Length-weight relationship and condition factor for twelve fish species from the Igarapé Fortaleza basin, a small tributary of the Amazonas River estuary

Abstract

Length and weight data are useful in fisheries management and standard results of fish monitoring programs. Length-weight relationship (LWR) is used for estimating the weight corresponding to a given length, and the condition factor is used to compare the body condition, fatness or health of fish populations. This study aimed to estimate the LWR and the condition factor for 12 freshwater fish species from the Igarapé Fortaleza basin, a tributary of the Amazonas River system in the State of Amapá, eastern Amazon (Brazil). The coefficient of determination, the allometric condition factor and the allometric coefficient varied among species, and were compared with populations elsewhere. In 83.3% of the species, the allometric coefficient remained within the expected range. This was the first record of LWR parameters for Acestrorhynchus falcirostris.

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

“…The values of a and b published for these five species are not similar to those found in the study, since they present lower and higher values. However, these differences can be explained mainly as being due to differences in environment, capture methods used and the sample number (Matos et al., 2019; Oliveira et al., 2020; Prestes et al., 2019). There is a need to standardize the methods of capture in order to encourage the regular monitoring of the fish assemblages, and by adding these data we can generate more accurate assessments of the fishing stock of a given region.…”

“…The type of growth of fish species is variable, causing changes in the values of these parameters. Furthermore, many factors can influence these values including species’ biology, food availability, environmental conditions, geographic region and climatic changes (Matos et al., 2019; Oliveira et al., 2020; Prestes et al., 2019; Sampaio et al., 2019).…”

“…Parameters, such as body weight and length of fish, can be used to perform the length‐weight relationship (LWR) calculation, as well as allowing the estimation of biomass based on the length frequency distribution (Froese, 2006; Le Cren, 1951; Oliveira et al., 2020).…”

“…The Amazon Basin is a huge ecosystem composed of many river sub‐basins. Currently, most length‐weight relationships of the fish species studied are based on individuals collected in the Amazon River (Freitas et al., 2017; Oliveira et al., 2020), Solimões River (Dieb‐Magalhães et al., 2015; Matos et al., 2019; Sampaio et al., 2019; Tribuzy‐Neto et al., 2015, 2018; Villacorta‐Correa & Saint‐Paul, 1999), Madeira River (Cella‐Ribeiro et al., 2015) and Xingu River (Giarrizzo et al., 2015). Thus, few studies using this approach analyze species collected in the Negro River basin, which is the second largest sub‐basin of the Amazon basin (Goulding et al., 2003).…”

Length‐weight relationships of five fish species from Brazilian Amazon coast hotspot estuaries

“…: size at first sexual maturity, spawning and recruitment period) bring a wider understanding of species and their environmental conditions, contributing to a more effective support for fisheries monitoring and management actions (Al Nahdi, Leaniz, & King, 2016; Giarrizzo et al., 2015; Morgan, 2018). Despite the socioeconomic importance of fisheries activities, many fish species and their population stock captured in estuarine ecosystems at the North of Brazil are still little or insufficient monitored (Blaber & Barletta, 2016; Oliveira, Silva, Prestes, & Tavares‐Dias, 2020), jeopardizing local fisheries sustainability at medium‐long term. Considering the demand for information to support fisheries management, this report presents estimation of LWR parameters of five estuarine fish species from an important Brazilian Amazon littoral region.…”