Three new species of Helicometroides Yamaguti, 1934 from Japan and Australia, with new molecular evidence of a widespread species

Integrated characterisation of nine species of the Schistorchiinae (Trematoda: Apocreadiidae) from Indo-Pacific fishes: two new species, a new genus, and a resurrected but 'cryptic' genus

We report nine species of the Schistorchiinae Yamaguti, 1942 (Apocreadiidae Skrjabin, 1942) from Indo-Pacific marine fishes. Molecular data (ITS2 and 28S rDNA and cox1 mtDNA) are provided for all species and the genus-level classification of the subfamily is revised. For Schistorchis Lühe, 1906, we report the type-species Sch. carneus Lühe, 1906 and Sch. skrjabini Parukhin, 1963. For Sphinteristomum Oshmarin, Mamaev & Parukhin, 1961 we report the type-species, Sph. acollum Oshmarin, Mamaev & Parukhin, 1961. We report and re-recognise Lobatotrema Manter, 1963, for the type and only species, L. aniferum Manter, 1963, previously a synonym of Sph. acollum. Lobatotrema aniferum is phylogenetically distant from, but morphologically similar to, Sph. acollum and Lobatotrema is recognised as a 'cryptic genus'. We propose Blendiella n. gen. for B. trigintatestis n. sp. and B. tridecimtestis n. sp. These species are broadly consistent with the present morphological concept of Schistorchis but are phylogenetically distant from the type-species; a larger number of testes and some other subtle morphological characters in species of Blendiella serve to distinguish the two genera. We report three species of Paraschistorchis Blend, Karar & Dronen, 2017: P. stenosoma (Hanson, 1953) Blend, Karar & Dronen, 2017 (type-species), P. seychellesiensis (Toman, 1989) Blend, Karar & Dronen, 2017, and P. zancli (Hanson, 1953) Blend, Karar & Dronen, 2017. Lobatotrema aniferum, P. stenosoma, and Sch. carneus each have two distinct cox1 populations either over geographical range or in sympatry. Available evidence suggests that most of these species, but not all, are widespread in the tropical Indo-Pacific.

Monorchiids (Digenea, Trematoda) of fishes in the Yucatán Peninsula, Mexico, with the description of three new species based on morphological and molecular data

Adult specimens of monorchiids (Digenea) were collected from the intestines of the white grunt, Haemulon plumierii Lacepède (Haemulidae), and the white mullet, Mugil curema Valenciennes (Mugilidae) from five localities off the Yucatán Peninsula and one locality in the Gulf of Mexico. Some specimens were photographed and sequenced for two molecular markers, the large subunit (LSU) of nuclear rDNA and the cytochrome c oxidase subunit 1 (cox1) of mitochondrial DNA. Other specimens were processed for morphological analyses. Newly generated sequences were aligned with other sequences available in GenBank. Bayesian inference and maximum likelihood analyses were implemented using the data sets of LSU and cox1 independently. Reciprocal monophyly evidenced through phylogenetic analyses, sequence divergence values for both molecular markers, and detailed morphological analyses, including scanning electron microscopy photomicrographs, revealed three new genetic lineages, i.e., species, as parasites of M. curema. The three new species are Sinistroporomonorchis mexicanus n. sp., Sinistroporomonorchis yucatanensis n. sp., and Sinistroporomonorchis minutus n. sp. Two additional species of monorchiids were sampled, characterised molecularly, and re-described, namely Sinistroporomonorchis glebulentus (Overstreet, 1971) from the white mullet, and Alloinfundiburictus haemuli (Overstreet, 1969), from the white grunt.