Voluta ebraea
Encyclopedia
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 population
s of Voluta ebraea may be suffering declines due to overfishing
and overexploitation
.
, Maranhão
, Ceará
, Rio Grande do Norte
, Paraíba
, Pernambuco
, Alagoas
, Sergipe
, Bahia
and Abrolhos Marine National Park
.
Voluta ebraea has a somewhat robust and solid shell, with a slightly elongate contour. 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 protoconch
is rounded, and presents two whorls. The shell as a whole has seven slightly convex whorl
s. Those whorls (including the body whorl
) are ornamented by several posteriorly-oriented sharp spines. The outer lip
is thick, and the aperture
is relatively long and narrow. As is the case in other volutes
, the columella
presents an array of strong oblique columellar folds
(also known as plicae, 9 to 11 of them in this species), which are more conspicuous anteriorly.The corneous
, claw-like operculum
partially covers the shell aperture.
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.
colored body, ornamented by numerous irregular and intertwined thin dark-red to brown colored lines, and several small spots of the same collor along the sides of the foot. Some of the most distinct external features are its very large foot, and a long siphon.
This species presents a Steoglossan type radula
, composed of a single row of rachidian or central teeth. Each one of these teeth exhibits several smaller acute denticles or cusps
. The radula is considered to be similar, though larger than that of the music volute
, a similar but distinct species.
of V. ebraea, as studies on that subject are fairly recent and/or rather scarce.
and rocks, and usually shows a preference for sandy substrata. It may be found from shallow water to depths around 40–70 m.
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
.
s, 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
).
, Anphichthys cryptocentrus.
of this species, it is believed that both overfishing
and overexploitation
are exeting a negative effect on natural populations. The Hebrew volute may occur in shallow water, which tends to facilitate its harvesting by the locals. Thus it is currently not observed in many areas in which it was known to be numerous before. It is not uncommon for hebrew volutes to be accidentally caught in bottom gill fishing nets and traps set by commercial fishing boats.
The imposex
phenomenon has been observed in the Voluta ebraea. 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 dock
ing areas, consequently exposing the nearby marine life to its deleterious effects.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
the Hebrew volute, is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of medium-sized sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine gastropod mollusk in the family Volutidae
Volutidae
Volutidae, common name volutes, are a taxonomic family of predatory sea snails that range in size from 9 mm to over 500 mm, marine gastropod mollusks...
, the volutes. The Hebrew volute is endemic to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, where it its collected both for food and for its shell, which is highly desired for ornamental purposes. Recent studies indicate that natural population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
s of Voluta ebraea may be suffering declines due to overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
and overexploitation
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource...
.
Distribution
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 and regions, including ParáPará
Pará is a state in the north of Brazil. It borders the Brazilian states of Amapá, Maranhão, Tocantins, Mato Grosso, Amazonas and Roraima. To the northwest it also borders Guyana and Suriname, and to the northeast it borders the Atlantic Ocean. The capital is Belém.Pará is the most populous state...
, Maranhão
Maranhão
Maranhão is a northeastern state of Brazil. To the north lies the Atlantic Ocean. Maranhão is neighbored by the states of Piauí, Tocantins and Pará. The people of Maranhão have a distinctive accent...
, Ceará
Ceará
Ceará is one of the 27 states of Brazil, located in the northeastern part of the country, on the Atlantic coast. It is currently the 8th largest Brazilian State by population and the 17th by area. It is also one of the main touristic destinations in Brazil. The state capital is the city of...
, Rio Grande do Norte
Rio Grande do Norte
Rio Grande do Norte is one of the states of Brazil, located in the northeastern region of the country, occupying the northeasternmost tip of the South American continent. Because of its geographic position, Rio Grande do Norte has a strategic importance. The capital and largest city is Natal...
, Paraíba
Paraíba
Paraíba Paraíba Paraíba (Tupi: pa'ra a'íba: "bad to navigation"; Brazilian Portuguese pronunciation: is a state of Brazil. It is located in the Brazilian Northeast, and is bordered by Rio Grande do Norte to the north, Ceará to the west, Pernambuco to the south and the Atlantic Ocean to the east...
