Introduction and Establishment of Tropical Ornamental Fish, Pterygoplichthys Spp. (Actinopterygii: Siluriformes: Loricariidae) in Hot Springs: Aquarium Trade as a Potential Risk for Biodiversity in Turkey

The aim of this study was to report non-native tropical ornamental freshwater fish species from the Pinarbasi Stream connected with hot-water sources in the Inonu Province (Eskisehir, Turkey). The morphological characters and meristic counts indicated that the examined specimens were: Pterygoplichthys disjunctivus (Weber, 1991), Pterygoplichthys pardalis (Castelnau, 1855), and their hybrids. We also present the evidence of their reproduction and establishment. Successful invasion of these species was evident, as their young-of-the-year and juvenile individuals were caught during the samplings from the same water course. Finally, we discuss the management implications of these species.WoSScopu

Assessing the potential impact of nonnative fish on native fish by relative condition

Nonnative species (NNS) pose one of the most common threats to the conservation of biodiversity. Given the difficulty in measuring and documenting the specific impacts of introduced species on native species, indices of condition may provide an easy and inexpensive alternative. The aim of this study was to understand the impact of NNS on some common and endemic freshwater fishes, examining their relative conditions in the absence (allopatry) and presence (sympatry) of nonnative fish species from 3 different regions in the western part of Turkey. Data from 19 sites, a total of 1672 fish of 11 cyprinid species, were used for calculation of condition indices. Relative condition was significantly higher in allopatry than sympatry for Capoeta sieboldii, Gobio gobio, Ladigesocypris ghigii, Leucaspius delineatus, and Phoxinus phoxinus; however, it was higher in sympatry only for Rhodeus amarus, whereas Barbus tauricus, Cyprinus carpio, Rutilus rutilus, Squalius fellowesii, and S. pursakensis showed no significant differences in relative condition between allopatry and sympatry. Results suggest that there was a possible impact of NNS on native species and that relative condition would provide an easy and useful alternative to get a preliminary evaluation of the impact of nonnative fish species as long as sampling follows proper methodology

Development of empirical standard weight equation for Pursak chub Squalius pursakensis, an endemic cyprinid species of Northwest Anatolia

Indices of condition enable the evaluation of the well-being of fish, with the assumption that heavier fish of a given length are in a better condition. Relative weight (W-r) is one of these indices; it is calculated by comparing the actual weight of a specimen with the ideal weight of a specimen in good physiological condition of the same length from the same species, i.e. standard weight (W-s). In this research, length and weight data over the distribution range for Pursak chub Squalius pursakensis, an endemic species distributed in the Sakarya and Porsuk drainages in Northwest Anatolia (Turkey), were used to compute a W-s equation by means of the empirical percentile (EmP) method. The W-s equation obtained was log(10) W-s = -4.657 + 2.614 log(10) TL + 0.127 (log(10) TL)(2), and the total length range of application was 80-340 mm. Since the EmP W-s equation was not influenced by length variation, the use of this equation to compute the relative weight (W-r) for S. pursakensis throughout its area of distribution is suggested