Induction of ovarian growth in Aegla platensis (Crustacea, Aeglidae) by means of neuroregulators incorporated to food

Abstract

The freshwater crab Aegla platensis was used as a model to induce ovarian growth by adding different neuroregulators to a pellet food formulation. Added compounds were the dopaminergic inhibitor spiperone or the enkephalinergic inhibitor naloxone, both of them at a dose of 10-8 mol/animal. Animals were fed on the enriched pellets twice a week. After 7 wk, the gonadosomatic index (GI) was calculated as (gonad fresh weight / body fresh weight) x 100. GI significantly increased only for those females fed on spiperone pellets, compared to a control group receiving pellets with no compound added. During the assayed period, spiperone would be reverting the arrest exerted by dopamine on the neuroendocrine stimulation of ovarian growth. On the other hand, for both spiperone and naloxone a higher GI was correlated to a higher lipid content of both gonads and/or hepatopancreas, suggesting an increased energetic demand in accordance with an active investment in reproduction.

Reproductive regulators in decapod crustaceans: an overview

“…Administration of 5-HT plus spiperone as well as spiperone alone stimulated ovarian maturation and embryonic development, and increased ovarian index and oocyte diameters in M. rosenbergii (Tinikul et al, 2009b). In vivo spiperone treatment has also been reported to stimulate ovarian maturation in crayfish Cherax quadricarinatus and subsequently produced an augmented percentage of spawning females (Cahansky et al, 2008). Cahansky and colleagues also reported that gonadosomatic index (GSI) in Aegla platensis was stimulated by food containing spiperone (Cahansky et al, 2008).…”

“…Naloxone, an antagonist of enkephalinergic receptors, can stimulate ovarian growth in both U. pugilator and P. clarkii (Sarojini et al, 1995a). Cahansky and colleagues (Cahansky et al, 2008) reported that ovarian maturation in A. platensis was stimulated by food containing naloxone. Kishori and Reddy (Kishori and Reddy, 2003) found an antagonistic action of opioid peptides in the regulation of ovarian maturation in the crab Oziotelphusa senex senex.…”

“…In vivo spiperone treatment has also been reported to stimulate ovarian maturation in crayfish Cherax quadricarinatus and subsequently produced an augmented percentage of spawning females (Cahansky et al, 2008). Cahansky and colleagues also reported that gonadosomatic index (GSI) in Aegla platensis was stimulated by food containing spiperone (Cahansky et al, 2008). Similarly, lipid and cholesterol levels of both ovaries and HP from Aegla uruguayana schmitt were substantially increased in response to spiperone (Castiglioni et al, 2009).…”

Indução do crescimento ovariano em Aegla uruguayana (Crustacea, Anomura, Aeglidae) mediante a incorporação de neuroreguladores ao alimento

“…Quando injetada durante o início da vitelogênese, a spiperona também produziu um aumento no índice gonadossomático em P. clarkii (100 µl) (RODRÍGUEZ et al, 2002a) e em N. granulata (50 µl) (ZAPATA et al, 2003). Em A. platensis Schmitt, 1942, o efeito da spiperona sobre a estimulação do desenvolvimento ovariano foi observada quando a mesma foi incorporada ao alimento (CAHANSKY et al, 2008).…”

“…Resultados de estudos utilizando a naloxana como neuroregulador mostraram que este é capaz de induzir a maturação dos ovários do caranguejo estuarino Uca pugilator (Bosc, 1802) , no lagostim P. clarkii (SAROJINI et al, 1996) e também em A. platensis (CAHANSKY et al, 2008). Em A. uruguayana, tanto a spiperona como a naloxana causaram indução ovariana, sendo esta indução mais pronunciada quando foi utilizada a spiperona.…”