Body shape and trawl cod end selectivity for nine commercial fish species

2003 ◽  
Vol 83 (6) ◽  
pp. 1309-1313 ◽  
Author(s):  
Zafer Tosunoğlu ◽  
Yeliz Doğanyilmaz Özbilgin ◽  
Hüseyin Özbilgin
Keyword(s):  
Fish Species ◽  
Body Shape ◽  
Morphological Characteristics ◽  
Mesh Size ◽  
Sea Bream ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Red Mullet ◽  
Common Pandora ◽  
Merlangius Merlangus

This study investigates the catch components of a commercially used demersal trawl cod end in Izmir Bay, and reveals some of the morphological characteristics of nine commercial fish species; red mullet (Mullus barbatus), hake (Merluccius merluccius), whiting (Merlangius merlangus euxinus), poor cod (Trisopterus minutus capelanus), tub gurnard (Trigla lucerna), common pandora (Pagellus erythrinus), axillary sea bream (Pagellus acarne), picarel (Spicara smaris) and annular sea bream (Diplodus annularis) in relation to mesh size and shapes. Furthermore selectivity of 40-mm polyethylene netting cod end for red mullet, hake, common pandora, axillary sea bream, picarel and annular sea bream is presented. The results are discussed in a way to understand the probable effects of fish body shape on mesh selectivity.

The size selectivity of whiting (Merlangius merlangus euxinus) caught by gillnet in the eastern Black Sea of Turkey

2014 ◽  
Vol 94 (7) ◽  
pp. 1539-1544
Author(s):  
Ferhat Kalaycı ◽  
Tuncay Yeşılçıçek
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Sexual Maturity ◽  
Mesh Size ◽  
Size Selectivity ◽  
Selectivity Curve ◽  
Merlangius Merlangus

The size selectivity of traditional gillnets for whiting, (Merlangius merlangus euxinus) was investigated in the eastern Black Sea between June 2010 and June 2011. Experimental fishing operations were carried out by using gillnets of 16, 17, 18, 20 and 22 mm mesh size. A total of 2038 specimens belonging to 16 different fish species were caught during the experiment. The Share Each Length's Catch Total method was used to fit gillnet selectivity curves. Gillnet selectivity was best described by a bi-modal selectivity curve. The modal catch sizes were estimated as 14.81, 15.74, 16.66, 18.51 and 20.37 cm for 16, 17, 18, 20 and 22 mm mesh sizes, respectively. Modal lengths and spread values increased with increasing mesh size. The majority of fish (71.8%) caught by 16 mm mesh size were less than the length at first sexual maturity.

scholarly journals Somatic growth and age of selected commercial fish species of the Cullera Coast, Iberian Peninsula, south-east Spain

2019 ◽  
Vol 66 (3) ◽  
Author(s):  
Angela Maria Jaramillo-Londono ◽  
Alejandra Vanina Volpedo ◽  
Jose Luis Diaz-Arevalo ◽  
Maria Eugenia Rodrigo-Santamalia ◽  
Vicent Bendito-Dura
Keyword(s):  
Fish Species ◽  
Somatic Growth ◽  
Mesh Size ◽  
Age And Growth ◽  
Biological Information ◽  
Growth Equation ◽  
Commercial Fish ◽  
Mullus Surmuletus ◽  
Von Bertalanffy Growth Equation ◽  
Uranoscopus Scaber

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.

scholarly journals Preliminary study on otolith chemistry and otolith morphology of two demersal fish species, European hake Merluccius merluccius (Linnaeus, 1758) and striped red mullet (Mullus surmuletus, Linnaeus, 1758) in the Sea of Marmara

2021 ◽  
Vol 38 (4) ◽  
pp. 515-521
Author(s):  
Habib Bal ◽  
Selim Esen
Keyword(s):  
Chemical Analysis ◽  
Fish Species ◽  
Demersal Fish ◽  
Migration Routes ◽  
Merluccius Merluccius ◽  
Tracking Stocks ◽  
Red Mullet ◽  
Mullus Surmuletus ◽  
The Difference ◽  
European Hake

