الفهرس | Only 14 pages are availabe for public view |
Abstract Four mutelid species (Mutela dubia, M. rostrata, Chambardia rub ens and C. letourneuxi) were collected from Benha region (Qaluobiya Governorate), Egypt from winter to autumn 2017 to elucidate their taxonomic status based on morphology and molecular technique as well as exploring their reproductive biology. Morphology and morphometric analysis of the shells (length, width, height, mantle edge, adductor muscle scar width, height asymmetry, hinge thickness, shell shapes, shell thickness, mean height and width indices) had showed differences between all species under investigation. .~ All species under investigation were dioecious except for M. rostrata that showed hermaphroditism In some specimens. In addition, they incubated eggs and lasidia only in the inner demibranch. Oogenesis is divided into oogonia, previtellogenic, vitellogenic and postvitellogenic oocytes, while the spermatogenesis differentiated into spermatogonia, spermatocytes, spermatids and spermatozoa. Sperm morulae were detected only in C. rubens. Reproductive cycle included four stages started with developing stage, followed by ripe (mature) then spawning stage and ended with spent stage. M. dubia and M. rostrata are considered as braditictic species while C. rub ens is a tachitictic one. Examinations by light and scanning electron microscopes revealed that the eggs of species under investigation had brown color and spherical shape with thin vitelline coat and the egg membrane of M. dubia had many folds on the surface, while it was nearly wrinkled in case of M. rostrata and smooth without any folds in case of C. rubens. Transmission electron microscopical studies showed that the |