Biomphalaria glabrata
Encyclopedia
Biomphalaria glabrata is a species
of air-breathing freshwater snail
, an aquatic
pulmonate gastropod mollusk in the family
Planorbidae, the ram's horn snail
s.
Biomphalaria glabrata is an intermediate snail host
for the trematode Schistosoma mansoni
, which is one of the main schistosomes
that infect humans. This snail is a medically important pest, because of transferring the disease intestinal schistosomiasis. (Intestinal schistosomiasis is the most widespread of all types of schistosomiasis
).
The parasite Schistosoma mansoni (which these snails and other Biomphalaria
snails carry) infects about 83.31 million people worldwide.
Biomphalaria glabrata/Schistosoma mansoni provides a useful model
system for investigating the intimate interactions between host and parasite. There is a great deal of information available about this snail, because it has been, and continues to be, under intensive study by many malacologists, parasitologists and other researchers, on account of its medical significance.
The shell of this species, like all planorbids, is sinistral
in coiling, but it is carried upside down, and thus it appears to be dextral.
: Puerto Rico, Dominican Republic
, Saint Lucia
, Haiti
(first report in 1891), Martinique, Guadeloupe, Antigua
, Vieques, Saint Martin
, Saint Kitts
, Curaçao
, Dominica (it was probably replaced by other Biomphalaria species in Dominica or it was eradicated), Montserrat
and in South America: Venezuela, Suriname
, French Guiana
and Brazil.
This species has recently expanded its native range, but there is reduced its abundance in the Caribbean, because of competition with non-indigenous species and environmental change.
It inhabits new localities
in the time of flooding.
of the shell is sunken. Also, like all planorbids, this species has a sinistral shell
, in other words, the coiling of the shell is left-handed. However, like all the snails in the subfamily Planobinae, this snail carries its coiled shell upside down, and thus the shell appears to be dextral in coiling. In other families of snails the spire is situated on top of the shell, here what shows on top of the shell is in fact the umbilicus.
Biomphalaria glabrata was discovered and described under the name Planorbis glabratus by American natualist Thomas Say
in 1818. Say's type description reads as follows:
Unfortunately Say listed an incorrect type locality: North Carolina
. The shell was probably actually from the West Indian island of Guadeloupe
.
The shell of animals from natural habitats is usually olivaceous (olive drab) in color. The width of the shell of adults snails is 6-10 mm.
An adult shell consist of aragonite
and sometimes there is also under 1.5 % of vaterite
especially near the margin of the shell.
cavity is described in Sullivan et al. (1974) and Jurberg et al. (1997).
length is estimated as about 929,10 Mb (millions of base pair
s; 0.95 ± 0.01 pg), which is a small genome size
among gastropods. Sequencing of the whole genome
was approved as a priority by National Human Genome Research Institute
in August 2004, in 2009 it was still in progress. Its participants also include the "Biomphalaria glabrata Genome Initiative" and the Genome Center at Washington University in St. Louis
.
The chromosome
s in this snail are small, and the haploid number of chromosomes is 18.
A complete genome sequence from the mitochondria of this species has been available since 2004: the mitochondrial genome
sequence has 13670 nucleotide
s.
The ancestor of Biomphalaria glabrata colonized Africa, and speciated
into all of the African Biomphalaria
species.
showing phylogenic relations of species in the genus Biomphalaria:
drains
in Saint Lucia.
Biomphalaria glabrata can also survive up to 16 hours in anaerobic water
using anaerobic respiration
.
Like other species, this snail is "light sensitive" and can be disrupted by artificial light.
s and decaying macrophytes.
They can be fed using fish food
and lettuce
when they are kept in captivity.
The periostracum
of the embryonic shell
(inside the egg) begin to grow in 48-hour old embryo
s. Amorphous calcium carbonate
appear in 54-60-hour old embryos. Calcification
(formation of aragonite) of the embryonic shell starts in the time interval between 60-hour old embryos and 72 hour-old ones. The weight of the shell of 72 hour-old embryo is 0.64 μg.
The weight of the embryonic shell in 5-day old (120 hours old) embryos a very short time before hatching, is 30.3 μg, and the width is 500 μm. The juvenile snail hatches from 5–6 days old eggs. The weight of the juvenile shell is 2.04 mg in four weeks after hatching. There is no vaterite in juvenile shells.
