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Öğe AGE AND GROWTH OF CAPOETA PESTAI (ACTINOPTERYGII: CYPRINIFORMES: CYPRINIDAE) IN A SMALL RIVER ENTERING LAKE EGIRDIR, TURKEY(Wydawnictwo Akad Rolniczej W Szczecinie, 2016) Emre, Yilmaz; Altin, Aytac; Ayyildiz, Hakan; Dolcu, Burak; Kucuk, Fahrettin; Ozen, OzcanBackground. Capoeta pestai (Pietschmann, 1933) is commercially important fish species in Turkey. The knowledge of the biology of this species is very scarce. This species has a 'critically endangered' status on the IUCN Red List. The objective of this study was to determine the age and growth rates of C. pestai, and to evaluate whether otolith morphometrics could be used as an age predictor. Material and methods. Fish were collected from a small river entering Lake Egirdir between January and December 2012. Fish samples were obtained from shallow parts of the river (30-40 cm depth) seasonally in a single station by using an electrofishing devise. Results. Annual growth increments were counted on the otoliths of 154 specimens, ranging from 6.2 to 26.8 cm total lengths. Estimated ages ranged from 0+ to 7+ years old. The von Bertalanffy growth curve was fitted to the age/total length data as follows: L-infinity = 47.83 cm (TL), K = 0.081, t(0) = -1.840, for females; L-infinity = 41.25 cm (TL), K = 0.086, t(0) = -1.99 for males; L-infinity = 52.45 cm (TL), K = 0.067, t(0) = -1.84 for all specimens. No significant differences in morphometric measures (length, width, and mass) were found between left and right otoliths (paired t-test, P > 0.05). Otolith length and width showed significant linear relations with the total length while otolith mass represented by power model. Conclusion. This study provides the first information on age, growth and otolith morphometric parameters of C. pestai. In addition, otolith morphometric measurements could possibly be used in future as an age predictor for C. pestai.Öğe Age and growth of common pandora, Pagellus erythrinus (Perciformes; Sparidae) from the Gokceada Island, North Aegean Sea(Arman Darya Inc, 2019) Ayyidiz, Hakan; Altin, Aytac; Kizilkaya, BayramThe aim of this study was to describe age, growth and the relationships between otolith morphometrics and fish length, weight and age of the common pandora, Pagellus erythrinus. This study was carried out from the shores of Gizli liman to Kefalos Cape in the north of Gokceada Island, between April-June 2018. The samples were collected at the depths of 40-120m by long lines. The 90 individuals obtained from P. erythrinus ranging in total length (TL) from 18.5 to 34.5 cm. The calculated length-weight relationships was calculated as W= 0.022TL(2.7767) (R-2 = 0.92). Individual ages were macroscopically determined by counting the annuli of sagittal otoliths. Estimated ages ranged from 2 - 14 years old. The von Bertalanffy growth curve was fitted to the age/total length data as follows: L-infinity = 51.13 cm, K= 0.061 and t(0) = -4.96. The common pandora sagittal otolith length, width and mass were measured between 7.67-12.95mm, 5.38-8.65mm and 0.0810-0.2706g, respectively. No significant differences in otolith morphometrics were found between left and right otoliths. This study provides valuable data for the stock assessment of common pandora in fishing grounds Gokceada Island located in the North Aegean Sea.Öğe Age and Growth of Red Porgy, Pagrus pagrus from the Island of Gokceada, North Aegean Sea(Istanbul Univ Press, Fac Aquatic Sciences, 2020) Ayyildiz, Hakan; Altin, Aytac; Kizilkaya, BayramThe aim of this study was to describe the age, growth and relationships between otolith morphometry and fish length, weight and age of the red porgy, Pagrus pagrus. This study was carried out from the shores of Gizli liman to Kefalos Cape in the north of Gokceada Island, between March and June 2018. The samples were collected at depths of 40-120 m by long lines. The 66 individuals obtained from red porgy ranged in total length (TL) from 13.5 to 50 cm. The calculated length-weight relationship was determined as W=0.016TL(2.9653) (R-2=0.98). Individual ages were macroscopically determined by counting the annuli of sagittal otoliths. Estimated ages ranged from 1-12 years. The von Bertalanffy growth curve was fitted to the age/total length data as follows: L-infinity=51.48 cm, K = 0.18 and t(0)=-0.27. The red porgy sagittal otolith length, width and mass were measured between 4.96-14.72 mm, 3.49-7.85 mm and 0.0199-0.2460 g, respectively. No significant differences in otolith morphometry were found between left and right otoliths. This study provides valuable data for the stock assessment of common pandora in the fishing grounds of Gokceada Island located in the North Aegean Sea.