Atherina Boyeri Research Articles

Parasite and genetic diversity of big-scale sand smelt (Atherina boyeri Risso, 1810) populations in their natural and expansion ranges in Ukraine.

The big-scale sand smelt (Atherina boyeri) is an Atlanto-Mediterranean amphidromous fish species found within the Black Sea. Here, we assess differences in the parasite fauna of big-scale sand smelt populations from their natural range in the northwestern Black Sea and from their expansion range in the Lower and Middle River Dnipro. In addition, we undertook a microsatellite analysis to assess the genetic similarity of fish from the different locations. We found that the parasite community of fish in their natural range was wider than that from their expansion range. While the Gulf of Odesa was most distant from all other localities by parasite community composition and the Dnipro Reservoir was characterised by an absence of parasites (newest and most distant expansion locality), only fish from the Danube Delta showed a significant genetic difference. Our results suggest that the parasite community of big-scale sand smelt is primarily influenced by environmental factors, such as habitat type, water salinity and/or prey composition. Both microsatellite analysis and parasite community species composition (e.g. the presence of the marine Telosentis exiguus in the Kakhovka Reservoir and freshwater Raphidascaris sp. in the Gulf of Odesa) confirmed that populations in the River Dnipro reservoirs had, at some time, been connected with native marine populations, thus also confirming the species' amphidromous nature.

An ichthyofaunal amendment with the length-weight relations and condition factors of some endemic and invasive freshwater fishes from Western Anatolia

In the scope of this study, fish fauna of Küçük Menderes River and its tributaries, updated with the comparison of the recent ichthyofaunal studies, as well as the length-weight relations (LWR) and condition factors (CF) were estimated for 7 freshwater fish species belonging to six families from the river basin: endemic Oxynoemacheilus eliasi, Cobitis fahireae; invasive, Carassius gibelio, Atherina boyeri, transloce Perca fluviatilis and the native Squalius fellowesii, Cyprinus carpio. The fish samples were collected with various fishnets and DC electro-fishing devices from six stations in 2018 and 2019. The LWR of the fishes was studied based on 379 specimens. The estimated values of parameter b ranged from 2.884 (A. boyeri) to 3.176 (C. fahireae). The coefficient of determination (R2) was changed between 0.792 to 0.980 for all sampling localities. In the study, Fulton’s condition factor ranged between 0.391 (S. fellowesii) to 3.080 (S. fellowesii); the relative condition factor ranged between 0.346 (O. eliasi) to 2.746 (S. fellowesii), respectively. This research is anticipated to contribute valuable insights for the conservation of the species, while also furnishing essential data to inform future fisheries management studies in the region.

Problems Experienced By Inland Water Fishermen During The Pandemic (Covid-19): The case of Yozgat Province

The fishermen of Yozgat province, which is located in the middle of the steppe without a seashore, export the fish they catch abroad. During the pandemic, export in fisheries is restricted. For this reason, the aim of this study was to investigate the difficulties and problems experienced by fishermen in Süreyyabey and Gelin Güllü Dam lakes during the pandemic period covering the years 2020-2021 (March-2020; March 2021). In the study, 2 different questionnaire forms were carried out by face-to-face interviews with fishermen and cooperative presidents. As a result of the study; In the fishing period of July-December 2020 (6 months), there was no fish export and the fishery paused. In January-March 2021, exports started to be made at a certain quota. It was determined that 63.63% (n=21) of a total of 33 fishermen in Cekerek Dam Lake quit fishing, 66.66% (n=14) started farming, 33.33% (n=7) migrated, and 36.36% (n=12) continued fishing during the pandemic. In Gelin Güllü Dam lake, 35 % (n=7) of the total 20 fishermen quit fishing, 20 % (n=4) started farming and 65 % (n=16) continued fishing. Carp (Cyprinus carpio), Silver (Atherina boyeri), Siraz (Capoeta pestai), Sudak (Sander lucioperca) species were caught in the region during the pandemic The problems experienced by the fishermen in the region; unregulated fishing, marketing, it was determined that they did not receive any government support.

