Showing papers on "Turridae published in 2012"
TL;DR: The formalized strategy applied here outlines an effective and reproducible protocol for large‐scale species delimitation of hyperdiverse groups and identified 27 novel species hypotheses not linked to available species names in the literature.
Abstract: Accelerating the description of biodiversity is a major challenge as extinction rates increase. Integrative taxonomy combining molecular, morphological, ecological and geographical data is seen as the best route to reliably identify species. Classic molluscan taxonomic methodology proposes primary species hypotheses (PSHs) based on shell morphology. However, in hyperdiverse groups, such as the molluscan family Turridae, where most of the species remain unknown and for which homoplasy and plasticity of morphological characters is common, shell-based PSHs can be arduous. A four-pronged approach was employed to generate robust species hypotheses of a 1000 specimen South-West Pacific Turridae data set in which: (i) analysis of COI DNA Barcode gene is coupled with (ii) species delimitation tools GMYC (General Mixed Yule Coalescence Method) and ABGD (Automatic Barcode Gap Discovery) to propose PSHs that are then (iii) visualized using Klee diagrams and (iv) evaluated with additional evidence, such as nuclear gene rRNA 28S, morphological characters, geographical and bathymetrical distribution to determine conclusive secondary species hypotheses (SSHs). The integrative taxonomy approach applied identified 87 Turridae species, more than doubling the amount previously known in the Gemmula genus. In contrast to a predominantly shell-based morphological approach, which over the last 30 years proposed only 13 new species names for the Turridae genus Gemmula, the integrative approach described here identified 27 novel species hypotheses not linked to available species names in the literature. The formalized strategy applied here outlines an effective and reproducible protocol for large-scale species delimitation of hyperdiverse groups.
297 citations
1 Jan 2012
TL;DR: In this article, a four-pronged approach was employed to generate robust species hypotheses of a 1000 specimen SouthWest Pacific Turridae data set in which: (i) analysis of COI DNA Barcode gene is coupled with (ii) species delimitation tools GMYC (General Mixed Yule Coalescence Method) and ABGD (Automatic Barcode Gap Discovery) to propose PSHs that are then visualized using Klee diagrams and evaluated with additional evidence, such as nuclear gene rRNA 28S, morphological characters, geographical and bathymet
Abstract: Accelerating the description of biodiversity is a major challenge as extinction rates increase. Integrative taxonomy combining molecular, morphological, ecological and geographical data is seen as the best route to reliably identify species. Classic molluscan taxonomic methodology proposes primary species hypotheses (PSHs) based on shell morphology. However, in hyperdiverse groups, such as the molluscan family Turridae, where most of the species remain unknown and for which homoplasy and plasticity of morphological characters is common, shell-based PSHs can be arduous. A four-pronged approach was employed to generate robust species hypotheses of a 1000 specimen SouthWest Pacific Turridae data set in which: (i) analysis of COI DNA Barcode gene is coupled with (ii) species delimitation tools GMYC (General Mixed Yule Coalescence Method) and ABGD (Automatic Barcode Gap Discovery) to propose PSHs that are then (iii) visualized using Klee diagrams and (iv) evaluated with additional evidence, such as nuclear gene rRNA 28S, morphological characters, geographical and bathymetrical distribution to determine conclusive secondary species hypotheses (SSHs). The integrative taxonomy approach applied identified 87 Turridae species, more than doubling the amount previously known in the Gemmula genus. In contrast to a predominantly shellbased morphological approach, which over the last 30 years proposed only 13 new species names for the Turridae genus Gemmula, the integrative approach described here identified 27 novel species hypotheses not linked to available species names in the literature. The formalized strategy applied here outlines an effective and reproducible protocol for large-scale species delimitation of hyperdiverse groups.
148 citations
TL;DR: The Terebridae, the sister group of Turridae, are characterized by very high radular variability, and the transformation of the marginal radular teeth within this single clade repeats the evolution of the radular apparatus across the entire Conoidea.
