Conus jorioi
Conus jorioi is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails, cone shells or cones.
Etymology
The name Conus jorioi honours Domingos Afonso Jorio from Guaraparí, Espírito Santo State, Brazil, in recognition of his contributions to Brazilian malacology. The species epithet “jorioi” is explicitly given as a tribute to him in the original description.Description
Conus jorioi is a medium-sized marine gastropod distinguished by a shell that reaches approximately 53 millimetres in length, a measurement that made it the largest cone snail known from Trindade Island at the time of its formal description. The shell possesses a distinctly broad and robust profile, giving it a more inflated appearance than many closely related Western Atlantic species. Its body whorl is strongly convex, contributing to a proportionally wider silhouette that contrasts noticeably with the more slender and cylindrical shapes typical of continental Brazilian cone snails. The spire is relatively high and prominently elevated, displaying clearly stepped whorls and pronounced sutural ramps that rise more steeply than in most congeners from nearby regions. This elevated spire, combined with a sharply defined shoulder, gives the shell a more angular geometry in dorsal view, a feature regarded as an important diagnostic character in Petuch’s original differentiation of the species.The shoulder region is characteristically angled and slightly carinate, creating a distinct break between the spire and body whorl that enhances the shell’s structural definition. The aperture is moderately wide relative to its overall shell size, with a smooth internal surface and a gradual narrowing toward the anterior end, reflecting the general morphology associated with predatory behaviour in the family Conidae. Fine spiral striations and subtle microscopic sculpturing appear toward the anterior portion of the shell, forming delicate textural elements that are often observed in cone snails adapted to high-energy shallow-water habitats. These surface sculptures, although not highly pronounced, suggest an ecological adaptation to the turbulent rocky environments of Trindade Island, where abrasion and wave impact shape shell evolution among local molluscan fauna.
The colouration of C. jorioi appears subdued, based on the holotype photographs, consisting mainly of pale beige to light brown tones interspersed with soft, irregular banding and indistinct blotches. This muted pigmentation provides effective camouflage against rocky substrates, a survival advantage in the shallow exposed marine zones inhabited by the species. Despite the availability of shell-based morphological information, no soft-body anatomical features have been described for C. jorioi, as only the holotype specimen has ever been documented and preserved without soft tissue. Consequently, critical biological elements such as radular structure, venom apparatus morphology, and reproductive anatomy remain unknown. The absence of such anatomical data is common among extremely rare cone snails from remote island environments, where sampling is limited and logistical barriers hinder further investigation.
Diagnostic distinctions highlighted in the original description emphasise the species’ broader shell-to-length ratio, its noticeably elevated and stepped spire, the thickness of the shoulder region, and its overall heavier shell construction. These combined traits justify its taxonomic recognition as a distinct endemic species, likely adapted to the unique environmental pressures of the isolated Trindade archipelago. The combination of shell robustness, muted coloration, and micro-sculptural adaptations further supports the view that C. jorioi reflects evolutionary specialization within a geographically constrained and ecologically demanding habitat.
Distribution
Conus jorioi is known exclusively from the marine waters surrounding Ilha de Trindade, a remote oceanic island of Brazil in the southwestern Atlantic; the species’ type locality and sole documented specimen originate from Trindade, where the holotype was collected on a rocky substrate at shallow depth.The only available museum and literature records indicate that the species was described from a single specimen and has not been reliably recorded from continental Brazilian localities or other nearby oceanic islands, a pattern that has led authors to treat C. jorioi as an insular endemic to the Trindade–Martin Vaz archipelago pending further surveys.
Because Trindade is remote and sampling of its shallow marine fauna has been intermittent and limited, the apparent restriction of C. jorioi to Trindade could reflect either true narrow endemism or an artefact of limited collecting effort; until further field work or additional specimen records are published, the species’ true geographic range beyond the type locality remains uncertain.
No peer-reviewed records or publicly accessible occurrence databases currently report additional verified localities for Conus jorioi beyond the original type series information; global taxonomic registries and specialist checklists therefore list the species with its Trindade provenance and no broader distributional data.