Broderipia subiridescens
A limpet-shaped top snail with red-netted white shell.
Broderipia subiridescens is a marine gastropod mollusk belonging to the Trochidae family, commonly known as top snails. Its shell, which reaches 6 mm in height and 4 mm in diameter, is limpet-shaped with an oval outline. The apex sits very close to the rear edge and is small, coiled to the right, and lying flat, though its tip is worn away. In profile, the short posterior slope is concave, while the longer anterior slope is convex; the shell is tallest near the apex. The surface appears nearly smooth, marked only by microscopic concentric growth lines. The shell is white, overlaid with a net-like pattern of red dots connected by red lines. The interior is only faintly pearly, with the external color pattern showing through. Compared to *Broderipia iridescens*, this species is smaller and more convex, with the apex positioned closer to the posterior margin. Its coloration and lack of granulation distinguish it from *Broderipia cumingii*. This species has been recorded in the Indian Ocean off Madagascar, though the record is considered doubtful.
Quick Facts
- Taxon
- Broderipia subiridescens
Facts from the source article.
Lore & Background
The shell of Broderipia subiridescens is limpet-shaped with an oval outline. The apex nearly attains the posterior margin, and in profile the posterior slope is very short and concave while the anterior is long and convex. The shell is highest near the apex. Its surface is nearly smooth, with microscopic concentric growth lines, and is white with a netted pattern of dots connected by lines of red. The minute apex is recumbent, spiral, and dextral, though the tip is eroded. The inside is scarcely nacreous, with the color pattern showing through.
This species is smaller than Broderipia iridescens and more convex, with the apex nearer the posterior margin. The interior is scarcely pearly. Its coloration and lack of granulation distinguish it from Broderipia cumingii.
The species occurs in the Indian Ocean off Madagascar, though this distribution is noted as doubtful.
Reader's Guide
Broderipia subiridescens is a species of marine gastropod mollusk in the family Trochidae, documented in a 1929 contribution to the study of Madagascar's fauna by Dautzenberg. Its significance lies in its morphological distinctions from related species: it is smaller and more convex than Broderipia iridescens, and its coloration and lack of granulation separate it from Broderipia cumingii. The shell's limpet shape, nearly smooth surface with microscopic growth lines, and distinctive red-netted pattern on white are key identifying features. The interior is scarcely nacreous, unlike some other top snails. The species' reported distribution off Madagascar is marked as doubtful, indicating uncertainty in its geographic range. As a member of Trochidae, it contributes to the diversity of limpet-shaped forms within this family of top snails.
Did You Know?
- The shell height of Broderipia subiridescens attains 6 mm and its diameter 4 mm.
- The apex is recumbent, spiral, and dextral, with the tip eroded.
- Its distribution in the Indian Ocean off Madagascar is considered doubtful.
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