Öğe Age and growth rates at the early life stages of common pandora (pagellus erythrinus) based on analysis of otolith microstructure(Natl Marine Fisheries Service Scientific Publ Office, 2018) Ayyildiz, Hakan; Altin, AytacWe investigated young-of-the-year (YOY) growth, age, and hatching distributions of common pandora (Pagellus erythrinus) by analyzing otolith microstructure. This study was carried out in shallow waters (0-20 m) off the island of Gokceada, Turkey, from June 2013 through June 2014. A total of 231 YOY common pandora were measured and aged. These fish ranged from 12 to 110 mm in total length and from 38 through 242 d in age. The indices for determining variability in daily age estimates (average percentage error and coefficient of variation) were 4.9% and 3.4%, respectively. Average daily growth rate was calculated from a linear regression of the age-length data set as 0.52 mm/d. A linear relationship was found between otolith morphometric measurements (otolith length, width, and radius) and total length for YOY common pandora. The hatching times of common pandora were back-calculated to occur from February through October, and 2 main hatching cohorts were evident in spring (March) and summer (August).Öğe Daily growth rates and hatch date distributions of common two-banded seabream, Diplodus vulgaris inhabiting the Canakkale shallow waters of Turkey(Cambridge Univ Press, 2015) Ayyildiz, Hakan; Ozen, Ozcan; Altin, AytacOtolith microstructure analysis was used to determine daily age, growth rate and hatching periods of young of the year (YOY) common two-banded seabream, Diplodus vulgaris, collected at two sites by using beach seine from Canakkale shallow waters between January and December 2007. Total length of the YOY D. vulgaris was between 12 and 86 mm and the daily ages ranged between 42 and 313 days. Somatic growth rate estimated by fitting a linear regression to the age-length data set was calculated as 0.273 mm day(-1). According to the length-age regression analysis, maximum daily growth rates were found 0.277 mm day(-1) in the lowest sea temperature period and minimum values of 0.274 mm day(-1) were observed in the declining sea temperature period. Analysis of covariance indicated that there were no significant differences in the linear growth equations for the two cohorts (F = 0.4008, P = 0.527). Hatching period of the YOY was estimated to occur between October and March with relatively higher frequency in January. This study has shown that YOY D. vulgaris is a winter spawner in the Canakkale shallow waters.Öğe Determination of the shelf life of fresh shrimp (Parapaneus longirostris) treated with Frische-Star(Ege Univ, Fac Fisheries, 2006) Colakoglu, Fatma Arik; Ormanci, Hasan Basri; Altin, AytacIn our country, fish products consumption is often fresh, so its structure easly perishable. This products' shelf life and consumption's quality are preservative for a long time very important economy and people health. Especially recent years; use of preservative substance is increase. Therefore, in this study determined microbiological and sensory changes in shelf life to fresh shrimp which were treated with frische-star. In microbiological analysis determined Pseudomonas, Enterobactericeae, and Total aerob bacteria. In sensory analysis invastigated colour, odour and flavour.