ACTA ICHTHYOLOGICA ET PISCATORIA (2016) 46 (4): 351–356 DOI: 10.3750/AIP2016.46.4.07 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 Özgür EMİROĞLU1, F. Güler EKMEKÇİ2, Sadi AKSU3, Sercan BAŞKURT1, M. Altuğ ATALAY4, and A. Serhan TARKAN5* 1 Faculty of Science, Department of Biology, Eskişehir Osmangazi University, Eskişehir, Turkey 2 Department of Biology, Hacettepe University, Faculty of Science, Ankara, Turkey 3 Vocational School of Health Services, Eskişehir Osmangazi University, Eskişehir, Turkey 4 General Directorate of Aquaculture and Fisheries, Ministry of Food, Agriculture and Livestock, Ankara, Turkey 5 Faculty of Fisheries, Muğla Sıtkı Koçman University, Muğla, Turkey Emiroğlu Ö., Ekmekçi F.G., Aksu S., Başkurt S., Atalay A., Tarkan A.S. 2016. Introduction and establishment of tropical ornamental fi sh, Pterygoplichthys spp. (Actinopterygii: Siluriformes: Loricariidae) in hot springs: Aquarium trade as a potential risk for biodiversity in Turkey. Acta Ichthyol. Piscat. 46 (4): 351–356. Abstract. The aim of this study was to report non-native tropical ornamental freshwater fi sh species from the Pınarbaşı Stream connected with hot-water sources in the İnönü Province (Eskişehir, 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. Keywords: aquarium species, hybrid, reproduction, invasion, management measures The ornamental aquarium trade, along with the stocking et al. (2013) screened aquarium species composition in for angling and aquaculture, is one of most important south-western Europe (mainly in Portugal and Spain) and pathways of freshwater fi sh introduction (Gozlan 2008). found out 1133 fi sh species are on sale. Its importance, however, has been underestimated and Several ornamental species, such as pond loach, only recently it was recognized as an important vector Misgurnus anguillicaudatus (Cantor, 1842), have of aquatic invasive species (Padilla and Williams 2004, already been established in the European countries of the Duggan et al. 2006, Copp et al. 2007, Strecker et al. 2011). Mediterranean climate zone. Only three ornamental fi shes In a global perspective, the aquarium-traced introductions have been reported in Turkish inland waters; goldfi sh, were reported to account for 21% of all freshwater fi sh Carassius auratus (Linnaeus, 1758); red piranha, introductions of more than 150 mainly freshwater fi shes Pygocentrus nattereri Kner, 1858; and vermiculated species (Fuller 2003, Gozlan 2008). Some continents, such sailfi n catfi sh, Pterygoplichthys disjunctivus (Weber, as North America, where hundreds of aquarium species 1991) with only goldfi sh being established (Tarkan et al. were reported to be in circulation, have been studied 2015). We would like to emphasize that eco-regions with more extensively (Rixon et al. 2005, Duggan et al. 2006). hot water springs are especially susceptible for unwanted A good example of less studied regions is the European introductions (Emiroğlu 2011). continent with the exception of the UK (Copp et al. 2007, Species of Pterygoplichthys, commonly known 2010). Andrews (1990) reported that around 208–589 as sailfi n catfi shes, are native to the South America. million freshwater fi sh specimens were imported to the They are very popular aquarium fi shes that have been UK between 1987 and 1989. Recently, Maceda-Veiga introduced into several countries on different continents * Correspondence: Prof. Dr. Ali Serhan Tarkan, Muğla Sıtkı Koçman Üniversitesi, Su Ürünleri Fakültesi, 48000, Kötekli, Muğla, Turkey, phone: (+90) 2522111888, fax: (+90) 2522111887, e-mail: (AST) [email protected], (ÖE) [email protected], (FGE) [email protected], (SA) [email protected], (SB) [email protected], (MAA) [email protected]. 352 Emiroğlu et al. such as the USA, the Philippines, Taiwan, and Turkey— be suitable for the species’ survival. In addition to the mainly because of their high tolerance to environmental introduced Pterygoplichthys spp., there are three endemic variations and feeding behaviour, which is very effective species co-habiting waters in İnönü town: Caucasian to clean algae from submerged surfaces (Hoover et al. bleak, Alburnus escherichii Steindachner, 1897; Sakarya 2004, Chavez et al. 2006, Yalçın Özdilek 2007, Wu et al. chub, Squalius pursakensis (Hankó, 1925); and Aphanius 2011, Nico et al. 2012). villwocki Hrbek et Wildekamp, 2003. Herbivorous sailfi n catfi shes are usually successful Material and methods. Fish samples were collected invaders across its invasive