. orientalis jaws were white, and rigid, bearing sharp teeth, while L. paluda jaws were gray and smooth bearing fewer blunt teeth and both are monostichodont. The salivary gland cell bodies were brunched band that extends from the jaws.

On the other hand, histological observations indicated that the salivary gland cells are packed with granules, the nucleus at the interior of the cell, and the cytoplasm at the edge of the cell. Each granulosa cell extends its duct that fills with mature secretory vesicles. While, in the plastic method, the cell membrane was irregular and the cytoplasm was opaque to lucent depending on the maturity of secretory granules.

The salivary glands of adult leeches were examined by SEM. They are composed of unicellular glands arranged in grape patterns with spherical, ovoid, and pear shapes in various cell sizes; the cell bunches of gland cells were highly developed and interconnected to each another by tiny channels. A more extensive canal that led to the jaws was created by combining channels from each bunch. The orifice is situated between the denticles.  Jaw and denticles are coated with cuticles except for the tip.

The results concluded that salivary gland cells of H. orientalis is larger than L. paluda. On the other hand, the quantity of papillae on the jaw of L. paluda is larger than H. orientalis.