Vermicularia knorrii, commonly known as the Florida worm snail, is a species of sea snail, a marine gastropod in the family Turritellidae.[1] V. knorrii has been concluded to be the junior synonym to Vermicularia lumbricalis.[1][2] The shell of Florida worm snail is light brown or tan in color with an apex that is white. It is found living in reefs on the coasts of the southern states of the United States to the top of South America. V. knorri use their ciliated appendages to trap plankton and sperm.

Vermicularia knorrii
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Family: Turritellidae
Genus: Vermicularia
Species:
V. knorrii
Binomial name
Vermicularia knorrii
Deshayes, 1843
Synonyms
  • Vermetus knorri Deshayes, 1843
  • Vermicularia lumbricalis Linnaeus, 1758

Distribution

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This species is found in the United States from Florida to North Carolina, the Gulf Coast, the eastern coast of Mexico, Aruba, The Bahamas, Antigua, Barbuda, Cuba, Jamaica, Puerto Rico, and Bermuda[3][4]. Vermicularia knorrii is strictly marine and does not live in brackish or fresh waters and is not terrestrial.[1] V. knorrii is found in waters with temperatures around 28 °C (82 °F).[5]

Habitat

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Vermicularia knorrii habitat ranges from 35.34°N to 12°N and 92°W to 64.7°W. They can be found between depths of 2–500 m (7–1,640 ft),[2] but typically live in water 14–110 m (46–361 ft).[4] The deepest recorded depth of Vermicularia knorrii is about 500 m (1,600 ft) on the continental slope of Texas, but it may have been another species wrongfully identified at the greater depths.[2] This places the Florida worm snail's habitat in the epipelagic and mesopelagic zones most often being found in the photic zone.

Unlike other Vermicularia species, the Florida worm snail does not form inter-coil structures but rather lives in hard substrates such as corals and sponges.[2] It stays in the substrate by cementing itself in it.[6] V. knorrii can be found in "boiler" reefs, rim reefs, subtidal, and patch reefs.[7] It appears to be vulnerable of desiccation, or the removal of water, usually during low tides.[citation needed]

Shell

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The shell of this species is 20–80 mm (0.79–3.15 in) in length.[8] When the shell is intact, the apex is pure white, somewhat translucent, and tightly coiled similarly to that of the genus Turritella. The regularly coiled apex is around 12.5 mm (0.49 in) in length. The subsequent whorls are brown, and they are loosely and irregularly coiled, such that the whorls do not touch. Their irregular shape helps them anchor into sponges, rocks, and corals. The irregular shape of their shells gives the Florida worm snail its name as they resemble the tubes made by tube worms.[9]

As they grow, Vermicularia shells start to uncoil due to the need to access food and to attach to substrate they live in stabley.[10] The shells are also used by hermit crabs, such as Calcinus verrillii, as shelter. The odd shapes of the worm snail shells affect the symmetry of the uropods.[11]

Feeding

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Due to the Florida worm snail living in sponges and corals, it is sessile and does not actively hunt for food. It is a suspension feeder[12] and catches food by expelling cilia and mucus[13] from its mantle. The mantle cavity elongates the gill surface and pushes out the cilia.[2] The cilia flow with the current, creating a mucus net that catches plankton. The snail then retracts the strings and uses its radula to eat the food.[14]

Reproduction and life cycle

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Although not much is known about the reproductive cycle of Vermicularia knorrii, it is thought to be gonochoristic and broadcast spawn.[12] It is theorized that Vermicularia knorrii has similar reproductive and life stages to its sister gastropod, Vermicularia spirata. Vermicularia spirata is protandrous hermaphroditic with small males being free living and eventually attaching to substrate when switching sexes. Both males and females have open pallial ducts, which serves as the fertilization pouch and seminal receptacle in the female. Females receive sperm from nearby males and fertilization occurs. Eggs are brooded in the mantle cavity of the mantle which hatch as veliger larvae with shells with two and a half whorls.[15] This is likely the reproduction cycle that V. knorrii follow as V. spirata have very similar gross morphology.[citation needed]

