Accepted: 26 January 2018 DOI: 10.1111/jzs.12217 ORIGINAL ARTICLE 3D morphology of pharyngeal dentition of the genus Capoeta (Cyprinidae): Implications for taxonomy and phylogeny Anna Ayvazyan1 | Davit Vasilyan2,3 | Madelaine Bohme€ 1,4 1Department of Geosciences, Eberhard- Karls-University Tubingen,€ Tubingen,€ Abstract Germany Capoeta is a herbivorous cyprinid fish genus, widely distributed in water bodies of 2JURASSICA Museum, Porrentruy, Western Asia. Recent species show a distinct biogeographic pattern with endemic Switzerland 3Universite de Fribourg, Fribourg, distribution in large fluvial drainage basins. As other cyprinids, the species of this Switzerland genus are characterized by the presence of the pharyngeal bone with pharyngeal 4 Senckenberg Center for Human Evolution teeth. Despite this, the detailed morphology of the pharyngeal teeth, its interspecific and Palaeoenvironment (HEP), Tubingen,€ Germany and topologic variations, and the importance for taxonomy and phylogeny of the genus Capoeta are still not established. For the first time, a detailed comprehensive Correspondence Anna Ayvazyan study of the pharyngeal dentition of 10 Capoeta species has been provided. The Email: [email protected] morphologic study of the pharyngeal dentition bases on the 3D microtomography Funding information and follows the purpose to evaluate the potential taxonomic and phylogenetic sig- This work was funded by the German nals of these elements, as well as to study interspecific and topologic variations of Academic Exchange Service (DAAD) and the SYNTHESYS Grant (ES-TAF-5970) to the the pharyngeal teeth. In this study, we propose a new methodology to categorize National Museum of Natural Sciences of the studied pharyngeal teeth in 18 shape classes. The results of this study show Madrid (MNCN). that the detailed 3D morphology of the pharyngeal teeth is a useful tool for the Contributing authors: Davit Vasilyan identification of isolated teeth at the generic and/or specific level and that in certain ([email protected] , [email protected]); Madelaine cases, the tooth position in the teeth rows can be identified. Additionally, the pre- € Bohme ([email protected]) liminary analysis shows that the morphology of the pharyngeal teeth provides a potential phylogenetic signal. Both these patterns are very important for the taxon- omy of cyprinid fishes and especially can be applied to fossil records. KEYWORDS 3D microtomography, Capoeta, Cyprinidae, pharyngeal teeth 1 | INTRODUCTION lower lip (Banarescu, 1999; Karaman, 1969; Turkmen,€ Erdogan, Yıl- dırım, & Akyurt, 2002). Extant cyprinid fishes are known with more than 2,000 species Currently, more than 20 Capoeta species are described based on and represent the most diverse family of bony fishes in Eurasia genetic studies and morphologic and meristic characters (Levin, and Africa (Nelson, 2006). In fresh water bodies, they build the Rubenyan, & Salnikov, 2005; Levin et al., 2012; Turan, Kottelat, & main part of the biodiversity of the fish community. The family Ekmekcßi, 2008). The earlier taxonomical studies of the genus Capo- includes several large clades (subfamilies), that is, Cyprininae and eta are based mainly on morphometrics and meristic characters Leuciscinae. In Western Asia among cyprinids, one of the widely (Karaman, 1969; Krupp & Schneider, 1989), whereas the recent distributed genera is the cyprinine Capoeta, which is considered as studies mostly rely on genetic analyses (Alwan, Esmaeili, & Krupp, endemic to the region. The monophyletic genus Capoeta includes 2016; Levin et al., 2012; Turan, 2008). herbivorous species, feeding mainly on algae and periphyton, Levin et al. (2012) studied the phylogenetic relationships of which they scrap from the substrate by the horny sheath on their the genus Capoeta based on the complete mitochondrial gene for | J Zool Syst Evol Res. 2018;1–12. wileyonlinelibrary.com/journal/jzs © 2018 Blackwell Verlag GmbH 1 2 | AYVAZYAN ET AL. cytochrome b sequences obtained from 20 species. According to 2 | MATERIALS AND METHODS the study (Levin et al., 2012), three main groups are recognized: the Mesopotamian, the Anatolian–Iranian, and the Aralo-Caspian. 