Ornamental aquaculture as a pathway for the introduction of non-native fish in coastal drainage of northeastern Brazil

Abstract

Aim We present the first record of the introduction of three non-native ornamental fish species, resulting from ornamental aquaculture escapes on the Northeast Mata Atlântica hydrographic ecoregion, with information on the reproductive activity. Methods The specimens were collected bimonthly between 2018 and 2019 using seine and sieve nets, and analyzed for determination of reproductive phases. Results A total of 830 specimens were collected, corresponding to the species Hyphessobrycon eques (N= 311), Poecilia reticulata (N= 500), and Xiphophorus maculatus (N= 19). We used 250 specimens for reproductive analysis. Hyphessobrycon eques and P. reticulata were reproductively active throughout the sampling period. Among the species, the smallest reproductive female measured 22.26 mm (H. eques), 12.53 mm (P. reticulata), and 17.58 mm (X. maculatus). The smallest males measured 20.64 mm (H. eques), 10.71 mm (P. reticulata), and 17.17 mm (X. maculatus). Conclusions The presence of reproductive specimens of H. eques and P. reticulata throughout the year supports the hypothesis of their establishment. We hypothesize that the introduction of X. maculatus is a recent event.

From the pond to the creek many years ago: life-history dynamics of feral poeciliids in Brazil

“…We also recorded a higher frequency of females. A similar pattern was found for feral P. reticulata and X. maculatus introduced into a stream located in Sergipe State and in Australia Luduvice & Brito, 2023). The prevalence of females may also be associated with high predation pressure, which may cause differential predation risk between females and males.…”

“…This is probably the lowest size found in introduced populations of feral P. reticulata and X. maculatus. In other sites and environments throughout Brazil and the world, the smallest reproductive size of feral guppy and southern platyfish ranged between 1.2-2.0 cm, and 1.7-2.0 cm SL respectively Andrade et al, 2008;Montag et al, 2011;Kırankaya & Ekmekçi, 2021;Luduvice & Brito, 2023). In the present study, we also found smallest females of P. reticulata and X. maculatus measuring 4.4-5.0 cm TL respectively, indicating a feralization process for both species.…”

“…Modifying human behavior is the key to prevent or minimize the potential ecological impacts of ornamental aquaculture in Brazil [see Magalhães & Jacobi (2017);Lima Junior et al (2018); Vitule et al (2019); Luduvice & Brito (2023)]. Therefore, the main management action should include awareness campaigns to educate people who work directly with the ornamental fish industry in the region (Magalhães et al, 2021).…”