Rajendra Prasad Singh1, Umapati Sahay2 & Pallavi Singh3
1. HOD, Dept. of Zoology, Marwari College, Ranchi.
2. Former University Professor & Head, Dept. of Zoology, Ranchi University & Dean Faculty of Science.
3. Research Scholar, V.B.U.
Received ………………….. Revised……………………
Abstract : Population dynamics of the helminths viz, Procamallanus spiculogubernaculus Agarwal (1958)1; Lytocestoides species and Crecentovitus biloculus Murhar (1963)2 harbouring Heteropneustes fossilis have been worked out. Following observations were made.
Highest incidence of P. spiculogubernaculus was in June in males and in May in females, of Lytocestoides species in March in males and in August in females and of C. biloculus in July in both sexes.
Highest intensity of P. spiculogubernaculus was in June in males and in May in females, of Lytocestoides species in April in males and females and of C. biloculus in September in both sexes.
Infection by single species of the helminth was observed in 71.72 %, by two species in 7.87 % in male fishes, whereas it was 74.16 % by one species and 9.62 % by two species in female fishes. This is due to competitive exclusion.
The density of P. spiculogubernaculus was maximum in June in males and in May in females, of Lytocestoides species in April in males and in August in females. The minimum density of P. spiculogubernaculus was in January in both sexes, of Lytocestoides species in August in males and in April in females, of C. biloculus in September in both sexes.
The relative density P. spiculogubernaculus was maximum during May and June and in October to February in both sexes, but was lowest during August in both sexes; of Lytocestoides species it was highest during April in male and during August in female fishes; of C. biloculus it was highest in August and lowest in September in both sexes.
The index of infection of P. spiculogubernaculus was maximum in June in males and in May in females; of Lytocestoides species during August in both sexes; of C. biloculus in July in both sexes. Lowest index of infection of P. spiculogubernaculus was in January in both sexes, of Lytocestoides species in July in males and in April in females, of C. biloculus in September in both sexes.
The highest dominance percentage of P. spiculogubernaculus was during June in males and during May in females, of Lytocestoides species during April in males and during July in females, of C. biloculus in July in both sexes. The lowest dominance percentage of P. spiculogubernaculus was in November in both sexes, of Lytocestoides species in August in males and during March in female fishes, of C. biloculus in September in both sexes.
In all the above helminths, the variance is greater than mean but the value of variance is higher in P. spiculogubernaculus than the rest of the two. This depicts that parasites are over-dispersed.
The observations made above have been explained scientifically giving plausible reasons in the light of researches done in past in the area of larval arrest, type of turn over, life cycle patterns, impact of climatic change and abiotic factors, reservoir parasitism, sex versus incidence, competitive exclusion, interaction among parasites, concurrent infection, r-k strategy, biochemical hostility, over dispersion and level of equilibrium.
Be First to Comment