Argulus sp. is well known as “Fish louse”. Argulus sp. is an ectoparasite mostly found on body surface and fins of fish. Body of Argulus spp. is divided into three regions: cephalothorax, thorax and abdomen. Length 3.00 — 5.12 mm. Body dorso-ventrally flattened. Two sucker to attach with fish. One pair of compound eye present that can be moved. Both reproductive and breathing organs are situated in the tail. Mouth is situated behind the probosis. Female is larger than male. The disease caused by Argulus sp. called argulosis.
Lernaea sp. is most harmful, parasite of cultured freshwater fish commonly name anchor worm. It is a copepod parasite. Elongated form with two anchoring device at the head to attach. Two greenish egg sacs at the posterior end. There are some small swimming legs which are very minute is numbers. Females are parasitic and males are free living, length 1.15- 1.52 mm (Without Uropod) and width 0.124-0.133 mm. The disease caused by Lernaea sp. called Lemaeosis.
It is a Nematode parasite, generally found in the intestine. Body cylindrical, filiforms and covered with a strong protecting cuticle which is flexible. Mouth is dorsoventrally slight bounded by six papillae. Male comparatively smaller than female. Male, body length 5.97-6 83 mm and width 0.91-1.12 mm. Female body length 8.78-8.96 mm and width 0.97-1.89mm. The disease caused by Procamallanus sp. called Procamallanosis
Lytocestus sp. is a parasite. It is known as “Entire worm”. Body elongated, dorsoventrally flattened, unsegmented leaf like. Tapering anteriorly into scolex, head consists of scolex and neck, scolex variable in shape, undifferentiated. Neck not markedly distinguished from scolex or trunk. Body length 15.23 – 18.11 mm and width 2.00 -3.54 mm. They are mainly found in shing, taki, magur etc. The disease caused by Lytocestus sp. called Lytocestosis
It is another Monogenean parasite, well known as skin fluke. Body length 0.400-0.413 mm and width 0.124-0.133 mm. Body ventrally flattened. Anterior end of body has two points and has no eyes. At hind end a disc-shaped attachment organ present bearing two central books surrounded by 16 smaller hooks. Various species of fish are affected by this parasite, mainly shing. Carp fish etc. The disease caused by Gyrodactylus sp. called Gyrodactylosis