Bravohollisia geruti, Tan & Lim, 2013

Tan, W. B. & Lim, L. H. S., 2013, Bravohollisia Geruti, New Species (Monogenea: Ancyrocephalidae) From Pomadasys Hasta (Osteichthyes: Haemulidae) Of Peninsular Malaysia, Raffles Bulletin of Zoology 61 (2), pp. 481-489 : 482-487

Bravohollisia geruti , new species

( Figs. 1 A–G, 2)

Type-host. — Pomadasys hasta Bloch, 1790

Type-locality. — O ff Pulau Ketam, Straits of Malacca, Peninsular Malaysia

Type specimens. — Holotype: ZRC.PAR.31

Paratypes: 2 paratypes ZRC .PAR.32–33 and 111 paratypes MZUM (P) 2013.468(P) – 2013.578(P).

Material examined. — 114 specimens studied; 114 measured

Etymology. — The specific appellation is derived from the local name of the host species “gerut-gerut”.

Description. — Body 682 (583–766) × 130 (114–148). Four eye-spots of pigmented granules, lenses not observed; anterior pair smaller than posterior pair. Alimentary system with subterminal mouth, muscular pharynx, oesophagus and intestinal caeca unite posterior to testis. Peduncle 157 (120–186) × 88 (68–109). Haptor small, 65 (51–84) × 93 (77–114). Four pyriform haptoral reservoirs observed associated with each of the four anchors. Lace-like net structure observed near tip of anchors. Four anchors with lateral external grooves extending from shaft to point; dorsal anchors with inner length 22 (19–25), outer length 21 (18–24), inner root 11 (9–13), outer root 5 (4–6), point 11 (10–13); ventral anchors with inner length 24 (22–27), outer length 22 (19–24), inner root 13 (11–14), outer root 5 (4–7), point 12 (10–13). Dorsal connective bar 33 (27–38) × 8 (6–9) with two anterior protuberances. Ventral connective bar 29 (23–34) × 7 (6–10). Fourteen marginal hooks of larval type, small, 11 (10–12). Ovary ovoid; oviduct arises from anterior margin of ovary; uterine pore near copulatory organ. Vaginal pore (Type hosts and type localities always listed first)

sclerotised, located dextrally submedial at midbody; proximal region sclerotised cup-shaped with pouch-liked appendix; distal section an elongate tube. Testis dorsal, posterior to ovary; vas deferens arises from anterior part of testis, loops around left caecum to ventral side, ascends, dilates forming first seminal vesicle; ductus ejaculatorius enters bell-shaped initial part of copulatory tube. Copulatory organ without accessory piece; bell-shaped initial part, depth 25 (20–28), width 21 (18–25); tapering tube, 50 (47–54). One prostatic reservoir enters copulatory tube.

Differential diagnosis. — This new species is observed to be different from previously described Bravohollisia spp. mainly in the shapes and sizes of the male copulatory organ

and connective bars and in the detailed structure of anchors. Comparative examinations of the specimens of the known and new species show that the new species possesses male copulatory organ with bell-shape initial part and tapering copulatory tube which is similar to that of B. kritskyi , B. rosetta and B. magna . However it differs from them in terms of size and length of copulatory tube: in the new species the initial part is 25 (20–28) × 21 (18–25), and short tapering tube 50 (47–54); in B. kritskyi the initial part is 39 (30–47) × 46 (39–53) and tapering tube 115 (109–128) with kink prior to ending; in B. rosetta the initial part is 27 (22–28) × 19 (16–20) and tapering tube with a hook-like distal tip is 87 (78–95) (Lim, 1995) whilst in B. magna the initial part is 50 × 45 (40–50) and the length of tapering tube with long whip-like ending is 130 ( Table 2). B. reticulata , B. gussevi , B. tecta , and B. pomadasis are different from the new species in having cup-shape initial part and copulatory tube of different length (cf. Table 2 & Fig. 3 ).

In this study, the scatterplot based on the morphometric data of the male copulatory organ separates the 744 Bravohollisia individuals into five distinct groups corresponding to the five species, B. rosetta , B. reticulata , B. gussevi , B. kritskyi , and Bravohollisia geruti , new species ( Fig. 3 ). This scatterplot confirms the observed morphological differences of the male copulatory organ of the present new species from that of B. rosetta , B. reticulata , B. gussevi and B. kritskyi ( Fig. 3 ; Table 2).

