DOI: 10.1515/ap-2016-0047 © W. Stefański Institute of Parasitology, PAS Acta Parasitologica, 2016, 61(2), 360–368; ISSN 1230-2821 Molecular characterization and phylogeny of some mazocraeidean monogeneans from carangid fish Neeraja Tambireddy 1 , Tripathi Gayatri 1 , Pathakota Gireesh-Babu 2 and Annam Pavan-Kumar 2 * 1 Aquatic Environment and Health Management Division: 2 Fish Genetics and Biotechnology Division, ICAR-Central Institute of Fisheries Education, Panch Marg, Off Yari Road, Versova, Andheri (W), Mumbai - 400 061, India Abstract Polyopisthocotylean monogenean parasites of fishes are highly host specific and have been used as an appropriate model to study the host-parasite co-evolution. In the present study, eight monogeneans of the order Mazocraeidea were characterized by nu- clear 28S rDNA sequences and their phylogenetic relationship with other polyopisthocotylean species was investigated. Neigh- bour-joining, maximum parsimony, maximum likelihood and Bayesian Inference methods were used for phylogenetic reconstruction. The topology sustained by high bootstrap was: (((Hexabothriidae (Mazocraeidae (Discocotylidae (Diplozoidae (Diclidophoridae (Plectanocotylidae (Heteromicrocotylidae (Microcotylidae (Heteraxinidae), (Thoracocotylidae, Gotocotyli- dae (Gastrocoylidae (Allodiscocotylidae: Protomicrocotylidae))). In addition, we have also developed DNA barcodes (COI se- quences) for six species and the barcodes clearly discriminated all the species. The polytomy within Protomicrocotylidae family is resolved in this study for the first time and it appears that within this family, Bilaterocotyloides species are basal compared to Neomicrocotyle and Lethacotyle species while the latter is the more derived. Keywords Monogeneans, Polyopisthocotylea, molecular phylogeny, 28S rDNA, DNA barcoding Introduction Monogeneans are one of the members of Neodermata or parasitic platyhelminthes. Most of the monogeneans are ectoparasites on fish and comprise two major groups, the Monopisthocotylea and Polyopisthocotylea that are differen- tiated by their mode of attachment to the host by a posterior organ named haptor (or opisthaptor). In the Polyopistho- cotylea (blood feeding), the posterior haptor consists of suck- ers or clamps, (Hayward 2005) whereas Monopisthocotylea (epithelium feeding) haptor contains one or two pairs of hooks (anchors). Polyopisthocotylean monogeneans are distinctly host specific than other groups of parasites (Poulin 1992; Kearn 1998; Whittington et al. 2000). Because of the high species diversity and host specificity, monogeneans have been widely used as an appropriate model to address the patterns and processes of parasite evolution (Desdevises et al. 2002; Šimková et al. 2002, 2006). The evolutionary relationships between different families of Polyopisthocotylea have been resolved using morphological characters earlier (Boeger and Kritsky 2001). Compared to morphology based phylogeny molecular markers provide much reliable information regard- ing evolutionary relationship (Scotland et al. 2003). In India, several researchers have generated comprehen- sive literature on morphological taxonomy for identifying monogenean parasites of Indian fishes (Jain 1958; Rama- lingam 1966, 1968; Agrawal et al. 2006; Pandey and Agar- wal, 2008). However, most of the species were not characterized using molecular markers and evolutionary rela- tionship has not been studied so far. With this background, the present study was carried out to characterize selected ma- zocraeidean parasites infecting carangid fishes using molecu- lar markers and to investigate their phylogenetic position. Materials and Methods A total of eight polyopisthocotylean monogeneans of the order Mazocraeidea Bychowsky, 1937 representing five families (Allodiscocotylidae Tripathi, 1959; Gastrocotylidae Price, 1943; Heteraxinidae Unnithan, 1957; Heteromicrocotylidae Unnithan, 1961 and Protomicrocotylidae Johnston & Tiegs, *Corresponding author: pavankumar@cife.edu.in Unauthenticated Download Date | 5/9/16 8:32 AM