Time-delayed effects of a single application of AgNPs on structure of testes and functions in Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae)

Silver nanoparticles (AgNPs) are currently themost frequently used engineered nanoparticles. The penetration of AgNPs into ecosystems is undeniable, and their adverse effects on organismreproduction are of fundamental importance for ecosystem stability. In this study, the survival time of the Egyptian beetle Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae), after a single application of 7 different doses,was calculated for 30 days. Then, for the group for which the effect on mortality was calculated as LOAEL - the Lowest Observed Adverse Effect Level, namely, 0.03 mg AgNPs/g body weight (b.w.t.), the following were assessed: structure and ultrastructure of gonads by TEM and SEM, cell viability by cytometry, DNA damage by the comet assay, and a variety of stress markers by spectrophotometric methods. A dose-dependent reduction in the survival time of the insects wa

Hermaphroditism in Brachidontes pharaonis (Fischer, 1876) (Bivalvia: Mytilidae) from the Alexandria Coast, Egypt

Brachidontes pharaonis (Fischer, 1876) was widely reported to cover completely hard substrates especially rocky shores with higher density in mid-littoral zones forming mytilid beds along Alexandria Coast, Egypt. During our study on the reproductive cycle of this species, one case out of 307 examined specimens was found to be hermaphrodite representing only 0.33% of the total sample. It had a shell length 28.25â¯mm and was collected during January 2017. The sex ratio of this population is different from 1:1, although this deference was not significant (X2â¯=â¯11.118, dfâ¯=â¯11, Pâ¯>â¯0.05). In this contribution, this case of hermaphroditism in B. pharaonis is described. The histological study showed the presence of male and female gametes in the same follicle and this was the most common situation in both lobes of the mantle. The male zone was showing different stages of spermatogenesis together with the female zones showed different stages of oogenesis with occurrence of young oocytes attached to the follicle wall. Keywords: Hermaphroditism, Brachidontes pharaonis, Sex ratio, Histology, Alexandria, Egyp