Lepotrema Ozaki, 1932 (Lepocreadiidae: Digenea) from Indo-Pacific fishes, with the description of eight new species, characterised by morphometric and molecular features

Abstract

We review species of the genus Lepotrema Ozaki, 1932 from marine fishes in the Indo-West Pacific. Prior to the present study six species were recognised. Here we propose eight new species on the basis of combined morphological and molecular analysis: Lepotrema acanthochromidis n. sp. ex Acanthochromis polyacanthus from the Great Barrier Reef (GBR); Lepotrema hemitaurichthydis n. sp. ex Hemitaurichthys polylepis and H. thompsoni from Palau and French Polynesia; Lepotrema melichthydis n. sp. ex Melichthys vidua from Palau and the GBR; Lepotrema amansis n. sp. ex Amanses scopas from the GBR; Lepotrema cirripectis n. sp. ex Cirripectes filamentosus, C. chelomatus and C. stigmaticus from the GBR; Lepotrema justinei n. sp. ex Sufflamen fraenatum from New Caledonia; Lepotrema moretonense n. sp. ex Prionurus microlepidotus, P. maculatus and Selenotoca multifasciata from Moreton Bay; and Lepotrema amblyglyphidodonis n. sp. ex Amblyglyphidodon curacao and Amphipron akyndynos from the GBR. We also report new host records and provide novel molecular data for two known species: Lepotrema adlardi Bray, Cribb & Barker, 1993 and Lepotrema monile Bray & Cribb, 1998. Two new combinations are formed, Lepotrema cylindricum (Wang, 1989) n. comb. (for Preptetos cylindricus) and Lepotrema navodonis (Shen, 1986) n. comb. (for Lepocreadium navodoni). With the exception of a handful of ambiguous records, the evidence is compelling that the host-specificity of species in this genus is overwhelmingly oioxenous or stenoxenous. This renders the host distribution in three orders and ten families especially difficult to explain as many seemingly suitable hosts are not infected. Multi-loci molecular data (ITS2 rDNA, 28S rDNA and cox1 mtDNA) demonstrate that Lepotrema is a good generic concept, but limited variability in sequence data and differences in phylogenies produced for different gene regions make relationships within the genus difficult to define.

Fig. 1

Phylogenetic analyses of the Lepotrema rDNA datasets. A, Phylogram from the unrooted Neighbour-joining analysis of the 5.8S-ITS2-28S dataset. Bootstrap support values shown at the nodes, with values of < 85 not shown. The scale-bar indicates the number of base differences; B, Phylogram from the Bayesian inference analysis of the 28S dataset. Posterior probabilities shown at the nodes, with values of < 85 not shown. Abbreviations: MB, Moreton Bay; FP, Austral Islands, French Polynesia; HI, Heron Island; LI, Lizard Island

Fig. 2

Phylogram from the unrooted Neighbour-joining analysis of the cox1 mtDNA dataset. Bootstrap support values shown at the nodes, with values of < 85 not shown. Abbreviations: MB, Moreton Bay; FP, Austral Islands, French Polynesia; HI, Heron Island; LI, Lizard Island

Figs. 3–7

Lepotrema spp. 3, 4, Lepotrema clavatum Ozaki, 1932; 3, Ventral view of voucher in probable type-series; 4, Ventral view, redrawn from Ozaki (1932); 5–7, Lepotrema adlardi (Bray, Cribb & Barker, 1993); 5, ex Abudefduf bengalensis, Ningaloo Reef, ventral view; 6, ex Abudefduf bengalensis, off Heron Island, ventral view; 7, ex Abudefduf bengalensis, off Lizard Island, ventral view. Scale-bars: 200 μm

Figs. 8–9

Lepotrema acanthochromidis n. sp. 8, ex Acanthochromis polyacanthus, off Heron Island, holotype, ventral view; 9, ex Acanthochromis polyacanthus, off Lizard Island, ventral view. Scale-bars: 200 μm

