biostudies-literatureMorales-Avila JRProfessorship Aquaculture and Sea-Ranching, GermanyCentro Interdisciplinario de Ciencias Marinas-Instituto Politécnico Nacional, MexicoConsejo Nacional de Ciencia y Tecnología, MexicoCONACYTBEIFI-IPNInstituto de Ciencias del Mar y Limnología from the Universidad Nacional Autónoma de México, Mexico138-148https://www.ebi.ac.uk/biostudies/studies/S-EPMC6732713biostudies-literatureUnknown10Plerocerci of the monotypic <i>Paranybelinia otobothrioides</i> were found parasitizing the subtropical neritic krill <i>Nyctiphanes simplex</i> in the Gulf of California, Mexico. The plerocerci were recovered from two microhabitats of the intermediate host, typically embedded inside the digestive gland (hepatopancreas) or rarely in the hemocoel. The morphology of the simple, single-layered blastocyst surrounding the entire scolex is unique within the Trypanorhyncha by having four large funnel-like pori or openings possibly with feeding and/or excretory function. One of the openings is located anteriorly and three at the posterior end. Scolex surface ultrastructure shows hamulate and lineate spinitriches covering the bothrial surface, capilliform filitriches at the anterior scolex end and International journal for parasitology. Parasites and wildlifePhylogenetic placement and microthrix pattern of <i>Paranybelinia otobothrioides</i> Dollfus, 1966 (Trypanorhyncha) from krill <i>Nyctiphanes simplex</i> Hansen, 1911.PMC673271320150113176164CONACYT-SAGARPA 2005-C01-11717IN202319IN200610-32016-C01-28420120130224CONACYT-FOSEMARNAT 2004-C01-0014420160495PAPIIT-UNAM IN210622SIP 2007027920140497CONACYT Ciencia Básica 2012- C0-1178615201209482010-C01-15285020195039IN21810620080490Palm HWMorales-Avila JRHernandez-Saavedra NYGomez-Gutierrez JRobinson CJfalsePhylogenetic placement and microthrix pattern of <i>Paranybelinia otobothrioides</i> Dollfus, 1966 (Trypanorhyncha) from krill <i>Nyctiphanes simplex</i> Hansen, 1911.Plerocerci of the monotypic <i>Paranybelinia otobothrioides</i> were found parasitizing the subtropical neritic krill <i>Nyctiphanes simplex</i> in the Gulf of California, Mexico. The plerocerci were recovered from two microhabitats of the intermediate host, typically embedded inside the digestive gland (hepatopancreas) or rarely in the hemocoel. The morphology of the simple, single-layered blastocyst surrounding the entire scolex is unique within the Trypanorhyncha by having four large funnel-like pori or openings possibly with feeding and/or excretory function. One of the openings is located anteriorly and three at the posterior end. Scolex surface ultrastructure shows hamulate and lineate spinitriches covering the bothrial surface, capilliform filitriches at the anterior scolex end and 2019-01-01T00:00:00Z2019 Dec2026-04-07T14:20:13.617Z2026-04-07T14:00:54.918ZS-EPMC67327133151682510.1016/j.ijppaw.2019.08.006