Sarcocystis platyrhynchosi, Hu & Zhang & Wu & Zeng & Tao, 2023

Hu, Junjie, Zhang, Mingzhu, Wu, Zhipeng, Zeng, Hongxia & Tao, Jianping, 2023, Description of SarCoCYSTIS PlaTYrhYNChoSI n. sp. (Apicomplexa: Sarcocystidae) from domestic ducks ANaS PlaTYrhYNChoS (Anseriformes: Anatidae) in China, Parasites & Vectors (50) 16 (1), pp. 1-8 : 5

Family Sarcocystidae Poche, 1913

Sarcocystis platyrhynchosi n. sp.

Diagnosis: Te sarcocysts were microscopic, up to 1694 μm long and 140 μm wide. Numerous brush–like vps of 3.8–4.3 μm in length were present on the cyst surface. TEM observation revealed that the sarcocysts had lanceolated vps of 2.3–2.5 × 0.3–0.5 μm, which narrowed in the stalk. Each vps contained bundled microtubules at the core that penetrated diagonally into the ground substance.

Taxonomic summary

Type intermediate host: Domestic duck Anas platyrhynchos .

Type locality: Shuangtu (31°15ʹ59 ʺ N, 108°94ʹ15 ʺ E, altitude 495 m a.s.l.), Yunyang County, Chongqing City , China .

Site of infection: Muscular tissues.

Definitive host: Unknown.

Etymology: Latin name of the intermediate hosts is used to name the species.

Molecular characterization: Sequences of the 18S rDNA (OP480004), 28S rDNA (OP480004) and mt cox 1 (OP485287) of the new species have been deposited in GenBank. At the 28S rDNA and mt cox 1 sequences, S. platyrhynchosi is unambiguously differentiated from Sarcocystis spp. obtained from Anseriformes birds.

Deposited specimens: Formalin–fixed tissues containing cysts of S. platyrhynchosi , as well as photomicrographs from LM and TEM examination of the sarcocysts, have been deposited at the Zoological Specimen Museum of Yunnan University, Kunming, China (collection number Prot202205) .

ZooBank registration: To comply with the regulations set out in Article 8.5 of the amended 2012 version of the International Code of Zoological Nomenclature [ 9], details of the new species have been submitted to ZooBank. Te Life Science Identifier ( LSID) of the article is urn:lsid:zoobank.org:pub:4FA38B3B-4505-4EF4-AC87-14067AD9FA7A . Te LSID for the new species name Sarcocystis platyrhynchosi is urn:lsid:zoobank.org:act:D1663E66-23C2-4E50-96C5-9E336318C8EE .

Remarks

To date, only four named Sarcocystis species ( S. rileyi , S. wobeseri , S. anasi and S. albifronsi ) and two unnamed Sarcocystis species have been recorded in avian intermediate hosts of the order Anseriformes ( Table 2). Among these, sarcocysts of S. rileyi are macroscopic, and those of the remaining five species are microscopic. Te LM study revealed that the sarcocysts of S. rileyi , S. wobeseri and Sarcocystis sp. 2 ex Anser caerulescens have thin and smooth walls, and that those of S. anasi , S. albifronsi and Sarcocystis sp. 1 ex A. caerulescens have thick and striated walls characterized by radial spines- or finger-like vps on the cyst surface. Te unltrastructures of the sarcocysts previously described from avian species of Anseriformes are categorized into three TEM wall types according to the classification provided by Dubey et al. [ 1]. One type includes vps with anastomosing branches that is similar to type 23 in S. rileyi ; the second type has minute undulations on the cyst wall that is similar to type 1d for S. wobeseri and Sarcocystis sp. 2 ex A. caerulescens ; and the third type has finger-like vps arranged in a palisade fashion that is similar to type 9a for S. anasi , S. albifronsi and Sarcocystis sp. 1 ex A. caerulescens . In our material, S. platyrhynchosi sarcocysts had short, brush– like vps on the cyst surface. Te TEM study revealed that the lanceolated vps had a narrow stalk and contained bundled microtubules that penetrated diagonally into the ground substance; this is roughly similar to the TEM wall type 9d or 11a based on outlines of the lanceolated vps or the features of bundled microtubules extended into ground substance, respectively. Tis TEM wall type differs remarkably from those of Sarcocystis spp. obtained previously from wild mallard ducks and other species of Anseriformes .