Although certainly present,
opercula are not known in Asgardospira, Lytospira or Lesueurilla (or in most fossil gastropods) but several euomphalines have a prominent calcified operculum (Yochelson & Linsley 1972; Yochelson 1979; Peel 2015).
furnieri
opercula that were prepared according to CASTRO-ROSAS & ESCARTIN (2002) were also used in this study.
The fruits have one to several locules, each with a single seed, with or without specialized structures for germination, such as stopper-like
opercula or valves that hinge open.
A second structure that can be used to determine the age of gastropods is the operculum (plural
opercula): a shield-like plate, often wholly organic, that the gastropod uses to close off its aperture and protect the soft body tissues inside the shell from predatory attacks and in intertidal species to prevent potential desiccation.
Neurogenesis suggests independent evolution of
opercula in serpulid polychaetes.
Three eggs had their
opercula detached and shells destroyed to allow examination and measurement of the operculum and internal micropylar plate.
Behavioral responses which include colouration of the fish skin and
opercula colouration were observed.
Abstract--Aging of tautog (Tautoga onitis) has historically required sacrificing fish to obtain
opercula and otoliths.
The combination group showed significant increases in metabolism in a number of regions, including the right hemisphere cluster (insula/putamen/ amygdala/superior and middle temporal region); the left middle temporal pole fusiform gyrus and anterior temporal region; the right middle and inferior frontal region; and the right rolandic
opercula.
The
opercula in both sexes bear small and irregularly arranged spots (Esmaeili et al.
We observed gill lice on gills (n = 34; 46.0% of all those observed), branchial rims (n = 22; 29.7% of all those observed),
opercula (n = 17; 23.0% of all those observed), and at the base of one pectoral fin (n = 1; <1% of all those observed) of kokanee salmon.