Biology Reference
In-Depth Information
Figure 10.2. Larva of Multicotyle purvisi (Aspidogastrea). Note the thick layer of
microfila, the ciliary tufts (two ventral, two dorsal, six posterior), the two large eyes,
the large posterior sucker, and the lack of an anterior sucker. Redrawn and modified
from Rohde (
1968
).
to niche finding in the host (i.e., migration to the stomach/duodenum),
feeding, or mate finding. Alternatively, or additionally, they may help in
preventing damage by the juvenile parasite to the delicate snail-host tissue.
The ultimate aims of autecology are to elucidate environmental con-
ditions that, in this case, lead to infection of intermediate and final hosts,
and to the persistence of populations and species. We know that flotation
of larvae in the water column leads to infection of snails, future studies
should try to quantify the conditions that are the prerequisites for
infection. How strong must the inhalation currents of snails be to guar-
antee infection? Are small snails that have weak inhalation currents
unsuitable hosts? What are the effects of water temperature and strength
of water currents on the likelihood of infection, etc.? Why are some snails
and turtles of one particular species infected while others are not? Likely
candidates to explain the differences are the conditions of the abiotic
environment that determine whether snails can exist at sufficient densities
to provide minimum population densities of parasites necessary to keep
the life cycle in a certain habitat going.
Lobatostoma manteri
Adult worms of this species (maximum length about 5 mm) live in the
small intestine of a marine teleost fish, the snub-nosed dart Trachinotus
