Aspectos ecomorfológicos e ultrassonograficos da reprodução em Sciades herzbergii (Teleostei: Ariidae)

Abstract

Estuarine areas, habitat of the Sciades herzbergii, have been increasingly suffering from anthropogenic actions, which in the long term could cause irreversible damage to the maintenance of this species and others that use this area to survive and maintain their natural stocks. In this way, we aim to learn about the reproductive maturational development of S. herzbergii through the ecomorphological, metabolic and ultrasound patterns. Specimens of S. herzbegii were collected in estuaries on Maranhão Island. After capture, the specimens were anesthetized in water containing 3% Benzocaine. Ultrasonography was performed in the region of the coelomic cavity, aiming to observe the gonads. The total length, standard length and total mass were obtained, followed by dissection and removal of the gonads, which will also be weighed and examined macroscopically. The gonads were collected for measurement, macroscopic and histological analysis. The developmental stages of the gonads of both sexes were verified macroscopically, based on the degree of turgidity, color, vascularization, visualization of gametes and weight/length of the gonads. Data analysis was carried out using the Statistical Analysis System for Windows SAS® software. The fish in this study showed negative allometry, investing more in increasing length than in weight as a growth strategy. The sex ratio was 4 females for each male (4:1). 5 maturation stages were found for S. herzbergii: immature, maturing, mature, regression and regeneration. Microscopically, within these stages, 7 phases of oocyte development were found: I, II, III, vtg1, vtg2, vtg3 and atresia. In this way, S. herzbergii presented asynchronous development, releasing oocytes as they mature. The species showed a predilection for spawning during the rainy season. This research brought unprecedented data and allowed the understanding of the different stages of the reproductive process of S. herzbergii, contributing to the knowledge of the reproductive dynamics of this species.