Latest Articles from Acta Ichthyologica et Piscatoria Latest 3 Articles from Acta Ichthyologica et Piscatoria https://aiep.pensoft.net/ Fri, 29 Mar 2024 00:36:22 +0200 Pensoft FeedCreator https://aiep.pensoft.net/i/logo.jpg Latest Articles from Acta Ichthyologica et Piscatoria https://aiep.pensoft.net/ Estimation of selectivity parameters for target and bycatch fishes of the trammel net fisheries in the northern Aegean Sea (eastern Mediterranean Sea) https://aiep.pensoft.net/article/103358/ Acta Ichthyologica et Piscatoria 53: 65-80

DOI: 10.3897/aiep.53.103358

Authors: Angeliki Adamidou, Konstantinos Touloumis, Manos Koutrakis, Athanassios C. Tsikliras

Abstract: The size selectivity of trammel nets was investigated in the northern Aegean Sea using 10 different inner-panel mesh sizes ranging from 16 to 70 mm nominal mesh size (bar length). Selectivity estimates were made for the eight most abundant target and bycatch fish species, namely black scorpionfish, Scorpaena porcus Linnaeus, 1758; annular seabream, Diplodus annularis (Linnaeus, 1758); red mullet, Mullus barbatus Linnaeus, 1758; surmullet, Mullus surmuletus Linnaeus, 1758; round sardinella, Sardinella aurita Valenciennes, 1847; European hake, Merluccius merluccius (Linnaeus, 1758); greater weever, Trachinus draco Linnaeus, 1758; and blotched picarel, Spicara flexuosum Rafinesque, 1810, which accounted for 51.5% by number and 42.7% by weight of the fish caught with trammel nets in the sea trials. The SELECT method was used to estimate the selectivity parameters. Five different selectivity functions (i.e., normal scale, normal location, gamma, log-normal, and bi-normal) were applied with the bi-normal function providing the best fit as it had the lowest deviance value for all species and the lowest values for the dispersion parameter (D/df). The mesh size of 16 mm in most of the cases retained specimens below the size at first maturity (Lm). The mesh size of 19 mm seems more appropriate for red mullet, surmullet, and blotched picarel, the mesh size of 22 mm for annular seabream and round sardinella, while for European hake and black scorpionfish, the mesh size larger than 26 mm would be more appropriate.

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Research Article Tue, 23 May 2023 15:37:53 +0300
Length–weight relations of 16 mesopelagic fishes (Actinopterygii: Myctophiformes and Stomiiformes) from the eastern Mediterranean Sea https://aiep.pensoft.net/article/97577/ Acta Ichthyologica et Piscatoria 52(4): 279-283

DOI: 10.3897/aiep.52.97577

Authors: Nicholas Badouvas, Stylianos Somarakis, Konstantinos Tsagarakis

Abstract: For many mesopelagic fishes, even basic knowledge regarding their biology is missing, greatly impeding their effective management. Here we present length–weight relations for 16 mesopelagic fishes sampled during research surveys in the Greek seas (eastern Mediterranean). The following species were studied: Benthosema glaciale (Reinhardt, 1837); Ceratoscopelus maderensis (Lowe, 1839); Diaphus holti Tåning, 1918; Diaphus metopoclampus (Cocco, 1829); Diaphus rafinesquii (Cocco, 1838); Hygophum benoiti (Cocco, 1838); Hygophum hygomii (Lütken, 1892); Lampanyctus crocodilus (Risso, 1810); Lobianchia dofleini (Zugmayer, 1911); Myctophum punctatum Rafinesque, 1810; Notoscopelus elongatus (Costa, 1844); Symbolophorus veranyi (Moreau, 1888) [Myctophidae]; Argyropelecus hemigymnus Cocco, 1829; Maurolicus muelleri (Gmelin, 1789) [Sternoptychidae]; Stomias boa (Risso, 1810); Chauliodus sloani Bloch et Schneider, 1801 [Stomiidae].With the exception of Diaphus holti and Symbolophorus veranyi, parameter b diverged significantly from isometry. Only two species (Benthosema glaciale and Chauliodus sloani) displayed negative allometry, while for the remaining 12 species a positive allometry was found, with the highest parameter b values estimated for Stomias boa and Diaphus rafinesquii. The median value of parameter b for all species was 3.236 and 50% of its values ranged from 3.173 to 3.323. Some variations of the parameter b were observed between our findings and other studies from the Atlantic and the western Mediterranean.

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Short Communication Mon, 19 Dec 2022 15:05:45 +0200
Alteration of the feeding behavior of an omnivorous fish, Scardinius acarnanicus (Actinopterygii: Cypriniformes: Cyprinidae), in the presence of fishing lights https://aiep.pensoft.net/article/63299/ Acta Ichthyologica et Piscatoria 51(2): 131-138

DOI: 10.3897/aiep.51.63299

Authors: Lambros Tsounis, George Kehayias

Abstract: Fishing with light is an old and common practice yielding a substantial catch volume globally. Despite the popularity of the method and the efforts to improve it, there is a lack of field studies on the effects of light on the feeding preferences of the attracted fishes. A previous report suggested that purse seine fishing lights can differentiate the feeding preferences of the approaching fishes, such as Atherina boyeri Risso, 1810 in Lake Trichonis (Greece). The presently reported study aims to verify these findings by investigating the diet of the endemic Scardinius acarnanicus Economidis, 1991. The feeding behavior of S. acarnanicus was studied from 2016 to 2019 through gut content analysis, in specimens from Lake Trichonis that came from purse seining with light and specimens caught without light. The same investigation was carried out comparatively in specimens taken by gillnets from two nearby lakes (lakes Ozeros and Amvrakia), where S. acarnanicus is present, but no fishing with light is exercised. The stomach content analysis conducted on 699 S. acarnanicus specimens revealed the intense effect of light on its diet resulting in the alteration of its feeding habits towards fish predation and especially Atherina boyeri. On the contrary, the specimens taken with the use of gillnets, from the three lakes, showed a typical omnivorous feeding behavior. The findings of the presently reported study support the assumption that the elevated concentration of fish close to fishing lights alters the feeding behavior of certain species making them predators. Considering that fishing with light is practiced worldwide, this could be of great ecological significance to the ichthyofauna not only of inland waters but also of marine areas, affecting perhaps several commercial species.

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Research Article Tue, 8 Jun 2021 10:13:35 +0300