The common pathogenic prodiplostomulum metacercaria in the flesh, mostly near the skin, of pond-produced channel catfish Ictalurus punctatus has been demonstrated to be Bolbophorus damnificus Overstreet & Curran n. sp. The catfish acquires the infection from the snail Planorbella trivolvis, the only known first intermediate host, and the species is perpetuated through the American white pelican Pelecanus erythrorhynchos, as confirmed by experimental infections with nestling and dewormed adult pelican specimens in conjunction with molecular data. It differs from the cryptic species Bolbophorus sp., also found concurrently in the American white pelican, by having eggs 123-129 microm rather than 100-112 microm long and consistent low values for nucleotide percentage sequence similarity comparing COI, ITS 1/2, 18S rRNA and 28S rRNA fragments. Bolbophorus sp. is comparable but most likely distinct from B. confusus (Kraus, 1914), which occurs in Europe and has eggs 90-102 microm long. Its intermediate hosts were not demonstrated. The adults of neither of the confirmed North American species of Bolbophorus were encountered in any bird other than a pelican, although several shore birds feed on infected catfish, and B. damnificus can survive but not mature when protected in the mouse abdominal cavity. B. ictaluri (Haderlie, 1953) Overstreet & Curran n. comb., a species different from B. damnificus, is considered a species inquirenda.

Keys to the six subfamilies, 22 genera within subfamilies and 128 species recognized within the Cyclocoelidae are provided. Lists of species in each genus are provided, along with taxonomic summaries that include type host, type locality, additional hosts, additional localities, previously proposed synonyms, and remarks for each species. The following synonymies are proposed: Cyclocoelum mutabile (Zeder, 1800)-Syn. C. microstomum (Creplin, 1929); Cyclocoelum leidyi Harrah, 1922-Syn. C. cuneatum Harrah, 1922; Cyclocoelum mehrotrai Sinha & Sahay, 1975-Syn. C. mathuri Jain, 1984; Selfcoelum allahabadi (Khan, 1935) n. comb.-Syns. Cyclocoelum agamprasadi Jain, 1983, Cyclocoelum erythropis Khan, 1935 and Cyclocoelum indicum Khan, 1935; Selfcoelum obliquum (Harrah, 1921) n. comb.-Syn. Cyclocoelum mehrii Khan, 1935; Uvitellina adelphus (Johnston, 1917)-Syn. Cyclocoelum (Uvitellina) dollfusi Tseng, 1930; Uvitellina kaniharensis (Gupta, 1958)-Syn. U. indica Siddiqi & Jairajpuri, 1962; Uvitellina simile (Stossich, 1902) n. comb.-Syn. U. magniembria Witenberg, 1923; Uvitellina vanelli (Rudolphi, 1819)-Syns. U. keri Yamaguti, 1933 and U. tageri Yamaguti, 1933; Wardianum triangulare (Harrah, 1922)-Syn. Wardianum catoptrophori Dronen, 2007; Haematotrephus limnodromi Dronen, Gardner & Jiménez, 2006-Syn. H. selfi Dronen, Gardner & Jiménez, 2008; and Hyptiasmus arcuatus (Brandes, 1892 of Stossich, 1902)-Syn. H. coelonodus Witenberg, 1923. Based on the lack of adequate descriptive information, Cyclocoelum cornu (Zeder, 1800); Cyclocoelum crenulatum (Rudolphi, 1809); Haematotrephus nigropunctatum (von Linstow, 1883) n. comb.; Haematotrephus robustus Ukoli, 1968; Hyptiasmus californicus (Wootton, 1966); and Hyptiasmus vigisi Savinov, 1960 are considered to be species inquirendae. Hyptiasmus witenbergi Tret'iakova, 1940 (described in a dissertation) is considered to be a nomen nudum. Comparative tables containing measurements, morphometric percentages and morphometric ratios for species in the family are provided and the comparative characteristics used to distinguish species in the Cyclocoelidae are discussed.

