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0000-0001-8628-0514 WOS: 000433261900004 Several Ponto-Caspian gobiids have expanded from their native distribution ranges to Europe and North America. As knowledge on their bio-ecological features in their native range is still limited, the trophic ecology of monkey goby Neogobius fluviatilis and Western tubenose goby Proterorhinus semilunaris was studied in three natural lakes in the Marmara Region of NW Turkey using the stable isotopes of delta C-13 and delta N-15. In two of the lakes, the trophic niches ( as the isotopic niche) of the gobies were highly divergent with co-existing native fishes, with no overlap. Moreover, mixing models suggests considerable inter-specific dietary differences. In all lakes, the trophic niches of gobies were never significantly larger than those of coexisting fishes. These results suggest that when introduced outside of their natural range, the gobies might integrate into new fish communities via exploiting resources that are underexploited by native fishes or will initially share resources with these species before their niches diverge, perhaps through competitive displacement. Scientific & Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Y009] This study was supported by The Scientific & Technological Research Council of Turkey (TUBITAK) (Project No: 114Y009).

Screening tools are being increasingly used to identify more effectively non-native species that pose an elevated risk of being invasive. Of the available decision-support tools, the Fish Invasiveness Screening Kit (FISK) has been widely used, but has recently been replaced by a generic screening tool, the Aquatic Species Invasiveness Screening Kit (AS-ISK), which is applicable to any aquatic species and complies with the minimum requirements for risk tools under the new EC alien invasive species Regulation. With its unique zoogeography and rich native fauna, Turkey is highly susceptible to non-native species' introductions and translocations. In order to inform non-native species policy and management regarding fishes in Turkey, AS-ISK was used to re-assess species previously screened using FISK and to assess additional non-native and translocated fish species. In this first calibration study of AS-ISK for Turkey, a basic score threshold of 28 was achieved, which reliably distinguished between potentially invasive (high risk) and potentially non-invasive (medium to low risk) fishes. Of the 64 species assessed, only one was ranked as 'low risk', 40 were categorised as 'medium risk', and the remaining 23 as 'high risk' of which five were translocated. Non-native species currently not present in Turkey, but that pose a high risk of being invasive, were Ameiurus melas, Ameiurus nebulosus, Hemiculter leucisculus, Hypophthalmichthys molitrix, Micropterus salmoides, Perccottus glenii, Pimephales promelas; whereas, the highest scoring translocated species were Cyprinus carpio, Esox lucius and Silurus glanis. When the potential effects of climate change on the assessments were considered, risk scores increased for some (sub) tropical fishes of which two are translocated species.

WOS: 000369639600006 Stocking of water bodies with non-native fish species for fisheries enhancement is a common practice worldwide. However, overall limited benefits in terms of revenues for local communities have so far been reported in some countries, whilst accidental introductions of several non-native fish species have occurred. To evaluate the benefits vs. costs associated with common carp Cyprinus carpio stocking practices, a three-year sampling study (2009-2011) was carried out across twelve adjacent artificial reservoirs of the Kocaeli Peninsula (north-west Anatolia, Turkey). Apart from common carp, 18 fish species in total were recorded, of which 12 native and six non-native, the latter comprising more than half of the total catch and dominated by gibel carp Carassius gibelio. Even though the abundance of common carp, natives and non-natives increased over the study period, common carp was always comparatively less abundant relative to most of the other species. Overall, the present findings indicate that stocking of common carp into the studied reservoirs has not fully met with the proposed objectives, likely a result of less-than-optimal age-0 fish release strategies and limited availability of spawning grounds. On the other hand, invasion especially by gibel carp is thought to be under way and this may ultimately impact on the abundance of the native fish fauna. Kocaeli UniversityKocaeli University; Scientific & Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2221]; Department of Science Fellowships & Grant Programs (BIDEB) This study was supported by the Research Fund of Kocaeli University. We thank to Zeki Sahin and Ersen Tokgoz for facilitating research in the Izmit area. Contribution by LV was through a 2221 - Fellowship Programme for Visiting Scientists on Sabbatical Leave provided by The Scientific & Technological Research Council of Turkey (TUBITAK) and The Department of Science Fellowships & Grant Programs (BIDEB).

