Douglassia minervaensis
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| Douglassia minervaensis | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Neogastropoda |
| Superfamily: | Conoidea |
| Family: | Drilliidae |
| Genus: | Douglassia |
| Species: | D. minervaensis |
| Binomial name | |
| Douglassia minervaensis Fallon, 2016 | |
Douglassia minervaensis is a species of sea snail, a marine gastropod mollusc in the family Drilliidae.[1]
The Douglassia minervaensis, is named after its type and the place of its only known occurrence, the Minerva Seamount.[2]
Description
The size of an adult shell attains 7.5 mm.
The shell is very small, reaching up to 7.9 mm total length, glossy, and fusiform with a truncated anterior.[2] It has up to 8½ whorls; the last is large (about 59% of total length) and asymmetric, the right side is swollen by a cup-handle-like varix positioned behind the anal sinus about one-quarter turn from the outer lip, giving a lopsided ventral view.[2] The protoconch consists of about 2¾ smooth whorls, the first partly immersed in the second.[2] Early teleoconch whorls bear broad, low ribs; the last two carry high, narrow ribs.[2] On the last whorl, bold axial ribs extend to the anterior fasciole but are strongly reduced or absent within a narrow, concave sulcus.[2] Ribs are narrower than the interspaces, number 7–8 on the penultimate whorl and 6 on the last to the varix, and have acute crests.[2] Growth striae are microscopic.[2] The sulcus is concave and narrow, with broad, low rib remnants to the suture and recurved striae reflecting the anal sinus.[2]
The spiral sculpture consists of 6–8 faint threads on the shell base and 6–8 faint threads on the anterior fasciole.[2] The outer lip is thin, projects slightly, and is mostly missing in the holotype; a stromboid notch is unknown.[2] The anal sinus lies on the whorl shoulder and has a rounded apex.[2] The inner lip is moderately wide, margined, thicker anteriorly, thinnest on the parietal wall, and forms a posterior lobe at the anal sinus.[2] The anterior canal is straight, short, and open, without a notch; the anterior fasciole is not swollen.[2] The Colour of the Douglassia minervaensis is a uniform light golden brown with a lighter, narrow peripheral spiral band, and white on the rib-shoulder crests.[2]
Distribution
This species occurs in the demersal zone of the Western Atlantic Ocean off Bahia, Brazil.