The growth rate, maximum birth rate
, and longevity of Biomphalaria glabrata was studied by Pimentel (1957). There can be up to seven generations in one year in laboratory. The generation time (the time it takes a snail from developing from an egg to laying an egg of its own) is 4–6 weeks. The lifespan is 15–18 months in natural conditions. The lifespan in laboratory conditions can be up to 18–24 months, but usually it is 9–12 months.
Biomphalaria glabrata is a simultaneous hermaphrodite, but self-fertilization is also possible. The mucus
of this snail species contains species-specific signals that allow individual snails to identify others of the same species, but the causative mucus components decay within 10 to 30 min. The typically unilateral copulations are initiated when a male actor mounts the shell of a prospective mate. The male actor then moves towards the frontal left edge of the partner's shell, where it probes the female gonopore with its penis to subsequently achieve penis intromission. Following a typically 5-87 min penis intromission with usually successful sperm transfer, the male actor retracts to terminate copulation. Mating roles are subsequently exchanged in about 45% of all copulations, with the male actor now taking the female role, and vice versa. In 2009, Biomphalaria glabrata was a subject of the study focusing on the Coolidge effect
in simultaneous hermaphrodites. The result of this research is that Biomphalaria glabrata shows the absence of any sex-specific effects of partner novelty, which means there is no Coolidge effect in this species.
for Schistosoma mansoni
in the Americas
and a vector of schistosomiasis
.
In medical research, the most commonly used Biomphalaria glabrata snail stock (used for the maintenance of Schistosoma mansoni) is albino, i.e. it is without pigment. It is descended from a mutant
albino stock which arose during research by Newton (1955). Not only did this albino variety prove to be highly susceptible to Schistosoma mansoni, but the lack of pigment allowed investigators using a dissecting microscope to view the development of the parasite within the snail. The black pigment normally found in snails that are taken from the field previously made this viewing too difficult.
Some other trematodes are also natural parasites of Biomphalaria glabrata:
Experimental parasites include:
in infected snails.
Interactions between snails and schistosomes are complex and there exists an urgent need to elucidate pathways involved in snail-parasite relationships as well as to identify those factors involved in the intricate balance between the snail internal defence system and trematode infectivity mechanisms that determine the success or failure of an infection
.
Molluscs appear to lack an adaptive immune system
like that found in vertebrates and, instead, are considered to use various innate mechanisms involving cell-mediated and humoral reactions
(non-cellular factors in plasma
/serum
or hemolymph
) that interact to recognize and eliminate invading pathogens or parasites in incompatible or resistant snails. However, a diverse family of fibrinogen
-related proteins (FREPs) containing immunoglobulin-like domains has been discovered in Biomphalaria glabrata and may play a role in snail defence. Circulating haemocytes (macrophage-like defence cells) in the snail haemolymph are known to aggregate in response to trauma, phagocytose small particles (bacteria, and fungi) and encapsulate larger ones, such as parasites. Final killing is effected by hemocyte-mediated cytotoxicity mechanisms involving non-oxidative and oxidative pathways, including lysosomal enzymes and reactive oxygen/nitrogen intermediates. Certain allele
s of cytosolic copper/zinc superoxide dismutase
(SOD1) have been associated with resistance also suggesting these processes are important in the snail internal defence system.
is a predator of Biomphalaria glabrata: it feeds on its eggs, juvenile and adult snails. It also acts as a competitor.
, from Egypt.
from plants Canavalia brasiliensis, Cratylia floribunda, Dioclea guianensis
, Dioclea grandiflora
and Dioclea virgata for adults of Biomphalaria glabrata is 50 μg mL−1.
The latex
of Euphorbia conspicua is toxic to adults of Biomphalaria glabrata.
Four species of the genus Solanum
from Brazil are toxic to Biomphalaria glabrata.
Some species of Annona
are toxic to adults of Biomphalaria glabrata and to its eggs.
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 air-breathing freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
pulmonate gastropod mollusk in the family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...
Planorbidae, the ram's horn snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s.
Biomphalaria glabrata is an intermediate snail host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
for the trematode Schistosoma mansoni
Schistosoma mansoni
Schistosoma mansoni is a significant parasite of humans, a trematode that is one of the major agents of the disease schistosomiasis. The schistosomiasis caused by Schistosoma mansoni is intestinal schistosomiasis....
, which is one of the main schistosomes
Schistosoma
A genus of trematodes, Schistosoma, commonly known as blood-flukes and bilharzia, includes flatworms which are responsible for a highly significant parasitic infection of humans by causing the disease schistosomiasis, and are considered by the World Health Organization as the second most...
that infect humans. This snail is a medically important pest, because of transferring the disease intestinal schistosomiasis. (Intestinal schistosomiasis is the most widespread of all types of schistosomiasis
Schistosomiasis
Schistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
).