Öğe Effect of Dietary Protein Level on Growth Performance and Nitrogen Excretion of the Yellow Tail Cichlid, Pseudotropheus acei(Israeli Journal Of Aquaculture-Bamidgeh, 2012) Guroy, Derya; Sahin, Izzet; Guroy, Betul; Altin, Aytac; Merrifield, Daniel LeeA 12-week growth trial was conducted to determine the effects of dietary protein on the growth of the yellow tail cichlid, Pseudotropheus acei, and on water quality in closed recirculating systems. Six test diets were formulated to contain protein levels ranging 25-50% by substituting corn oil and alpha-starch for fishmeal. Diets were assigned to triplicate groups of 10 fish in a completely randomized design. The feed conversion ratios of fish fed the 35% and 50% crude protein diets were significantly (p<0.05) lower than that of fish fed the 30% protein diet. The protein efficiency ratio declined as the dietary protein level increased. Dietary protein levels significantly influenced total ammonia-nitrogen excretion (TAN); fish fed 50% protein excreted higher concentrations of ammonia-nitrogen than fish fed 25-35% dietary protein (p<0.05). Results suggest that inclusion of more than 35% protein in diets containing 10% crude lipid does not benefit juvenile yellow tail growth performance. Further, as TAN excretion and feed costs increased at protein levels beyond 35%, we recommend a diet containing 35% protein and 10% lipid for promoting good growth of juvenile yellow tail cichlids under the conditions used in the present trial.Öğe Feeding habits and diet overlap of juveniles of 2 sparids, Diplodus puntazzo (Walbaum, 1792) and Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), from the North Aegean Sea of Turkey(Tubitak Scientific & Technological Research Council Turkey, 2015) Altin, Aytac; Ozen, Ozcan; Ayyildiz, Hakan; Ayaz, AdnanThe stomach contents of juvenile sharpsnout seabream, Diplodus puntazzo, and juvenile two-banded seabream, Diplodus vulgaris, were investigated in order to determine feeding habits and diet overlap among them. Fish were collected from October 2008 to August 2009 using a beach seine net from the Canakkale coasts of Turkey. A total of 129 juvenile D. puntazzo (ranging from 13 mm to 77 mm total length) and 951 D. vulgaris (ranging from 15 mm to 97 mm total length) were collected during the sampling periods in the study area. The stomach content analyses showed that the diet of both species mainly comprised copepods and amphipods. In addition, algae were found in the stomach contents. No significant differences were found between the feeding habits of juvenile D. vulgaris and D. puntazzo (ANOSIM; global R statistic = -0.0158; P > 0.05). An important overlap in the diet calculated using the Schoener index was recorded as 0.75 for D. puntazzo and D. vulgaris. Consequently, there was a significant diet overlap and competition for available resources among the feeding habits of D. vulgaris and D. puntazzo in juvenile periods.Öğe FEEDING HABITS OF THE MARBLED GOBY, POMATOSCHISTUS MARMORATUS (ACTINOPTERYGII: PERCIFORMES: GOBIIDAE), IN THE CANAKKALE STRAIT, NORTHERN AEGEAN SEA, TURKEY(Wydawnictwo Akad Rolniczej W Szczecinie, 2015) Altin, Aytac; Ozen, Ozcan; Ayyildiz, Hakan; Daban, I. BurakPomatoschistus marmoratus (Risso, 1810) is a small demersal fish and one of the dominant species inhabiting shallow waters of the Mediterranean. Information, however, on their feeding habits are still scarce. In this study, the stomach contents of P. marmoratus were investigated in order to determine feeding habits according to seasons and sizes. The fish were collected monthly from 3 stations between October 2008 and August 2009, using a beach seine, from the shallow waters of the Canakkale Strait, Turkey. A total of 383 P. marmoratus, ranging from 13 to 69 mm TL, were analysed. The most important prey items in the stomach contents were copepods and amphipods. The numerical abundance of each food item in the stomach contents varied significantly with season. The diet of juvenile P. marmoratus consisted mainly of copepods. The occurrence of largest prey items such as amphipods and bivalves appeared relatively higher in adults. However, no significant differences were found between the feeding habits of juveniles and adults.