El parasitismo por Profilicollis bullocki (Acanthocephala: Polymorphidae) en Emerita analoga (Anomura: Hippidae) según condiciones contrastantes de abundancia de hospedadores definitivos en Chile

Abstract

In Chile, the intermediate host of the acanthocephalan Profilicollis bullocki is the mole crab Emerita analoga, with seabirds as the definitive hosts, who arrive in mass during summer, enhancing the spread of acanthocephalan eggs to the environment. Thus, the magnitude of this parasitosis in E. analoga should attain higher values after the yearly arrival of seabirds. This study was performed in two periods contrasting in the abundance of marine birds, September-November 2008 (late winter-spring) and December 2008-January 2009 (summer), at 3 sandy beaches of the Biobío region, Chile. The abundance of birds was highest in summer, mainly due to the arrival of the Franklin`s gull Larus pipixcan to the study sites. It was observed that the cephalotorax length (LCT) of E. analoga was much smaller in summer than in spring, and that the prevalence and abundance of P. bullocki increased with LCT. Although the prevalence of P. bullocki was higher before the arrival of birds, the slopes of the linear regressions between the abundance and intensity with LCT were higher after the arrival of the birds to the study sites. These results are partly explained by the comparatively large LCT of mole crabs before the arrival of seabirds, and by an intense recruitment pulse of small E. analoga after the arrival of seabirds, thus provoking a dilution effect on the prevalence.

Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

“…The life cycles of almost all acanthocephalan and digenetic species, as well as some nematodes and cestodes, include at least one intermediate host that accumulates parasites over time ( Thomas, Guégan & Renaud, 2009 ). In addition, size-dependent responses of prevalence to parasite exposure have been demonstrated in other complex host-parasite interactions involving migratory birds and crustaceans ( Latham & Poulin, 2003 ; Smith, 2007 ; Zambrano & George-Nascimento, 2010 ). In the same line, parasite burden increases with body size of the toadfish Aphos porosus Valenciennes, 1837, an intermediate host of cestodes, nematodes, trematodes, and acantocephalans ( Cortés & Muñoz, 2008 ).…”

“…We observed that molecrab recruitment strongly varied across geographic locations, with site-dependent peaks occurring in summer, autumn, and spring (but see Contreras, Defeo & Jaramillo, 1999 ). An increase in non-infected recruits can have negative (positive) effects on prevalence (aggregation) across the host population (e.g., Zambrano & George-Nascimento, 2010 ), which might decouple the relationship between exposure and the parasitosis in the intermediate host. Further field-based comparative experiments would be useful to tease apart the effects of exposure, egg mortality, and recruitment timing on parasite aggregation.…”

A comparative assessment of the morphology ofProfilicollis altmani(Acanthocephala, Polymorphidae) from crustaceans and shore birds in Peru, with special notes on hook elemental analysis (EDXA), SEM imaging, histopathology, and molecular profile

“…Most of the host related environmental work pertaining to this species, was, however, reported from Pacific South America. In Chile, sea birds arriving in mass numbers during the summer enhance the spread of acanthocephalan eggs to the environment, producing higher values of infection in E. analoga [ 58 , 80 ]. The identity of definitive host species was found to be relevant to morphometric and reproductive variations (fecundity) of P. altmani with acanthocephalans of 2 species of Larus attaining larger body size than those in 2 other genera of gulls from the Chilean coast [ 56 ].…”

Parasite burden in decapod crustaceans from the central coast of Chile: is there any association with the relationship with definitive host abundances?

“…Esto demuestra que altas cargas de parásitos en sus hospedadores intermediarios no implica que estén en lugares con altas abundancias de hospedadores definitivos, especialmente al relacionarlos con hospedadores secundarios (e.g., digéneos en crustáceos). Existen algunos estudios, que han encontrado relaciones significativas entre la abundancia de hospedadores definitivos y la prevalencia o abundancia de parásitos en hospedadores intermediarios (e.g., Fredensborg et al, 2006;Zambrano & George-Nascimento, 2010), pero esto depende del ciclo de vida de los parásitos y de su transmisión. Por ejemplo, las aves que tienen digeneos adultos pueden liberar los huevos del parásito en las heces, en zonas intermareales donde se encuentran los hospedadores intermediarios, es decir gasterópodos que son directamente infectados con larvas miracidios de digeneos que eclosionan de los huevos.…”

“…En el ambiente marino, los crustáceos son depredados por un vertebrado (pez, ave o mamífero) donde el endoparásito se desarrolla hasta alcanzar el estado adulto (Rohde, 2005). Sin embargo, a pesar de la importancia que cumplen los crustáceos en el ciclo de vida de endoparásitos marinos, en Chile son muy pocos los estudios parasitológicos realizados en crustáceos decápodos (Muñoz & Olmos, 2008;Oliva et al, 2008;Saldanha et al, 2009;Zambrano & George-Nascimento, 2010), sobre todo en aquellos que habitan en pozas del intermareal rocoso, pese a la alta abundancia que tienen en este ambiente.…”