Lepeophtheirus pectoralis Lepeophtheirus pectoralis Lepeophtheirus pectoralis is a species of parasitic copepod. It is a parasite of flatfish, the most frequent hosts being the European flounder ("Platichthys flesus"), the plaice ("Pleuronectes platessa"), and the dab ("Limanda limanda"). It feeds on the mucus, skin and blood of the fish, with oviferous females being found in the pectoral and pelvic fins of the host, while immature individuals and males are found in the rest of the body. Its life cycle consists of five phases and ten stages. The first two stages are free swimming nauplius I and II, while the third stage is the
Hypselodoris kanga white. The inner edge of each gill is reddish orange in the upper quarter, deep blue in the mid region and white in the basal quarter. The smooth outer side of each gill is orange-red in the upper quarter and the rest has a background colour of light blue with a row of large yellow spots. The two outer corners of each gill are bordered with red at the tip becoming dark blue at the base. This species can reach a total length of at least 70 mm and has been observed feeding on yellow sponges from the genus "Dysidea".