Although the anchors of this new species are different in terms of detailed shape to the anchors of B. kritskyi , they are both metrically similar ( Table 2). This metrical similarity between the anchors of this new species and that of B. kritskyi is supported by the scatterplot resulting from the PCA of the morphometric data of the anchors, which separates the 744 specimens into four groups which correspond to B. kritskyi—Bravohollisia geruti , new species (overlapping), B. reticulata , B. rosetta , and B. gussevi ( Fig. 4). The anchors of this new species are bigger than those of B. tecta and B. pomadasis (cf. Table 2 & Fig. 4). B. magna differs from the present new species in the shape and size of anchors (cf. Table 2 & Fig. 4).

Morphologically the connective bars of the new species are different in terms of sizes and shapes from all the known species (cf. Table 2 & Fig. 5 ). The bars of this new species are bigger than those of B. tecta but are smaller than the bars of B. magna , B. rosetta , B. kritskyi , and B. gussevi (cf. Table 2 & Fig. 5 ). The bars of B. pomadasis and B. reticulata are almost similar in size as the bars of the new species but differ in terms of shape (cf. Table 2 & Fig. 5 ). The scatterplot resulting from PCA of the morphometric data of dorsal and ventral connective bars shows the new species is distinct from B. reticulata , B. kritskyi , B. rosetta , and B. gussevi ( Fig. 5 ). The morphometric measurements of the bars of B. reticulata , B. kritskyi , B. rosetta , and B. gussevi tend to overlap ( Fig. 5 ). The lace-like nets of this new species resemble that of B. kritskyi but differ from the reticulate-like, rosette-like and stellate-like nets of B. reticulata , B. rosetta , and B. gussevi , respectively (see Lim, 1995; Fig. 4). The difference between the rosette-like nets and the lace-like nets is in the endings of the nets which is expanded in the former and not expanded in the latter.

The validity of this new species is also confirmed by the morphometric analysis (PCA) using all morphometric data from anchors, connective bars, copulatory organ and marginal hook ( Fig. 6 ). The combination of PC1 and PC3 provide the best separation of the 744 specimens into the five groups which correspond to the four known and one new species of Bravohollisa. The biplot indicates that the main character in differentiating the four known and the new species is mainly in the length of the male copulatory organ ( Fig. 7 ) supporting our observation (see above).

Figures

Fig. 1. Sclerotised parts of Bravohollisia geruti, new species:A, dorsal bar; B, dorsal anchors; C, ventral bar; D1, D2, ventral anchors (slight variations); E, marginal hook; F, copulatory organ; G, anchor with associated haptoral reservoir (hr) and secretory nets (sn). Abbreviations: parameters measured: il, inner length; ir, inner root length; ol, outer length; or, outer root length; pt, point length; ptl, point length taken by Lim (1995) (see Table 2); bw, bar width; bl, bar length; ml, marginal hook length; cil, copulatory organ initial length; ctl, copulatory organ total length; woi, greatest width of initial part.

Fig. 3. PCA scatterplot of 744 specimens of five Bravohollisia spp. from off Peninsular Malaysia based on morphometric data of the copulatory organ. Horizontal and vertical barplots indicate one dimensional summary of the PC (PC1 and PC2) axes. Male copulatory organs re-drawn to scale from original publications. (A–C not included in PCA).

Fig. 5. PCA scatterplot of 744 specimens of five Bravohollisia spp. from off Peninsular Malaysia based on morphometric data of the dorsal and ventral bars.Horizontal and vertical barplots indicate one dimensional summary of the PC (PC1 and PC2) axes. Bars re-drawn to scale from original publications. (A–C not included in PCA).

Fig.6.PCA scatterplot of the 744 specimens of the five Bravohollisia spp. from off Peninsular Malaysia based on all morphometric data of anchors, copulatory organs, bars and marginal hooks. The horizontal and vertical barplots indicate one dimensional summary of the PC (PC1 and PC3) axes.

Fig. 7. Biplot of the first and third principal components for the five Bravohollisia species with mean coordinates of the species indicated.