The parasite Schistosoma mansoni (which these snails and other Biomphalaria
Biomphalaria
Biomphalaria is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies.Biomphalaria is the type genus of the tribe Biomphalariini....
snails carry) infects about 83.31 million people worldwide.
Biomphalaria glabrata/Schistosoma mansoni provides a useful model
Animal model
An animal model is a living, non-human animal used during the research and investigation of human disease, for the purpose of better understanding the disease without the added risk of causing harm to an actual human being during the process...
system for investigating the intimate interactions between host and parasite. There is a great deal of information available about this snail, because it has been, and continues to be, under intensive study by many malacologists, parasitologists and other researchers, on account of its medical significance.
The shell of this species, like all planorbids, is sinistral
Sinistral
Sinistral and dextral are scientific terms that describe chirality or relative direction in a number of disciplines.The terms are derived from the Latin words for “left” and “right” ....
in coiling, but it is carried upside down, and thus it appears to be dextral.
Distribution
Biomphalaria glabrata is a Neotropical species. Its native distribution includes the CaribbeanCaribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
: Puerto Rico, Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
, Saint Lucia
Saint Lucia
Saint Lucia is an island country in the eastern Caribbean Sea on the boundary with the Atlantic Ocean. Part of the Lesser Antilles, it is located north/northeast of the island of Saint Vincent, northwest of Barbados and south of Martinique. It covers a land area of 620 km2 and has an...
, Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...
(first report in 1891), Martinique, Guadeloupe, Antigua
Antigua
Antigua , also known as Waladli, is an island in the West Indies, in the Leeward Islands in the Caribbean region, the main island of the country of Antigua and Barbuda. Antigua means "ancient" in Spanish and was named by Christopher Columbus after an icon in Seville Cathedral, Santa Maria de la...
, Vieques, Saint Martin
Saint Martin
Saint Martin is an island in the northeast Caribbean, approximately east of Puerto Rico. The 87 km2 island is divided roughly 60/40 between France and the Kingdom of the Netherlands ; however, the Dutch side has the larger population. It is one of the smallest sea islands divided between...
, Saint Kitts
Saint Kitts
Saint Kitts Saint Kitts Saint Kitts (also known more formally as Saint Christopher Island (Saint-Christophe in French) is an island in the West Indies. The west side of the island borders the Caribbean Sea, and the eastern coast faces the Atlantic Ocean...
, Curaçao
Curaçao
Curaçao is an island in the southern Caribbean Sea, off the Venezuelan coast. The Country of Curaçao , which includes the main island plus the small, uninhabited island of Klein Curaçao , is a constituent country of the Kingdom of the Netherlands...
, Dominica (it was probably replaced by other Biomphalaria species in Dominica or it was eradicated), Montserrat
Montserrat
Montserrat is a British overseas territory located in the Leeward Islands, part of the chain of islands called the Lesser Antilles in the West Indies. This island measures approximately long and wide, giving of coastline...
and in South America: Venezuela, Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...
, French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
and Brazil.
This species has recently expanded its native range, but there is reduced its abundance in the Caribbean, because of competition with non-indigenous species and environmental change.
It inhabits new localities
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...
in the time of flooding.
Shell description
Like all planorbids, the shell of Biomphalaria glabrata is planispiral, in other words coiled flat like a rope, and the spireSpire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
of the shell is sunken. Also, like all planorbids, this species has a sinistral shell
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...
, in other words, the coiling of the shell is left-handed. However, like all the snails in the subfamily Planobinae, this snail carries its coiled shell upside down, and thus the shell appears to be dextral in coiling. In other families of snails the spire is situated on top of the shell, here what shows on top of the shell is in fact the umbilicus.
Biomphalaria glabrata was discovered and described under the name Planorbis glabratus by American natualist Thomas Say
Thomas Say
Thomas Say was an American naturalist, entomologist, malacologist, herpetologist and carcinologist. A taxonomist, he is often considered to be the father of descriptive entomology in the United States. He described more than 1,000 new species of beetles and over 400 species of insects of other...
in 1818. Say's type description reads as follows:
Unfortunately Say listed an incorrect type locality: North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
. The shell was probably actually from the West Indian island of Guadeloupe
Guadeloupe
Guadeloupe is an archipelago located in the Leeward Islands, in the Lesser Antilles, with a land area of 1,628 square kilometres and a population of 400,000. It is the first overseas region of France, consisting of a single overseas department. As with the other overseas departments, Guadeloupe...
