Stock Status of Pufferfish <i>Lagocephalus sceleratus</i> (Gmelin, 1789) Along the Egyptian Coast, Eastern Mediterranean Sea

Abstract

Stock of pufferfish Lagocephalus sceleratus was evaluated using specimens that collected monthly from the commercial fishing boats at landing sites along whole the Egyptian Mediterranean coast during 2012. Specimens were ranged from 5 to 83cm (TL) in length with an average 43.01± 13.5cm and total weight from 2.1-5400g with an average of 1103.27±850.83 g. The length-weight relationship revealed negative allometric growth for males, females and combined sexes with insignificant difference between males and females at (P > 0. 05). The highest condition factor (1. 13) was recorded for immature/smaller fishes while the lowest value 0. 86 was recorded for largest female individual. Age determination by two methods (length frequency analysis and vertebrae) revealed seven years old with no significance difference between mean lengths at age of two methods at (P > 0. 05). Von Bertalanffy growth parameters for combined sexes of length frequency were L∞ = 106.34 cm, K = 0.17 year -1 and t o = 0.0228 year -1 , while they were L∞ = 101.63cm and K = 0.189 year -1 and t o = 0.1186 for vertebrae data. By using data of length frequency, the population parameters were, total mortality (Z=1. 01 year -1 ), natural mortality (M= 0. 347 year -1 ), fishing mortality (F= 0. 663 year) and exploitation ratio (E= 0. 657). The length at first capture (Lc) was 32. 34cm, while length at recruitment (Lr) was 25. 95cm. Yield per recruit (Y/R) at current parameters was 447.26g. The maximum sustainable yield per recruit (MSY) was 467. 42g, at fishing mortality (F MSY ) 0.403 year -1 Which is lower than current fishing mortality. The (Y/R) at the biological reference points (F 0. 1 & F max ) were 423.72 g and 467.42g respectively. The fishing mortalities at these points were 0. 203 year -1 and 0. 403 year -1 for F 0. 1 and Fmax respectively giving lower values than current fishing mortality reflecting over-exploitation status. Inspite of, the fishing of pufferfish is prohibited by the Egyptian law, its stock in the eastern Mediterranean is overexploited but still growing well and the younger individuals are in good condition reflecting a good adaptation in new habitat, and explain the illegal trade of this species in different markets. The over exploitation suggests reduce it or Y/R to level of F 0. 1 for the point of conservation regardless its poisonous effect. The importance of present data of such species could emphasis the need of special management plan for conserve and better use of economically valuable fishery resources.

The biology and ecology of the invasive silver-cheeked toadfish (Lagocephalus sceleratus), with emphasis on the Eastern Mediterranean

“…Despite the multiple negative impacts of L. sceleratus, most Mediterranean studies have been dedicated to the high content of tetrodotoxin (TTX) in its tissues, with only a handful investigating its biology (Sabrah 2006;Aydin 2011;Nader et al 2012;Kalogirou 2013;Farrag 2014;Khalaf et al 2014;Rousou et al 2014;Ersönmez et al 2017;Zengin and Türker 2020). As well, two studies reported on the abundance of L. sceleratus in Egypt (Farrag et al 2015;Elhaweet et al 2016) and another from Antalya Bay, Turkey (Özbek et al 2017).…”

An in-depth study of the biology, trophic ecology and catchability of the invasive pufferfish Lagocephalus sceleratus from southern Turkey, eastern Mediterranean Sea

“…This species was first recorded in the Mediterranean in 2003, from Gokova Bay in southwestern Turkish waters (Akyol et al 2005). It is both the largest (maximum weight of 10 kg; Ulman et al 2022) and most abundant pufferfish species in many localities in the eastern Mediterranean (Farrag et al 2015, Turan 2022. Within just ten years of its first Mediterranean record, it expanded rapidly to nearly every Mediterranean sub-region (strangely, with the exception of southern France and Corsica), and within 15 years it was also recorded in the much cooler Black Sea and the Strait of Gibraltar (Rambla- Alegre et al 2017, Bilecenoglu andOzturk 2018).…”

Age and Growth of the Freshwater Pufferfish Tetraodon lineatus Linnaeus 1758 from Lake Nasser, Egypt

“…(Goher et al, 2021). The freshwater pufferfish Tetraodon lineatus is considered a discarded catch in Lake Nasser as pufferfishes, in general, are prohibited by the Egyptian law neither for fishing nor trading due to their toxicity as food (Farrag et al, 2022). Consequently, the population of the pufferfish has increased recently causing losses to entangled fish and damage to the fishing gears (Farrag et al, 2016).…”

“…Tetraodontidae species range in size from about 7cm to over 75cm. They have four large teeth that are fused into an upper and lower plate; this gives them their name ("tetra" meaning four and "odont" meaning teeth), and the body is typically spiny with short fins (Farrag, 2022). Most tetraodontids feed on molluscs such as clams or oysters; some also feed on crustaceans or small fish.…”