Gibbula umbilicaris
Encyclopedia
Gibbula umbilicaris is a species
of sea snail
, a marine gastropod mollusk in the family
Trochidae
, the top snails.
is acuminate. There are about seven whorls
, slightly convex, spirally striate, microscopically obliquely striate. The lirae are generally subobsolete on the last whorl. The periphery is obtusely angulate. The aperture
is rather small, oblique, rounded-quadrate, angled at the base and smooth within. The columella is arcuate above, straightened below.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Trochidae
Trochidae
The Trochidae, common name top snails, are a taxonomic family of very small to large sea snails, marine gastropod molluscs in the clade Vetigastropoda ....
, the top snails.
Description
The size of an adult shell varies between 10 mm and 25 mm. The conical shell is umbilicate. Its color is cinereous, reddish, or purplish-brown, obscurely clouded, dotted or flamed with white The conical spireSpire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
is acuminate. There are about seven whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
, slightly convex, spirally striate, microscopically obliquely striate. The lirae are generally subobsolete on the last whorl. The periphery is obtusely angulate. The aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is rather small, oblique, rounded-quadrate, angled at the base and smooth within. The columella is arcuate above, straightened below.