Lernaeid parasites prevalence in commercial freshwater fish species at various fish farms in Pakistan

Abstract

Reports abound on Lernaea parasitizing the brood stock, fingerlings, and marketable-sized culturable freshwater fish species in various parts of the world. We investigated seven small-scale aquaculture farms and how the prevailing Lernaea is impacting them. Randomly seven fish farms were selected to determine the prevalence percentage of lernaeid ectoparasites. Relevant information of the fishponds to estimate the various aspects such as effects of water source and quality, feed, stocking density, treatment used, and weight and length of fish, concerned with Lernaea infestation and prevalence was gathered. The results indicated that Catla catla (F. Hamilton, 1822) showed highest prevalence (41.7%) among the seven fish species, whereas Oreochromis niloticus showed zero. Other five fish species Ctenopharyngodon idella, Cirrhinus cirrhosis, Cyprinus carpio, Labeo rohita and Hypophthalmichthys molitrix showed 13.2%, 8.1%, 7.7%, 7.4%, 0.9% prevalence, respectively. In Royal Fish Farm 84.3% lernaeid infestation was observed, while no parasite was observed in the Vicent’s Chunnian fish farm. The water source, quality, feed, fertilizers, stocking density, water temperature, and potential treatment options displayed varying tendencies among fish farms and prevalence. Depending on the weight and length, the highest prevalence (56.7%, and 66.7%) was observed in 3501-4000 g and 81-90 cm groups. The infestation rate varied in various fish body parts with the dorsal fin the most vulnerable organ and showed 2.3% overall prevalence (while 18.4% contribution within total 12.6% infestation). Out of 147 infected fish samples, 45 were extensively contaminated by Lernaea spread. In conclusion, our findings confirm that Lernaea could pose a considerable threat to marketable fish, and various treatment options should be educated to the farmers to help mitigate the spread and potential losses. Furthermore, Catla catla is more vulnerable to Lernaea infestation (41.7%), so are the fish species being cultured at higher stocking densities.

Prevalence of Lernaea cyprinacea Infections in Indian Major Carp at Fish Farms of Bihar, India

“…The results of the present study showed that Lernaea cyprinacea has a higher prevalence in L. catla (41.30%) as compared to the other fishes (L. rohita and C. mrigala) present in the same ponds. The results were agreed with Tasawar et al [20] who reported 96 infected L. catla fish samples (prevalence 80%) out of 120, and Bilal et al [21] who reported 60 infected L. catla fish samples (prevalence 41.7%) out of 144. Apart from this Abbas et al [22] reported the highest number of Lernaea (100) in L. catla, and Aslam et al [23] showed more prevalence of Lernaied parasite in Indian Major Carp.…”

Molecular and morphological identification of Lernaea spp. in Cyprinid fishes from two districts in Yogyakarta, Indonesia

“…The pH, oxygen, temperature, and salinity values were within the anticipated range [ 38 , 39 ]. Along with stocking density, climatic factors, and environmental conditions play a significant role in the prevalence of Lernaeid ectoparasites at various geographic locations [ 4 ].…”

“…Parasitic infection is a common illness affecting freshwater ornamental fishes. Parasites in fish may impede development and cause death, resulting in decreased fecundity [ 4 ].…”

Identification of Lernaea Species in Icthyofauna in District Mardan KPK, Pakistan

“…The parasite Laernaea cyprineace is most abundant and harmful among the members of the family Larnaea. (Bilal et al, 2021). The Lernaeid are the sh parasites that belong to the main group of Crustacea (Copepoda).…”