Conidae

Conidae
A group of shells of various species of cone snails
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Caenogastropoda
Clade: Hypsogastropoda
Clade: Neogastropoda
Superfamily: Conoidea
Family: Conidae
Fleming, 1822[1]
Subfamilies and genera

See text

Synonyms
  • Californiconinae Tucker & Tenorio, 2009
  • Conilithidae Tucker & Tenorio, 2009
  • Puncticulinae Tucker & Tenorio, 2009
  • Taranteconidae Tucker & Tenorio, 2009

Conidae (also previously referred to as Coninae), with the current common name of "cone snails", is a taxonomic family (previously subfamily) of predatory sea snails, marine gastropod molluscs in the superfamily Conoidea.

The 2014 classification of the superfamily Conoidea, groups only cone snails in the family Conidae. Some previous classifications grouped the cone snails in a subfamily, the Coninae.

Conidae currently (March 2015) contains over 800 recognized species. Working in 18th century Europe, Linnaeus knew of only 30 species which are still considered valid.

The snails within this family are sophisticated predatory animals.[2] They hunt and immobilize prey using a modified radular tooth along with a venom gland containing neurotoxins; the tooth is launched out of the snail's mouth in a harpoon-like action.

Because all cone snails are venomous and capable of "stinging" humans, live ones should be handled with great care or preferably not at all.

Current 2014 taxonomy

In the Journal of Molluscan Studies, in 2014, Puillandre, Duda, Meyer, Olivera & Bouchet presented a new classification for the old genus Conus. Using 329 species, the authors carried out molecular phylogenetic analyses. The results suggested that the authors should place all living cone snails in a single family, Conidae, containing four genera: Conus, Conasprella, Profundiconus and Californiconus. The authors grouped 85% of all known cone snail species under Conus, They recognized 57 subgenera within Conus, and 11 subgenera within the genus Conasprella.[3]

History of the taxonomy

Overview

Prior to 1993, the family Conidae contained only Conus species. In 1993, significant taxonomic changes were proposed by Taylor, et al.,:[4] the family Conidae was redefined as several subfamilies. The subfamilies included many subfamilies which had previously been classified in the family Turridae, and the Conus species were moved to the subfamily Coninae.

In further taxonomic changes which took place in 2009 and 2011, based upon molecular phylogeny (see below), the subfamilies which were previously in the family Turridae were elevated to the status of families in their own right. This left the family Conidae once again containing only those species which were traditionally placed in that family: the cone snail species.

1993, Taylor et al, Bouchet & Rocroi

According to Taylor, et al. (1993)[4] and the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005,[5] this family consisted of seven subfamilies.

2009, Tucker & Tenorio

In 2009, John K. Tucker and Manuel J. Tenorio proposed a classification system for the cone shells and their allies (which resorb their inner walls during growth) was based upon a cladistical analysis of anatomical characters including the radular tooth, the morphology (i.e., shell characters), as well as an analysis of prior molecular phylogeny studies, all of which were used to construct phylogenetic trees.[6] In their phylogeny, Tucker and Tenorio noted the close relationship of the cone species within the various clades, corresponding to their proposed families and genera; this also corresponded to the results of prior molecular studies by Puillandre et al. and others.[7][8][9][10][11][12][13] This 2009 proposed classification system also outlined the taxonomy for the other clades of Conoidean gastropods (that do not resorb their inner walls), also based upon morphological, anatomical, and molecular studies, and removes the turrid snails (which are a distinct large and diverse group) from the cone snails, and creates a number of new families.[6] Tucker and Tenorio’s proposed classification system for the cone shells and their allies (and the other clades of Conoidean gastropods ) is shown in Tucker & Tenorio cone snail taxonomy 2009.

2011, Bouchet et al.

