Postmortem examination of Australian sea snakes ( Hydrophiinae): Anatomy and common pathologic conditions

Polyphyly of the Dinurinae Looss, 1907 (Digenea: Hemiuridae) and resurrection of the Mecoderinae Skrjabin & Guschanskaja, 1954 based on novel collection of Tubulovesicula laticaudi Parukhin, 1969 from marine elapid snakes in Sri Lanka

With one exception, the only known hemiurid trematodes that do not use teleost fishes as definitive hosts instead occur in marine elapid snakes. These comprise six species across four genera and three subfamilies, and so presumably indicate at least three independent invasions of marine snakes from teleost fishes. Here, one of these taxa, Tubulovesicula laticaudi Parukhin, 1969 (= T. orientalis Chattopadhyaya, 1970 n. syn.) is reported from Sri Lanka, collected from Shaw's sea snake Hydrophis curtus (Shaw) (Elapidae: Hydrophiinae: Hydrophinii), the annulated sea snake H. cyanocinctus Daudin and the yellow sea snake H. spiralis (Shaw) off Nayaru in the Bay of Bengal, and from H. spiralis in Portugal Bay, Gulf of Mannar. Novel molecular data, for COI mtDNA and ITS2 and 28S rDNA, are the first for a species of Tubulovesicula Yamaguti, 1934. Nominally, Tubulovesicula belongs in the Dinurinae Looss, 1907, but in phylogenetic analyses based on 28S rDNA, our sequences for T. laticaudi resolved relatively distant from that for representatives of Dinurus Looss, 1907, the type-genus, rendering the subfamily polyphyletic. Tubulovesicula laticaudi resolved closest to data for the type-species of the Plerurinae Gibson & Bray, 1979, but that subfamily is also polyphyletic. These findings lead us to re-evaluate an alternative classification considered by Gibson & Bray (1979). We propose restricting the Dinurinae for forms with a permanent sinus-organ (Dinurus, Ectenurus Looss, 1907; Erilepturus Woolcock, 1935; Paradinurus Vigueras, 1958; Qadriana Bilqees, 1971) and resurrect the Mecoderinae Skrjabin & Guschanskaja, 1954 for forms with a temporary sinus-organ (Mecoderus Manter, 1940, Allostomachicola Yamaguti, 1958, Stomachicola Yamaguti, 1934 and Tubulovesicula).

Descriptions of Two Digenean Trematodes Found from a Chinese Sea Snake, Laticauda semifasciata, in Republic of Korea

We intended to describe 2 digenean trematodes found from a Chinese sea snake, Laticauda semifasciata, as the new fauna in the Republic of Korea. The snake was caught offshore of Aewol-eup, Jeju-do, in August 2017. Two species of fluke were found in the lung and intestinal tract of the snake in the process of necropsy. They were identified as Pulmovermis cyanovitellosus Coil and Kuntz, 1960 and Harmotrema laticaudae Yamaguti, 1933, respectively based on the morphological characters. Pulmovermis cyanovitellosus showed elongated body with well-developed and elongated male genital system and compact vitelline. And H. laticaudae was characterized by linguiform body with heavily armed cirrus with excretory system. This is the first time both species have been reported and described off the Korean coast. We provide morphological descriptions with some comments on their biology and geographical distribution. In addition, the taxonomic validity of the genus Hydrophitrema Sandars, 1960 was discussed, in terms of morphological descriptions and host ranges. This study provides novel insight into digenean fluke species existing off the coast of Korea.