.
The shell of animals from natural habitats is usually olivaceous (olive drab) in color. The width of the shell of adults snails is 6-10 mm.
An adult shell consist of aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
and sometimes there is also under 1.5 % of vaterite
Vaterite
Vaterite is a mineral, a polymorph of calcium carbonate. It was named after the German mineralogist Heinrich Vater. It is also known as mu-calcium carbonate and has a JCPDS number of 13-192. Vaterite, like aragonite, is a metastable phase of calcium carbonate at ambient conditions at the surface...
especially near the margin of the shell.
Anatomy
The anatomy of the mantleMantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
cavity is described in Sullivan et al. (1974) and Jurberg et al. (1997).
Genetics
The genomeGenome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
length is estimated as about 929,10 Mb (millions of base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
s; 0.95 ± 0.01 pg), which is a small genome size
Genome size
Genome size is the total amount of DNA contained within one copy of a single genome. It is typically measured in terms of mass in picograms or less frequently in Daltons or as the total number of nucleotide base pairs typically in megabases . One picogram equals 978 megabases...
among gastropods. Sequencing of the whole genome
Full genome sequencing
Full genome sequencing , also known as whole genome sequencing , complete genome sequencing, or entire genome sequencing, is a laboratory process that determines the complete DNA sequence of an organism's genome at a single time...
was approved as a priority by National Human Genome Research Institute
National Human Genome Research Institute
The National Human Genome Research Institute is a division of the National Institutes of Health, located in Bethesda, Maryland.NHGRI began as the National Center for Human Genome Research , which was established in 1989 to carry out the role of the NIH in the International Human Genome Project...
in August 2004, in 2009 it was still in progress. Its participants also include the "Biomphalaria glabrata Genome Initiative" and the Genome Center at Washington University in St. Louis
Washington University in St. Louis
Washington University in St. Louis is a private research university located in suburban St. Louis, Missouri. Founded in 1853, and named for George Washington, the university has students and faculty from all fifty U.S. states and more than 110 nations...
.
The chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s in this snail are small, and the haploid number of chromosomes is 18.
A complete genome sequence from the mitochondria of this species has been available since 2004: the mitochondrial genome
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
sequence has 13670 nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
s.
The ancestor of Biomphalaria glabrata colonized Africa, and speciated
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
into all of the African Biomphalaria
Biomphalaria
Biomphalaria is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies.Biomphalaria is the type genus of the tribe Biomphalariini....
species.
Phylogeny
A cladogramCladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
showing phylogenic relations of species in the genus Biomphalaria:
Ecology
Biomphalaria glabrata inhabits small streams, ponds and marshes. These snails can survive in aestivation for a few months when removed from their freshwater habitat or when the habitat dries out. For example, the snail lives in banana plantationBanana plantation
A banana plantation is a commercial agricultural facility found in tropical climates where bananas are grown. -Geographic distribution of banana plantations:...
drains
Drain (plumbing)
A drain is the primary vessel for unwanted water to be flumed away, either to a more useful area, funnelled into a receptacle, or run into the sewers as waste.-Waste versus re-circulated drains:...
in Saint Lucia.
Biomphalaria glabrata can also survive up to 16 hours in anaerobic water
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
using anaerobic respiration
Anaerobic respiration
Anaerobic respiration is a form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain; it is respiration without oxygen...
.
Like other species, this snail is "light sensitive" and can be disrupted by artificial light.
Feeding habits
Biomphalaria glabrata feeds on bacterial films, algae, diatomDiatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s and decaying macrophytes.
They can be fed using fish food
Fish food
Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macro nutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish...
and lettuce
Lettuce
Lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important...
when they are kept in captivity.
Life cycle
Biomphalaria glabrata snails lay egg masses at rather a high rate (about 1 per day). One snail can lay 14,000 eggs during its whole life span.The periostracum
Periostracum
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including mollusks and brachiopods. Among mollusks it is primarily seen in snails and clams, i.e. in bivalves and gastropods, but it is also found in cephalopods such as the...
of the embryonic shell
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...
(inside the egg) begin to grow in 48-hour old embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s. Amorphous calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
appear in 54-60-hour old embryos. Calcification
Calcification
Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...
(formation of aragonite) of the embryonic shell starts in the time interval between 60-hour old embryos and 72 hour-old ones. The weight of the shell of 72 hour-old embryo is 0.64 μg.
