Variação espaço-temporal na estrutura de tamanho de jovens de agulhinha-branca, Hyporhamphus unifasciatus (RanzanI, 1841) em Itamaracá - PE

Abstract

Several species use estuarine environments for their protection, feeding, and reproduction. However, these areas are more susceptible to several human impacts. Hyporhamphus unifasciatus uses these environments, and due to the large fish landing in the last 20 years at Pernambuco state the species has potentially been impacted by human action. Thus, this study aimed to evaluate the spatio-temporal variation of the size and weight structure of young H. unifasciatus individuals through the standard length (SL) and total weight (TW) variation between three periods and by diferentes sample location. Sampling was carried out in replicates at two points (estuary and surf zone) for 12 months between the periods 2001-2002 (year 1), 2018-2019 (year 2), and 2020-2021 (year 3). The specimens, the SL and TW measurements were taken, and the specimens are deposited in the UFRPE's Ichthyology Collection. From these measurements, the frequency, weight-length relationship, and condition factor for the species population were calculated. Altogether, 436 individuals of the species were obtained, being 147 in year 1, 134 in year 2, and 155 in year 3. From these data, I did observe differences between the SL and TW between the estuary and surf zone for two of the three periods. Through the weight-length relationship, positive allometry did also observed for the three periods analyzed and, finally, significant differences were found between the growth pattern between the periods. These results indicate that through the analyzed population parameters, apparently is not overfished, however, this definition depends on more research being carried out in the area to obtain the status of the fish stock of this species.