Abstract:
Bats are hosts to a variety of ectoparasites, which may impact their health and the
transmission of zoonotic pathogens. However, studies on bat parasites in Sri Lanka
are very limited and are mainly restricted to the bats in the wet zone. Therefore, the
overall objective of this study was to examine the prevalence, diversity and
distribution of ectoparasites associated with selected bat species from the Mannar
Island and Pooneryn area of the Northern Province of Sri Lanka. A total of 246 bats
were captured using mist nets at dawn and dusk. All captures and handling were
permitted by the Department of Wildlife and Conservation, Sri Lanka
(WL/3/2/30/2024). Ectoparasites were collected from the captured live bats and
preserved in 70% ethanol. Morphological identification of parasites was carried out
using published taxonomic keys and guides. Parameters such as parasite prevalence,
abundance, mean intensity, Shannon-Weiner diversity index and average parasitic
load per host species were calculated. Ectoparasites were found in all five species of
bats surveyed. Scotophilus kuhlii had ectoparasites in 23 (21.9%) of them, while
Cynopterus sphinx had ectoparasites only in 2 (3.85 %) of them. A single infection
was observed in C. sphinx, Scotophilus heathi (0.09%), Pipistrellus coromandra
(2.94%) and Taphozous longimanus (25%) bat species while, multiple infections
were seen in S. kuhlii. Bat flies from family Nycteribiidae, a mite species from family
Spinturnicidae and a hard tick from family Ixodidae were found among a total of 183
ectoparasites. The dominance of Nycteribia species, including three Nycteribia fly
species and five other unidentified species from the family was noted. Although
parasites in S. kuhlii showed the highest diversity (H’=1.77) and parasitic load (175),
collectively parasitic loads did not show a significant difference (one way ANOVA,
p>0.05) within the five-host species from a single study region or between the two
regions: Mannar Islands and Pooneryn. S. kuhlii harbor larger numbers of
ectoparasites and experience higher frequency of infections as they live in colonies
as opposed to other host species sampled. This study suggests that roosting behavior
may contribute to differences in patterns of host-parasite associations, while regional
factors (arid vs. dry regions) may not. The present study further contributes to bridge
the knowledge gap on host parasite associations in bats of arid and dry zones in Sri
Lanka, as the first such scientific attempt.
