Operculum (gastropod) - Wikipedia
The operculum (from Latin operculum 'cover, covering'; pl. opercula or operculums) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a ...
(PDF) Malacopedia The gastropod operculum - ResearchGate
2020年11月28日 · The operculum is a larval structure that covers the shell’s aperture in gastropod lar-vae. It evolved to be maintained as an adult structure and has further modifications in sever-al...
What is the function of the operculum in a snail? - Reptile …
Perhaps the most essential function of the operculum in gastropods is to allow snails to resist drying out, or desiccation. This is very important in intertidal marine snails during low tide, and this also enables operculate freshwater and land snails to survive periods of drought and dry weather.
Constructional morphology, origin, and evolution of the gastropod operculum
Gastropod opercula are classified here on a new morphogenetic basis, which distinguishes three main types: (1) flexiclaudent spiral (mostly multispiral) operculum, the shape of which does not coincide with that of the aperture, (2) rigiclaudent spiral (usually paucispiral) operculum, the shape of which fits that of the aperture, and (3 ...
Operculum (gastropod) - WikiMili, The Best Wikipedia Reader
2021年11月11日 · The operculum (from Latin operculum 'cover, covering'; pl. opercula or operculums) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a ...
Phylogeny and Classification of Extant Gastropoda
Patellogastropods have the most diverse shell microstructure of any group of gastropods; the shell is never nacreous but otherwise may consist of a cross-lamellar, prismatic, or foliated structure. The protoconch is uncoiled and tubular, and larvae are lecithotrophic. An operculum is present in larvae, but is absent in juveniles and adults.
Class Gastropoda - Digital Atlas of Ancient Life
2021年9月16日 · Gastropods are the second largest class of animals (after the Insecta)—with 40,000–90,000 living species and at least 13,000 extant and fossil genera (Ponder and Lindberg, 2020)—and are also one of the most evolutionarily successful groups in the variety of ecosystems and habitats that they occupy.
The operculum is a larval structure that covers the shell’s aperture in gastropod larvae. It evolved to be maintained as an adult structure and has further...
Developmental role of dpp in the gastropod shell plate and co …
2012年6月15日 · The operculum is a proteinaceous and sometimes calcified structure that is secreted by specific gland cells on the posterior part of the foot (Voltzow, 1994). Additionally, just as the shell coils in many gastropod species, the operculum also shows a spiral growth pattern.
Activity: Gastropod Shell Description | manoa.hawaii.edu ...
Gastropod shells are exoskeletons. What is the function of the shell in these organisms? What are some of the advantages and disadvantages of having an exoskeleton?
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