Abstract: The anatomy and evolution of the radular apparatus in predatory marine gastropods of the superfamily Conoidea is reconstructed on the basis of a molecular phylogeny, based on three mitochondrial genes (COI, 12S and 16S) for 102 species. A unique feeding mechanism involving use of individual marginal radular teeth at the proboscis tip for stabbing and poisoning of prey is here assumed to appear at the earliest stages of evolution of the group. The initial major evolutionary event in Conoidea was the divergence to two main branches. One is characterized by mostly hypodermic marginal teeth and absence of an odontophore, while the other possesses a radula with primarily duplex marginal teeth, a strong subradular membrane and retains a fully functional odontophore. The radular types that have previously been considered most ancestral, “prototypic” for the group (flat marginal teeth; multicuspid lateral teeth of Drilliidae; solid recurved teeth of Pseudomelatoma and Duplicaria), were found to be derived conditions. Solid recurved teeth appeared twice, independently, in Conoidea – in Pseudomelatomidae and Terebridae. The Terebridae, the sister group of Turridae, are characterized by very high radular variability, and the transformation of the marginal radular teeth within this single clade repeats the evolution of the radular apparatus across the entire Conoidea.
40 citations
TL;DR: The juxtaposition of extremely conserved signal sequences with hypervariable mature peptide regions is unprecedented and raises the possibility that in these gene superfamilies, the signal sequences are conserved as a result of an essential role they play in enabling rapid sequence evolution of the region of the gene that encodes the active toxin.
Abstract: An impressive biodiversity (>10,000 species) of marine snails (suborder Toxoglossa or superfamily Conoidea) have complex venoms, each containing approximately 100 biologically active, disulfide-rich peptides. In the genus Conus, the most intensively investigated toxoglossan lineage (∼500 species), a small set of venom gene superfamilies undergo rapid sequence hyperdiversification within their mature toxin regions. Each major lineage of Toxoglossa has its own distinct set of venom gene superfamilies. Two recently identified venom gene superfamilies are expressed in the large Turridae clade, but not in Conus. Thus, as major venomous molluscan clades expand, a small set of lineage-specific venom gene superfamilies undergo accelerated evolution. The juxtaposition of extremely conserved signal sequences with hypervariable mature peptide regions is unprecedented and raises the possibility that in these gene superfamilies, the signal sequences are conserved as a result of an essential role they play in enabling rapid sequence evolution of the region of the gene that encodes the active toxin.
39 citations
Journal Article•
TL;DR: Gastropod species were examined from nine sites along the coasts of Sindh and Balochistan, Pakistan and belonging to two orders namely, Archaeo- and Neogastropoda and five families (Trochidae,Turbinidae, Thaidae, Turridae, and Buccinidae) were studied.
Abstract: Gastropod species were examined from nine sites along the coasts of Sindh and Balochistan, Pakistan. Ten species of gastropods namely, Monodonta canalifera (Lamarck, 1801), Turbo coronatus (Gmelin, 1791), Thais carinifera (Lamarck, 1816), T. bufo (Lamarck, 1822), T. hippocastanum (Linnaeus, 1758), T. rudolphi (Lamarck, 1822), T. tissoti (Petit, 1853), Morula granulata (Duclos, 1832), Turricula javana (Linnaeus, 1767) and Babylonia spirata (Linnaeus, 1758; Swainson, 1822), belonging to two orders namely, Archaeo- and Neogastropoda and five families (Trochidae, Turbinidae, Thaidae, Turridae, and Buccinidae) were studied. The species were identified on the basis of their chonchological characteristics.
9 citations
Journal Article•
TL;DR: The present study evaluated turrids from by catch recourses from Kasimedu, Cuddalore, Mudasalodai and Pazhayar along the Tamilnadu coastline to observe the abundance and seasonal distribution of the turrid assemblage.
Abstract: Marine gastropods of the family turridae encompass the largest living group of venomous snails. The ta xonomy of this group is generally derelict along the southeas t coast of India. The present study was carried out to observe the abundance and seasonal distribution of the turrids assemblage and this survey evaluated turrids from t he by catch recourses from Kasimedu, Cuddalore, Mudasalodai and Pazhayar along the Tamilnadu coastline. Totally 17 53 individuals belonging to 16 species of turrids were collected. The highest abundance of 16 species of turrids present in Pazhayar, whereas 13 species were in Mudasalodai 10 in Kasimedu and 6 in Cuddalore. Among these, Tu rricula javana, Lophiotoma indica and T. tornata were maxim um abundant at all the four stations. The Shannon d iversity index (H’log2) of turrids was varied from 1.94 ‐ 0. 68 and the species richness was varied from 2.21 to 0.31 where as seasonal contribution of turrids are maximum in pre-monsoon at Pazhayar and minimum in summer at Cuddalore. The species evenness was varied from 0.9 to 0.6 in Mudasalodai. The information regarding t he
2 citations