The weight of the embryonic shell in 5-day old (120 hours old) embryos a very short time before hatching, is 30.3 μg, and the width is 500 μm. The juvenile snail hatches from 5–6 days old eggs. The weight of the juvenile shell is 2.04 mg in four weeks after hatching. There is no vaterite in juvenile shells.
The growth rate, maximum birth rate
Birth rate
Crude birth rate is the nativity or childbirths per 1,000 people per year . Another word used interchangeably with "birth rate" is "natality". When the crude birth rate is subtracted from the crude death rate, it reveals the rate of natural increase...
, and longevity of Biomphalaria glabrata was studied by Pimentel (1957). There can be up to seven generations in one year in laboratory. The generation time (the time it takes a snail from developing from an egg to laying an egg of its own) is 4–6 weeks. The lifespan is 15–18 months in natural conditions. The lifespan in laboratory conditions can be up to 18–24 months, but usually it is 9–12 months.
Biomphalaria glabrata is a simultaneous hermaphrodite, but self-fertilization is also possible. The mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
of this snail species contains species-specific signals that allow individual snails to identify others of the same species, but the causative mucus components decay within 10 to 30 min. The typically unilateral copulations are initiated when a male actor mounts the shell of a prospective mate. The male actor then moves towards the frontal left edge of the partner's shell, where it probes the female gonopore with its penis to subsequently achieve penis intromission. Following a typically 5-87 min penis intromission with usually successful sperm transfer, the male actor retracts to terminate copulation. Mating roles are subsequently exchanged in about 45% of all copulations, with the male actor now taking the female role, and vice versa. In 2009, Biomphalaria glabrata was a subject of the study focusing on the Coolidge effect
Coolidge effect
In biology and psychology, the Coolidge effect is a phenomenon—seen in nearly every mammalian species in which it has been tested—whereby males exhibit continuous sexual activity if they are introduced to receptive sexual partners, but will eventually stop having sex if the partner has already...
in simultaneous hermaphrodites. The result of this research is that Biomphalaria glabrata shows the absence of any sex-specific effects of partner novelty, which means there is no Coolidge effect in this species.
Parasites
Biomphalaria glabrata is a major intermediate hostIntermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...
for Schistosoma mansoni
Schistosoma mansoni
Schistosoma mansoni is a significant parasite of humans, a trematode that is one of the major agents of the disease schistosomiasis. The schistosomiasis caused by Schistosoma mansoni is intestinal schistosomiasis....
in the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
and a vector of schistosomiasis
Schistosomiasis
Schistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
.
In medical research, the most commonly used Biomphalaria glabrata snail stock (used for the maintenance of Schistosoma mansoni) is albino, i.e. it is without pigment. It is descended from a mutant
Mutant
In biology and especially genetics, a mutant is an individual, organism, or new genetic character, arising or resulting from an instance of mutation, which is a base-pair sequence change within the DNA of a gene or chromosome of an organism resulting in the creation of a new character or trait not...
albino stock which arose during research by Newton (1955). Not only did this albino variety prove to be highly susceptible to Schistosoma mansoni, but the lack of pigment allowed investigators using a dissecting microscope to view the development of the parasite within the snail. The black pigment normally found in snails that are taken from the field previously made this viewing too difficult.
Some other trematodes are also natural parasites of Biomphalaria glabrata:
- Ribeiroia marini
Experimental parasites include:
- Angiostrongylus vasorumAngiostrongylus vasorumAngiostrongylus vasorum, also known as French heartworm, is a species of parasitic nematode in the family Metastrongylidae. It causes the disease canine angiostrongylosis in dogs.Not much is known about the biology of this species.- Description :...
- (experimental) - Echinostoma caproni - (experimental)
- Echinostoma paraensei - (experimental)
- Echinostoma trivolvis - as second (experimental) intermediate host (referred as Echinostoma revolutum in Anderson & Fried (1987)).
- Plagiorchis elegans can experimentally infect Biomphalaria glabrata and it can cause its parasitic castration, but the snail is incompatible for its full development.
Interaction with schistosome
Schistosoma mansoni can infect juveniles of Biomphalaria glabrata much more easily than it can adults. Schistosoma mansoni causes parasitic castrationParasitic castration
Parasitic castration is the strategy, by a parasite, of blocking reproduction by its host, completely or in part. For example, Hemioniscus balani, a parasitic castrator of hermaphroditic barnacles, feeds on ovarian fluid, so that its host loses female reproductive ability but still can function as...
in infected snails.