Dietary ingredient composition affects faecal waste production and characteristics in yellowtail kingfish (Seriola lalandi)

This study investigated the effect of different animal-based ingredients on faecal waste production and characteristics in yellowtail kingfish (Seriola lalandi). Seven ingredients of animal origin were tested: KM – krill meal; SHM – shrimp head meal; NIM – natural ingredient meal consisting of freeze dried krill (Euphausia superba), sand eel (Ammodytes marinus), smelt (Atherina boyeri) and squid (Loligo patagonica) (all included at 25% on dry matter basis); PHA – poultry meal with high ash content; PLA – poultry meal with low ash content; HFM – hydrolysed feather meal and POM – pork meal. Ingredients were incorporated at 30% (HFM – 15% inclusion) in a basal diet, which was predominantly marine-based. Yellowtail kingfish (mean initial weight 41 g) were fed the experimental diets restrictively, in triplicate groups. Fish performance, nutrient digestibility and faecal waste production were investigated over a 35 day experimental period. In addition, faecal characteristics were visually evaluated, and faeces removal efficiency and particle size distribution (PSD) were measured. Organic matter digestibility (OM) differed between diets, hereby altering the amount of faecal waste produced (g OM/kg DM FI). Test ingredients affected faeces removal efficiency by settling (%) and the amount of non-removed faeces (g OM/kg DM FI). Effects of ingredients on faeces removal efficiency were small compared to effects on faecal waste production. SHM, inclusion resulted in an improved faeces removal efficiency, while other animal-based ingredients did not improve faeces removal efficiency. Overall, this study highlights the importance of ingredient digestibility (and thus faecal waste production) for solid waste management in yellowtail kingfish.

Eustrongylides spp. parasite risk management in Atherina boyeri from Lake Trasimeno.

Atherina boyeri is the primary source of fishing profit in Lake Trasimeno and a common host for Eustrongylides spp. larvae. The presence of Eustrongylides in fish is a public health concern, and effective risk management procedures are necessary to guarantee that infected products do not reach the market. Currently, in the European Union, there is no official sampling plan for fresh fish that defines sample size, inspection methods, and criteria for accepting or rejecting the product. An approach to Eustrongylides risk management is proposed in this study. A total of 270 batches of A. boyeri, each consisting of 29 specimens, were collected and examined visually in 3 years (2020-2023). The prevalence of the parasite was 20% in 2020, and in the first months of 2021, it grew up to ⁓40%, then dropped to 12.50% in December 2021 and settled at 16% in February 2022. In January and February 2023, the prevalence fell below 1%. The mean abundance was calculated and used to establish a threshold value to determine fish marketability. In 2020 and 2021, several batches were judged not marketable, and in some batches, a freezing treatment was implemented to ensure the inactivation of the parasite. In the last months of 2022 and in January and February of 2023, the presence of parasites in captured fish was negligible, and this allowed the marketability of fish as fresh. The proposed sampling plan was effective in preventing the commercialization of potentially hazardous products.

Gümüş balığının (Atherina boyeri Risso, 1810) geleneksel ve yapay sinir ağları yöntemleriyle büyüme parametreleri

In this study, the growth parameters of big-scale sand smelt (Atherina boyeri Risso, 1810) in İznik Lake has been determined with traditional (length weight relationships (LWRs), von Bertalanffy (VB), condition factor (CF)) and modern approaches (Artificial Neural Networks - ANNs). A total of 635 specimens (44.84% female and 55.16% male) were collected from the local fisherman during the hunting season between April 2018 to April 2019. Mean fork length (FL) (mm, min-max), mean W (g, min-max) and mean CF (value, min-max) were estimated as 67.31 mm (40.10 - 97.77 mm), 2.57g (0.53 - 7.50 g), and 0.790 (0.170-1.520) for all individuals. The length-weight relationships were determined W=0.00001437L2.8602 for female, W=0.00001570L2.8266 for male and W=0.00001328L2.8717 for all individuals. The von Bertalanffy equations were determined Lt=136.218 [1-e(-0.240(t+0.51))] for female, Lt=155.042 [1-e(-0.185(t+0.73))] for male, and Lt=146.916 [1-e(-0.205(t+0.64))] for all individuals. The values in training (MSE (Mean Squared Error) 4.52559e-5, R (correlation coefficients) 9.09347e-1), verification (MSE 4.86111e-5, R 9.00931e-1) and test data (MSE 3.391999e-5, R 9.43465e-1) were found in calculations made with ANNs. It was determined that ANNs could be an alternative for evaluating growth estimation.

