Seasonal occurrence of the tapeworm Proteocephalus longicollis and its transmission from copepod intermediate host to fish

Abstract

Seasonal occurrence in terms of prevalence, intensity of infection, abundance and density of the tapeworm Proteocephalus longicollis (Zeder, 1800) and its transmission between its intermediate host (Cyclops abyssorum prealpinus) and definitive host (common whitefish, Coregonus lavaretus) in Lake Annecy, an oligotrophic lake in the western part of the Alps, France, were studied in the period of 1998-2000. A copepod Cyclops abyssorum prealpinus (Kiefer, 1939), the dominant species among planktonic crustaceans in the lake, served as the only intermediate host for this parasite. Infection with plerocercoids was higher in adult copepods (predominantly females) than in copepodite stages IV and V. The prevalence rate of 25% found in C. abyssorum prealpinus females in June 1998 represents a unique infection rate of intermediate hosts with fish tapeworms in natural conditions. The final host, the common whitefish Coregonus lavaretus (L.), was heavily infected with P. longicollis throughout the year (prevalence 90%; mean abundance 40.3; maximum intensity of infection more than 500 tapeworms per fish); immature tapeworms predominated in all samples (P<0.01). Transmission of tapeworm larvae from copepods to the common whitefish took place most intensively in summer and autumn, and depended on seasonal changes in the density of the C. abyssorum prealpinus population, infection of this copepod with plerocercoids and their density in the lake. In addition, transmission efficiency also seems to be determined by the longevity of tapeworm larvae in the intermediate host, timing of predation of the fish host and rapid development of the parasite within this host during the summer period. Overall transmission potential of P. longicollis was low, with only about 9% of juvenile specimens reaching maturity in common whitefish.

Seasonal variation of parasitism in pejerrey Odontesthes bonariensis (Atheriniformes, Atherinopsidae) from La Viña reservoir (Córdoba, Argentina)

“…Therefore, the lack of association between body condition and C. macdonaghi burden, sounds biologically feasible. The positive correlation observed between parasite density and Wr may be indicative of a higher consumption of copepods, the intermediate host (HANZELOVA;GERDEAUX, 2003;PIASECKI et al, 2004). The zooplankton consumption rate (COLAUTTI et al, 2003) and gonadal maturity that happened by the end of winter, may have also implication on the pejerrey Wr.…”

“…An optimal pejerrey production may be challenged by high parasite burden or prevalence (MANCINI et al, 2005). The fish parasite life cycle involves invertebrates and vertebrates as intermediate hosts such as planktonic crustaceans, fishes and birds (HANZELOVA; GERDEAUX, 2003;MARTINS et al, 2005). The pejerrey is a zooplanktivore fish, fed primarily microcrustaceans (Cladocera and Copepoda).…”

Seasonal changes of immunocompetence and parasitism in chub (Leuciscus cephalus), a freshwater cyprinid fish

“…The seasonal dynamic of glochidium was studied for three species of freshwater fish, where higher abundance was connected predominantly with spring (Blažek and Gelnar 2006 (Hanzelová and Gerdeaux 2003) or seasonal composition of fish food for nematode Raphidascaris acus (Šimková et al 2005) are the factors facilitating the success of the complex life cycle. These features could also explain the seasonal repartition of the endoparasite species in chub.…”

Associations between fish reproductive cycle and the dynamics of metazoan parasite infection

“…The presence and efficiency of crustacean intermediate hosts and the transfer to definitive hosts are crucial for the seasonal dynamics of Proteocephalus species (Kennedy and Hine 1969;Scholz 1999;Hanzelova´and Gerdeaux 2003).…”