Length-weight relationships and biological data on guayana pike-congerCynoponticus savanna(Bancroft, 1831)

Abstract

Summary This study presents the first references available for Cynoponticus savanna length–weight relationships (LWR) as well as other biological information, based on its unique population in the South Atlantic Ocean, specifically, Todos os Santos Bay, on the Brazilian central coast. A total of 464 individuals were obtained from artisanal fishing landings between July 2012 and June 2013. Total lengths ranged from 14.5 to 139.6 cm. The length‐weight relationship was BW = 0.716 TL3.31. Length at first maturity (Lm) was 48.9 cm. Reproduction began gradually in May, reaching a peak around December, with most individuals completing reproduction by January. The gonadosomatic index (GSI) was highest in January (GSI = 0.21) and lowest in March (GSI = 0.024). The male index (GSI = 0.073) was lower than in females (GSI = 0.10) (P < 0.01). This study presents the first population data for C. savanna, which is under threat due to overfishing and habitat loss.

Traditional fisher perceptions on the regional disappearance of the largetooth sawfish Pristis pristis from the central coast of Brazil

“…However, given that functionally distinct species may make a significant contribution to the structure and function of ecosystems (Lyons & Schwartz 2001, Pendleton et al 2014, Leduc et al 2015, it is likely that the disappearance of sawfish affects estuarine ecosystems. Furthermore, under current conditions, where overfishing, habitat degradation, pollution and destructive fishing practices all remain prevalent, it is likely that in addition to significant ecological impacts the local extinction of swordfish will have wider socio-economic effects along the Bahia coast, including important negative impacts on the livelihood of local populations (Barros et al 2008, Reis-Filho & Specht 2015.…”

“…These estuaries are all characterized by the presence of well developed mangrove forests, which are dominated by Avicennia schaueriana and Rhizophora mangle and, to a lesser degree, by Laguncularia racemosa. The fishing practices occurring in these estuaries are typical of small-scale artisanal fisheries, including the use of traditional vessels (both non-motorized and motorized) for locomotion and seine nets, hooks and harpoons as fishing gears (Soares et al 2011, Reis-Filho & Specht 2015. …”

Microgobius meekias a potential bio‐indicator of habitat disturbance in shallow estuarine areas: a useful tool for the assessment of estuarine quality

“…As a first step (local scale), this study assessed the potential of M. meeki for use as an indicator of local disturbance in the estuary of the Paraguaçu River, one of the most important habitats for fish diversity on the Brazilian coast (Reis‐Filho et al ., ; Reis‐Filho & Oliveira, ; Reis‐Filho & Specht, ). The undisturbed condition comprised intertidal habitats with well‐preserved mangrove forest, muddy sediments and no discharge of pollutants.…”

Historical perspective of artisanal encircling gillnet use at the Brazilian coast: Changes in fishing behaviour is mirrored by dwindling stocks

“…In these regions, small-scale and artisanal fisheries include the use of traditional vessels (small, wooden or fibreglass, motor-powered or sail-propelled), seine nets (ranging from 10 to 100 m length), gillnets and purse seines ranging from 100 to 1,000 m length and stretched mesh sizes varying from 10 to 150 mm. Hooks, harpoons and blue crab traps are the main fishing gears (Cetra & Petrere, 2014;Reis-Filho et al, 2014;Reis-Filho, Sampaio, Oliveira, Nunes, & Barros, 2018;Reis-Filho & Specht, 2015;Soares, Lopez, Muto, & Giannini, 2011). Local livelihoods involve combinations of smallscale agriculture and extractive activities related to fishing, mostly fish, shellfish and plant products, which are a source of income traded to purchase consumer goods (Caroso, Tavares, & Pereira, 2011;Reis-Filho, 2016).…”