Length–weight relationships comparison between juveniles and adults of fish species from the mangroves of south Brazil

Abstract

This study reports the length‐weight relationships (LWRs) for 8 fish species that inhabit mangroves. Many fisheries depend on mangroves, which serve as nursery and feeding areas for the juvenile stage of fishes, shrimp, and other fishery resources. In this sense, mangroves provide many ecosystem services, therefore increasing the basic biological knowledge of these ecosystems can help to understand their functioning and create conservation strategies. The majority of LWR studies do not consider juveniles, and it is important to consider these differences as juveniles can grow differently from adults. The fishes were collected from Perequê mangrove, Paraná, Brazil between 2008 and 2010. A variety of fishery gears were employed, including trammel nets, fyke nets, and traps made with plastic bottles combined with four baits. The specimens were measured (weight and length), sexed and evaluated for maturational stage. For the adults, the LWRs were calculated separately by the sex, while juvenile LWRs were estimated together. In general, there were differences in growth type between sexes and life stages. Some species showed differences compared to FishBase estimations, but this could be due to the lengths (and life stage) of the individuals used in the present study compared to FishBase. The discrepancies between adult, juvenile and FishBase estimations showed the importance of considering these aspects in studies using LWR.

Length-weight relationship of four species of ornamental fish from the lower Rio Negro basin in the Brazilian Amazon

“…Studies on the length-weight relationship (LWR) of fishes have been published in great numbers in recent years (Santos, Sampaio, Barroso, Nunes, & Piorski, 2018;Carvalho, Bot, & Spach, 2020;Lubich, Santos, Freitas, & Souza, 2020;Lubich, Olentino, Freitas, & Yamamoto, 2021;Olentino, Lubich, Leal, & Yamamoto, 2021;Oliveira, Silva, Prestes, & Dias, 2020;Possamai, Passos, & Carvalho, 2020;Prestes, Oliveira, Dias, Soares, & Cunha, 2019). As a result, knowledge about the biology of the species has increased through the analysis of the growth pattern and body conditions, by using the allometric coefficient, and by estimating fish weight based on length and vice versa (Froese, 2006).…”

Length-weight relationships of native and non-native fishes in a subtropical coastal river of the Atlantic Rain Forest

“…Also, the LWR allows the assessment the body condition, which can provide information about fitness, such as growth, reproduction, behavior, and survival, indicating the health of fish populations (Gubiani et al, 2020). The variability in the LWR can be influenced by several factors such as the life stage, season, and environmental conditions, thus re-estimates of LWR are recommended to complement species information and allow comparisons through space and time (Froese, 2006;Possamai et al, 2020). The LWR could be helpful to evaluate the variation in exotic fish communities and the effects of control programs and management policies (Sánchez-González et al, 2020).…”

Length-weight relationships and microhabitat effect on relative health condition of mangrove fishes from Chiapas, Mexico

“…González-Acosta et al, 2004;Rojas-Herrera et al, 2009;Velázquez-Velázquez et al, 2009;González-Sansón et al, 2014;Sandoval-Huerta et al, 2015), however, these studies often correspond to organisms caught within coastal lagoons, estuaries or by commercial fishing. Studies on condition and LWR models for mangrove fishes are scarce (Possamai et al, 2020).…”