Otoliths are calcium carbonate (CaCO3) accumulations. Under the influence of different ecosystems morphological and chemical composition change. In this study, economically important two demersal fish species; European hake Merluccius merluccius (Linnaeus, 1758) and Stripet red mullet (Mullus surmuletus Linnaeus, 1758) was examined. Otoliths (Sagitta) belonging to these two species have been studied both chemically and morphologicall. Morphometric measurements of otoliths (length, mm; width, mm; area, mm2; perimeter, mm) in the sagittal of each species was made by the Leica M125 tri-ocular microscope. In the chemical analysis of otoliths, strontium (Sr), magnesium (Mg) and calcium (Ca) trace element amounts, the ratios of Sr and Mg trace elements to Ca element (Sr/Ca and Mg/Ca) were determined. For the micro-chemical analysis of otoliths ICP-MS was used. The highest magnesium (24.92±9.57 mmol/mol) and strontium (26.17±1.81 mmol/mol) element values were found in the otolith of red mullet. The difference between strontium (Sr) and magnesium (Mg) amounts for two fish species was found to be significant (P<0.05). In addition to it was found that the difference between them in the amount of calcium is significant (P<0.001). The shape indexes of otoliths are significantly different between the two fish species. Especially in terms of roundness (RD) and aspect ratio (AR) (P<0.001). The results of this study provide information about the habitats of two economic importance demersal fish species. Since such studies can give information about the habitat areas of fish species, they are important for tracking stocks, migration routes and sustainable fisheries.

scholarly journals Effect of a lateral square-mesh panel on the catch pattern and catch efficiency in a Mediterranean bottom trawl fishery

2020 ◽  
Vol 21 (1) ◽  
pp. 105
Author(s):  
SARA BONANOMI ◽  
JURE BRČIĆ ◽  
BENT HERRMANN ◽  
EMILIO NOTTI ◽  
ALESSANDRO COLOMBELLI ◽  
...  
Keyword(s):  
Mesh Size ◽  
Lateral Position ◽  
Bottom Trawl ◽  
Important Species ◽  
Commercial Fish ◽  
Trawl Fishery ◽  
Red Mullet ◽  
Commercially Important ◽  
The Mediterranean ◽  
Trawl Fisheries

The current legal codends used in Mediterranean bottom trawl fisheries are at high risk of retaining undersized individuals of several commercial fish species. This entails that codends alone are unable to provide the desired exploitation pattern. A simple technological measure that potentially can provide higher release efficiency of undersized fish are Square-Mesh Panels (SMPs). SMPs are often applied in the upper section of the trawl belly, just ahead the codend. However, recent studies in the Mediterranean have demonstrated that SMPs mounted in this position provided limited release efficiency, because very few fish came into contact with their meshes. In attempt to improve SMPs efficiency in the Mediterranean bottom trawl fisheries, we applied them on the lateral sides of the last tapered section of the trawl belly, just ahead of the codend, and fitted two guiding panels in the trawl belly to enhance fish-SMP contact. We compared the catch performance of a standard commercial trawl with a 52 mm diamond-mesh codend and of a similar trawl fitted with lateral SMPs (70 mm mesh size) in the belly using a twin trawl. The study focused on red mullet (Mullus barbatus), a commercially important species, but data for gurnard (Chelidonichthys lucerna and Chelidonichthys cuculus)  were also obtained and analysed. In contrast to previous research on SMPs mounted in the top panel of the trawl, in this study SMPs induced a significant effect on catch performance for red mullet, demonstrating that their lateral position involved greater fish-SMP contact. However, since the test trawl lost a significant amount of legal-sized red mullet compared with the standard trawl, the effect was not wholly positive, possibly due to an excessively large mesh size. Therefore, future studies should be encouraged to test lateral SMPs with smaller mesh sizes.

The influence of age on reproductive success and diet in Australasian gannets (Morus serrator) breeding at Pope's Eye, Port Phillip Bay, Victoria

2007 ◽  
Vol 55 (5) ◽  
pp. 267 ◽  
Author(s):  
T. M. Pyk ◽  
A. Bunce ◽  
F. I. Norman
Keyword(s):  
Reproductive Success ◽  
Food Availability ◽  
Fish Species ◽  
Breeding Success ◽  
Breeding Period ◽  
Chick Growth ◽  
Jack Mackerel ◽  
Commercial Fish ◽  
Red Mullet ◽  
Morus Serrator

