Africonus

Africonus
Apertural and abapertural views of shell of Conus borgesi Trovão, 1979
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Caenogastropoda clade Hypsogastropoda clade Neogastropoda
Superfamily:	Conoidea
Family:	Conidae
Genus:	Conus
Subgenus:	Africonus Petuch, 1975
Type species
Conus cuneolus Reeve, 1843
Synonyms
Lautoconus

Africonus is a subgenus of sea snails, marine gastropod mollusks in the genus Conus, family Conidae, the cone snails and their allies.^[1]

In the new classification of the family Conidae by Puillandre N., Duda T.F., Meyer C., Olivera B.M. & Bouchet P. (2015), Africonus has become a subgenus of Conus: Conus (Lautoconus) Monterosato, 1923 (type species: Conus mediterraneus Hwass in Bruguière, 1792) represented as Conus Thiele, 1929 ^[2]

Distinguishing characteristics

The Tucker & Tenorio 2009 taxonomy distinguishes Africonus from Conus in the following ways:^[3]

• Genus Conus sensu stricto Linnaeus, 1758

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.^[3]

• Subgenus Africonus Petuch, 1975

Shell characters (living and fossil species)

The protoconch is paucispiral, the whorl tops may be concave when viewed in cross section, with cords on the whorl tops that may be lost in middle spire whorls or persist thereafter. The shell has a shallow to moderately deep anal notch. The periostracum is smooth and thin, and the operculum is small.

Radular tooth (not known for fossil species)

The anterior section of the radula is usually shorter than the posterior section but in some species they are subequal in length, the lumen of the radular tooth is wide, a basal spur is present, the barb is short, and the blade is long and extends along most of the anterior section of the radular tooth. Serrations are usually in multiple rows with one or two rows of large serrations and rows of smaller serrations on either side, although serrations can be in a single row in juveniles or small specimens.

Geographical distribution

These species are endemic to the Cape Verde Islands in the West African Region.

Feeding habits

These species are vermivorous (meaning that they prey on marine worms).^[3]

Species list

This list of species is based on the information in the World Register of Marine Species (WoRMS) list. Species within the genus Africonus 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]

The following species were synonymized:^[1]

• Africonus echinophilus Petuch, 1975 was accepted as Conus echinophilus (Petuch, 1975). This species should not be placed in Africonus; it: synonym of Lautoconus echinophilus^[5]

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.^[3] Published accounts of genera within the Conidae that include the genus Africonus include J.K. Tucker & M.J. Tenorio (2009), and Bouchet et al. (2011).^[6]

Testing in order to try to understand the molecular phylogeny of the Conidae was initially begun by Christopher Meyer and Alan Kohn,^[7] 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 currently recognized by the World Register of Marine Species as "alternative representations." ^[8] 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.^{[3][9][10][11][12][13][14][15][16][17][18]}

In 2015, in the Journal of Molluscan Studies, 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 cone snails in a single family, Conidae, containing four genera: Conus, Conasprella, Profundiconus and Californiconus. The authors group 85% of all known cone snail species under Conus, They recognize 57 subgenera within Conus, and 11 subgenera within the genus Conasprella.^[2]

References

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

• "Conidae". National Center for Biotechnology Information (NCBI). 
• To World Register of Marine Species
• Gastropods.com: Conidae setting forth the genera recognized therein.
• Checklist of the Living Conidae, by Paul Kersten.
• Cone Shells - Knights of the Sea