, Pernambuco
Pernambuco
Pernambuco is a state of Brazil, located in the Northeast region of the country. To the north are the states of Paraíba and Ceará, to the west is Piauí, to the south are Alagoas and Bahia, and to the east is the Atlantic Ocean. There are about of beaches, some of the most beautiful in the...
, Alagoas
Alagoas
Alagoas is one of the 27 federative units of Brazil and is situated in the eastern part of the Northeast Region. It borders: Pernambuco ; Sergipe ; Bahia ; and the Atlantic Ocean . It occupies an area of 27,767 km², being slightly larger than Haiti...
, Sergipe
Sergipe
Sergipe , is the smallest state of the Brazilian Federation, located on the northeastern Atlantic coast of the country. It borders on two other states, Bahia to the south and west and Alagoas to the north, and to the east is the Atlantic Ocean...
, Bahia
Bahia
Bahia is one of the 26 states of Brazil, and is located in the northeastern part of the country on the Atlantic coast. It is the fourth most populous Brazilian state after São Paulo, Minas Gerais and Rio de Janeiro, and the fifth-largest in size...
and Abrolhos Marine National Park
Abrolhos Marine National Park
The Abrolhos Marine National Park is a Marine Park located in the Abrolhos Archipelago since 1983.The Abrolhos are an archipelago of 5 islands with coral reefs off the southern coast of Bahia state in the northeast of Brazil, between 17º25’—18º09’ S and 38º33’—39º05’ W.-External links:***...
.
Shell description
The shell length of this species may reach and exceed 200 mm, up to 220 mm, although lengths from 100 mm to 150 mm are more common.Voluta ebraea has a somewhat robust and solid shell, with a slightly elongate contour. 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 protoconch
Protoconch
A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
is rounded, and presents two whorls. The shell as a whole has seven slightly convex whorl
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
s. Those whorls (including the body whorl
Body whorl
Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...
) are ornamented by several posteriorly-oriented sharp spines. The outer lip
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is thick, and the aperture
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is relatively long and narrow. As is the case in other volutes
Voluta
Voluta is a genus of medium to large sea snails, marine gastropod molluscs in the family Volutidae, the volutes. -Species:Species in the genus Voluta include:* Voluta ebraea Linnaeus, 1758* Voluta morrisoni...
, the columella
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
presents an array of strong oblique columellar folds
Plait (gastropod)
A plait is an anatomical feature which is present the shells of some snails, or gastropods. This sculpture occurs often in the shells of marine gastropod mollusks in the clade Neogastropoda, but it is also found in some pulmonate land snails....
(also known as plicae, 9 to 11 of them in this species), which are more conspicuous anteriorly.The corneous
Corneous
Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals....
, claw-like operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
partially covers the shell aperture.
Sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
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
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
also differs between males and females.
Anatomy
The Hebrew volute has a pale ivoryIvory
Ivory is a term for dentine, which constitutes the bulk of the teeth and tusks of animals, when used as a material for art or manufacturing. Ivory has been important since ancient times for making a range of items, from ivory carvings to false teeth, fans, dominoes, joint tubes, piano keys and...
colored body, ornamented by numerous irregular and intertwined thin dark-red to brown colored lines, and several small spots of the same collor along the sides of the foot. Some of the most distinct external features are its very large foot, and a long siphon.
This species presents a Steoglossan type radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
, composed of a single row of rachidian or central teeth. Each one of these teeth exhibits several smaller acute denticles or cusps
Cusp (dentistry)
A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...
. The radula is considered to be similar, though larger than that of the music volute
Voluta musica
Voluta musica, common name the Music volute, is a species of medium-sized sea snail, a marine gastropod mollusk in the family Volutidae, the volutes...
, a similar but distinct species.
Ecology
Much is yet to be reveled about the ecologyEcology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
of V. ebraea, as studies on that subject are fairly recent and/or rather scarce.
