Canaania obesa (Platyhelminthes: Dicrocoeliidae): redescription and new hosts records

Abstract

The digenetic trematode Canaania obesa Travassos, 1944 (Dicrocoeliidae) was described as a parasite of the bile ducts of the rodent Akodon cursor Winge, 1887 (Cricetidae) collected in Santa Teresa, state of Espírito Santo, Brazil. In the present study, we report the occurrence of C. obesa infecting three additional sigmodontinae rodent species: Akodon montensis Thomas, 1913; Oligoryzomys nigripes Olfers, 1818 and Nectomys squamipes Brants, 1827, from three municipalities situated at Serra dos Órgãos, Rio de Janeiro, Brazil. Scanning electron microscopy showed that this helminth has a leaf-like shape with conical extremities and the ventral mid body protrudes at the acetabulum level. The microtopography of the tegument shows a heterogeneous surface with smooth or wrinkled areas and several randomly distributed papillae. The cirrus is located just posterior to the oral sucker and is covered by smooth tegument without spines or papillae. The excretory pore is subterminal. The eggs are elliptic and operculate at one of the extremities. The present study adds new taxonomic characters to C. obesa. The municipalities of Nova Friburgo, Teresópolis and Sumidouro are new geographical areas of distribution, and A. montensis, O. nigripes and N. squamipes are new host records for C. obesa

Helminth metacommunity structure of wild rodents in a preserved area of the Atlantic Forest, Southeast Brazil

“…Considering the helminth fauna of A. montensis, all helminth species found in the present study were previously reported (MALDONADO Jr. et al, 2010;SIMÕES et al, 2011;PANISSE et al, 2017). Other genera and species already registered for this host include Angiostrongylus lenzii, S. lanfrediae, Syphacia carlitosi, Litomosoides silvai, Trichuris sp., Echinostoma luisreyi in Brazil (SIMÕES et al, 2011;GRESSLER et al, 2017), Eucoleus sp., Platynosomoides sp., Tapironema coronatum and Trichuris navonae in Argentina (ROBLES, 2011;PANISSE et al, 2017).…”

“…Helminth communities of wild animals are still poorly understood, given the diversity of species that this group shows and their distinct patterns of host specificity and susceptibility (HUGOT et al, 2001;POULIN, 2007). Most of the studies about helminths of rodents in Brazil report helminth faunas or occurrences of specific parasites (MALDONADO JR. et al, 2010;PINTO et al, 2011;ARAUJO et al, 2014;WERK et al, 2016). Few studies reported the helminth community structure of wild small mammals (MALDONADO JR. et al, 2006;PÜTTKER et al, 2008;SIMÕES et al, 2010SIMÕES et al, , 2011.…”

The influence of habitat fragmentation on helminth communities in rodent populations from a Brazilian Mountain Atlantic Forest

“…Maldonado et al (2010) asserted that the rodent genus Akodon is probably the major definitive host of this helminth. Maldonado et al (2010) asserted that the rodent genus Akodon is probably the major definitive host of this helminth.…”

“…Maldonado et al (2010) asserted that the rodent genus Akodon is probably the major definitive host of this helminth. Thus, the transmission of the trematode may depend on the ingestion of the invertebrate host (Maldonado et al, 2010) by a sigmodontinae rodent (Travassos, 1944). The most common intermediate hosts of this genus are gastropods (Fried & Graczyk, 1997) or ants of the genus Formica (Urquhart et al, 1998).…”

“…The trematode C. obesa occurred predominantly in A. montensis . Maldonado et al (2010) asserted that the rodent genus Akodon is probably the major definitive host of this helminth. Canaania obesa belongs to the Dicrocoeliidae family.…”