REPRODUCTIVE BIOLOGY OF MARBLED SWAMP EEL, Synbranchus marmoratus BLOCH, 1975 IN GARGALHEIRAS RESERVOIR, RIO GRANDE DO NORTE, BRAZIL

A biologia reprodutiva do peixe hermafrodita mussum, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) foi investigada no açude Marechal Dutra, Acari, Rio Grande do Norte, utilizando os exemplares capturados mensalmente no período de julho de 2010 á janeiro de 2011. Os peixes capturados foram numerados, pesados, medidos, dissecados as e gônadas foram retiradas, pesadas e identificadas quanto ao sexo. A relação peso-comprimento foi determinada para sexos agrupados. O índice gonadossomático (IGS) e o fator de condição (K) foram verificados. As fases do desenvolvimento das gônadas foram investigadas usando técnicas macroscópicas. As características macroscópicas do desenvolvimento gonadal mostraram quatro tipos sexuais diferentes na população dos peixes capturados, sendo: machos primários, fêmeas, intersexos e machos secundários. As fêmeas foram mais frequentes durante todo o período de estudo (74%). A espécie mostrou um crescimento do tipo alométrico negativo, com maior incremento em comprimento do que em peso. O fator de condição mostrou seu menor valor no mês de agosto e dois picos sendo, um em dezembro de 2010 e outro em janeiro de 2011. O IGS indicou um período reprodutivo que vai de julho a agosto de 2010, mostrando correlação negativa ao fator de condição. S. marmoratus mostra uma estratégia reprodutiva sazonal que aperfeiçoa seu sucesso reprodutivo dentro das condições climáticas do semiárido.Palavras-chave: Symbranchus marmoratus, índice gonadossomático, fator de condição, aspectos gônadais, açúde semiárido.The Reproductive biology of the hermaphrodite fish the marbled swamp eel, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) was investigated in the Marechal Dutra reservoir, Acari, Rio Grande do Norte, using samples captured monthly during the period of July 2010 to July 2011. The captured fish specimens were numbered, weighed, measured, dissected and their gonads was removed, weighed and identified as to sex and developmental stages of gonads. The length-weight relationship was determined for grouped sex. The gonadosomatic index (GSI) and condition factor (K) were calculated. The developmental stages of the gonads were investigated using macroscopic techniques. The macroscopic characteristics of gonadal development showed four different sexual types in the sampled population: primary males, females, transitional individuals and secondary males. Females were more frequent during the entire study period. This species showed a negative allometric growth with a higher increase in length than weight. The condition factor showed its lowest value in August and showed two peak values in December 2010 and in January 2011. The GSI indicated a reproductive period from July to august 2010 and was negatively correlated with the condition factor. S. marmoratus presents a seasonal reproductive strategy which optimizes its reproductive success under the semiarid climatic conditions.Keywords: Synbranchus marmoratus; gonadosomatic index; condition factor; gonadal aspects; semiarid reservoir

Anticonvulsant Effects of Fractions Isolated from Dinoponera quadriceps (Kempt) Ant Venom (Formicidae: Ponerinae)

Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt) protects mice against bicuculline (BIC)-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC) resulting in six fractions referred to as DqTx1-DqTx6. A liquid chromatography-mass spectrometry (LC/MS) analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL) was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM), DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Pró-reitoria de Pesquisa da Universidade Federal do Rio Grande do Norte (PROPESQ/UFRN)Fundaçao de Apoio à Pesquisa do Estado do Rio Grande do Norte (FAPERN)Univ Fed Rio Grande do Norte, Dept Physiol, BR-59078970 Natal, RN, BrazilUniv Sao Paulo, Dept Biol, BR-14040901 Ribeirao Preto, SP, BrazilUniv Fed Sao Paulo, Dept Biophys, BR-04023062 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Pharmacol, BR-04023062 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Biosci, BR-11015020 Sao Paulo, SP, BrazilBiophysics Department, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP 04023-062, BrazilPharmacology Department, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP 04023-062, BrazilBiosciences Department, Universidade Federal de São Paulo (UNIFESP), Santos, SP 11015-020, BrazilWeb of Scienc