Helminth Community of Catla catla (Hamilton, 1822) in River Indus at Jamshoro, Sindh, Pakistan:Taxonomy, Prevalence, and Zoonotic Significance of Parasitic Helminths

Abstract

Background: Helminthic parasites present a significant risk to fish health, commercial fisheries and food security in South Asia. Although Catla catla (Hamilton, 1822), one of the most commercially important freshwater carps in the region, was economically important, the helminth fauna of the Indus River in Sindh province had been virtually unrecorded before this work.

Methods: A total of 26 Catla catla samples were taken in the River Indus at Jamshoro, Sindh, Pakistan, between January 2018 and January 2020. Typical parasitological methods such as dissection, teasing, staining (borax carmine), and microscopic analysis were used. Morphotaxonomic identification was done by the use of known taxonomic keys.

Findings: Nine out of 26 hosts (34.6) had helminth parasites. It was possible to identify six helminth taxa: three trematodes: Thaparotrema pedicellatum Verma, 1927; Isoparorchis trisimilitubis Southwell, 1913; Echinochasmus Dietz, 1909; two nematodes: Procamallanus (Spirocamallanus) sp. and R All taxa are new host or locality records. The prevalence of trematodes was 23.07, nematodes 7.69 and acanthocephalans 3.84.

Conclusions: This paper is the first detailed morphotaxonomic description of the helminth community of the Catla catla in the Indus River at Jamshoro and presents six new records of hosts and locality in Pakistani parasitology. The zoonotic potential of Echinochasmus and the ill-known acanthocephalan Dispirin highlights the importance of scaled-up parasitological surveillance in Pakistani freshwater fisheries.

Keywords: Catla catla; Helminthology; Trematoda; Nematoda; Acanthocephala; Indus River; Parasitology; Pakistan; Zoonosis; Fish parasites.