Part 2 A look at features' provides detailed coverage of morphology and features for each of the lifecycle phases typical of frogs, and includes the oral disc
, an important diagnostic feature of many tadpoles.
Because preserved tadpoles undergo some degree of integument deformation through time, which may alter eye position and or vent position relative to other features, and cause fading of color pattern and other markings, we used oral disc
morphology to determine the identity of the tadpoles.
Only mouthparts of the oral disc
(i.e., labial tooth rows, papillae, and jaw sheaths; McDiarmid and Altig, 1999) of larval anurans are keratinized (Luckenbill, 1965), and these are the sites of Bd infection (Knapp and Morgan, 2006).
The ethological changes were accompanied (like oral disc
closure, wilting, and swelling) in the experiment.
For example, Johnston (1982) showed that after grazing on algae, tadpoles left marks on the substrate, and suggested that labial teeth anchored the oral disc
to the substrate while the tadpoles removed food from the substrate with their jaw sheaths.
Chemical elimination is effective, but requires the laborious introduction of toxic injections directly into the oral disc
of each anemone.
Six structures of the coral were assayed: oral disc
, tentacles, costae, septa, calice, and coenosarc.
Prior to use, 3-year dark-treated anemones (n = 180) with oral disc
diameters of about 2 to 3 mm were placed in 100-ml containers filled with filtered (0.45 [[micro]meter]) seawater (FSW).