The influence of age on reproductive success and diet was examined in ‘old’ (experienced; 12 years and older) and ‘young’ (5–8 years of age) Australasian gannets (Morus serrator) breeding at Pope’s Eye, Port Phillip Bay, Victoria during the 2002–2003 breeding period. Although food availability, as indicated by commercial fish catches, throughout this breeding period was low, there were no significant differences in breeding success or chick growth between groups. Nevertheless, old birds tended to have higher reproductive success, replacing more lost eggs and fledging chicks of a greater mass. However, old birds also laid more eggs that failed to hatch. Five fish species, including jack mackerel (Trachurus declivis), barracouta (Thyrsites atun), redbait (Emmelichthys nitidus), anchovy (Engraulis australis) and red mullet (Upeneichthys vlamingii), were important in the gannet diet during this breeding period. There were no significant differences in dietary parameters, including range of species and size of prey, between old and young gannets, nor were there any differences between those of the chicks and their parents, suggesting that adults do not forage selectively for their chicks. This study showed that even during a period of presumed low food availability, when experienced (older) birds might be expected to have enhanced success, the differences between these and less experienced (younger) birds may not be apparent.

scholarly journals Bioaccumulation of Metals/Metalloids and Histological and Immunohistochemical Changes in the Tissue of the European Hake, Merluccius merluccius (Linnaeus, 1758) (Pisces: Gadiformes: Merlucciidae), for Environmental Pollution Assessment

2020 ◽  
Vol 8 (9) ◽  
pp. 712
Author(s):  
Antonio Salvaggio ◽  
Roberta Pecoraro ◽  
Chiara Copat ◽  
Margherita Ferrante ◽  
Alfina Grasso ◽  
...  
Keyword(s):  
Fish Species ◽  
Inductively Coupled Plasma ◽  
Pollution Assessment ◽  
Hepatic Tissue ◽  
Trophic Chain ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Coastal Species ◽  
High Level ◽  
European Hake

Pollution and other types of environmental stress do not spare marine environments, especially those affected by high industrial pressure. Fish, especially coastal species, are used for monitoring the marine environment because they are particularly efficient as bioindicators thanks to their ability to bioaccumulate and biomagnify along the trophic chain. The aim of this research is to evaluate the bioaccumulation and the indirect bioindication ability of the European Hake, Merluccius merluccius (Linnaeus, 1758), one of the most important commercial fish species of the Mediterranean Sea. Morphological and histological alterations of the main target organs, such as liver and gills, have been investigated and the results showed a steatosis in the hepatic tissue. The accumulation of heavy metals has been analyzed by inductively coupled plasma mass spectrometry and for several metals it was showed a different concentration in the two sexes. Moreover, the expression of metallothioneins 1 and Heat Shock Protein 70 has been assessed by immunohistochemistry and did not show high level of expression. We underline the importance of contamination evaluation in commercial fish species and the utilization of the ichthyofauna as bioindicator of environmental quality.

scholarly journals Plastic Occurrence in Commercial Fish Species of the Black Sea

2021 ◽  
Vol 22 (Special Issue) ◽  
Author(s):  
Ulgen Aytan ◽  
Fatma Basak Esensoy ◽  
Yasemen Senturk ◽  
Esra Arifoglu ◽  
Kaan Karaoglu ◽  
...  
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
The Black Sea ◽  
Plastic Pollution ◽  
Commercial Fish ◽  
Vital Functions ◽  
The Status ◽  
The Mean ◽  
Merlangius Merlangus ◽  
Sarda Sarda

The occurrence of micro- (<5 mm), meso- (5–25 mm) and macroplastics (>25mm) was investigated in seven commercial fish species of the Black Sea. Plastics were found in gastrointestinal track of all species analysed: Engraulis encrasicolus, Trachurus mediterraneus, Sarda sarda, Belone belone, Pomatus saltatrix, Merlangius merlangus and Mullus barbatus. A total of 352 plastic particles were removed from 190 individuals (29% of all individuals examined). The mean number of plastic particles per fish was 0.81±1.42 par.ind-1 (considering all fish analysed, n=650) and 2.06±1.09 par.ind-1 (considering only the fish that ingested plastic, n=190). The most common types of plastics were fibres (68.5%), followed by films (19%), fragments (11.9%), foams (0.3 %) and microbeads (0.3%). The most common plastic colour was black (39.3%) followed by blue (19.5%) and transparent (18.1%). The length of plastics ranged from 0.05 to 26.5 mm with an average of 1.84±2.80 mm. 93.2% of plastics were microplastics, 6.5 % as mesoplastics and 0.3% macroplastics. Plastic occurrence was higher in S. sarda (plastic in 70% of the analysed individuals) and lower in M. merlangus (plastic in 9% of the analysed individuals). The main synthetic polymers identified by Fourier-transform infrared (FTIR) spectroscopy were polypropylene (29.8%), polyester (17.5%), acrylic (15.8%), polyethylene (14%) and polystyrene (1.8%) and 21.1% of polymers were cellulosic. Results show that commercial fish of the Black Sea is contaminated by plastics. This might affect vital functions of fish and pose a risk to ecosystem and human health. The study contributes to a better understanding of the status of plastic pollution in the fish from different habitats of the Black Sea and provides baseline data to implement the Marine Strategy Framework Directive in the basin.