Figs. 10–14

Lepotrema hemitaurichthydis n. sp. 10, ex Hemitaurichthys polylepis, Palau, holotype, ventral view; 11, ex Hemitaurichthys polylepis, off Tubuai, Austral Islands, ventral view; 12, ex Hemitaurichthys polylepis, off Tubuai, Austral Islands, paratype with lobate testes; 13, ex Hemitaurichthys polylepis, off Tubuai, Austral Islands, paratype with lobate testes; 14, ex Hemitaurichthys thompsoni, Fatu Hiva, Marquesas, ventral view. Scale-bars: 200 μm

Figs. 15–21

Lepotrema spp. 15, 16, Lepotrema melichthydis n. sp.; 15, ex Melichthys vidua, Palau, holotype, ventral view; 16, ex Melichthys vidua, off Heron Island, ventral view; 17, Lepotrema amansis n. sp. ex Amanses scopas, off Heron Island, holotype, ventral view; 18–21, Lepotrema cirripectis n. sp.; 18, 19, ex Cirripectes filamentosus, off Lizard Island; 18, Holotype, ventral view; 19, Paratype, ventral view; 20, ex Cirripectes stigmaticus, off Lizard Island, ventral view; 21, ex Cirripectes chelomatus, off Heron Island, ventral view. Scale-bars: 200 μm

Figs. 22–28

Lepotrema spp. 22, Lepotrema justinei n. sp. ex Sufflamen fraenatum, New Caledonia, holotype, ventral view (redrawn from Bray & Justine, 2012); 23–25, Lepotrema moretonense n. sp.; 23, ex Prionurus microlepidotus, off Amity, North Stradbroke Island, holotype, ventral view; 24, ex Prionurus maculatus, Moreton Bay, ventral view; 25, ex Selenotoca multifasciata, Moreton Bay, ventral view. 26, 27, Lepotrema amblyglyphidodonis n. sp.; 26, ex Amblyglyphidodon curacao, off Heron Island, holotype, ventral view; 27, ex Amphiprion akyndynos, off Heron Island, ventral view; 28, Lepotrema canthescheniae Bray & Cribb, 1996 ex Cantheschenia grandisquamis, off Heron Island, ventral view (redrawn from Bray & Cribb, 1996c). Scale-bars: 200 μm

Figs. 29–35

Lepotrema spp. 29, 30, Lepotrema monile Bray & Cribb, 1998. 29, ex Pomacentrus wardi, off Heron Island, ventral view (redrawn from Bray & Cribb, 1998); 30, ex Stegastes apicalis, off Heron Island, ventral view; 31, Lepotrema sp. 1 ex Rhinecanthus aculeatus, off Lizard Island, ventral view; 32, Lepotrema sp. 2 ex Rhinecanthus aculeatus, Palau, ventral view; 33, Lepotrema sp. 3 ex Sufflamen chrysopterum, off Heron Island, ventral view; 34, Lepotrema sp. 4 ex Parma polylepis, off Heron Island, ventral view; 35, Lepotrema sp. 5, micrograph of hologenophore ex Ctenochaetus striatus, off Heron Island, ventral view. Scale-bars: 200 μm

Figs. 36–39

Lepotrema spp. 36, Lepotrema incisum (Hanson, 1955) ex Melichthys buniva, Hawaii, ventral view (redrawn from Hanson, 1955); 37, Lepotrema xanthichthydis (Yamaguti, 1970) ex Xanthichthys ringens, Hawaii, ventral view (redrawn from Yamaguti, 1970); 38, Lepotrema cylindricum (Wang, 1989) n. comb. ex Monacanthus chinensis or Navodon septentrionalis, off Fujian, China, ventral view (redrawn from Wang, 1989); 39, Lepotrema navodonis (Shen, 1986) n. comb. ex Thamnoconus modestus, off Zhejiang, China, ventral view (redrawn from Shen, 1986). Scale-bars: 200 μm