Stock Assessment of Atherina Boyeri Risso, 1810 Using Two Different Methodological Approaches (length-based VPA and Catch-only CMSY), in a Freshwater Ecosystem

Stock Assessment of Atherina Boyeri Risso, 1810 Using Two Different Methodological Approaches (length-based VPA and Catch-only CMSY), in a Freshwater Ecosystem

Morphometric Traits of the Sagittae of Big Scaled Silverside (Atherina boyeri (Risso, 1810)) Captured from the East Coast of Libya

Morphometric Traits of the Sagittae of Big Scaled Silverside (Atherina boyeri (Risso, 1810)) Captured from the East Coast of Libya

Formuation and evaluation of novel nutritious fish snacks made from SandSmelt (Atherina boyeri)

Formuation and evaluation of novel nutritious fish snacks made from SandSmelt (Atherina boyeri)

The Seasonal Fish Diversity of Aliağa, a Heavy Industry Zone on the Turkish Coast of the Aegean Sea

The stress on the marine environment caused by industrialization in developing economies is indisputable. The Aliağa region, which has unique features such as being heavily influenced by industrialization and having different types of marine habitats was preferred as a monitoring point. By determining the current status of fish density and diversity, the focus was on obtaining data that could allow future comparisons. Without the seasonal variability, 39 fish species representing 14 families were identified, with two abundant families: ten species in both Sparidae and Labridae. The greatest fish diversity was recorded respectively in the spring, summer and autumn. Abundant species were Boops boops with 19.3%, Chromis chromis (17.4%), Spicara smaris (15.0%) and Atherina boyeri (12.5%) in total abundance. A total of 1.89 individuals/m2 that weighed 20.43 g/m2 were identified in the study period.

Spatio-temporal Variation of Shallow Microhabitats and Associated Juvenile Fish Assemblages in a Mediterranean Lagoon

Coastal lagoons are known to host numerous resident and migrant fish species. Spatio-temporal variation in abiotic and biotic conditions in these ecosystems results, however, in a mosaic of microhabitats that could differently affect juvenile growth and survival. To deepen our understanding of juvenile fish habitat requirements and their spatio-temporal use of lagoons, microhabitat characteristics and fish assemblages were monitored jointly in a small temperate lagoon (the Prévost lagoon), from March to October 2019. A total of 2206 juvenile fishes belonging to 22 species were collected. Resident lagoon species, especially Atherina boyeri, dominated the assemblage (74%), while, among migrant species, Sparus aurata (8%) and Liza aurata (5%) were the most represented. Changes in overall juvenile abundance were mainly temporal, following the seasonal shifts in water temperature, salinity, and chlorophyll a concentration (44.9% of the co-inertia). However, our results revealed that distinct types of microhabitats exist in small lagoons and that juvenile fish distribution among them is non-random. Indeed, fish species richness mainly differed among sampling sites in relation to their distance from the inlet and the complexity of the three-dimensional habitat structure (36.5% of the co-inertia). Juveniles preferentially selected microhabitats with medium to high structural complexity, which were essentially created by macroalgae. However, microhabitat preferences were both species and ontogenetic stage dependent, with more contrasting microhabitat requirements in young juveniles. These results underline the need for conservation measures to consider each lagoon as a dynamic mosaic of microhabitats with radically different importance for the juveniles of the various fish species that colonize them.

Anaphylactic Shock to Mediterranean Silverside (Atherina boyeri) Caused by Nonparvalbumin Allergens.

Anaphylactic Shock to Mediterranean Silverside (Atherina boyeri) Caused by Nonparvalbumin Allergens.

Five-years management of an emerging parasite risk (Eustrongylides sp., Nematoda) in a fishery supply chain located on Trasimeno Lake (Italy)

In the last few years, the widespread diffusion of potentially zoonotic parasitic nematodes of the genus Eustrongylides in the Trasimeno Lake, Central Italy, prompted Food Business Operators (FBOs) operating in the freshwater fish supply chain to define preventive measures to reduce or eliminate this new hazard from fishery products. The results of the self-checks for parasite risk management of a fishermen's cooperative over a five-year period (January 2016–April 2021) are presented. Nine freshwater commercial species, perch ( Perca fluviatilis ), largemouth black bass (Micropterus salmoides ), big-scale sand smelt ( Atherina boyeri ), eel ( Anguilla anguilla ), black bullhead ( Ictalurus melas ), carp ( Cyprinus carpio ), tench ( Tinca tinca ), goldfish ( Carassius auratus ), and pumpkinseed sunfish ( Lepomis gibbosus ), differently processed (filleted, whole gutted or whole ungutted), were investigated . The presence of visible parasites was assessed by visual inspection during processing and recorded. Eustrongylides sp. were found in all species examined except for goldfish. Eustrongylides sp. occurrence was negligible in large mouth black bass, eel, carp, and tench, while increasing prevalence rates over the years were observed in fillets of perch <400 g (from 4.2% in 2016 to 68% in 2021), batches of sand smelt (<1%–40%) and pumpkinseed sunfish (6%–99%). Still low but slightly increasing prevalence rates were also observed for black bull head. The rising of the infection in perch, sand smelt, and pumpkinseed sunfish lead to a progressive implementation of preventive measures including the definition of a sampling plan for the visual inspection followed by trimming or removal of the parasites from the muscle or the application of a threshold value to define the marketability of fish batches. This is the first study describing an approach for the management of the emerging risk posed by nematodes of the genus Eustrongylides in a freshwater fishery supply chain. Besides providing an updated epidemiological scenario in Lake Trasimeno, where this parasite was described for the first time in Italy in 2015, it could support other FBOs in the implementation of preventive measures to safeguard consumers' health and trust. • Eustrongylides sp. nematodes are becoming widespread in the Trasimeno Lake, Italy (85). • The local freshwater fishery supply chain is affected by Eustrongylides sp. (85). • 5-years of self-checks for parasites of a fishermen's cooperative are presented (82). • Nine commercial species differently processed were investigated (65). • Prevalence in perch, sand smelt and pumpkinseed sunfish are noticeably increased (85).

