Page 56 - 《渔业研究》2025年第5期

第 5 期 丁 鹏等： 光唇鱼寄生济宁碘泡虫新种的鉴定和描述 597

Identification and description of Myxobolus jiningensis n. sp. from
Acrossocheilus fasciatus

DING Peng，ZHANG Xiaoyi，NIE Pin，LIU Yang *
(School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China)

Abstract: [Objective] This study aims to identify the Myxobolus species infecting the gills of Acrossocheilus
fasciatus. [Methods] Morphological, histological and molecular analyses were carried out to characterize this
parasite. [Results] It formed elliptical plasmodia in gills of fish host, with 96 μm long and 58 μm wide. Mature
spores were pyriform in valvular view, measuring (11.5±0.3) μm (11.2–12.4 μm) in length and (6.1±0.3) μm
(5.2–6.4 μm) in width. Two equal-sized polar capsules were pyriform, measuring (6.0±0.5) μm (5.1–6.9 μm) in
length and (2.2±0.1) μm (2.0–2.5 μm) in width, each with 4–6 polar-filament coils. Comparison with all de-
scribed Myxobolus spp. revealed that the present Myxobolus species did not match any known species. Histolo-
gical examination showed the parasite located within the gill lamellae of A. fasciatus, with plasmodia contain-
ing spores at various developmental stages. SSU rDNA sequence analysis demonstrated that the sequence of this
Myxobolus species did not match any sequence in GenBank database. The present Myxobolus species showed
the highest genetic similarity to M. dykovae (EU643627) and M. tasikkenyirensis (EU643626), with sequence
identities values of 94.16% and 92.60%, respectively. Phylogenetic analysis placed the present Myxobolus spe-
cies in a distinct clade with other gill-parasitic Myxobolus spp. [Conclusion] Consequently, this parasite infect-
ing the gills of A. fasciatus is identified as a novel Myxobolus species, named M. jiningensis n. sp. It is the first
myxosporean species reported from A. fasciatus, providing baseline data for future studies on the myxosporean
parasites of this fish.
Key words: Acrossocheilus fasciatus; Myxobolus jiningensis n. sp.; SSU rDNA sequence; species identification