TOP SHELLS ARE GREAT FOR CREATING THE NAUTICAL LOOK
Pearl Top Shell
TThe Trochidae, commonly known as top-snails or top-shells, comprise a family of sea snails varying in size. These marine gastropod mollusks belong to the subclass Vetigastropoda. They are often referred to as top-snails because the shell of many species resembles a toy spinning top.
The size of an adult Top shell can range from less than 1/4 to 5 inches in length. The shell's shape also varies widely, from the low, ear-shaped auriform with a broad opening to the elongated, slender conical forms characteristic of typical top shells. Shapes may include subglobose, turbinate, or helicoid. The height of these shells can be less than 1/4 inch up to 6 inches. They possess a small number of whorls, which can have exteriors that vary greatly, from smooth or shiny to highly sculptured.
The internal shell has a nacreous (pearlized) layer. It features a brown, completely corneous, circular, multispiral operculum that snugly fits the aperture. This operculum consists of many whorls that increase gradually in size with a central nucleus. The aperture can be complete, tetragonal, or rounded and lacks a reflected lip. Generally, the peristome is not continuous. These shells are typically vividly colored and feature darker bands. Unlike the Turbinidae family, the Trochidae family's species have an operculum that is always corneous and multispiral, never calcareous.
The animal bears a resemblance to the Turbinidae in general form. Top snails exhibit primitive features such as a heart with two atria. They have preserved a single kidney, while the second osphradium has disappeared through evolution. Their mantle cavity houses one gill. Along the foot's side, there are at least three pairs of sensory epipodial tentacles. The head features a short, wide rostrum. The intertentacular lobes are either simple or digitated, and they may be separate or joined at the front, occasionally becoming obsolete. The presence of jaws varies, being either developed or absent. The radula type is rhipidoglossate, with the central rhachidian teeth always prominent and well-formed. Typically, there are five lateral teeth on each side, although the number can be greater. The marginal teeth are slender and exceedingly numerous.
The Top Shell family is distributed globally in tropical, temperate, and arctic waters. These snails are some of the most prevalent along Europe's rocky coasts. While most species inhabit the intertidal or shallow subtidal zones, others can be found in deeper waters. They typically thrive on firm, appropriate substrates such as rocky shores and reefs.
Species within the Trochidae family are dioecious, with fertilization taking place externally through the release of eggs and sperm. Top snail eggs may be deposited singly or within gelatinous clusters in the water. Upon hatching, individuals may emerge as free-swimming planktonic larvae or as juvenile crawlers possessing a brief swimming phase.
The Top Shell family of snails consists of herbivores, grazing with their radulae on rocky surfaces, feeding on algae and vegetable detritus, and more rarely by filter-feeding, as observed in the genus Umbonium.
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Vetigastropoda
Order: Trochida
Superfamily: Trochoidea
Family: Trochidae
Rafinesque, 1815
(REF: Williams S.T., Donald K.M., Spencer H.G. & Nakano T. (2010) Molecular systematics of the marine gastropod families Trochidae and Calliostomatidae (Mollusca: Superfamily Trochoidea). Molecular Phylogenetics and Evolution 54)(REF: "WoRMS - World Register of Marine Species - Trochidae Rafinesque, 1815")(REF: Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia)(REF: Poutiers, J. M. (1998). Gastropods in: FAO Species Identification Guide for Fishery Purposes: The living marine resources of the Western Central Pacific Volume 1. Seaweeds, corals, bivalves and gastropods. Rome, FAO, 1998)
Q0-12
A Pearl Top Shell measuring up to 1 inch ...... .12
Q1-12
A Pearl Top Shell measuring 1 to 2 inches ...... .21
Natural Top Shells
TT1-12
One quarter pound of Natural Top Shells measuring up to 1/4 inch......$1.59