Empirical standard weight equations and length-weight and length-length relationships were estimated for Barbus pergamonensis, Capoeta bergamae, and Ladigesocypris irideus, three endemic cyprinid species of Turkey that are still not widely studied. To the best knowledge of the authors, empirical standard weight equations for the three species and L-W parameters for L. irideus are given here for the first time. In this study, length and weight data for B. pergamonensis, C. bergamae, and L. irideus were collected throughout the watercourses of Mugla Province and were used to develop species-specific W-s equations. The results were for B. pergamonensis (total length [TL] range: 6-22 cm) log(10)W(s) = -5.713 + 3.718 log(10)TL - 0.166 (log(10)TL)(2), for C. bergamae (TL range: 8-29 cm) log(10)W(s) = -5.224 + 3.311 log(10)TL - 0.083 (log(10)TL)(2), and for L. irideus (TL range: 6-10 cm) log(10)W(s) = -13.298 + 12.116 log(10)TL - 2.471 (log(10)TL)(2). This study also reported new maximum TLs for the three species, together with species-specific length-weight and length-length equations.

The aim of this study was to learn the invasion speed and sex ratio, which would be indicative of invasive character, of a nonnative fish species, gibel carp, by reporting its new localities in the Marmara region of northwestern Turkey. Whether the occurrence of gibel carp in freshwater bodies of the Marmara region was random (i.e. chance element) was tested. The question of population increase since first introduction was also examined. Among 14 new locations for gibel carp found during this study, the majority were in mostly lentic ecosystems. The invasion rate of gibel carp in the Marmara region, since its first introduction in the early 1980s, is approximately 1 new water body per year (1.17; number of sites invaded by gibel carp = 35). Females significantly outnumbered males in 10 out of the 12 populations studied, with the sex ratio deviating from unity (1:1) in all populations except 2. The regional extent of gibel carp occurrence increased with the number of years since first introduction (y = 1.34x - 2651.1, F = 47.41, P < 0.001, rs = 0.95). The implications for conservation of native fishes are discussed., Bu çalışma Marmara Bölgesi’nde gümüşi havuz balığı için yeni dağılım alanlarını rapor etmeyi, balığın istila hızını ve istilacı karakterinin iyi bir göstergesi olan cinsiyet oranlarını belirlemeyi amaçlamaktadır. Ayrıca Marmara Bölgesi içsularındaki gümüşi havuz balığı varlığının tesadüfi (şans eseri) olup olmadığı ve zamanla sayısının artıp artmadığı test edildi. Gümüşi havuz balığı için çoğu durgun su ortamı olmak üzere 14 yeni bölge tespit edildi. Gümüşi havuz balığının Marmara Bölgesi’ne ilk girişinden (1980’lerin başı) günümüze kadar geçen sürede her yıl ortalama 1 yeni alanı istila ettiği bulundu (1.17, gümüşi havuz balığı tarafından istila edilen saha sayısı = 35). Çalışılan 12 popülasyonun 10’nunda dişiler erkeklere göre önemli derecede fazlaydı, sadece iki populasyonda cinsiyet oranı eşitti. Gümüşi havuz balığının sayısındaki artış ilk aşılanmasından günümüze kadar geçen zamanla doğru orantılıydı (y = 1.34x – 2651.1, F = 47.41, P < 0.001, rs= 0.95). Yerel türlerin korunması ile ilgili sorunlar tartışıldı.

Yabancı bir tür olan gümüşi havuz balığı, Carassius gibelio’nun aşırı bir avcılık baskısı ile avlandığı Uluabat Gölü’ndeki yerleşme başarısını anlayabilmek amacıyla, bu balığın biyolojik özellikleri ve populasyon yapısı Haziran 2009 ile Mayıs 2010 tarihleri arasında incelenmiştir. Ayrıca, elde edilen bulgular bu balığın doğal olarak ve aşılanmış olarak bulunduğu bölgelerdeki populasyonları ile karşılaştırılmıştır. Gümüşi havuz balığının Uluabat Gölü’ndeki ticari avcılığı bu balığın populasyonunu etkilememiş ancak 12 yaş grubu ile doğal ve aşılanmış alanlardan karşılaştırma yapılan populasyonlar arasında en uzun yaşama ve en ağır büyümeye sahip populasyon olduğu görülmüştür. Üreme mevsimi Mart ile Mayıs ayları arasındadır. Doğal alanı dışındaki bölgeler içinde, bu balığın Uluabat populasyonu cinsi olgunluğa daha erken erişmiş ve nispi fekonditesi daha yüksek olarak bulunmuştur. Yüksek üreme yatırımı, erken cinsi olgunluğa erişme, yüksek nispi fekondite ve gonadosomatik indeks değerleri ile ortaya çıkmış ve ginogenetik üreme stratejisi ile birlikte bu balığın Uluabat Gölü’ndeki yerleşme başarısı için anahtar faktör olabileceği sonucuna varılmıştır. To assess establishment success of a heavily exploited population of non-native gibel carp Carassius gibelio, biological traits and population structure of the species from a large eutrophic lake (Lake Uluabat, Turkey) were investigated from June 2009 to May 2010 and attributes were compared with the published information from the introduced and native range. Commercial harvesting of gibel carp did not seem to affect population size and viability of gibel carp in Lake Uluabat but it had one of the slowest growth rate represented by twelve age groups, and its life span was one of the longest recorded for the populations both in its natural and introduced areas. The reproductive season lasted from March to early May. Size at maturity was earlier and relative fecundity was higher than those in the introduced range. Higher investment in reproduction displayed by earlier maturation, higher relative fecundity and gonadosomatic index with gynogenetic spawning in Lake Uluabat is likely to be the key factor for establishment success of gibel carp.

