The cuticular structure of juveniles of several oribatids of different families with wrinkled cuticles were compared: Hermannia gibba, Tectocepheus velatus, Scutovertex minutus, Achipteria coleoptrata and Eupelops occultus. Both the surface and internal structures of the "plissée" were studied. Light microscopy revealed several patterns in mites studied with Masson's triple stain and these results were supported by TEM. Although the "plissée" looks similar at the body surface, the structure and ultrastructure differ among groups. Some types of wrinkling is supported by small muscles, probably for changing body shape. Differences in the structure of the cuticle of the prosoma and opisthosoma were observed. The differences in the wrinkling in the cuticle in diferent lines is associated with change in the body shape in response to different moisture conditions.
The cuticle of Rhysotritia duplicita (Euphtiracaroidea: Euphtiracaridae), Phthiracarus sp., Steganacarus magnus, S. striculus and Tropacarus carinatus (all Phthiracaroidea: Phthiracaridae) was studied by light and transmission electron microscopy. A combination of light and electron microscopy were used to precisely characterize and classify the cuticular layers in oribatid mites and show how they differe in mites and other arthropods. In Rhysotritia duplicata the cuticle of the aspis (upper shield of the prosoma) differs significantly from that of the opisthosoma. Moreover, prosomal cuticle in this species is different from that of all others species studied. There were no structural differences in the cuticle of the prosoma and opisthosoma of species of the superfamily Phthiracaroidea (Phthiracarus, Steganacarus and Tropacarus) in spite of the differences in external apparence. Moreover, in Tropacarus, the rough sculpturing of the cuticle results from the very rough exocuticle, which is unlike the thick smooth cerotegument of the cuticle in Steganacarus.
The microanatomy of several oribatid and one acaridid mite was studied to determine the role of free cells (haemocytes) in mites. Mites from the field as well as laboratory cultures were observed and analyzed histologically using Masson triple stain. The mites were offered various foods and kept in fluctuating moisture conditions. The presence of haemocytes was significantly correlated with the transport between internal organs of various substance. Three types of transport were recorded: (i) enzymes into the alimentary tract, including the incorporation of haemocytes into the gut walls. This process seemed to be correlated with the amount and type of food and frequently with the presence of internal extraintestinal bacteria associated with mesenchyma; (ii) metabolites, like guanine from mesenchyma into the alimentary tract followed by expulsion from the body via the gut. This process is correlated with food of high nitrogen content or dry conditions; (iii) resorption of nutrients from eggs during an induced quiescent state under unfavourable conditions by small haemocytes.
In the present paper, we describe the ultrastructure of the spermatozoon of the notocotylid Notocotylus noyeri (Joyeux, 1922) by means of transmission electron microscopy. The mature spermatozoon of N. noyeri exhibits the general pattern described in the majority of digeneans: two axonemes of the 9 + "1" pattern of the Trepaxonemata, nucleus, mitochondria, parallel cortical microtubules, spine-like bodies and ornamentation of the plasma membrane. The glycogenic nature of the electron-dense granules was evidenced applying the test of Thiéry. The ultrastructural features of the spermatozoon of N. noyeri present some differences in relation to those of the Pronocephalidea described until now, but confirm a general pattern for the Notocotylidae, namely a spermatozoon with two mitochondria and an anterior region with ornamentation of the plasma membrane associated with spine-like bodies. The posterior extremity of the spermatozoon exhibits only some microtubules after the disorganisation of the second axoneme. The present study confirms that some ultrastructural characters of the sperm cell such as the presence or absence of lateral expansions, the number of mitochondria and the morphology of both anterior and posterior spermatozoon extremities are useful for phylogenetic purposes within the Pronocephaloidea. Thus, unlike notocotylids, pronocephalids exhibit external ornamentation and a lateral expansion in the anterior spermatozoon region. Moreover, notocotylid spermatozoa present two mitochondria, whereas pronocephalid spermatozoa exhibit a single mitochondrion. Finally, pronocephalids are characterised by a type 2 posterior spermatozoon extremity, whereas notocotylids exhibit a type 3 posterior spermatozoon extremity., Papa Ibnou Ndiaye, Jordi Torres, Catarina Eira, Vladimir V. Shimalov, Jordi Miquel., and Obsahuje bibliografii