Modified and/or new keys to the four subfamilies now recognized within the Megaperidae Manter, 1934 n. comb. (Syn. Apocreadiidae Skrjabin, 1942) as well as the genera within each subfamily are presented. Two new genera, Paraschistorchis n. gen. and Plesioschistorchis n. gen., both within the Schistorchiinae Yamaguti, 1942, are erected and keys are provided to the species considered in both new genera-distinguished by possessing caeca that end either in separate ani or blindly. Plesioschistorchis callyodontis (Yamaguti, 1942) n. comb. and Plesioschistorchis haridis (Nagaty, 1957) n. comb. are re-described from new material collected from the common parrotfish, Scarus psittacus Forsskål (Perciformes: Scaridae), inhabiting the Red Sea off Egypt; S. psittacus represents a new host record for both species. The taxonomic status of Schistorchis sensu stricto Lühe, 1906 is examined and revised, a key to the four species we consider in this genus offered, and the monotypic genus Megacreadium Nagaty, 1956 declared a junior synonym of Schistorchis. Members of Schistorchis sensu stricto possess a unique "complex" (i.e. highly cellular/glandular) instead of "simple" (i.e. entirely muscular) type of oral sucker that is quite large in relation to body size; an elongate, somewhat sub-rectangular-shaped body; 5+ testes arranged in at least two rows; caeca that open via separate ani; a long post-testicular region; a median genital pore either at the anterior margin of or just anterior to the ventral sucker; and species of Schistorchis sensu stricto parasitize the intestine of marine fish within the Order Tetraodontiformes Berg. With the revision of this genus, we re-describe Schistorchis carneus Lühe, 1906 from the lower and mid-intestine of the white-spotted puffer, Arothron hispidus (Linnaeus) (Tetraodontiformes: Tetraodontidae), collected in the Red Sea off Egypt. Finally, a plea is made for further study of the Megaperidae n. comb. focusing, in particular, on the following: (1) obtaining new type/voucher materials of Plesioschistorchis manteri (Gupta & Tandon, 1984) n. comb. and Schistorchis paruchini Kurochkin, 1974; (2) elucidating the life histories (i.e. intermediate hosts) of members of the Postporinae Yamaguti, 1958 and Schistorchiinae; and (3) generating DNA sequence data for more species of megaperids to help future workers produce increasingly accurate taxonomic classifications that better reflect phylogenetic relationships within this ecologically diverse group of digeneans.

No abstract

Podocotyle pearsei Manter, 1934 is documented from the intestine of Vaillant’s grenadier, Bathygadus melanobranchus Vaillant (Macrouridae: Bathygadinae), collected from the northeastern and western Gulf of Mexico from 783–841 m depth. The finding of P. pearsei in B. melanobranchus represents the first originally published report of this genus from this host and the fifth documented host species for P. pearsei. We report three unidentified species of Podocotyle, represented by one individual each, from the intestine of the western Atlantic grenadier, Nezumia atlantica (Parr) (Macrouridae: Macrourinae), and from Bathygadus favosus Goode & Bean (Macrouridae: Bathygadinae) found at 637 m, 710 m and 1,143 m depths in the northeastern Gulf of Mexico off Florida and from the Caribbean Sea off Colombia. We provide a checklist of the parasites known from the three macrourid species relevant to this study, comment on the biogeography of the five species of Podocotyle now known from the deep sea and discuss the low host specificity observed across this genus. The high number of fish hosts for Podocotyle (i.e. type hosts include at least 22 piscine families) encompassing a wide phylogenetic diversity and diet makes it unlikely that members of a single genus could evolve such a broad array of life histories (i.e. utilize dissimilar intermediate hosts), and we predict in the future that Podocotyle will be taxonomically divided up. Morphological and especially molecular work is needed for Podocotyle as well as for other digenean genera known to inhabit the deep sea. Podocotyle sp. 1 & 2 represent the first originally published reports of this genus from N. atlantica while Podocotyle sp. 3 represents the first report of this genus from B. favosus. Podocotyle koshari Nagaty, 1973 is declared a species inquirenda, and a dichotomous key to the 27 species of Podocotyle we recognize is provided.