scholarly journals Ecomorphology and use of food resources: inter- and intraspecific relationships of fish fauna associated with macrophyte stands

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Aline V. R. Prado ◽  
◽  
Erivelto Goulart ◽  
João P. A. Pagotto ◽  
◽  
...  
Keyword(s):  
Fish Species ◽  
Body Shape ◽  
Niche Breadth ◽  
Fish Fauna ◽  
Morphological Characteristics ◽  
Morphological Diversity ◽  
Food Resources ◽  
Trophic Niche ◽  
Eichhornia Azurea ◽  
The Relationship

ABSTRACT Based on the form-function interaction and its consequence to niche exploitation by fish species, the study aimed to identify ecomorphological patterns and to investigate the possibility of explaining the trophic niche breadth using the pattern of intraspecific ecomorphological diversity. We tested the following hypotheses: i) the morphology explains variations in diet among fish species; ii) the intraspecific ecomorphological diversity is related to the breadth of the trophic niche explored by the species, so that species that feed on a wider range of resources have greater variation in body shape compared to those specialized in resource consumption. Fish were collected in stands of the aquatic macrophytes Eichhornia azurea and Eichhornia crassipes in lentic environments of the Upper Paraná River floodplain, Brazil. Two major trends were observed in the morphological space: fish with body shapes adapted to explore the substrate and others with a design that facilitates the capture of food items in more structured habitats. The relationship of diet with body shape was confirmed by significant relationships between matrices of trophic and morphological distances, providing evidence that morphology is related to interspecific variations in the use of trophic resources. However, the ranges of morphological and intraspecific trophic variations were not significantly related, rejecting the second hypothesis about the relationship between intraspecific ecomorphological diversity and trophic niche breadth. The morphological characteristics often have multiple ecological roles, which could result in trade-off among these functions. Thus, fish with highly specialized morphology may show specialist feeding or even generalist habit, because in this case some resources may be difficult to exploit, even by a specialist. Species with low and high morphological diversity demonstrated narrow trophic niche and the availability of resources may have been essential for consumption. Therefore, species morphology is related to the use of food resources and ecomorphology can be considered an important tool for the prediction of the exploited niche space by species in assemblages. However it is not possible to predict if species with greater intraspecific morphological diversification indeed have wider niche, since the abundance or scarcity of the available food resources may interfere with trophic niche breadth.

scholarly journals Bioaccumulation of some Heavy Metals in Red mullet (Mullus barbatus) and Common pandora (Pagellus erythrinus) in Zliten Coast, Libya

2021 ◽  
Vol 13 (1) ◽  
pp. 91
Author(s):  
Keri Alhadi Ighwela ◽  
Ragab Farag Al-Kazaghly ◽  
Mohamed Hamid
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Concentration ◽  
Fish Species ◽  
Heavy Metal Concentration ◽  
Human Consumption ◽  
Pagellus Erythrinus ◽  
Red Mullet ◽  
Mullus Barbatus ◽  
Common Pandora

Highlight Investigated in heavy metal bio-accumulation in red mullet (Mullus barbatus) and Common pandora (Pagellus erythrinus) collected in Zliten Coast, Libya.Based on the samples collected, the muscle tissue of fish species may be considered suitable for human consumption.The metal concentration levels observed were in range of acceptable limits proposed by regulations of WHO and FAO.AbstractThe current study aimed to determine the heavy metal concentration like as copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) and mercury (Hg) in the liver, gills, gonad and muscles in two fish species (red mullet (Mullus barbatus), and common Pandora (Pagellus erythrinus) collected from the Zliten coast in Libya. The levels of heavy metals were determined by using an atomic absorption spectrophotometer (AAS). The results showed that the concentration of heavy metals in the sampled fishes less than the permissible limits for human consumption. In addition, the bioaccumulation for Cu, Pb, Cd, and Hg by both fish species was: liver >gills > gonads > muscles, while Zn follows the sequence: gonads > liver > gills > muscles. 

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