{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:59:15Z","timestamp":1790762355798,"version":"4.1.0"},"reference-count":33,"publisher":"Cambridge University Press (CUP)","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"unspecified","delay-in-days":272,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Helminthol."],"published-print":{"date-parts":[[2026]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    The structure of the praesoma in the acanthocephalan\n                    <jats:italic>Arhythmorhynchus teres<\/jats:italic>\n                    Van Cleave, 1920 at the middle acanthella I stage has been examined by light and transmission electron microscopy methods. Acanthocephalan specimens were retrieved from naturally infected intermediate hosts,\n                    <jats:italic>Bulychevia ochotensis<\/jats:italic>\n                    (Brandt, 1851) (Amphipoda, Talitridae). In the studied acanthellae, the primordia of the proboscis receptacle, proboscis, circular muscles, proboscis retractor, and cerebral ganglion are clearly differentiated in the praesoma. The tegument contained giant nuclei arranged into annular rows oriented transversely to the longitudinal axis of the body. At the anterior pole of the acanthellae, three apical nuclei were present; they were densely grouped and considerably smaller than the giant nuclei. The proboscis primordium consisted of vertical cytoplasmic strands (hook primordia) that, together with the basal cytoplasm of the anterior pole tegument, formed an outgrowth protruding into the acanthella\u2019s body cavity. Thus, similar to the other members of the class Palaeacanthocephala, the proboscis of acanthocephalan\n                    <jats:italic>A. teres<\/jats:italic>\n                    is initially formed in an inverted state. Two layers of muscles surround the proboscis: the proboscis retractor and a layer of circular musculature that closely surrounds the developing proboscis, forming a muscular sheath. Six nuclei are found in certain areas of the cytoplasm of the circular muscles. The tubular proboscis retractor surrounds the proboscis together with the primordium of circular musculature, extends around the cerebral ganglion, and attaches to the base of the proboscis receptacle. Four nuclei at the apex of the inverted proboscis were located in the cytoplasm of the hook primordia, while another two nuclei were in the cytoplasm of the circular musculature primordium.\n                  <\/jats:p>","DOI":"10.1017\/s0022149x26102429","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:02:48Z","timestamp":1790758968000},"source":"Crossref","is-referenced-by-count":0,"title":["Microanatomy and ultrastructure of praesoma in acanthellae of\n                    <i>Arhythmorhynchus teres<\/i>\n                    Van Cleave, 1920 (Acanthocephala: Palaeacanthocephala)"],"prefix":"10.1017","volume":"100","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9497-584X","authenticated-orcid":false,"given":"E.","family":"Skorobrekhova","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/05t43vz03","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Biological Problems of the North FEB RAS"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"S0022149X26102429_r18","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s004360100380","article-title":"Ultrastructure of the acanthella of Paratenuisentis ambiguus (Acanthocephala)","volume":"87","author":"Hehn","year":"2001","journal-title":"Parasitology Research"},{"key":"S0022149X26102429_r14","unstructured":"Hamann, O (1891) Die Nemathelminthen. Beitr\u00e4ge zur Kenntnis ihrer Entwicklung, ihres Baues und ihrer Lebensgeschichte. Erstes Heft. Monographie der Acanthocephalen (Echinorhynchen), Ihre Entwicklung, Histogenie, Anatomie, nebst Beitr\u00e4gen zur Systematik und Biologie. Besonderer Abdruck aus der Jenaischen Zeitschrift f\u00fcr Naturwissenschaft (XXV), N.F. (XVIII). Fischer, Jena."