Description ⁷

The buttonsnail, Modulus modulus, is a small marine gastropod of the family Modulidae. The shell is top-shaped and low-spired, and is wider than it is high, consisting of 3-4 or 5-6 strongly convex and angulate whorls. The body whorl is disproportionately larger then the other whorls. The margin of each whorl has a ridge or keel formed by a prominent spiral cord and parallel to 3-4 weaker spiral cords. The aperture is nearly round and the lip is moderately thin and crenulate (serrate-scalloped). The columella terminates in a deep notch that accommodates the pallial tentacles of the inhalant siphon. The shell color is usually yellowish white, splotched with purple or brown, although this is often obscured by the periostracum and algal epiphytes in living specimens. The colummela has a purple tinge and the columellar notch has a purple spot. The operculum is round, thin, and horny (Houbrick 1980, Abbot and Morris 1995).The living animal is light green to mossy green in overall appearance. The head is equipped with a short, bilobe-tipped snout and two thin tentacles. The fully exposed foot is slightly smaller than the shell diameter (Houbrick 1980).

Distribution ⁸

Modulus modulus occurs from North Carolina south to Brazil, and also in Bermuda (Abbot and Morris 1995).

Look alikes ⁹

The congener Modulus papei also resides in Florida waters, although it is primarily a rocky intertidal species (USFWS 2007) and is therefore unlikely to occur in the same habitat as M. modulus.

Reproduction ¹⁰

Reproduction is sexual. Sexes are separate and fertilization is internal.In the Indian River Lagoon population studied by Houbrick (1980), mating occurred in early winter and egg mass deposition took place in the spring. Females produce cylindrical gelatinous egg masses that are deposited on seagrass surfaces.

Link to Access Genomic Data ¹¹

http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=75128&lvl=0

Sources and Credits

1. (c) Bernadette, some rights reserved (CC BY-NC), uploaded by Bernadette
2. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/photos21/42887.jpg
3. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/photos25/50513.jpg
4. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/photos21/42210.jpg
5. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/photos21/42134.jpg
6. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/photos17/35272.jpg
7. (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11526437
8. Adapted by matbio from a work by (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11526438
9. (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11526440
10. (c) Smithsonian Marine Station at Fort Pierce, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11526442
11. (c) Emily Rose Sharkey, all rights reserved

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Global Biodiversity Information Facility (GBIF)
• NatureServe Explorer 2.0
• SeaLifeBase
• World Register of Marine Species

Range Map

(c) Discover Life and original sources, some rights reserved (CC-BY-NC-SA)

iNat Map