دانلود رایگان مقاله مورفولوژی تابعی فک بالا و غدد حلقی مورچه قرمز

Abstract

The maxillary and propharyngeal gland of all 3 castes of Monomorium pharaonis were examined with light and electron microscopy. Although both glands possess a pouch in which secretion can be stored temporarily, a proper reservoir is lacking. The paired maxillary gland opens at the base of the maxilla and consists of 4 secretory cells, which are smaller in workers as compared to queens and males. A digestive role is unlikely as the gland is not directly linked to the digestive system and the amount of rER is negligible. The propharyngeal gland consists of 2 clusters of 16 secretory cells, which open in the pharyngeal atrium through a duct. Secretory cells are smallest in males. Two types of endoplasmic vesicles are observed around the end apparatus, suggesting a release of at least 2 substances. High levels of rER indicate the production of digestive enzymes as one of its functions. No differences between mated versus virgin queens were observed for both glands. Further experiments on chemical and behavioural essays can improve our understanding of the role of both glands in the ant colony. Literature on this topic is very inconsistent. We provide a survey to unravel this chaotic nomenclature issue

4. Discussion

In this paper the maxillary glands and propharyngeal glands of the 3 castes of M. pharaonis were examined morphologically in order to understand their role in the colony. Due to the ambivalent nomenclature in literature on this topic, however, data comparison is complicated. Therefore we unravelled all inconsistencies (Table 2). Previously, gland morphology was often based on the position of the gland in the head. Since interspecific differences in gland position are common, this is not a straightforward criterium. A classification method which relies on the site where secretion is released, results in a more straightforward nomenclature. Although Emmert (1966) in the 60's already named the gland according to the site where secretion is discharged, other authors did not follow his logic. The name ‘maxillary gland’ in this paper corresponds with the location where its duct cells open: at the base of the maxilla. The secretion products of the propharyngeal gland on the other hand are released in the anterior region of the pharynx.