Ectoparasite communities on the gills of peruvian morwong Cheilodactylus variegatus Valenciennes 1833 (Pisces: Cheilodactylidae)

A research to study ectoparasite infracommunities from branchials on some community components of parasitefauna of 80 Cheilodactylus variegatus (32 females and 48 males) collected from Chorrillos Fishmarket, Lima, Perú, between May and July 1996 xas done. Fishes showed a standard length between 16.10 and 28.50 cm (mean = 21.58 ± 2.64). 604 specimens were collected with a mean abundance of 7.42 (1-36). The mean parasite species richness 1.3 (1-3) was not correlated with standard body length. Two fishes were not infected, 53 (66.25%) showed infection with 1 parasite species, and 24 (30%) and 1 (1.25%) had multiple infection, 2 and 3 parasite species, respectively. We found three ectoparasites: Paramicrocotyle nemadactylus (Prevalence = 91.25%; mean Intensity = 7.21; mean Abundance = 6.46 ± 7.30), Clavellotis dilatata (Prevalence = 36.25%; mean Intensity = 2.58; mean Abundance = 0.93 ± 2.03) and Caligus cheilodactylus (Prevalence = 2.50%; mean Intensity = 1; mean Abundance = 0.02). We did not find effect of sex and standard length with prevalence and mean abundance of infection of the first two ectoparasites. A slight interspecific association and covariations between abundance of. P. nemadactylus and C. dilatata employed comparatively seven indexes of association as Dice (0.470), Jaccard (0.800), Sörensen (0.888), Ochiai (0.521), Kulczynski 2 (0.578), Coeficient f (0.599), Forbe (0.906) and correlation of Pearson (r = 0.125; P = 0.271). The mean diversity in the infracommunities of C. variegatus was (H′)= 0.1722; The relative diversity was (J') = 0.3609 and Simpson Index (C) = 0.9846. P. nemadactylus and C. dilatata showed the higher prevalence and mean abundance of infection with the first gill.