In 2011, Bouchet et al. proposed a new classification in which several subfamilies were raised to the rank of family:[14]

The classification by Bouchet et al. (2011)[14] was based on mitochondrial DNA and nuclear DNA testing, and built on the prior work by J.K. Tucker & M.J. Tenorio (2009), but did not include fossil taxa.[6][14]

Molecular phylogeny, particularly with the advent of nuclear DNA testing in addition to the mDNA testing (testing in the Conidae initially began by Christopher Meyer and Alan Kohn[15]), is continuing on the Conidae.[7][8][9][10][11][12][13][16][17][18][19][20][21][22]

2009, 2011, list of genera from Tucker & Tenorio, and Bouchet et al

This is a list of what were recognized extant genera within Conidae as per J.K. Tucker & M.J. Tenorio (2009), and Bouchet et al. (2011):[6][14] However, all these genera have become synonyms of subgenera within the genus Conus as per the revision of the taxonomy of the Conidae in 2015 [3]

1993 to 2011 list of genera

Following Taylor et al., from 1993 to 2011, the family Conidae was defined as including not only the cone snails, but also a large number of other genera which are commonly known as "turrids". However, as a result of molecular phylogeny studies in 2011, many of those genera were moved back to the Turridae, or were placed in new "turrid" families within the superfamily Conoidea. The following list of genera that used to be included in Conidae is retained as a historical reference:

Cone snail venom characteristics and biotech

Cone snail venom apparatus

There are approximately 30 records of humans killed by cone snails. Human victims suffer little pain, because the venom contains an analgesic component. Some species reportedly can kill a human in under five minutes, thus the name "cigarette snail" as supposedly one only has time to smoke a cigarette before dying. Cone snails can sting through a wetsuit with their harpoon-like radular tooth, which resembles a transparent needle.[23]

Normally, cone snails (and many species in the superfamily Conoidea) use their venom to immobilize prey before engulfing it. The venom consists of a mixture of peptides, called conopeptides. The venom is typically made up of 10 to 30 amino acids, but in some species as many as 60. The venom of each cone snail species may contain as many as 200 pharmacologically active components. It is estimated that more than 50,000 conopeptides can be found, because every species of cone snail is thought to produce its own specific venom.

Cone-snail venom has come to interest biotechnologists and pharmacists because of its potential medicinal properties. Production of synthetic conopeptides has started, using solid-phase peptide synthesis.

W-conopeptide, from the species Conus magus is the basis of the analgesic drug Prialt, an approved treatment for pain said to be 1000 times as powerful as morphine and used as a last resort in specific application. Conopeptides are also being looked at as anti-epileptic agents and to help stop nerve-cell death after a stroke or head injury. Conopeptides also have potential in helping against spasms due to spinal cord injuries, and may be helpful in diagnosing and treating small cell carcinomas in the lung.

The biotechnology surrounding cone snails and their venom has promise for medical breakthroughs; with more than 50,000 conopeptides to study, the possibilities are numerous.[24]

