Analysis of reproductive patterns of fishes from three Large Marine Ecosystems

Abstract

Fish reproductive biology plays an important role for fishery management, especially in developing countries. The aim of this study was to compile all available information and analyze reproduction patterns of marine fishes in three Large Marine Ecosystems (LMEs): North, East, and South Brazil Shelves. We tested the hypothesis that the onset and duration of spawning season differ among these three LMEs; compared the ratio between length at first maturity and asymptotic length with the global trend observed; analyzed sex ratios; and tested whether females allocate more energy into reproduction than males. The following data were compiled from published sources and "gray" literature: sex ratio, spawning season, gonadosomatic indices (GSI), and length at first maturity (L m ). The reproductive load was estimated as L m /L ∞ . The median extension of the spawning season in the North, East, and South Brazil Shelves were 6.5, 6.0, and 5.0 months, respectively, with higher frequency during austral summer in South Brazil. Marine fishes from these three LMEs can be grouped in summer and non-summer spawners. About 96% of the cases the reproductive load was between 0.3 and 0.8, which is slightly shifted toward smaller values, compared with the global range of 0.4-0.9. Gonadosomatic indices for females were higher. Contrary to some expectations, there is seasonality in the reproduction of tropical fishes. However, seasonality is stronger in southern populations. Size at first maturity is not efficiently used as a tool for fisheries management in the ecosystems analyzed.

Reproductive Biology of Ripon Barbel (Labeobarbus Altianalis) In River Kuja-Migori Basin, Kenya

“…However, in the present study sex ratio did not deviate from the expected 1:1. Skewed sex ratios could suggest migration activity associated with breeding periods, a shorter life span for one sex, distribution range, and environmental variations (Aruho et al, 2018;Trindade-Santos & Freire, 2015). It was also established by Manal et al, (2016) that in some fish species unbalanced sex ratio may be due to vulnerability to fishing.…”

Length at first sexual maturity of economically important fishes in the Brazilian Northeast Coast

“…When considering fishes from both sexes that are economically important in the North Coast of Maranhão, Brazil (Table 1) The species O. palometa (Berry and Smith-Vaniz, 1978;Duque-Nivia et al, 1995), L. synagris (Freitas, 2009;Lessa et al, 2004;Trindade-Santos and Freire, 2015) and B. bagre (Véras and Almeida, 2016) had a higher L50 than that calculated in previous studies. The species M. furnieri (Carneiro et al, 2005;Haimovici and Ignacio, 2005;Santos et al, 2015), T. lepturus (Magro, 2005;CMFRI, 2016;Costa et al, 2018) and M. curema (Araújo and Silva, 2013; Trindade-Santos and Freire, 2015) had similar or lower L50 compared to other studies.…”

Does fish growth respond to fishing restrictions within Marine Protected Areas? A case study of the striped red mullet in the south‐west Adriatic Sea (central Mediterranean)

“…Body growth is a universal attribute of life and an important life history trait for fishes, due to its implications in terms of uptake of energy and material resources from the environment, transformation into their body mass, and allocation among maintenance, growth and reproduction. Over ontogeny, fishes increase in body mass by orders of magnitude, from eggs to much larger mature adults, with body size and growth that mediate crucial processes such as predation and reproduction (Meekan et al, 2006; Sibly et al, 2015; Trindade‐Santos & Freire, 2015). Adult size in fish ranges from a few millimetres (e.g.…”