range (Zworykin and Budaev from the Pınarbaşı Stream (near the town of İnönü) 2013) and several factors facilitate their invasion into a fed by hot spring waters. This stream originates from variety of ecosystems. The most import are: their water a rocky region in western part of the basin and joins pollution tolerance, low oxygen level tolerance (aided by the Porsuk River, a major tributary of the Sakarya accessory respiration), predation defence tools, such as River (39°48′48.60′′N, 30°07′04.05′′E–39°49′00.08′′N spiny fi ns and hard external armour (Zworykin and Budaev 30°07′53.90′′E). At the sampling site, the stream is 2013), advanced spawning behaviour (batch spawning, approximately 250 cm wide, the current is slow, and the extended spawning period, and parental care) (Hoover temperature is 22–26ºC throughout the year. The mean et al. 2004, Liang et al. 2005). The above-mentioned pH and mean electrical conductivity are 6.69 and 442 S · advanced surviving features of sailfi n catfi shes may have cm–1, respectively. The water depth is between 30 and 150 negative impact on the ecosystem and the biodiversity cm with a muddy and plant-covered substrate. There are (Hoover et al. 2004, Zworykin and Budaev 2013). Their several artifi cial channels and weirs along the water course. grazing behaviour may alter the food web, especially when Pterygoplichthys spp. occur in 1290 m long section of the they become abundant (Smith 1981). They eat demersal stream, being most abundantly along the natural part (590 eggs of autochthonic species and out-compete other m). The stream is mainly covered by mud and submerged herbivore species (Hoover et al. 2004). Also, piscivorous aquatic vegetation (Fig. 1). birds were reported to be affected by strong spines of these fi shes (Bunkley-Williams et al. 1994, Hoover et al. 2004). Their burrowing behaviour in the river banks may cause some socioeconomic problems such as the water turbidity and soil erosion. Moreover, sailfi n catfi shes also damage gillnets (Hubilla et al. 2007). Mendoza et al. (2015) using risk screening tool for freshwater fi shes (Freshwater Invasiveness Screening Kit-FISK; Copp et al. 2009) determined a high invasiveness potential for Pterygoplichthys species in Mexico. The same has been estimated for several European countries (Simonović et al. 2013, Perdikaris et al. 2016) and Turkey (Tarkan et al. 2014). In those studies, high risk of invasiveness of this fi sh was associated with its advanced reproductive Fig. 1. A section of the Pınarbaşı Stream where features, previous history of successful introductions, Pterygoplichthys species were most abundantly caught detrimental impacts to the recipient ecosystems, and its environmental versatility. Fish samples were collected on 09 March 2016 and In Turkey, only a single specimen of Pterygoplichthys 15 March 2016 with an electrofi shing device (Samus disjunctivus was reported from the Asi River (southern 725-PWM2). Collected fi shes were euthanized using an Turkey) (Yalçın-Özdilek 2007). The above-mentioned overdose of 2-phenoxyethanol and transported on ice to the author noted that this single specimen indicated potentially laboratory where they were examined for morphometric serious ecological problems, if the species is established, characters. especially for rich endemic fi sh fauna of the river. However, The standard length and total length of the specimens following-up surveys found no other P. disjunctivus were measured to the nearest mm and weighted to the specimens in the river. Although the exact date is unknown, nearest 0.01g. The fi sh were macroscopically examined the most plausible way for Pterygoplichthys species to and photographed. Some meristic characters such as the enter the Asi River and the hot water resources in İnönü number of branched fi n rays of dorsal, pectoral, and ventral town is the result of aquarium release or escape. Indeed, fi ns were counted. The specimens were identifi ed using one wholesaler admitted that he released many aquarium taxonomic keys of Weber (1991, 1992) and Armbruster fi shes into spring waters around İnönü town (Sakarya and Page (2006). All the counts and measurements were River Basin, north-western of Turkey) some 7–8 years done according to Weber (1992), which largely follows ago when he went bankrupt. Our surveys have confi rmed Boeseman (1968) except the following ratios: head width that aquarists still damp these species and personal ÷ distance between posterior eye