A description of two new species of Ligophorus Euzet & Suriano, (Monogenea: Ancyrocephalidae) from Malaysian mugilid fish using principal component analysis and numerical taxonomy

Abstract

Ligophorus belanaki n. sp. and Ligophorus kederai n. sp. are described from Liza subviridis Valenciennes, 1836 and Valamugil buchanani Bleeker, 1854, respectively. Ligophorus kederai n. sp. has fenestrated ventral anchors, while in L. belanaki n. sp. the ventral anchor is not fenestrated. Ligophorus belanaki n. sp. is similar to L. careyensis, one of its coexisting congeners, in the overall shape and size of hard parts, but differs in having a flat median piece in the structure of the AMP (antero-median protuberance of the ventral bar), copulatory organ with non-ornamented initial part and longer vaginal tube, compared to raised median piece in the AMP, ornamented initial part and comparatively shorter vaginal tube in L. careyensis. Ligophorus kederai n. sp. is similar to L. fenestrum, a coexisting congener, in having fenestrated ventral anchors, but differs in having longer points and narrower base. Ligophorus fenestrum, unlike L. kederai n. sp., also possesses fenestrated dorsal anchors. The principal component analysis (PCA) scatterplots indicate that the two new and eight known Ligophorus species from Malaysian mugilids can be differentiated based on the morphometries of their anchors, ventral bars and copulatory organ separately and when combined together. Numerical taxonomy (NT) analyses based on Jaccard's Index of Similarity and neighbour-joining clustering, is used to facilitate comparison of these two new species with the 50 known Ligophorus based on morphological and metric characters. The two new species are different from each other and the other 50 species in the overall shapes and sizes of hard parts, as indicated by the NT analyses.

Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

“…We hope the development of monogeneaGM will contribute to reducing the bottleneck for large scale data analysis in the study of monogeneans. Indeed, as there has been a surge in alpha taxonomy and systematic biology studies of Ligophorus in recent years ( Abdallah, De Azevedo & Luque, 2009 ; Siquier & Ostrowski de Núñez, 2009 ; Blasco-Costa, Míguez-Lozano & Balbuena, 2012 ; Dmitrieva et al, 2012 ; Dmitrieva, Gerasev & Gibson, 2013 ; Soo & Lim, 2012 ; Soo & Lim, 2015 ; El Hafidi et al, 2013 ; Kritsky, Khamees & Ali, 2013 ; Sarabeev & Desdevises, 2014 ; Marchiori et al, 2015 ; Rodríguez-González et al, 2015b ; Soo, Tan & Lim, 2015 ), the analysis can only get more interesting as data from other species from other hosts in other geographical regions are added. We expect the data analysis tools in monogeneaGM to continue to evolve to handle complexities of data analysis when this happens.…”

“…We obtained 530 specimens (metadata in Table S2 ; sample sizes in Table S3 ) belonging to 13 Ligophorus species ( Soo & Lim, 2012 ; Soo & Lim, 2015 ; Soo, Tan & Lim, 2015 ) from two species of adult mullet host: Liza subviridis Valenciennes, 1836 ( n = 52) and Moolgarda buchanani Bleeker, 1853 ( n = 29) from several locations in tropical Western Peninsular Malaysia ( Fig. S1 ).…”

“…The fish were obtained from local fishermen in the vicinity of the sampling locations, dead at the time of purchase. Seven of the 13 species: L. bantingensis Soo & Lim, 2012 , L. careyensis Soo & Lim, 2012 , L. chelatus Soo & Lim, 2012 , L. funnelus Soo & Lim, 2012 , L. navjotsodhii Soo & Lim, 2012 , L. parvicopulatrix Soo & Lim, 2012 and L. belanaki Soo & Lim, 2015 were found on Liza subviridis ; the remainder: L. fenestrum Soo & Lim, 2012 , L. kedahensis Soo & Lim, 2012 , L. kederai Soo & Lim, 2015 , L. grandis Soo, Tan & Lim, 2015 , L. johorensis Soo, Tan & Lim, 2015 , and L. liewi Soo, Tan & Lim, 2015 , were found on M. buchanani . For all 81 fish examined, the Ligophorus species found in M. buchanani were never observed in Liza subviridis , and vice versa.…”

“…With the development of new tools for geometric morphometric and phylogenetic comparative methods, we are in a position to retest the Rohde-Hobbs hypothesis. To this end, we compared the size of the male copulatory organ (mean tube length data from Soo & Lim, 2012 ; Soo & Lim, 2015 ; Soo, Tan & Lim, 2015 ) and three of its selected morphological characters ( Table 2 : position of copulatory organ entrance at the main lobe of accesory piece; accesory piece of male copulatory complex; shape of accesory piece of male copulatory complex) against anchor shape and size variation. Ancestral node positions were estimated as before using the function in the package.…”

The first record of Ligophorus Euzet & Suriano, 1977 (Monogenea: Dactylogyridae) on Crenimugil buchanani (Teleostei: Muglidae) from Thailand based on morphological and molecular analyses

“…Ligophorus Euzet & Suriano, 1977 is a monogenean genus belonging to the family Dactylogyridae Yamaguti, 1963, which shows strong specificity to 17 mugilid fishes throughout the world (Soo and Lim, 2015). The genus now contains more than 50 nominal species (Soo and Lim, 2012; El Hafidi et al ., 2013a,b; Kritsky et al ., 2013; Sarabeev et al ., 2013), most of which have been reported from the Mediterranean Sea, Black Sea, and Red Sea; coasts of South America; coasts of Japan and China; and the Sea of Malaysia (the last species was reported from here in 2012–2015) (Euzet and Suriano, 1977; Fernandez-Bargiela, 1987; Hu and Li, 1992; Dmitrieva and Gerasev, 1996; Pan, 1999; Zhang et al , 2001; Sarabeev et al , 2005; Rubtsova et al , 2006, 2007; Abdallah et al , 2009; Marcotegui and Martorelli, 2009; Siquier and Nunez, 2009; Dmitrieva et al ., 2012; Soo and Lim, 2012, 2015).…”