Interactions between snails and schistosomes are complex and there exists an urgent need to elucidate pathways involved in snail-parasite relationships as well as to identify those factors involved in the intricate balance between the snail internal defence system and trematode infectivity mechanisms that determine the success or failure of an infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
.
Molluscs appear to lack an adaptive immune system
Adaptive immune system
The adaptive immune system is composed of highly specialized, systemic cells and processes that eliminate or prevent pathogenic growth. Thought to have arisen in the first jawed vertebrates, the adaptive or "specific" immune system is activated by the “non-specific” and evolutionarily older innate...
like that found in vertebrates and, instead, are considered to use various innate mechanisms involving cell-mediated and humoral reactions
Humoral immunity
The Humoral Immune Response is the aspect of immunity that is mediated by secreted antibodies produced in the cells of the B lymphocyte lineage . B Cells transform into plasma cells which secrete antibodies...
(non-cellular factors in plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
/serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
or hemolymph
Hemolymph
Hemolymph, or haemolymph, is a fluid in the circulatory system of some arthropods and is analogous to the fluids and cells making up both blood and interstitial fluid in vertebrates such as birds and mammals...
) that interact to recognize and eliminate invading pathogens or parasites in incompatible or resistant snails. However, a diverse family of fibrinogen
Fibrinogen
Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
-related proteins (FREPs) containing immunoglobulin-like domains has been discovered in Biomphalaria glabrata and may play a role in snail defence. Circulating haemocytes (macrophage-like defence cells) in the snail haemolymph are known to aggregate in response to trauma, phagocytose small particles (bacteria, and fungi) and encapsulate larger ones, such as parasites. Final killing is effected by hemocyte-mediated cytotoxicity mechanisms involving non-oxidative and oxidative pathways, including lysosomal enzymes and reactive oxygen/nitrogen intermediates. Certain allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
s of cytosolic copper/zinc superoxide dismutase
Superoxide dismutase
Superoxide dismutases are a class of enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. As such, they are an important antioxidant defense in nearly all cells exposed to oxygen...
(SOD1) have been associated with resistance also suggesting these processes are important in the snail internal defence system.
Predators
The freshwater snail Marisa cornuarietisMarisa cornuarietis
Marisa cornuarietis, common name the giant ramshorn snail, is a species of large freshwater snail with an operculum, an aquatic gastropod mollusk in the family Ampullariidae, the apple snail family....
is a predator of Biomphalaria glabrata: it feeds on its eggs, juvenile and adult snails. It also acts as a competitor.
Competitors
Melanoides tuberculata is considered to be a competitor of Biomphalaria glabrata, but all the intraspecific interactions are not fully understood yet. Although in various countries there were contradictory results, and despite this situation being unpredictable and thus possible ecological damage might result, Melanoides tuberculata is nonetheless used in an attempt to control or reduce populations of Biomphalaria glabrata in Brazil, in the West Indies, and in Venezuela.Symbionts
A single-celled symbiont Capsaspora owczarzaki was discovered in the haemolymph of Biomphalaria glabrata in 2002.Hybrid
There is one known hybrid: Biomphalaria glabrata × Biomphalaria alexandrinaBiomphalaria alexandrina
Biomphalaria alexandrina is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails and their allies.- Habitat :...
, from Egypt.
Toxicology
The absolute lethal concentration (LC100) of glucose/mannose-binding lectinsMannan-binding lectin
Mannose-binding lectin , also named mannose- or mannan-binding protein , is an important factor in innate immunity.-Function:MBL belongs to the class of collectins in the C-type lectin superfamily, whose function appears to be pattern recognition in the first line of defense in the pre-immune...
from plants Canavalia brasiliensis, Cratylia floribunda, Dioclea guianensis
Dioclea guianensis
Dioclea guianensis is a species of legume native to the Americas....
, Dioclea grandiflora
Dioclea grandiflora
Dioclea grandiflora is a species of legume native to the Americas.The seeds of Dioclea grandiflora contain a well-characterized lectin named DGL which is similar to other legume lectins....
and Dioclea virgata for adults of Biomphalaria glabrata is 50 μg mL−1.
The latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
of Euphorbia conspicua is toxic to adults of Biomphalaria glabrata.
Four species of the genus Solanum
Solanum
Solanum, the nightshades, horsenettles and relatives, is a large and diverse genus of annual and perennial plants. They grow as forbs, vines, subshrubs, shrubs, and small trees, and often have attractive fruit and flowers. Many formerly independent genera like Lycopersicon or Cyphomandra are...
from Brazil are toxic to Biomphalaria glabrata.