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References

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  1. ^ a b c WoRMS. "Vermicularia knorrii (Deshayes, 1843)". World Register of Marine Species. Retrieved 15 April 2024.
  2. ^ a b c d e Anderson, Brendan Matthew (2018). The evolution of unusual shell morpohologies in fossil and living Turritellidae (Gastropoda) (PhD thesis). Cornell University. doi:10.7298/X4S75DK9. hdl:1813/59723.
  3. ^ Sang, Stephanie; Friend, Dana Suzanne; Allmon, Warren Douglas; Anderson, Brendan Matthew (May 2019). "Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway". Ecology and Evolution. 9 (9): 5309–5323. Bibcode:2019EcoEv...9.5309S. doi:10.1002/ece3.5120. ISSN 2045-7758. PMC 6509377. PMID 31110681.
  4. ^ a b "Malacolog 4.1.1: Western Atlantic Mollusk Species Database at The Academy of Natural Sciences". www.malacolog.org. Retrieved 15 April 2024.
  5. ^ "Vermicularia knorrii". ru.reeflex.net. Retrieved 15 April 2024.
  6. ^ Kobluk, David R; Lysenko, Mary A (1 November 1986). "REEF-DWELLING MOLLUSCS IN OPEN FRAMEWORK CAVITIES, BONAIRE N.A., AND THEIR POTENTIAL FOR PRESERVATION IN A FOSSIL REEF". Bulletin of Marine Science. 39 (3): 657–672 – via Ingenta.
  7. ^ Rodrigues, Lisa; Dunham, David; Coates, Kathryn (1 January 2000). "Shelter Preferences in the Endemic Bermudian Hermit Crab, Calcinus Verrilli (Rathbun, 1901) (Decapoda, Anomura)". Crustaceana. 73 (6): 737–750. doi:10.1163/156854000504769. ISSN 1568-5403.
  8. ^ Welch, John J. (19 January 2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". PLOS ONE. 5 (1): e8776. Bibcode:2010PLoSO...5.8776W. doi:10.1371/journal.pone.0008776. ISSN 1932-6203. PMC 2808249. PMID 20098740.
  9. ^ Leal, José H. (17 January 2014). "The Florida Worm Snail". shellmuseum. Retrieved 15 April 2024.
  10. ^ Gould, Stephen Jay (1 June 1969). "Ecology and Functional Significance of Uncoiling in Vermicularia Spirata: An Essay on Gastropod Form". Bulletin of Marine Science. 19 (2): 432-445(14) – via Ingenta.
  11. ^ Rodrigues, Lisa J.; Dunham, David W.; Coates, Kathryn A. (2002). "The Effect of Shelter Type on Uropod Symmetry in Calcinus verrilli (Anomura: Diogenidae)". Journal of Crustacean Biology. 22 (2): 298–303. doi:10.1163/20021975-99990236. ISSN 0278-0372. JSTOR 1549953.
  12. ^ a b "Vermicularia knorrii, Florida wormsnail". www.sealifebase.ca. Retrieved 15 April 2024.
  13. ^ Bieler, Rüdiger; Petit, Richard E. (8 July 2011). "Catalogue of Recent and fossil "worm-snail" taxa of the families Vermetidae, Siliquariidae, and Turritellidae (Mollusca: Caenogastropoda)". Zootaxa. 2948 (1): 1–103. doi:10.11646/zootaxa.2948.1.1. ISSN 1175-5334.
  14. ^ "Common Shells of Honeymoon Island State Park Nature Center". www.honeymoonislandnaturecenter.org. Retrieved 15 April 2024.
  15. ^ Bieler, RüDiger; Hadfield, Michael (May 1990). "Reproductive biology of the sessile gastropod Vermicularia spirata (Cerithioidea: Turritellidae)". Journal of Molluscan Studies. 56 (2): 205–219. doi:10.1093/mollus/56.2.205 – via ResearchGate.
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