Öğe Fish biodiversity in the shallow waters around the Gokceada Island, Turkey(Arman Darya Inc, 2020) Altin, Aytac; Ayyildiz, Hakan; Kale, SemihThe aim of the current study is to determine the fish biodiversity in the shallow waters (0 - 20 m) of Gokceada in the North Aegean Sea. The samples were collected monthly between June 2013 - June 2014 using by a beach seine (0 - 2 m) and beam trawl (5 - 20 m). Field sampling was carried out in two stages. A preliminary sampling survey was carried out in the first phase (March-April 2013). During this period, sampling was conducted in each station around the entire island where sampling gear was feasible to use, and the most productive sampling stations were determined. The second stage was the biodiversity monitoring work. During the study period, 13-monthly sampling surveys were carried out at six seine and dredge stations around the island. During the whole period, a total of 30509 individuals belonging to 80 species were sampled. From the seine samplings (0-2 m), 18702 individuals from 40 species were obtained. The beam trawl samplings (5-10 and 10-20 m) identified 11807 individuals from 66 species. Biodiversity indices were calculated, and species diversities and abundances were determined for the seasons. The most copious seasons in terms of number of species abundance was identified in fall and summer. Fish species diversity and abundance maps were generated for each station. As a result, it was determined that the coastal ecosystems of Gokceada, northern Aegean Sea, incorporated many important habitats that is rich in biodiversity. In addition, many commercial species that had been over-exploited in the region was determined to use these coastal habitats for feeding, breeding, sheltering, and growing.Öğe Gillnet selectivity for bogue boops boops caught by drive-in fishing method from Northern Eagean Sea, Turkey(2009) Ayaz, Adnan; Kale, Serkan; Cengiz, Ozgur; Altinagac, Ugur; Ozekinci, Ugur; Öztekin, Alkan; Altin, AytacThis study was carried out in six different stations in the Northern Aegean Sea between February-May 2008. In the study, the three different fishing nets which were intensively being used by the region fishermen, the net height of which was 105 meshes and the mesh sizes of which were 44, 46 and 50 mm. In the operations performed with the drive-in fishing method, 5867 and 740 kg fish pertaining to the total 30 species were caught and 4791 were got from bogue being the target species. This value composes of approximately 82% of the total catching. SELECT method was used to fit gill net selectivity curves. Log normal model gave the best fit for the bogue selection. It was observed that modal length and spread values increased as far as the net mesh grew. It was determined that the length groups of bogue individuals we got in our study were quite above the first reproduction length. For this reason, it was seen that the gillnets used in the region did not create fishing pressure over the population. © Medwell Journals, 2009.Öğe Gillnet Selectivity for Bogue Bopps boops Caught by Drive-in Fishing Method from Northern Eagean Sea, Turkey(Medwell Online, 2009) Ayaz, Adnan; Kale, Serkan; Cengiz, Ozgur; Altinagac, Ugur; Ozekinci, Ugur; Öztekin, Alkan; Altin, AytacThis study was carried out in six different stations in the Northern Aegean Sea between February-May 2008. In the study, the three different fishing nets which were intensively being used by the region fishermen, the net height of which was 105 meshes and the mesh sizes of which were 44, 46 and 50 mm. In the operations performed with the drive-in fishing method, 5867 and 740 kg fish pertaining to the total 30 species were caught and 4791 were got from bogue being the target species. This value composes of approximately 82% of the total catching. SELECT method was used to fit gill net selectivity curves. Log normal model gave the best fit for the bogue selection. It was observed that modal length and spread values increased as far as the net mesh grew. It was determined that the length groups of bogue individuals we got in our study were quite above the first reproduction length. For this reason, it was seen that the gillnets used in the region did not create fishing pressure over the population.