Length-weight relationships and condition factors of the sand smelt Atherina boyeri (Risso, 1810) estimated from commercial and experimental catches in Lake Trichonis (Western Greece)

Total length-weight relationships (LWRs) from 3583 individuals of Atherina boyeri (Risso, 1810) caught in Lake Trichonis (Western Greece), using a commercial encircled net and experimental Nordic type benthic and pelagic multi-mesh gillnets, were estimated during 2019-2020. The variation of the parameter b for all seasons combined was significantly allometric, for both encircled towed and gillnets, with a quite robust fit (R^2 equals 0.925 and 0.947, respectively) and values equal to 2.254 and 2.089, respectively. The specimens were significantly lighter in summer than in the other seasons. The slopes of the LWRs significantly differ between seasons and exhibited relatively low values when compared to other ecosystems worldwide and in the same ecosystem in previous periods of time. Τhe estimated values of the Le Cren index were significantly higher than the Allometric and the Fulton ones.

Assessing the Fisheries and Ecosystem Structure of the Largest Greek Lake (Lake Trichonis)

An Ecopath with Ecosim (EwE) modeling approach was used to explore the ecological structure of the largest lake in Greece (Lake Trichonis). Until the mid-1990s, the lake was receiving a high level of pollution and the fishing pressure was intense, while since the early 2000s, fisheries and other human pressures gradually declined. Nowadays, the lake’s fisheries mainly target Atherina boyeri due to the absence of market demand for the other fish species in the lake, resulting in a low overall fisheries pressure on the fish stocks. The model was built with data collected through: (a) field samplings, (b) in-depth targeted interviews of professional fishermen and (c) historical archive information. The model considered 22 functional groups, while fishing activities were represented by three classes according to the used gears. The outputs of the model revealed that the ecosystem is dominated by low trophic level species (also identified as keystone species), indicating the significance of bottom-up control in the regulation of food web processes. Ecological indicators depicted that the lake’s ecosystem is mature and resilient to external disturbances. The methodological approach used in this study was shown to be helpful for studies addressing ecosystem structure, in particular with limited data availability.

Food and ecology or how dietary alterations can affect an aquatic ecosystem

Fishing ensures necessary food for humans and is inextricably linked with the environment because coastal communities developed special fishing procedures to achieve better exploitation of the aquatic resources. Lake Trichonis, Greece’s largest natural lake, is a freshwater ecosystem in which a marine species (Atherina boyeri) has entered and dominate the ichthyofauna. This species is exploited by purse seine fishing with the use of light, and previous studies revealed that the fishing lights create a particular food chain reaction, which promotes predation among the attracted fish species, one of which is Scardinius acarnanicus that preys upon A. boyeri. The purse seine fishers typically return to the lake alive S. acarnanicus, due to its low market demand, although it is the main predator of their catch. This custom, apart from causing income losses, promotes instability in the fish populations, while eventually altered the foraging behaviour of S. acarnanicus and made it a fish-predator instead of a typical omnivorous species. Based on data from official fish landing recordings, interviews with local fishers, and responses to questionnaires completed by residents of villages around Lake Trichonis, the present study investigates how changes in the dietary habits of the lakeside communities over time have led to the low market demand for S. acarnanicus. The present findings revealed an interesting relation between the dietary preferences of the local population and their ecological consequences for the fish community of this lake. This will eventually lead to the increase in the top predator (S. acarnanicus) and an inevitable decrease in the main catch (A. boyeri), affecting not only the ecological status of the lake, but also the socioeconomic characteristics of the human populations in this area. From another perspective, the results demonstrate a paradigm of adapted evolution by a wild fish under the pressure of human activities.

