Fish parasites can reflect environmental quality in fish farms

Abstract

In the aquatic environment, fish are subject to different pollutants and environmental variations that favour stress on animals, making them vulnerable to pathogens. Fish parasites are excellent biological indicators of environmental quality, as their parasitic population may increase or decrease in response to changes in water parameters and/or the presence of pollutants. Ectoparasites are considered excellent indicators of environmental quality because they have a monoxenic life cycle with high reproductive rates that have been responsible for the immediate response to changes in aquatic biota. In turn, parasites with a heteroxenous life cycle are also responsive to environmental variation because, with the mortality of intermediate hosts, their population can be easily changed. However, studies with endoparasites and their relation with the environment are more numerous, as they are accumulators of pollutants, especially trace elements, either via fish or through stages of development outside the host that also contribute to the accumulation of metals. Moreover, Digenea, Acanthocephala, Nematoda and Cestoda parasites can compete for trace elements that are bioavailable in the environment, as fish with a greater abundance of parasites have a lower concentration of toxic metals in their tissues. Furthermore, they have a high affinity for trace elements that are toxic to human and fish health (arsenic, mercury, lead and cadmium). This review is a comprehensive overview of the use of fish parasites as environmental sentinels and describes their potential as bioindicators of effect and accumulation, and evaluates their application in fish farms environments.

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“…), Ergasilus sp., Maxillopoda, Nematodes (Anisakis sp. ), Isopods and Helminthes (Jerônimo et al 2022;Hoai 2020;Diamant et al 2001). The highest prevalence of infection observed was with the gill racks, which were Flukes (helminthes), Isopods and monogeneans and were recorded in nearly 88% of the examined fish.…”

Comparison of Ectoparasites infestation for fresh and saltwater Fishes from Euphrates, and Razzaza Lake, Iraq

“…Fish parasites serve as valuable biological indicators for assessing environmental quality due to their ability to respond to changes in water parameters and the presence of contaminants, leading to fluctuations in their population (3). Tilapia, a kind of fish, has been widely distributed worldwide.…”

“…Diseases in fish, especially those caused by parasites, can cause a decrease in the quality of fish and health problems in humans (2). Ectoparasites are widely recognized as valuable indicators of environmental quality due to their monoxenic life cycle characterized by rapid reproduction rates, enabling them to promptly respond to changes in aquatic biota (3).…”

Inventarisasi Ektoparasit Ikan Lele (Clarias Sp. ) Dan Nila (Oreochromis Niloticus) Di Kabupaten Timor Tengah Utara

“…Namun produksi akuakultur masih terkendala masalah penyakit seiring meningkatnya intensifikasi akuakultur [3], [4]. Salah satu penyakit yang sering menyerang ikan dan menyebabkan pertumbuhannya terhambat adalah parasit [5], [6], selain itu parasit juga dapat menyebabkan infeksi sekunder pada ikan [7] Parasit dapat bertahan dalam lingkungan akukultur dan menjadi berbahaya ketika intensitasnya tinggi sehingga dapat menyebabkan penyakit pada ikan [8], oleh sebab itu keberadaan parasit pada ikan dapat juga digunakan sebagai indikator biologis kualitas lingkungan suatu lokasi perairan [9], [10]. Parasit pada lokasi akuakultur juga dapat masuk karena masuknya jenis ikan yang baru [11].…”