Models of sexual maturation as a tool for the conservation of commercial fish in a RAMSAR site of Brazil

Almeida, Zafira da Silva de; Carvalho, Irayana Fernanda da Silva; Diniz, Ana Luiza Caldas; Neta, Raimunda Nonata Fortes Carvalho; Torres, Cláudio Leão; Serra, Ilka Márcia Ribeiro de Sousa

doi:10.1063/1.5079159

Cited by 2 publications

(2 citation statements)

References 10 publications

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“…The most excellent harvest of the population of C. auratus in the present study was made from individuals of 19 to 21 cm, which was above the length of first maturity (Lm50) and the estimated size at first capture (Lc50) by the fishing gears [53]. "The first sexual maturation is an important point in the animal's life history and must be taken into account for successful fish management" [54]. "The occurrence of such a situation suggests that individuals of the species get the chance to join the stock before becoming vulnerable to capture by the available fishing gear.…”

Section: Conclusion and Discussionmentioning

confidence: 87%

Stock Assessment and Virtual Population Analysis of Carassius auratus (Linnaeus, 1758) in the Al-Diwaniya River, Middle of Iraq

Mohamed

2024

AJFAR

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A total of 1128 individuals of C. auratus were collected from the Diwaniyah River, Iraq. Samples were collected between November 2016 and October 2017 using different fishing gears aiming to assess the stock assessment and virtual population analysis. Fish length ranged from 8.0 to 33.0 cm, with a length-weight relationship exhibiting positive allometric growth. Asymptotic length (L∞) was estimated at 33.0 cm, the growth coefficient (K) was 0.16, and the growth performance index (Ǿ) was 2.241. The values of total (Z), natural (M) and fishing (F) mortality rates were 0.89, 0.47, and 0.42, respectively. The exploitation rate (E) was 0.48. Length with a 50% probability of capture (LC50) was estimated at 18.7 cm and was higher than the length at first maturity (Lm50). The recruitment consisted of one seasonal pulse from April to July. The exploitation rate (E) was below the biological target reference points (E0.1 and Emax), indicating the stock was under exploitation state. The result of the virtual population analysis revealed that most of the fishing mortality happened in mid-lengths (18-26 cm) with a maximum rate at a length of 25 cm. Natural losses were highest among individuals within the length range of 8.0 to 15 cm and then decreased gradually to the length group of 30. For management purposes, this study suggests that more yields can be obtained by increasing the fishing activities on this invasive species, such as increasing the number of fishing boats and decreasing the mesh size to decline its abundance in the long term.

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Section: Conclusion and Discussionmentioning

confidence: 87%

Stock Assessment and Virtual Population Analysis of Carassius auratus (Linnaeus, 1758) in the Al-Diwaniya River, Middle of Iraq

Mohamed

2024

AJFAR

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“…According to the virtual population analysis (VPA), most catches of T. ilisha in this study occurred in midlengths of 18-26 cm. Further, Almeidaa et al (2018) stated that the first sexual maturation is an important point in the animal's life history and must be considered for successful fish management. In the present study, there was a difference between the length at the first capture of T. ilisha (L c50 = 20.6 cm) and the length at first maturity (L m50 ).…”

Section: Virtual Population Analysismentioning

confidence: 99%

Stock assessment and virtual population analysis of River shad, Tenualosa ilisha (Bloch & Schneider, 1801) in the Shatt Al-Arab River, Iraq

Mohamed

2022

Arch. Agric. Environ. Sci.

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Historically, the river shad, Tenualosa ilisha fishery is the most significant marine fishery from the economic-socio point of view in Basrah province for a long time, but its contribution declined from 90.2% of total landings in 1965-1973 to 5.8% in 2020. The stock and virtual population analysis of the species in the Shatt Al-Arab River, Iraq was assessed using FiSAT II software. Samples were collected from two sites in the river from November 2015 to October 2016. A total of 462 individuals of T. ilisha ranging from 7.0 to 42.5 cm were collected. The length-weight relationship was derived, indicating a positive allometric growth for the species. L∞, K, and Ø were 59.1 cm, 0.27, and 2.975, respectively. Total (Z), natural (M) and fishing (F) mortalities were 1.94, 0.59, and 1.35, respectively. The exploitation rate (E) was 0.70. Length at first capture (Lc50) was found to be 24.4 cm. The recruitment pattern of T. ilisha was continuous throughout the year with two unequal prominent peaks. The relative yield per recruit analysis revealed that the current exploitation rate (E) of T. ilisha was higher than both E0.1 and Emax. Also, the 40 cm length group was more vulnerable to fishing according to VPA analysis, followed by the 34 cm and 26 cm length groups. For management purposes, it must be introduced an extensive T. ilisha management action plan by protecting brood species during the breeding season by imposing a ban on fishing in the Shatt Al-Arab River during the main spawning migration and conserving the small T. ilisha (Milat <23.0 cm) from catching.

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Models of sexual maturation as a tool for the conservation of commercial fish in a RAMSAR site of Brazil

Cited by 2 publications

References 10 publications

Stock Assessment and Virtual Population Analysis of Carassius auratus (Linnaeus, 1758) in the Al-Diwaniya River, Middle of Iraq

Stock Assessment and Virtual Population Analysis of Carassius auratus (Linnaeus, 1758) in the Al-Diwaniya River, Middle of Iraq

Stock assessment and virtual population analysis of River shad, Tenualosa ilisha (Bloch & Schneider, 1801) in the Shatt Al-Arab River, Iraq

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