Length-weight relationships in seven ornamental freshwater species of Characiformes from the Unini River basin (Brazilian Amazon)

Abstract

The aim of the current study was to address length‐weight relationships (LWRs) in seven ornamental fish species from the Unini River basin—the main tributary of lower Negro River (Brazilian Amazon). Specimens were seasonally sampled by using hand nets and beach seines (mesh size < 1 mm) in five different occasions (August 2009—December 2010). Preserved specimens (initially kept in 10% formalin and transferred to 70% ethanol 10 days later) were measured and weighted in laboratory. The LWR was calculated based on a log‐transformed linear regression. The maximum standard length of each species was different from the ones previously reported at Fishbase. In addition, b values were different from the ones reported for the four species whose data were available in the literature.

Length-weight relationships of ornamental fish from floodplain lakes in the Solimões River basin (Iranduba, Amazonas, Brazil)

“…The data used were collected from formalin fixed samples (20,21), this occurred because of the difficulty of the identification of small fishes correctly in the field. Following Barros et al (6), we suggest that this information is very necessary for future research about ornamental fish from floodplain lakes, since there is few information available in the literature.…”

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

“…To date, 1,165 species are known to inhabit the Negro River (Beltrão et al., 2019), but studies on the length‐weight relationships have been performed mainly for ornamental fish species (Barros et al., 2018; Lemos et al., 2015; Santos et al., 2012), which are historically exploited in the Rio Negro basin, mainly in the upper and middle Rio Negro stretches, where fishing occurs more intensely, and represent just over 90% of the species exported by the state of Amazonas (Anjos et al., 2009).…”

Length‐weight relationship of 12 species of freshwater fish caught in the middle and lower stretches of the Negro River basin, Brazilian Amazon

“…for the species in this basin (Barros et al, 2018;Lemos et al, 2015;Lubich et al, 2020;Mereles et al, 2020;Olentino et al, 2021;Quara de Carvalho Santos et al, 2012), due to the low fishing intensity and the high costs of research expeditions for sampling fish in this region (Lubich et al, 2020). As such, the present study describes the LWR of 12 freshwater fish species that inhabit lakes in the middle and lower stretches of the Negro River basin (Amazonas State, Brazil).…”

“…Therefore, because they have different characteristics, these environments allow diversification of fish species. Despite the increase in descriptions of new species, there are few studies published that provide information on the parameters of the length‐ weight relationship for the species in this basin (Barros et al., 2018; Lemos et al., 2015; Lubich et al., 2020; Mereles et al., 2020; Olentino et al., 2021; Quara de Carvalho Santos et al, 2012), due to the low fishing intensity and the high costs of research expeditions for sampling fish in this region (Lubich et al., 2020). As such, the present study describes the LWR of 12 freshwater fish species that inhabit lakes in the middle and lower stretches of the Negro River basin (Amazonas State, Brazil).…”