In vivo effects of both methyl farnesoate and 17-hydroxyprogesterone on vitellin levels in ovary, hepatopancreans and hemolymph. A comparison between crayfish and crabs.

FERRÉ, LILIAN E.; CANOSA, IVANA S.; SILVEYRA, GABRIELA R.; PAOLUCCI, MARINA; MEDESANI, DANIEL A.; RODRIGUEZ, ENRIQUE M

Sapporo

Congreso; International Association of Astacology, 2014 meeting; 2014

IAA

Adult females of both the red claw crayfish Cherax quadricarinatus and the estuarine crab Neohelice granulata were fed twice a week on a diet (33% of protein) enriched with methyl farnesoate (MF) or 17-hydroxyprogesterone (PROG) at a dose of 2 nmol/g for 30 days, during the post-reproductive period (May-June) and under controlled conditions of both temperature and photoperiod. Freshwater was used for C. quadricarinatus, while saline water (12g/L) was used for N. granulata. At the end of the assay, fresh body weight was determined, together with both the ovarian and  hepatopancretic fresh weight, in order to determine, respectively, the gonadosomatic (GSI) and hepatosomatic (HSI) indexes. Besides, the vitellin level was determined by ELISA in ovary, hepatopancreas and hemolymph. A significant (p>0.05) increase of both GSI and vitellin level was seen by effect of MF, in both species studied. PROG produced the same significant (p<0.05) effect, but only on N. granulata females. Correspondingly, higher (p<0.05) vitellogenin levels were detected in hemolymph of these females exposed to either MF or PROG.  No significant (p>0.05) differences with control were noted concerning HSI, for any species. The significance of these results for the endocrine control of vitellogenesis is discussed for each species, as well as the potential use of hormone administration through diet for aquaculture purposes, taking into account that the post-reproductive period is the most refractory for inducing reproduction, within the annual reproductive cycle.