Çekerek Barajı'ndan (Yozgat, Turkey) Avlanan Gümüş Balığının (Atherina boyeri) Yağ Asidi ve Besin Kompozisyonundaki Mevsimsel Değişimleri

Seasonal variations of proximate and fatty acid compositions of the muscle tissue of sand smelt (Atherina boyeri) harvested in Cekerek (Sureyyabey) Dam were investigated. Seasonal nutritional composition of sand smelt muscle in October, March and July were found as 17.00%; 16.72%; 15.64% for protein, 1.95%; 2.00%; 2.86% for lipid, 79.25%; 79.17%; 78.06% for moisture and 1.80%; 2.10%; 2.49% ash, respectively. Sand smelt showed the lowest protein values in summer, while the highest protein values were observed in autumn and spring. The highest lipid content of sand smelt was found in summer (P &amp;lt; 0.05). The moisture content of sand smelt in summer was significantly (p&amp;lt;0.05) lower than those of the content in autumn and spring. The lowest ash content was observed in autumn (1.80%) whereas sand smelt gave the highest ash level was in summer. During the seasons, the proximate and FA composition values of sand smelt showed variations (p&amp;lt;0.05). Seasonal fatty acid compositions of sand smelt ranged from 24.63 to 25.69% for saturated fatty acid (SFA), from 20.75 to 26.43% for monounsaturated (MUFA), and from 28.29% to 36.11% polyunsaturated fatty acid (PUFA). Palmitic acid (16:0), stearic acid (18:0), palmitoleic acid (16:1ω7), oleic acid (18:1ω9), linoleic acid (LA, 18:2ω6), arachidonic acid (ARA, 20:4ω6), linolenic acid (18:3ω3), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3) were major fatty acids of sand smelt in different seasons. The highest proportion of EPA (5.59-7.22%) and DHA (12.33-19.77%) were observed in spring. The results showed that sand smelt is good source of n-3 PUFAs and is rich in EPA+DHA for human nutrition.

Length-Weight Relationship of 15 Different Freshwater Fish Species in the Gediz River Basin (Turkey) Lentic System

The aim of study is to determine the length-weight relationship of freshwater fish species in the Gediz River basin lentic system. Fish samples were collected between November 2016 and April 2017 using multi mesh gillnets and beach seine nets from six different locations in the Gediz River basin lentic system. Length–weight relationship was estimated for 15 fish species (Luciobarbus lydianus, Barbus pergamonensis, Cyprinus carpio, Carassius gibelio, Petroleuciscus smyrnaeus, Alburnus battalgilae, Squalius fellowesii, Chondrostoma holmwoodii, Vimba vimba, Rhodeus amarus, Pseudorasbora parva, Atherina boyeri, Cobitis kurui, Gambusia holbrooki and Knipowitschia mermere), belonging to 8 different families (Cyprinidae, Leuciscidae, Acheilognothidae, Gobionidae, Atherinidae, Cobitidae, Poeciliidae, Gobiidae). Computed exponent b and R2 values ranged from 1.9348 to 4.3466 and 0.7072 to 0.9986, respectively. In the study, a longer maximum length value was determined for the two species than reported in the literature. In addition, this study presents the first records of LWR parameters for four endemic species in the basin.

HISTOPATHOLOGICAL ASPECTS CAUSED BY NEMATOD PARASITE Eustrongylides excisus OBSERVED IN SOME FISH SPECIES OF EĞIRDIR LAKE, TURKEY

The present study was carried out between January and October 2018, in order to determine the infection of Eustrongylides excisus Jägerskiöld, 1909 in some fish species inhabiting Eğirdir Lake - the second largest freshwater lake of Turkey. Parasite infection was detected in host species belonging to Konya tooth-carp (Aphanius iconii Akşiraz, 1948), Big-scale sand smelt (Atherina boyeri Risso, 1810), Caucasian dwarf goby (Knipowitschia caucasica Berg, 1916) and pike-perch (Sander lucioperca Linnaeus, 1758). The highest prevalence of infection (21.4%) was determined in S. lucioperca. The mean intensity ranged from 1.25 nematode/fish in K. caucasica to 2.3 nematodes/fish, in S. lucioperca. The nematode E. excisus was recorded for the first time on Caucasian dwarf goby, a non-native fish species in Eğirdir Lake. In addition, this research provides useful data regarding histopathology effects of E. excisus in all studied teleost species. Hyperaemia, edema, microhaemorrhages, inflammatory reaction and necrosis were observed around the encysted parasites.

Alteration of the feeding behavior of an omnivorous fish, Scardinius acarnanicus (Actinopterygii: Cypriniformes: Cyprinidae), in the presence of fishing lights

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.