Some species of Annona
Annona
Annona is a genus of flowering plants in the pawpaw/sugar apple family, Annonaceae. It is the second largest genus in the family after Guatteria, containing approximately 110 species of mostly neotropical and afrotropical trees and shrubs....
are toxic to adults of Biomphalaria glabrata and to its eggs.
Further reading
- Genetics as known up to 2006:
- Adema C. M., Luo M.-Z., Hanelt B., Hertel L. A., Marshall J. J., Zhang S.-M., DeJong R. J., Kim H.-R., Kudrna D., Wing R. A., Soderlund C., Knight M., Lewis F. A., Caldeira R. L., Jannotti-Passos L. K., Carvalho O. d. S. & Loker E. S. (2006) "A bacterial artificial chromosome library for Biomphalaria glabrata, intermediate snail host of Schistosoma mansoni". Memórias do Instituto Oswaldo Cruz 101(Suppl. I): 167-177. text, PDF.
- Feeding behaviour:
- Townsend C. (August 1973) "The food-finding orientation mechanism of Biomphalaria glabrata (Say)". Animal Behaviour 21(3): 544-548. .
- Boissier J, Rivera E. R. & Mone H. (June 2003) "Altered Behavior of the Snail Biomphalaria glabrata as a Result of Infection with Schistosoma mansoni". Journal of Parasitology 89(3): 429-433. JSTOR
- Egg-laying process:
- Boyle J. P. & Yoshino T .P. (1 February 2000) "The effect of water quality on oviposition in Biomphalaria glabrata (Say, 1818) (Planorbidae), and a description of the stages of the egg-laying process". Journal of Molluscan Studies 66(1): 83-94. abstract
- Competition in laboratory:
- Giovanelli A., Vieira M. V. & da Silva C. L. P. A. C. (2002) "Interaction between the Intermediate Host of Schistosomiasis in Brazil Biomphalaria glabrata (Planorbidae) and a Possible Competitor Melanoides tuberculata (Thiaridae): I. Laboratory Experiments." Memórias do Instituto Oswaldo Cruz 97(3): 363-369. PDF
- Circulatory system:
- Santos M. A. V. & Diniz J. A. P. (2009). "Aspectos ultraestruturais de hemócitos de Biomphalaria glabrata Say (1818) (Gastropoda: Planorbidae) analisados sob microscopia eletrônica de transmissão". ["Ultrastructural aspects of hemocytes from Biomphalaria glabrata Say (1818) (Gastropoda: Planorbidae) analysed with transmission eletronic microscopy"]. Acta Amazonica 39(3): 707-712. doi:10.1590/S0044-59672009000300027.
- Biochemistry:
- Marxen J. C., Nimtz M., Becker W. & Mann K. (21 August 2003) "The major soluble 19.6 kDa protein of the organic shell matrix of the freshwater snail Biomphalaria glabrata is an N-glycosylated dermatopontin". Biochim Biophys Acta 1650(1-2): 92-98. 10.1016/S1570-9639(03)00203-6Doiare three Japanese family names that are pronounced identically, with the first kanji of each pair of characters meaning "earth." Since they are the same phonetically, they are romanized identically: "do" for the first character and "i" for the second...
- Marxen J. C., Nimtz M., Becker W. & Mann K. (21 August 2003) "The major soluble 19.6 kDa protein of the organic shell matrix of the freshwater snail Biomphalaria glabrata is an N-glycosylated dermatopontin". Biochim Biophys Acta 1650(1-2): 92-98. 10.1016/S1570-9639(03)00203-6
- Interactions with Schistosome:
- Moné Y., Gourbal B., Duval D., Du Pasquier L., Kieffer-Jaquinod S., et al. (2010). "A Large Repertoire of Parasite Epitopes Matched by a Large Repertoire of Host Immune Receptors in an Invertebrate Host/Parasite Model". PLoS Neglected Tropical DiseasesPLoS Neglected Tropical DiseasesPLoS Neglected Tropical Diseases is an open access, online scientific journal devoted to the study of neglected tropical diseases. Submissions go through pre-publication peer review for scientific rigor and relevance to a specific set of overlooked diseases, including helminth, bacterial, viral,...