Öğe Growth and hatching of annular seabream, Diplodus annularis, from Turkey determined from otolith microstructure(Cambridge Univ Press, 2014) Ayyildiz, Hakan; Ozen, Ozcan; Altin, AytacOtolith microstructure analysis was used to determine daily growth rate and hatching periods of young of the year (YOY) annular seabream, Diplodus annularis, collected by using beach seine from Canakkale shallow waters between January and December 2007. Total length of the YOY D. annularis was between 20 and 85 mm and the daily ages ranged between 27 and 205 d. Somatic growth rate, estimated by fitting a linear regression to the age-length data set, was calculated as 0.369 mm d(-1). Seasonal changes in the growth rate of the YOY D. annularis have been found to be 0.381, 0.369, 0.357 and 0.308 mm d(-1) for individuals that hatched in spring, summer, autumn and winter, respectively. Analysis of covariance indicated that there were no significant differences (P > 0.05) in the growth rates between the seasons. Hatching period of the YOY D. annularis was estimated to occur between March and September, with relatively higher hatching frequency in June.Öğe Growth, mortality and hatch-date distributions of striped sea bream Lithognathus mormyrus inhabiting the Canakkale Strait, Turkey(Cambridge Univ Press, 2014) Ayyildiz, Hakan; Ozen, Ozcan; Altin, AytacThis paper studies age, growth and hatch date distributions of young of the year striped sea bream Lithognathus mormyrus from Canakkale near shores by using a beach seine during September 2006-December 2007. Using otolith microstructure analysis, a total of 416 specimens ranging from 20 to 103mm L-T were aged and found to be between 30 and 307 days old. Average growth rates were estimated to 0.325mmd(-1). The juvenile instantaneous mortality coefficient was found to be 0.0219, which corresponds to a daily mortality of 2.16%. The hatching period of the striped sea bream was determined to occur between April and January, with relatively higher hatching frequency in August.Öğe Hatching Time and Early Growth of Diplodus sargus sargus Inhabiting a Coastal Area of Gokceada Island, Turkey(Springer International Publishing Ag, 2020) Ayyildiz, Hakan; Altin, AytacDaily growth increments in sagittal otoliths were used to estimate the age and growth of young of the year (YOY) white seabream, Diplodus sargus sargus collected between June 2013 and June 2014 at 6 different locations in the shallow waters (<20 m) off Gokceada, Turkey. Estimated ages from otolith daily growth increments (DGI) were found 42-238 days old. The mean daily growth rate of YOY D. sargus sargus was estimated as 0.046 cm/day. ANCOVA indicated that there was significant difference in daily growth rates between the locations (F = 22.92, df = 5, P < 0.001). The maximum daily growth rate of 0.055 cm/day was found in the location 2, while the minimum value of 0.037 cm/day was observed in the location 4. Hatching time was determined by subtracting the daily age of the fish from the sampling date and then hatch date frequency distributions were determined to occur from January through June, and 2 main hatching peaks were observed from the different locations. Linear relationships between otolith morphology (otolith length; OL, width; OW and radius; OR) and fish length (TL) were obtained.Öğe Length-weight relationships of forty-nine fish species from shallow waters of Gokceada Island, northern Aegean Sea(Tubitak Scientific & Technological Research Council Turkey, 2015) Altin, Aytac; Ayyildiz, Hakan; Kale, Semih; Alver, CenkLength-weight relationships (LWRs) of 49 fish species belonging to 18 families from the shallow waters (0-20 m) of Gokceada Island were reported. Fish specimens were sampled monthly with a beach seine (0-2 m) and beam trawl (5-20 m) between June 2013 and June 2014. The b values estimates varied between 2.66 and 3.59. Five of the 49 species (Arnoglossus kessleri, Scorpaena maderensis, Symphodus ocellatus, Symphodus rostratus, and Gobius geniporus) presented maximum length values that exceeded their maximum lengths listed in FishBase.Öğe Selectivity of Fishhooks Used in Blotched Picarel (Spicara maena) in Artisanal Fishery in Dardanelles(Medwell Online, 2009) Altinagac, Ugur; Kara, Aydin; Ozekinci, Ugur; Ayaz, Adnan; İşmen, Ali; Altin, Aytac; Begburs, Cenkmen R.In the study, selectivity of two different types of (short and long shanked but same gap sized) fishhooks used in Blotched Picarel (Spicara maena) in artisanal fishery were determined in Dardanelles. In the calculation of selectivity parameters of fishhooks Holt method was used. The trials were carried out in 3 different regions in the Dardanelles between 12.09.2006-01.16.2008. For hooks gap size of which are 6.10, 7.60 and 9.05 mm, for long shanked hook the optimum catching length was determined as 13.21, 16.46 and 19.60 cm, respectively and for short shanked hook the optimum catching length was determined as 12.69, 15.81 and 18.83, respectively.