Histological Changes in Cuticle of the Red Swamp Crayfish, Procambarus clarkii During Molting Cycle

Seasonal variations in abundance and sex ratio of the freshwater crayfish Procambarus clarkii from four freshwater localities, River Nile, Egypt

“…While in females, the abdominal appendages called as swimmerets and used for egg incubation, in addition to presence of annulus ventralis between the 4 th and 5 th periopods and used for storage of semen. These characters are in agreement with those mentioned by De La Bretonne and Romaire (1989), Mubarak (2001), Ibrahim and Khalil (2009), Amer (2015), and Amer et al (2016).…”

“…Recently, several studies were carried out on P. clarkii from the Egyptian freshwaters comprised studies of the effects of eye stalk ablation on molting cycle (Amer et al, 2015a), investigation changes in telson setae and uropods during different molt stages and substages (Amer et al, 2015b), and changes in the incubated egg of ovigerous females of the freshwater crayfish, P. clarkii during early autumn under laboratory conditions (Amer et al, 2015c). While physiological changes in organic components of hepatopancreas, muscles and haemolymph during molting stages were treated by Ghanem et al (2016), and studies on the biometric relationships (El Sayed et al, 2015) and histological changes in cuticle structure and number of layers of carapace cuticle during different molting stages (Amer et al, 2016) as well as gatstroliths formation, biomineralization and X-ray micro analyzer (EDX) during molting cycle of the red swamp crayfish, Procambarus clarkii from Egyptian freshwaters (Amer et al, 2017) were also treated. However, no detailed studies are available on the fluctuations in the abundance and sex ratios of this species at different localities subjected to variable human impacts.…”

La dureza total del agua afecta la muda, calcificación, crecimiento y supervivencia de Cryphiops caementarius (Palaemonidae)

“…Estos resultados demuestran que la cutícula del cefalotórax fue más activa en acumular calcio y lograr mayor rigidez, probablemente para proteger los órganos vitales alojados en esta parte del cuerpo del animal. En A. astacus, el contenido de calcio del medio se relaciona con el grosor del caparazón del animal (Waervågen et al, 2016) y el mayor grosor y rigidez del caparazón de P. clarkii, se obtiene en la intermuda (Amer et al, 2016). Cripps y Nakamura (1979) encontraron que la reducción del crecimiento en longitud de M. rosenbergii se da en agua con durezas de 300 a 500 mg L -1 , mientras que con 65 mg L -1 el crecimiento es mayor.…”

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“…For adults, a comfortable level of dissolved oxygen in water is 6-8 mg/l, and the Ph level is 6.0-8.0. M. Amer et al (2015) studied the maturation period of Florida crayfish eggs in the natural conditions of the Nile River basin and proposed to divide them into ten stages of development during maturation. G. Vogt et al (2008) pointed out that the marbled crayfish is the only crustacean in the world that reproduces by apomictic parthenogenesis.…”