Ligophorus liewi, Oym & Wb & Lhs, 2015

Oym, Soo, Wb, Tan & Lhs, Lim, 2015, Three new species of Ligophorus Euzet & Suriano, 1977 (Monogenea: Ancyrocephalidae) from Moolgarda buchanani (Bleeker) off Johor, Malaysia based on morphological, morphometric and molecular data, Raffles Bulletin of Zoology 63, pp. 49-65 : 54-59

Ligophorus liewi , new species

( Figs. 4A, B , 5A–F )

Type host. Moolgarda buchanani (Bleeker, 1853) . Type locality. Straits of Johor, Peninsular Malaysia (01°2’6”N 103°5’4”E) .

Materials examined. All specimens collected from the Straits of Johor, Peninsular Malaysia. Holotype: NHMUK 2014.11 .10.4, coll. Liew Kim Seng, 19 December 2013 . Paratypes: NHMUK 2014.11.10.5–2014.11.10.8, ZRC. PAR.43– ZRC.PAR.44 and MZUM (P) 2014.7(P) – 2014.30(P), coll. Liew Kim Seng, 19 December 2013 .

Etymology. The specific name, liewi is named for Mr. Liew Kim Seng who collected these monogeneans.

Description. Body elongate, 1064 (823–1270) × 128 (90–166), three pairs of head organs, two pairs pigmented eye spots, posterior with lenses and bigger than anterior pair. Mouth subterminal, ventral. Haptor well demarcated, size 91 (51–144) × 175 (118–214); 14 larval-type marginal hooks, similar, length 12 (10–13); two pairs of anchors; two dorsal anchors, inner length 48 (45–50), outer length 43 (41–45), inner root 19 (18–22), outer root 8 (6–11), point 12 (10–14); two ventral anchors with fenestration, inner length 48 (45–51), outer length 48 (45–49), inner root 18 (12–21), outer root 11 (7–15), point 11 (9–12); two connecting bars: dorsal bar broad V-shape, 48 (54–63) × 6 (5–8); ventral bar inverted V, 48 (44–52) × 9 (6–12), AMP consists of two membranous lateral pieces and a raised median piece, distance between lateral pieces, 8 (6–10). Testis single, elongate, ovoid, postero-dorsal to ovary. Single elongate prostatic reservoir with prostatic duct leaving reservoir to enter bigger lobe of bilobed initial of copulatory tube. Male copulatory organ consists of copulatory tube, length 81 (71–88) with bilobed initial part and a grooved accessory piece with a tapered, bent distal part, 36 (29–42). Ovary J-shaped, elongate with recurved posterior region. Vaginal opening and tube not observed. Vitellarium in lateral fields approximately co-extensive with intestinal caeca, confluent just posterior to intestinal bifurcation, just anterior to ovary and just posterior to cyclocoel.

Description. Body elongate, 1124 (955–1304) × 175 (131– 214), three pairs of head organs, two pairs pigmented eye spots, posterior with lenses and bigger than anterior pair. Mouth subterminal, ventral. Haptor well demarcated, size 89 (64–118) × 200 (148–235); 14 larval-type marginal hooks, similar, length 12 (11–13); two pairs of anchors; two dorsal Differential diagnosis. This is one of three species of the genus Ligophorus with fenestrated anchors. Ligophorus fenestrum has fenestrated ventral and dorsal anchors ( Soo & Lim, 2012) whilst L. kederai and L. liewi , new species, have only fenestrated ventral anchors ( Soo & Lim, 2015). Analyses of molecular data show L. liewi , new species, and L. kederai are sister taxa ( Fig. 3 ) but L. liewi , new species, differs from L. kederai in the morphometry of the anchors ( Table 1) and morphology of the accessory piece of the copulatory organ; grooved tube with tapered and bent distal end in L. liewi , new species, ( Fig. 5F ) compared to a simple grooved tube in L. kederai ( Soo & Lim, 2015) . Ligophorus liewi , new species, is grouped closest to L. fenestrum in the PCA scatterplot ( Fig. 1 ) but differs from L. fenestrum in the shape and fenestration of the anchors, AMP of the ventral bar and accessory piece of the copulatory organ. Ligophorus liewi , new species, has a narrower anchor base, fenestrated ventral anchors, an AMP which comprises of two lateral membranous pieces + a raised median piece and a grooved accessory piece with a tapered and bent distal end ( Figs. 5A, C, D, F ) compared to a broad anchor base, fenestrated ventral and dorsal anchors, an AMP comprising of a single bifurcated piece and a simple grooved accessory piece in L. fenestrum ( Soo & Lim, 2012) . Ligophorus liewi , new species, is also similar to L. surianoae in possessing similar anchors, bars and male copulatory organ. However, L. liewi , new species, differs in having fenestrated ventral anchors, a shorter dorsal bar 48 (54–63) and a shorter male copulatory tube 81 (71–88) as compared to non-fenestrated anchors, a longer dorsal bar 56 (48–68) and a longer male copulatory tube 99 (95–103) in L. surianoae .

Figures

Fig. 4. Photomicrographs of the sclerotised hard parts Ligophorus liewi, new species (A & B), L. johorensis, new species (C & D) and L. grandis, new species (E & F). A, C & E, anchors and bars; B, D & F, male copulatory organ.

Fig. 5. Sclerotised hard parts of L. liewi, new species (A–F) and L. johorensis, new species (G–L): A & G, dorsal anchors; B & H, dorsal bar; C & I, ventral anchors; D & J, ventral bar (dorsal view); E & K, marginal hook; F & L, male copulatory organ.

Fig. 3. Maximum-parsimony (MP) trees generated from (A) 28S dataset and (B) 28S+ITS1 dataset using PAUP* with Ergenstrema mugilis as the outgroup. Percentages of the bootstrap values are shown along the branches. *denotes new species

Fig. 1. Principal Component Analysis (PCA) scatterplot of 465 Ligophorus specimens based on all hard parts (marginal hook, anchors, bars and male copulatory organ). Vertical and horizontal bar plots indicate one-dimensional summary of the principal component axes, PC1 and PC2.