Doğal olarak Kuzey Amerika'da yayılım gösteren ve 19. yüzyılın sonlarında Avrupa'ya sportif balıkçılık, süs veya akvaryum balığı olarak getirilen Güneş balığı (Lepomis gibbosus) hakkında Türkiye'de bugüne kadar sadece dağılımı ile ilgili sınırlı bilgiler mevcuttur. Bu amaçla sunulan çalışmada ülkemiz tatlı sularında yaklaşık 30 seneden beri bulunan ancak hakkında çok az bilgi bulunan güneş balığının Sarıçay havzasında (Milas-Muğla) biyolojik ve ekolojik özellikleri incelenmiştir. Bu kapsamda Haziran 2009 - Mayıs 2010 tarihleri arasında aylık periyotlarla arazi çalışmaları yapılmış ve 1040 bireyin boy, ağırlık ve eşeyleri saptanmıştır. İncelenen örneklerin boy, ağırlık, yaş ve eşey dağılımları, boy-ağırlık, yaş-ağırlık ve yaş-boy ilişkileri ile kondisyon faktörü ortaya konmuştur. Güneş balığı Sarıçay Deresi'nde 5 senelik bir yaşam döngüsüne sahip olup, büyümesi türün istilacı olarak kabul edildiği Avrupa ve doğal olarak dağılım gösterdiği Amerika'daki popülasyonlarıyla benzerlik göstermiştir. Erken cinsi olgunluğa erişme, uzun bir üreme dönemi ve yüksek bir üreme çabası gibi gelişmiş üreme özellikleri sergilemiştir. Habitat seçimleri ise daha önceki çalışmaları destekler nitelikte olup, daha çok derin, akıntısız ve vejetasyondan uzak bölgelerdir. Çalışmanın sonuçları bu yabancı türün Sarıçay Deresi'nde istilacı bir karaktere sahip olduğunu göstermiştir ve bu türün zarar statüsünün belirlenmesi ve yönetim planlarının oluşturulması için temel oluşturmaktadır. There is limited information only on distribution of non-native freshwater fish species pumpkinseed (Lepomis gibbosus) in Turkish waters, which was introduced into European waters in late 19th century from North America where it is naturally distributed. For this purpose in the present study, biological and ecological properties of pumpkinseed which is very poorly known in Turkey despite of its presence for almost 30 years in Turkish waters were investigated in Sarıçay Stream (Milas, Muğla). In this scope, totally 1040 fish samples were collected monthly bases fro m Sarıçay Stream, from June 2009 to May 2010 and their length, weight and sex were determined. The distribution of length, weight, age and sex, length-weight, age- length, age-weight relationships, condition factor of the population were examined. With this study, basic information needed for control of this species will be provided and consequently future risk assessments for natural flora and fauna can be estimated. Pumpkinseed had 5 years life span in Sarıçay Stream and its growth was found to be similar to other populations from European countries where it is known as invasive and North America where it is naturally distributed. Reproductive features revelaed relatively advanced traits with longer sapwning period, higher reproductive effort and early size at maturity. Habitat choices confirmed previous studies showing that preference of deep, still, and absence of vegetative areas. The present study indicated that pumkinseed in Sarıçay Stream had an invasive character and provided a baseline for proper management measures and risk assessment of this species. 72