Öğe Spatial distribution modelling of juvenile common pandora (pagellus erythrinus linnaeus, 1758) in relation to habitat in the shallow waters of gökçeada using GIS(CEUR-WS, 2015) Kale, Semih; Altin, Aytac; Ayyildiz, Hakan; Ozen, OzcanThe distribution of juvenile Pagellus erythrinus (Linnaeus, 1758) species was studied by the abundance, density and habitat preferences in the shallow waters of Gökçeada. Fish samples were obtained in experimental beach seine and beam trawl surveys carried out between 2013 June to 2014 May in the shallow waters of Gökçeada. To understand the habitat preferences of the species, sediment samples were collected and sediment composition was determined by grain size distribution analysis. The spatial distribution of juvenile Pagellus erythrinus species in relation to the habitat structure was estimated and modelled using Geographic Information System (GIS) and geostatistical tools. It was observed that juvenile Pagellus erythrinus species prefer the rocky areas which in 5-10 m water depth in the shallow waters of Gökçeada. Copyright © 2015 for the individual papers by the papers' authors.Öğe Temporal Variations of the Demersal Fish Community in the Shallow Waters of Canakkale Strait, North Aegean Sea, during the Course of a Mucilage Event(Central Fisheries Research Inst, 2015) Altin, Aytac; Ozen, Ozcan; Ayyildiz, HakanThe main aim of this study was to determine the mucilage event effect on the temporal variations of the shallow water demersal fish community in the Canakkale Strait. Sixty-one different demersal fish species were collected with a beach seine between September 2006 and August 2009. Mucilage event was observed between September 2007 and July 2008 (mucilage period) in the shallow waters of Canakkale Strait. Species abundance and richness decreased in winter and increased in spring and in summer and was related to water temperature variations. Demersal fish species composition was significantly different between seasons but these differences were mainly related to water temperature variations. For the same seasons in different years (pre-mucilage, during mucilage, and post-mucilage), no differences of fish abundance and species richness were evident. In conclusion, the fish community data from our shallow water samplings during the course of a mucilage event does not suggest any significant change in the abundance and species richness of the shallow water demersal fish assemblage in Canakkale Strait.Öğe Validating daily otolith increment formation in young of the year pagellus acarne in the Çanakkale region(Arman Darya Inc, 2024) Ayyildiz, Hakan; Kurtkaya, Emre; Celik, Pinar; Altin, AytacAccurate age estimation is essential for population dynamics modeling and fisheries management. Otoliths serve as a critical resource for age determination in ichthyological studies, capitalizing on the embedded growth increments. The periodicity of these increments, however, requires thorough validation to confirm the accuracy of age assessments. This study validated daily increment deposition in sagittal otoliths of young-of-year Pagellus acarne from & Ccedil;anakkale, Turkey using Alizarin Red S (ARS), a fluorescent calcium-binding marker. Specimens (n=107; 1.8-4.7cm TL) were exposed to ARS concentrations of 0 (control), 50, 100, 150, 200, and 300mg/L for 24h, then reared 13 days. After a recovery period of 13 days, the second dyeing was performed with the aim of having a specific fluorescent mark to test the 13 rings found between the 2 fluorescent marks. Otoliths were examined under fluorescent microscopy. ARS marks were detectable in 81.57% of otoliths at >= 100mg/L, with the highest visibility at 300mg/L. Survival exceeded 84.2% across treatments. Increment counts between the first and second ARS marks (13 days) and from the second mark to the edge (20 days) matched elapsed time. Ages from wild fish (n=95) ranged 39-201 days with a growth rate of 0.176mm/day. This research demonstrates ARS is an effective, low-impact tool for periodicity validation and provides the basis for accurate age determination and population modeling of this ecologically important species in the region.
