Voluta ebraea, common name the Hebrew volute, is a species of medium-sized sea snail, a marine gastropod mollusk in the family Volutidae, the volutes. The Hebrew volute is endemic to Brazil, where it its collected both for food and for its shell, which is highly desired for ornamental purposes. Recent studies indicate that natural populations of Voluta ebraea may be suffering declines due to overfishing and overexploitation.
This sea snail is found only along the north and northeastern Brazilian coast in the littoral zone. This species is endemic to those areas. It is present in many Brazilian states, including Pará, Maranhão, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe and Bahia.
Voluta ebraea has a somewhat robust and solid shell, slightly elongate. It is colored cream externally, with a complex series of darker-reddish brown markings and lines that are said to resemble Hebraic figures. The interior of the shell can vary in color from pale to strong orange.
The shell has seven slightly convex whorls. Those whorls (including the Body whorl) are ornamented by several posteriorly-oriented sharp spines. The aperture is relatively long, and as is the case in other volutes, the columella presents an array of strong oblique columellar folds (9 to 11 of them in this species), which are more conspicuous anteriorly.
Sexual dimorphism can be observed in the shells of this species: the shells of the males tend to be more elongate with a smoother outer surface, whereas the shells of the females are generally wider and more nodulose. The angle of the spire also differs between males and females.
Much is yet to be reveled about the ecology of V. ebraea, as studies on that subject are fairly recent and/or rather scarce.
Like other members of the Neogastropoda, Voluta ebraea is dioecious, which means each individual organism belonging to this species is distinctly male or female. It is also sexually dimorphic, which means there is a difference in form between individuals of different sex within this species.
As is the case in several other volutids, the Hebrew volute is carnivorous and predatory. It is known to feed on the cardiid bivalve mollusk Trachycardium muricatum in the wild, whereas in captivity it has been reported to feed on the sea snails Stramonita haemastoma (a muricid carnivorous gastropod) and Tegula viridula (a top snail).
The flesh of Voluta ebraea is edible, and it is locally collected for food in many areas. Its shell is also considered a popular and beautiful decorative object, and is sold as souvenir in local markets and craft stores in several regions of Brazil.
Though little is known about the conservation status of this species, it is believed that both overfishing and overexploitation are exeting a negative effect on natural populations. This species may occur in shallow water, which tends to facilitate its harvesting by the locals. Voluta ebraea is currently not observed in many areas in which it was known to be numerous before.
The imposex phenomenon has been observed in the Hebrew volute. The development of masculine sexual organs in the females exposed to organic tin compounds, such as tributyltin (TBT), may have several negative consequences for entire populations of this species, from sterilization of individuals to the complete extinction of those populations. Such compounds are biocide and antifouling agents, commonly mixed in paints to prevent marine encrustations on boats and ships. Therefore it is not uncommon for high concentrations of such compounds to be present in the sea water near shipyards and docking areas, consequently exposing the nearby marine life to its deleterious effects.
- ^ Rosenberg, G. (2009). "Malacolog 4.1.1: A Database of Western Atlantic Marine Mollusca". http://www.malacolog.org/search.php?nameid=5650. Retrieved 2009-10-25.
- ^ a b c d e f g h Rios, E. C. (1994). Seashells of Brazil (2nd ed.). Rio Grande: FURG. ISBN 8585042362.
- ^ a b c d "Conquiliologistas do Brasil". http://www.conchasbrasil.org.br/english/conchology/descricao.asp?id=238. Retrieved 2009-09-28.
- ^ a b c d e f g Dias, T. L. P. (2009). "First field study of the Brazilian endemic marine gastropod Voluta ebraea (Mollusca: Volutidae)". Marine Biodiversity Records (United Kingdom: Cambridge University Press). http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=3462444&fulltextType=RA&fileId=S1755267208000109.
- ^ a b c Castro, Í. B.; et al. (2008). "Imposex in endemic volutid from Northeast Brazil (Mollusca: Gastropoda)". Brazilian Archives of Biology and Technology (Brazil) 51 (5): 1065-1069. ISSN 1516-8913. http://www.scielo.br/pdf/babt/v51n5/a24v51n5.pdf.
- ^ Motta, S. S.; Pinheiro, J. C. L.; Mathews-Cascon, H. (2004). "Comportamento predatório de Voluta ebraea Linnaeus, 1758 MOLLUSCA: GASTROPODA: VOLUTIDAE em condições de laboratório" (in Portuguese). Resumos do XXV Congresso Brasileiro de Zoologia (Brasília): 292. http://www.unb.br/ib/zoo/CBZ/resumos/Mollusca.pdf.