2.1 | Sampling Later, Zareian, Esmaeili, Heuıdari, Khoshkholgh, and Mousavi- Sabet (2016) based on mitochondrial cytochrome b gene Pharyngeal dentitions of 10 Capoeta species from different water sequences distinguished three main groups: the Capoeta trutta basins of Anatolia, Iraq, Iran, Armenia, Georgia, and Syria are studied group (the Mesopotamian Capoeta group), the Capoeta damascina (Table 1). The comparative material of pharyngeal bones is stored at complex group (the Anatolian–Iranian group), and the Capoeta the Bavarian State Collection for Anthropology and Palaeoanatomy, capoeta complex group (the Aralo-Caspian group) (Zareian et al., Munich (SNSB); the National Museum of Natural Sciences of Madrid 2016). (MNCN); the Palaeontological Collection of Tubingen€ University A diagnostic character of all cyprinid fishes is the presence of the (GPIT); and Senckenberg Naturmuseum Frankfurt (SMF). The sam- pharyngeal bone with pharyngeal teeth located in up to three rows pled information about studied specimens and locations is listed in (Howes, 1991). It builds as a result of ossification of the right and left Table 1 and Figures 1 and 2. The osteologic and morphologic fifth ceratobranchials and forms tooth-bearing pharyngeal jaw, which description of the pharyngeal bones and teeth follows the nomencla- is specialized for food processing. The morphology of the pharyngeal ture introduced in Figure 3. jaw and pharyngeal tooth shape and configuration also have taxo- The left pharyngeal bones of adult individuals are used in the nomic significance for cyprinids (Howes, 1991) and can be repre- study (except for Capoeta umbla and C. damascina). Each pharyngeal sented by a formula, for example, 4.3.2-2.3.4; these numbers indicate bone possesses 9 to 10 teeth (pharyngeal teeth a3, a5, c1, and c2 in the amount of the teeth on the left and right jaws from the first to Capoeta saadii and b2, c1, and c2 in Capoeta buhsei are missing). So, the third and the third to the first row correspondingly. The number in total, the morphologic characters of 84 teeth are examined and of tooth rows and the amount of teeth in the each row are men- analyzed. The other samples of the same species were examined tioned as one of the significant taxonomic characters for the genus according to an established morphologic set of characters. Capoeta (Banarescu, 1999; Karaman, 1969; Krupp & Schneider, 1989). Besides this, several studies have shown that the pharyngeal 2.2 | Species identification dentition can also be considered as an essential character complex for the study of cyprinid evolution (Ahnelt, Herdina, & Metscher, The studied species were collected and identified by different schol- 2015; Bohme,€ 2002; Pasco-Viel et al., 2010; Zardoya & Ignacio, ars. C. saadii and C. buhsei are collected by Ignacio Doadrio in 2015, 1999; Zeng & Liu, 2011). However, little is known about the mor- C. umbla by Angela Van den Driesch, C. trutta and Capoeta sp. by phology of pharyngeal bones and teeth of the genus Capoeta, as well Eva Maria Cornelssen in 1978, Capoeta baliki and Capoeta sieboldii as its significance for taxonomy and phylogeny. by Madelaine Bohme€ in 2010, C. capoeta by Samvel Pipoyan in Heckel (1843) described the pharyngeal teeth of cyprinid fishes 2012, Capoeta sevangi by Anna Ayvazyan in 2014, and C. damascina for the first time. He classified them according to the grinding sur- by Nisreen Alwan in 2008. All species are identified by the collectors faces in four main groups and 13 subgroups. One of the subgroups based on external morphology and meristic characters. described by him with “shovel-shaped teeth” includes the genus Capoeta sp. from the Dokan Reservoir, Iraq, was collected by Capoeta. According to Heckel (1843), the teeth formula of the genus Cornelssen and stored as dried skeleton in SNSB as Barbus belayewi. Capoeta is 2.3.4-4.3.2 (respectively from the third to the first and According to our results, this specimen is closely related but not from the first to the third row). By examining different species of identical to the species C. trutta, which is also supported by the the genus, later studies (Banarescu, 1999; Karaman, 1969; Krupp & detailed study and comparison of the morphology of the last Schneider, 1989) found four or five teeth to be present in the main unbranched ray of the dorsal fin (unpublished results). row, two to four in the second row, and two in the third row. Banar- escu (1999) gave a rough morphologic description of the pharyngeal 2.3 | X-ray microtomography teeth and mentioned that the teeth in the main row are compressed and have irregular shape and those in the second and third rows are The pharyngeal bones were prepared in small polystyrene boxes for more or less cylindrical in shape (Banarescu, 1999). However, the scanning. detailed morphology, interspecific and topologic variations, and the The pharyngeal bones of the extant Capoeta species were importance of the tooth morphology for taxonomy and phylogeny of scanned using X-ray computed tomography (lCT). MicroCT images this genus are still not established. were taken using the microtomography system Phoenix v|tome|xsat Taking this into account, the main goals of this publication were the Tubingen€ University and Erlangen University, as well as NIKON (i) to provide a detailed morphologic description