},{"key":"S0022149X26102429_r28","doi-asserted-by":"publisher","DOI":"10.2307\/3275416"},{"key":"S0022149X26102429_r1","first-page":"235","article-title":"Description of larval Acanthocephalus parksidei Amin 1975 (Acanthocephala, Echinorhynchidae) from its isopod intermediate host","volume":"49","author":"Amin","year":"1982","journal-title":"Proceedings of the Helminthological Society of Washington"},{"key":"S0022149X26102429_r32","doi-asserted-by":"publisher","DOI":"10.2307\/3276191"},{"key":"S0022149X26102429_r31","doi-asserted-by":"publisher","DOI":"10.2307\/3277770"},{"key":"S0022149X26102429_r30","volume-title":"Morpho-Functional and Phylogenetic Peculiarities of Skin Muscles in Acanthocephalan. Evolutionary Factors of the Formation of Animal Life Diversity","author":"Nikishin","year":"2005"},{"key":"S0022149X26102429_r19","doi-asserted-by":"publisher","DOI":"10.1007\/s004350100039"},{"key":"S0022149X26102429_r17","first-page":"37","article-title":"Fine structure and Energy Dispersive X-Ray Analysis (EDXA) of the proboscis hooks of Rhadinorhynchus ornatus, Van Cleave 1918 (Rhadinorhynchidae: Acanthocephala)","volume":"13","author":"Heckmann","year":"2012b","journal-title":"Scientia Parasitologica"},{"key":"S0022149X26102429_r16","first-page":"27","article-title":"Comparative chemical element analysis using Energy Dispersive X-ray Microanalysis (EDXA) for four species of Acanthocephala","volume":"13","author":"Heckmann","year":"2012a","journal-title":"Scientia Parasitologica"},{"key":"S0022149X26102429_r21","doi-asserted-by":"publisher","DOI":"10.1007\/s00435-001-0054-4"},{"key":"S0022149X26102429_r20","doi-asserted-by":"publisher","DOI":"10.1023\/A:1011925516086"},{"key":"S0022149X26102429_r13","first-page":"199","article-title":"Muscular anatomy of the praesoma of Macracanthorhynchus hirudinaceus (Acanthocephala)","volume":"41","author":"Dunagan","year":"1974","journal-title":"Proceedings of the Helminthological Society of Washington"},{"key":"S0022149X26102429_r24","first-page":"791","article-title":"The development of Polymorphus minutus (Goeze, 1782) (Acanthocephala) in the intermediate host","volume":"141","author":"Hynes","year":"1957","journal-title":"Proceedings of the Zoological Society of London"},{"key":"S0022149X26102429_r12","doi-asserted-by":"publisher","DOI":"10.2307\/3273647"},{"key":"S0022149X26102429_r23","doi-asserted-by":"publisher","DOI":"10.2307\/3280399"},{"key":"S0022149X26102429_r8","doi-asserted-by":"publisher","DOI":"10.14411\/fp.2014.053"},{"key":"S0022149X26102429_r9","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000082342"},{"key":"S0022149X26102429_r7","doi-asserted-by":"publisher","DOI":"10.1017\/S0022149X00034040"},{"key":"S0022149X26102429_r10","doi-asserted-by":"publisher","DOI":"10.2307\/3276777"},{"key":"S0022149X26102429_r3","doi-asserted-by":"publisher","DOI":"10.15407\/zoo2025.05.457"},{"key":"S0022149X26102429_r6","volume-title":"Biodiversity of the Tauysk Bay of the Sea of Okhotsk","author":"Atrashkevich","year":"2005"},{"key":"S0022149X26102429_r15","doi-asserted-by":"publisher","DOI":"10.1017\/S003118200007236X"},{"key":"S0022149X26102429_r11","volume-title":"Biology of the Acanthocephala","author":"Crompton","year":"1985"},{"key":"S0022149X26102429_r33","doi-asserted-by":"publisher","DOI":"10.1016\/S0065-308X(00)46008-2"},{"key":"S0022149X26102429_r2","doi-asserted-by":"publisher","DOI":"10.15407\/zoo2022.04.265"},{"key":"S0022149X26102429_r22","doi-asserted-by":"publisher","DOI":"10.1007\/s00436-017-5398-x"},{"key":"S0022149X26102429_r26","doi-asserted-by":"publisher","DOI":"10.2307\/3272679"},{"key":"S0022149X26102429_r27","doi-asserted-by":"publisher","DOI":"10.2307\/3272873"},{"key":"S0022149X26102429_r5","unstructured":"Atrashkevich, GI (2002) Taxonomic status, distribution, and biology of the acanthocephalan Arhythmorhynchus teres Van Cleave, 1920 (Acanthocephala: Polymorphidae), a background parasite of birds from the Northwest Pacific. In Parazitologicheskiye issledovaniya v Sibiri i na Dal\u2019nem Vostoke (Parasitological Research in Siberia and Far East). Novosibirsk: Lada. [In Russian]"},{"key":"S0022149X26102429_r4","first-page":"28","article-title":"Developmental changes and distribution of chemicals in elemental analysis of acanthocephalan hooks using EDXA and EDAX-TEAM systems","volume":"26","author":"Amin","year":"2025b","journal-title":"Scientia Parasitologica"},{"key":"S0022149X26102429_r25","volume-title":"Biology of the Acanthocephala","author":"Miller","year":"1985"},{"key":"S0022149X26102429_r29","volume-title":"Cytomorphology of Acanthocephalans","author":"Nikishin","year":"2004"}],"container-title":["Journal of Helminthology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0022149X26102429","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:02:52Z","timestamp":1790758972000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0022149X26102429\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026]]},"references-count":33,"alternative-id":["S0022149X26102429"],"URL":"https:\/\/doi.org\/10.1017\/s0022149x26102429","relation":{},"ISSN":["0022-149X","1475-2697"],"issn-type":[{"value":"0022-149X","type":"print"},{"value":"1475-2697","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026]]},"article-number":"e133"}}