Dyraspis
Dyraspis is a proposed genus of sea snails, marine gastropod mollusks in the family Conidae, the cone snails and their allies.[1] This genus currently (November 2011) is still treated by some experts as an "alternative representation" of this group of species.
When the "alternative representations" are not used, this group of species is instead still placed in the Linnaean genus Conus.
Distinguishing characteristics
The Tucker & Tenorio 2009 taxonomy distinguishes Ductoconus from Conus in the following ways:[2]
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- Shell characters (living and fossil species)
- The basic shell shape is conical to elongated conical, has a deep anal notch on the shoulder, a smooth periostracum and a small operculum. The shoulder of the shell is usually nodulose and the protoconch is usually multispiral. Markings often include the presence of tents except for black or white color variants, with the absence of spiral lines of minute tents and textile bars.
- Radular tooth (not known for fossil species)
- The radula has an elongated anterior section with serrations and a large exposed terminating cusp, a non-obvious waist, blade is either small or absent and has a short barb, and lacks a basal spur.
- Geographical distribution
- These species are found in the Indo-Pacific region.
- Feeding habits
- These species eat other gastropods including cones.[2]
- Genus Dyraspis Iredale, 1949
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- Shell characters (living and fossil species)
- The shell is turgid. The protoconch is paucispiral, a few cords are present on whorl tops and nodules usually persist on all whorls. The anal notch is shallow, and the anterior notch is well developed. Interior constrictions are absent. No operculum has been observed. The periostracum is only present in the regions on either side of the midbody area and has a unique color pattern of back and pinkish lines.
- Radular tooth (not known for fossil species)
- The anterior section of the radula is equal to or slightly shorter than the posterior section. The blade is long and may extend the full length of the anterior section. A basal spur is present, and the barb is short. The radular tooth has multiple rows of serrations and a terminating cusp.
- Geographical distribution
- The only species in this genus is endemic to Australia.
- Feeding habits
- The only species in this genus is vermivorous (meaning that the cones prey on marine worms) feeding upon polychaete worms and eunicids.[2]
Species list
This list of species is based on the information in the World Register of Marine Species (WoRMS) list. Species within the genus Dyraspis include:[1]
The following species names are recognized as "alternate representations" (see full explanation below) in contrast to the traditional system, which uses the genus Conus for all species in the family:[1]
Significance of "alternative representation"
Prior to 2009, all species within the family Conidae were placed in one genus, Conus. In 2009 however, J.K. Tucker and M.J. Tenorio proposed a classification system for the over 600 recognized species that were in the family. Their classification proposed 3 distinct families and 82 genera for the living species of cone snails. This classification was based upon shell morphology, radular differences, anatomy, physiology, cladistics, with comparisons to molecular (DNA) studies.[2] Published accounts of genera within the Conidae that include the genus Dyraspis include J.K. Tucker & M.J. Tenorio (2009), and Bouchet et al. (2011).[3]
Testing in order to try to understand the molecular phylogeny of the Conidae was initially begun by Christopher Meyer and Alan Kohn[4], and is continuing, particularly with the advent of nuclear DNA testing in addition to mDNA testing.
However, in 2011, some experts still prefer to use the traditional classification, where all species are placed in Conus within the single family Conidae: for example, according to the current November 2011 version of the World Register of Marine Species, all species within the family Conidae are in the genus Conus. The binomial names of species in the 82 cone snail genera listed in Tucker & Tenorio 2009 are recognized by the World Register of Marine Species as "alternative representations." [5] Debate within the scientific community regarding this issue continues, and additional molecular phylogeny studies are being carried out in an attempt to clarify the issue.[6][7][8][2][9][10][11][12][13][14]
References
- ^ a b c Dyraspis Iredale, 1949. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=576858 on 07/13/11.
- ^ a b c d e Tucker J.K. & Tenorio M.J. (2009), Systematic Classification of Recent and Fossil Conoidean Gastropods, ConchBooks, Hankenheim, Germany, 295 pp.
- ^ Bouchet P., Kantor Yu.I., Sysoev A. & Puillandre N. (2011). "A new operational classification of the Conoidea". Journal of Molluscan Studies 77: 273-308.
- ^ Interview of Professor Alan Kohn, Professor Emeritus, Zoology http://www.seashell-collector.com/articles/interviews/2009-kohn.html
- ^ http://www.marinespecies.org/aphia.php?p=taxdetails&id=14107 Classification: Traditionally, all cone shells have been included in the Linnaean genus Conus. Tucker & Tenorio (2009) have recently proposed an alternative shell- and radula-based classification that recognizes 4 families and 80 genera of cones. In WoRMS, we currently still recognize a single family Conidae (following Puillandre et al. 2011), but Tucker & Tenorio's 80 genera classification is presented as "alternative representation". [P. Bouchet, 14 Aug. 2011]
- ^ 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
- ^ P. Bouchet, Yu I. Kantor, A. Sysoev, and N. Puillandre (March 2011), A New Operational Classification of the Conoidea, Journal of Molluscan Studies 77:273-308, at p. 275.
- ^ N. Puillandre, E. Strong, P. Bouchet, M. Boisselier, V. Couloux, & S. Samadi (2009), Identifying gastropod spawn from DNA barcodes: possible but not yet practicable, Molecular Ecology Resources 9:1311-1321.
- ^ 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. Mollecular Phylogenetics and Evolution 46: 215-223.
- ^ S.T. Williams & T.F. Duda, Jr. (2008), Did tectonic activity stimulate Oligo-Miocene speciation in the Indo-West Pacific? Evolution 62:1618-1634.
- ^ 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.
- ^ 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.
- ^ T.F. Duda, Jr. & E. Rolan (2005), Explosive radiation of Cape Verde Conus, a marine species flock, Molecular Ecology 14:267-272.
- ^ B. Vallejo, Jr. (2005), Inferring the mode of speciation in the Indo-West Pacific Conus (Gastropoda: Conidae), Journal of Biogeography 32:1429-1439.
Further reading
- Kohn A. A. (1992). Chronological Taxonomy of Conus, 1758-1840". Smithsonian Institution Press, Washington and London.
- Monteiro A. (ed.) (2007). The Cone Collector 1: 1-28.
- Berschauer D. (2010). Technology and the Fall of the Mono-Generic Family The Cone Collector 15: pp. 51-54
- Puillandre N., Meyer C.P., Bouchet P., and Olivera B.M. (2011), Genetic divergence and geographical variation in the deep-water Conus orbignyi complex (Mollusca: Conoidea), Zoologica Scripta 40(4) 350-363.
External links