Habitat
The Hebrew volute dwells in sandy bottoms, among coralCoral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
and rocks, and usually shows a preference for sandy substrata. It may be found from shallow water to depths around 40–70 m.
Life cycle
Like other members of the cladeClade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Neogastropoda
Neogastropoda
Neogastropoda is an unranked taxonomic clade of sea snails, marine gastropod mollusks. For many years prior to 2005 Neogastropoda was an order.- Description :...
, Voluta ebraea is dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
, which means each individual organism belonging to this species is distinctly male
Male
Male refers to the biological sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization...
or female
Female
Female is the sex of an organism, or a part of an organism, which produces non-mobile ova .- Defining characteristics :The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male...
. It is also sexually dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
, which means there is a difference in form between individuals of different sex within this species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
Feeding habits
As is the case in several other volutidVolutidae
Volutidae, common name volutes, are a taxonomic family of predatory sea snails that range in size from 9 mm to over 500 mm, marine gastropod mollusks...
s, the Hebrew volute is carnivorous and predatory. It is known to feed on the cardiid bivalve mollusk Trachycardium muricatum
Trachycardium muricatum
Trachycardium muricatum, or the yellow cockle, is a species of bivalve mollusc in the family Cardiidae. It can be found along the Atlantic coast of North America, ranging from North Carolina to the West Indies and Brazil....
in the wild, whereas in captivity it has been reported to feed on the sea snails Stramonita haemastoma
Stramonita haemastoma
Stramonita haemastoma, common name the Red-mouthed rock shell or the Florida Dog Winkle, is a species of predatory sea snail, a marine gastropod mollusc in the family Muricidae, the rock snails. -Distribution:...
(a muricid
Muricidae
Muricidae, common name murex snails or rock snails, is a large and varied taxonomic family of small to large predatory sea snails. With approximately 1,600 living species the Muricidae represent almost 10% of the Neogastropoda. Additionally, 1,200 fossil species have been recognised...
carnivorous gastropod) and Tegula viridula
Tegula viridula
Tegula viridula is a species of sea snail, a marine gastropod mollusk in the family Turbinidae, the turban snails....
(a top snail
Trochidae
The Trochidae, common name top snails, are a taxonomic family of very small to large sea snails, marine gastropod molluscs in the clade Vetigastropoda ....
).
Biological interactions
The Hebrew volute is known to be a prey of the Bocon toadfishBocon toadfish
The Bocon toadfish is a species of tropical toadfish in the family Batrachoididae....
, Anphichthys cryptocentrus.
Human use
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.Conservation
Though little is known about the conservation statusConservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
of this species, it is believed that both overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
and overexploitation
Exploitation of natural resources
Main article: OverexploitationSome exploitation of natural resources is an essential condition of the human existence. This refers primarily to food production and necessities...
are exeting a negative effect on natural populations. The Hebrew volute may occur in shallow water, which tends to facilitate its harvesting by the locals. Thus it is currently not observed in many areas in which it was known to be numerous before. It is not uncommon for hebrew volutes to be accidentally caught in bottom gill fishing nets and traps set by commercial fishing boats.
The imposex
Imposex
Imposex is a descriptive term applied to some sea snails, marine gastropod molluscs which, under the toxic effects of pollutants, develop sex organs that are in contrast to their actual sex...
phenomenon has been observed in the Voluta ebraea. The development of masculine sexual organs in the females exposed to organic tin compounds, such as tributyltin
Tributyltin
Tributyltin compounds are a group of compounds containing the 3Sn moiety, such as tributyltin hydride or tributyltin oxide. They are the main active ingredients in certain biocides used to control a broad spectrum of organisms...
(TBT), may have several negative consequences for entire populations of this species, from sterilization of individuals to the complete extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
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 dock
Dock
-In transportation:*Dock , a structure for handling ships**Drydock, a basin that can be flooded and drained to allow a load to come to rest on a dry platform**Ferry slip, a docking facility that receives a ferryboat...
ing areas, consequently exposing the nearby marine life to its deleterious effects.