WOS: 000499710400001 The Ponto-Caspian region is an important source area for some invasive gobiid fishes. These fishes have colonised several freshwater ecosystems in Europe, as well as in North America. As knowledge on their habitat utilisation in their native range remains limited, the seasonal habitat uses of Western tubenose goby, Proterorhinus semilunaris and monkey goby Neogobius fluviatilis were studied in four natural lakes in the Marmara Region (NW Turkey). Habitat use of both species was highly variable between the lakes and seasons, with P. semilunaris showing higher plasticity. In general, the main habitats used by P. semilunaris were shallow waters in littoral areas that had vegetation cover, whereas N. fluviatilis consistently used sandy substratum in deeper waters that lacked vegetation. These results suggested there was high plasticity in the habitat utilisation of these two gobiids, especially in P. semilunaris, which potentially facilitates their ability to establish and invade novel environments. The habitats that are especially vulnerable to P. semilunaris invasion are medium size substrates which provide individuals with sufficient interstitial space for refuge. Waters providing differing habitats, such as sandy substrata, might inhibit their colonisation, but are potentially more vulnerable to N. fluviatilis invasion. Scientific AMP; Technological Research Council of Turkey (Tubitak) [114Y009] This study was supported by the Scientific & Technological Research Council of Turkey (Tubitak) (Project No: 114Y009). The authors thank Ali Ozden, who facilitated the sampling in Lake Manyas.

WOS: 000390394000043 The pumpkinseed Lepomis gibbosus was introduced to Europe and parts of the Mediterranean Region more than 100 years ago. However, relatively little is known of its potential ecological impacts on the native species and freshwater ecosystems of Anatolia (Turkey), where the species is currently established in ponds and rivers. In this study, interactions between L. gibbosus and native and non-native stream fishes were investigated between June 2009 and May 2010 in Saricay Stream, a Mediterranean-type water course. Microhabitat preferences for depth, substratum composition, distance from bank and from vegetation, plant cover, velocity, turbidity and light intensity were studied by Constrained Quadratic Ordination. The species sampled in larger frequency of occurrence (and for which microhabitat relationships could be investigated) comprised endemic Smyrna chub Petroleuciscus smyrnaeus and Aegean chub Squalius fellowesii, and nonnative L. gibbosus (both juveniles and adults) and topmouth gudgeon Pseudorasbora parva. Adult L. gibbosus were found to prefer locations closer to the bank with less turbid water, plant cover, light intensity, woody structure and with sandy substratum whilst avoiding riffle habitats with coarser debris, deeper water, dense submersed aquatic vegetation and higher velocities. These preferences overlapped with those for the other nonnative species P. parva, but not with those for the endemic species and for L. gibbosus juveniles. The results of this studysuggest that the potential for adverseimpacts throughcompetition for habitat of adult L. gibbosus with the native fish fauna is not apparent in Saricay Stream. Research Fund of Mugla Sitki Kocman UniversityMugla Sitki Kocman University [09/28] This study was supported by the Research Fund of Mugla Sitki Kocman University (Project No: 09/28). We thank the General Directorate of Protection and Control, Ministry of Agriculture and Rural Affairs, Republic of Turkey for providing permission to carry out sampling for the present study.

WOS: 000351332300001 The ecological requirements and distribution of the native and non-native freshwater fish species of the Mugla Province were studied between 2009 and 2011. In total, 19 fish species including 5432 specimens were collected from 17 water bodies. Almost 40% of the fish were from non-native species, which were encountered frequently only from four water bodies. Squalius fellowesii was by far the most abundant species followed by Lepomis gibbosus and Ladigesocypris ghigii. Canonical correspondence analysis (CCA) explained 76% of the variation (first axis) between species and environmental variables, amongst which altitude, electrical conductivity and water temperature were the most influential. Based on habitat similarities, unweighted pair group means analysis (UPGMA) separated species into four clusters. Results revealed that species' optimum levels and ecological tolerances can be species-specific, even though non-native and widespread endemic species across the basin tended to have higher tolerance ranges for different environmental variables. [09/28] This study was supported by a Research Fund granted to Mugla Sitki Kocman University (Project No: 09/28). We thank Mufit Ozulug for the species identifications, and Guler Ekmekci and anonymous reviewer for invaluable suggestions to improve the manuscript. We also thank the Republic of Turkey Ministry of Agriculture and Rural Affairs for providing the permits necessary to conduct the study.