4(9): e813. doi:10.1371/journal.pntd.0000813
- Moné Y., Gourbal B., Duval D., Du Pasquier L., Kieffer-Jaquinod S., et al. (2010). "A Large Repertoire of Parasite Epitopes Matched by a Large Repertoire of Host Immune Receptors in an Invertebrate Host/Parasite Model". PLoS Neglected Tropical Diseases
- Mineralogy:
- Marxen J. C., Becker W., Finke D., Hasse B. & Epple M. J. (2003) "Early mineralization in Biomphalaria glabrata: microscopic and structural results". Journal of Molluscan Studies 69(2): 113-121. abstract
- Prymak O., Tiemann H., Sötje I., Marxen J. C., Klocke A., Kahl-Nieke B., Beckmann F., Donath T. & Epple M. (October 2005) "Application of synchrotron-radiation-based computer microtomography (SRICT) to selected biominerals: embryonic snails, statoliths of medusae, and human teeth". Journal of Biological Inorganic ChemistryJournal of Biological Inorganic ChemistryJournal of Biological Inorganic Chemistry is a peer-reviewed scientific journal. It is an official publication of the Society of Biological Inorganic Chemistry and published by Springer Science+Business Media...
10(6): 688-695. 10.1007/s00775-005-0023-3Doiare three Japanese family names that are pronounced identically, with the first kanji of each pair of characters meaning "earth." Since they are the same phonetically, they are romanized identically: "do" for the first character and "i" for the second...
.
- Phylogeography:
- Dejong R. J., Morgan J. A., Wilson W. D., Al-Jaser M. H., Appleton C. C., Coulibaly G., D'Andrea P. S., Doenhoff M. J., Haas W., Idris M. A., Magalhães L. A., Moné H., Mouahid G., Mubila L., Pointier J. P., Webster J. P., Zanotti-Magalhães E. M., Paraense W. L., Mkoji G. M. & Loker E. S. (November 2003) "Phylogeography of Biomphalaria glabrata and B. pfeifferi, important intermediate hosts of Schistosoma mansoni in the New and Old World tropics". Molecular Ecology 12: 3041–3056. , 10.1046/j.1365-294X.2003.01977.xDoiare three Japanese family names that are pronounced identically, with the first kanji of each pair of characters meaning "earth." Since they are the same phonetically, they are romanized identically: "do" for the first character and "i" for the second...
.
- Dejong R. J., Morgan J. A., Wilson W. D., Al-Jaser M. H., Appleton C. C., Coulibaly G., D'Andrea P. S., Doenhoff M. J., Haas W., Idris M. A., Magalhães L. A., Moné H., Mouahid G., Mubila L., Pointier J. P., Webster J. P., Zanotti-Magalhães E. M., Paraense W. L., Mkoji G. M. & Loker E. S. (November 2003) "Phylogeography of Biomphalaria glabrata and B. pfeifferi, important intermediate hosts of Schistosoma mansoni in the New and Old World tropics". Molecular Ecology 12: 3041–3056. , 10.1046/j.1365-294X.2003.01977.x
- Toxicology:
- Luna J. de S., Santos A. F. dos, Lima M. R. F. de, Omena M. C. de, Mendonça F. A. C. de, Bieber L. W. & Sant’Ana A. E. G. (28 February 2005) "A study of the larvicidal and molluscicidal activities of some medicinal plants from northeast Brazil". Journal of EthnopharmacologyJournal of EthnopharmacologyThe Journal of Ethnopharmacology is an academic journal dealing with the traditional medicinal use of plants and other substances....
97(2): 199-206. 10.1016/j.jep.2004.10.004Doiare three Japanese family names that are pronounced identically, with the first kanji of each pair of characters meaning "earth." Since they are the same phonetically, they are romanized identically: "do" for the first character and "i" for the second...
- Luna J. de S., Santos A. F. dos, Lima M. R. F. de, Omena M. C. de, Mendonça F. A. C. de, Bieber L. W. & Sant’Ana A. E. G. (28 February 2005) "A study of the larvicidal and molluscicidal activities of some medicinal plants from northeast Brazil". Journal of Ethnopharmacology
External links
- Biomphalaria glabrata Genome Initiative
- [ftp://ftp.ensembl.org/pub/traces/biomphalaria_glabrata/ data of sequenced genome] at National Human Genome Research InstituteNational Human Genome Research InstituteThe National Human Genome Research Institute is a division of the National Institutes of Health, located in Bethesda, Maryland.NHGRI began as the National Center for Human Genome Research , which was established in 1989 to carry out the role of the NIH in the International Human Genome Project...
- What is Biomphalaria glabrata - UNM Biology Department Home Page