| Drepanotrema anatinum | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Superorder: | Hygrophila |
| Family: | Planorbidae |
| Genus: | Drepanotrema |
| Species: | D. anatinum |
| Binomial name | |
| Drepanotrema anatinum (d'Orbigny, 1835) [1] | |
| Synonyms [2] | |
List
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Drepanotrema anatinum is a species of freshwater gastropod belonging to the family Planorbidae. It is found in the neotropical region of the Americas. [3] [4]
Drepanotrema anatinum was originally described as Planorbis anatinus in 1835 by Alcide d'Orbigny. [1] In 1933, Carlos G. Aguayo found many species of planorbids to be synonymous with D. anatinum, and revised the taxonomy. Synonymous taxa included Planorbis anatinus (A. d'Orbigny, 1835), Planorbis haldemani (C. B. Adams 1849), Planorbis esperanzensis (Tyron, 1866), Planorbis isabel (G. B. Sowerby II, 1877), Planorbis yzabalensis (Crosse & P. Fischer, 1879), and Planorbis aracacensis (Gundlach, 1857). [4]
This species was the first to be listed under Drepanotrema during the original description of the genus in 1880 (then a subgenus). [5]
Drepanotrema anatinum has a brown, amber, or honey colored shell, though it appears black when living. It may possess black stripes just inside the aperture or a yellow stripe across the front of the shell. [6] The shell measures between 3.2 and 4 mm (0.13 and 0.16 in) in width and 1.5 to 1.8 mm (0.059 to 0.071 in) in height. [6] [7] [8] There are about 3–6 crescent-shaped whorls, with the last being relatively wide. [7] [8] The whorls are rounded, giving a convex appearance to the shell. The aperture is also crescent-shaped, and is angled so that the right side of the lip sits lower on the body. There may be a microscopic sculpture consisting of tightly packed growth lines and small bumps, which is more prominent on the upper surface of the shell. [6] [7] The spire is sunken on both sides, but is deeper on the side held uppermost in life. [8]
It is somewhat similar to Drepanotrema lucidum , but both the mantle and shell are darker in coloration, the foot is shorter, rounder, and has black dots, the whorls expand more rapidly, and the black stripes on the cephalic tentacles are more prominent. [7] [8]
The radula (toothy tongue-like appendage) of D. anatinum has smaller teeth than Drepanotrema cultratum , but otherwise is very similar. The teeth are arranged in 37 columns and 158 rows. One central column of rachidian teeth is bordered by 18 combined columns of both lateral and marginal teeth on each side. [9]
Drepanotrema anatinum may be found across much of the neotropical region, including Cuba, Haiti, Panama, and Brazil. [4]