See also

References

  1. ↑ Fleming J. (June 1822). The philosophy of zoology, a general view of the structure, functions and classification of animals 2. Constable & Co., Edinburgh, 618 pp., Conidae is on the page 490.
  2. ↑ Piper R. (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
  3. 1 2 Puillandre, N.; Duda, T.F.; Meyer, C.; Olivera, B.M.; Bouchet, P. (2015). "One, four or 100 genera? A new classification of the cone snails". Journal of Molluscan Studies. 81: 1–23. doi:10.1093/mollus/eyu055.
  4. 1 2 Taylor J. D., Kantor Y. I. & Sysoev A. V. (1993). "Foregut anatomy, feeding mechanisms, relationships and classification of Conoidea (Toxoglossa) (Gastropoda)". Bull. Nat. Hist. Mus. (Zool.) 59: 125–169.
  5. ↑ Bouchet P.; Rocroi J.-P.; Frýda J.; Hausdorf B.; Ponder W.; Valdés Á. & Warén A. (2005). "Classification and nomenclator of gastropod families". Malacologia: International Journal of Malacology. Hackenheim, Germany: ConchBooks. 47 (1-2): 1–397. ISBN 3-925919-72-4. ISSN 0076-2997.
  6. 1 2 3 4 Tucker J.K. & Tenorio M.J. (2009) Systematic classification of Recent and fossil conoidean gastropods. Hackenheim: Conchbooks. 296 pp., at p. 133
  7. 1 2 P.K. Bandyopadhyay, B.J. Stevenson, J.P. Ownby, M.T. Cady, M. Watkins, & B. Olivera (2008), The mitochondrial genome of Conus textile, coxI-conII intergenic sequences and conoidean evolution. Molecular Phylogenetics and Evolution 46: 215-223.
  8. 1 2 S.T. Williams & T.F. Duda, Jr. (2008), Did tectonic activity stimulate Oligo-Miocene speciation in the Indo-West Pacific? Evolution 62:1618-1634.
  9. 1 2 R.L. Cunha, R. Castilho, L. Ruber, & R. Zardoya (2005), Patterns of cladogenesis in the venomous marine gastropod genus Conus from the Cape Verde Islands Systematic Biology 54(4):634-650.
  10. 1 2 T.F. Duda, Jr. & A.J. Kohn (2005), Species-level phylogeography and evolutionary history of the hyperdiverse marine gastropod genus Conus, Molecular Phylogenetics and Evolution 34:257-272.
  11. 1 2 T.F. Duda, Jr. & E. Rolan (2005), Explosive radiation of Cape Verde Conus, a marine species flock, Molecular Ecology 14:267-272.
  12. 1 2 B. Vallejo, Jr. (2005), Inferring the mode of speciation in the Indo-West Pacific Conus (Gastropoda: Conidae), Journal of Biogeography 32:1429-1439.
  13. 1 2 N. Puillandre, S. Samadi, M. Boesselier, A. Sysoev, Y. Kantor, C. Cruaud, A. Couloux, & P. Bouchett (2008), Starting to unravel the toxoglossan knot: molecular phylogeny of the "turrid" (Neogastropoda: Conoidea), Molecular Phylogenetics and Evolution 47:1122-1134.
  14. 1 2 3 4 5 6 7 8 Bouchet, P.; Kantor, Yu.I.; Sysoev, A.; Puillandre, N. (2011). "A new operational classification of the Conoidea". Journal of Molluscan Studies. 77 (3): 273–308. doi:10.1093/mollus/eyr017.
  15. ↑ Interview of Professor Alan Kohn, Professor Emeritus, Zoology "Archived copy". Archived from the original on 2012-02-27. Retrieved 2011-12-04.
  16. ↑ Tucker, J. K. & Stahlschmidt, P. (2010) A second species of Pseudoconorbis (Gastropoda: Conoidea) from India. Miscellanea Malacologica 4(3):31-34.
  17. ↑ Watkins, M., Corneli, P.S., Hillyard, D., & Olivera, B.M. (2010) Molecular phylogeny of Conus chiangi (Azuma, 1972) (Gastropods:Conidae). The Nautilus 124(3):129-136.
  18. ↑ Tucker, J. K., Tenorio, M. J. & Stahlschmidt, P. (2011) The genus Benthofascis (Gastropoda: Conoidea): a revision with descriptions of new species. Zootaxa 2796:1-14.
  19. ↑ Tucker, J. K. & Tenorio, M. J. (2011) New species of Gradiconus and Kohniconus from the western Atlantic (Gastropoda: Conoidea: Conidae, Conilithidae). Miscellanea Malacologica 5(1):1-16.
  20. ↑ Petuch, E. J. & Sargent, D. M. (2011) New species of Conidae and Conilithidae (Gastropoda) from the tropical Americas and Philippines. With notes on some poorly-known Floridian species. Visaya 3(3):116-137.
  21. ↑ Petuch & Drolshage (2011) Compendium of Florida Fossil Shells, Volume 1 MDM Publications, Wellington, Florida, 432 pp.
  22. ↑ C.M.L. Afonso & M.J. Tenorio (August 2011), A new, distinct endemic Africonus species (Gastropoda, Conidae) from Sao Vicente Island, Cape Verde Archipelago, West Africa, Gloria Maris 50(5): 124-135
  23. ↑ "Venomous snails: One slip, and youre dead...". Nature. 429: 798–799. doi:10.1038/429798a.
  24. ↑ Becker, S.; Terlau, H. (2008). "Toxins from Cone Snails: Properties, Applications and Biotechnological Production". Applied Microbiology and Biotechnology. 79 (1): 1–9. doi:10.1007/s00253-008-1385-6.
  25. ↑ Kaas, Quentin; Yu Rilei; Jin Ai-Hua; Dutertre Sébastien; Craik David J (Jan 2012). "ConoServer: updated content, knowledge, and discovery tools in the conopeptide database". Nucleic Acids Res. England. 40 (Database issue): D325–30. doi:10.1093/nar/gkr886. PMC 3245185Freely accessible. PMID 22058133.

Further reading

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