Envenomation of Humans: In Fact and Fiction.

Prominent hallmarks of the widely distributed, mainly tropical marine snail genus are: (1) its unusually high species diversity; it is the largest genus of animals in the sea, with more than 800 recognized species; and (2) its specialized feeding behavior of overcoming prey by injection with potent neurotoxic, paralytic venoms, and swallowing the victim whole. Including the first report of a human fatality from a sting nearly 350 years ago, at least 141 human envenomations have been recorded, of which 36 were fatal. Most species are quite specialized predators that can be classified in one of three major feeding guilds: they prey exclusively or nearly so on worms, primarily polychaete annelids, other gastropods, sometimes including other species, or fishes.

Conidae (Mollusca, Gastropoda) of Lakshadweep, India.

Lakshadweep, the northernmost region of the Chagos-Maldives-Lakshadweep group of islands located southwest of the Malabar coast of India in the Arabian Sea, is the only chain of coral atolls in India. This paper documents the diversity of the molluscan family Conidae from the seas around all ten inhabited islands of Lakshadweep. Of the 78 species of cone snails now reported from Lakshadweep, 49 were recorded in this study.

Cryptic species differentiated in Conus ebraeus, a widespread tropical marine gastropod.

Anomalous mitochondrial and nuclear gene sequences in individuals of the widely distributed tropical marine gastropod Conus ebraeus that were not distinguishable by shell shape and color pattern characters suggested the presence of a second, cryptic species. We tested this hypothesis by genetic, morphological, and ecological comparisons of additional individuals from the site in Okinawa where the two forms co-occurred. Radular tooth size and shape, prey type in nature, and microhabitats utilized differed markedly between the two forms.

Hidden diversity in a hyperdiverse gastropod genus: discovery of previously unidentified members of a Conus species complex.

Molecular sequence data are a powerful tool for delimiting species, particularly in cases where morphological differences are obscure. Distinguishing species in the Conus sponsalis complex of tropical marine gastropods has long been difficult, because descriptions and identification has relied exclusively on shell characters, primarily color patterns, and these often appear to intergrade among putative species. Here we use molecular sequence data from two mitochondrial gene regions (16S rRNA and cytochrome oxidase subunit I) and one nuclear locus (a four-loop conotoxin gene) to characterize the genetic discontinuity of the nominal species of this group currently accepted as valid: the Indo-West Pacific C.

Species-level phylogeography and evolutionary history of the hyperdiverse marine gastropod genus Conus.

Phylogenetic and paleontological analyses are combined to reveal patterns of species origination and divergence and to define the significance of potential and actual barriers to dispersal in Conus, a species-rich genus of predatory gastropods distributed throughout the world's tropical oceans. Species-level phylogenetic hypotheses are based on nucleotide sequences from the nuclear calmodulin and mitochondrial 16S rRNA genes of 138 Conus species from the Indo-Pacific, eastern Pacific, and Atlantic Ocean regions. Results indicate that extant species descend from two major lineages that diverged at least 33 mya.

Microhabitat factors affecting abundance and diversity of Conus on coral reefs.

Frequency and per cent cover of particular substratum types are shown to be important factors influencing abundance and diversity of mobile, predatory benthic invertebrates on spatially complex coral reef platforms. The most favorable portions of reefs for the gastropod Conus have <20% cover of algal-bound sand and <20% cover of living coral. The former microhabitat provides diurnal shelter for smaller Conus, harbors dense prey populations, and is typically interspersed with sand- and rubble-filled depressions in which many of the gastropods shelter during the day.

Effect of habitat complexity on population density and species richness in tropical intertidal predatory gastropod assemblages.

Structural complexity of the habitat significantly increases population density and number of species in assemblages of predatory gastropod molluscs (families Conidae, Muricidae, Mitridae and Vasidae) on intertidal, generally smooth, horizontal limestone platforms fringing tropical Pacific islands. The important topographic features are physical (depressions partly filled with coral rubble) and biotic (thick algal turf binding sand). Higher population density and species richness in areas with than without such natural refuges, and following experimental addition of artificial refuges on portions of habitat lacking them support this hypothesis.