Tumidotheres maculatus
Encyclopedia
Tumidotheres maculatus is a species
of crab
that lives commensally
or parasitically
in the mantle cavity of molluscs
. It is found along much of the western Atlantic Ocean
and was first described by Thomas Say
in 1818.
in the western Atlantic Ocean
, extending from the seas of Martha's Vineyard
(United States
) to Golfo San Matías (Argentina
).
in T. maculatus which corresponds with the differing ecology of the two sexes. Males are typically less than 6 millimetre (0.236220472440945 in) in carapace
width, and are able to leave the host. Females grow up to 16 mm (0.62992125984252 in) wide, and, having reached adulthood, spend their entire lives in the host.
of molluscs; it is unclear whether the host is harmed by the crabs presence, that is whether the relationship is commensal
or parasitic
. It is associated with a wide range of mollusc hosts, most of which are bivalves
. They include Argopecten irradians
, Atrina rigida
, Modiolus americanus
, Mytilus edulis and Flexopecten felipponei
. It has also been found in a tunicate
of the genus Molgula
, in the tubes of the tubeworm Chaetopterus variopedatus
and on the asteroid (starfish) Asterias vulgaris.
In molluscan hosts, T. maculatus uses its legs to cling to the gills of its host, and feeds on strands of food aggregated by the host. Reported rates of infestation of T. maculatus on mollusc hosts vary widely, from 0%–20% on Argopecten irradians
at St. Joseph Bay
, Florida
, to 97.6% on Mytilus edulis at Quicks Hole, Massachusetts
.
by Thomas Say
in 1818, under the name Pinnotheres maculatus. It was transferred to the new genus Tumidotheres, alongisde T. margarita by Ernesto Campos in 1989. It may be the species referred to by Carl Linnaeus as Cancer parasiticus in his 1763 work Centuria Insectorum
, and the one he called Cancer pinnophylax in the 1767 12th edition
of Systema Naturae
.
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 crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
that lives commensally
Commensalism
In ecology, commensalism is a class of relationship between two organisms where one organism benefits but the other is neutral...
or parasitically
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
in the mantle cavity of molluscs
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
. It is found along much of the western Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and was first described by 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.
Distribution
Tumidotheres maculatus has a wide rangeRange (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
in the western Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, extending from the seas of Martha's Vineyard
Martha's Vineyard
Martha's Vineyard is an island located south of Cape Cod in Massachusetts, known for being an affluent summer colony....
(United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
) to Golfo San Matías (Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
).
Description
There is conspicuous sexual dimorphismSexual 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:...
in T. maculatus which corresponds with the differing ecology of the two sexes. Males are typically less than 6 millimetre (0.236220472440945 in) in carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
width, and are able to leave the host. Females grow up to 16 mm (0.62992125984252 in) wide, and, having reached adulthood, spend their entire lives in the host.
Ecology
Tumidotheres maculatus is an endosymbiontEndosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
of molluscs; it is unclear whether the host is harmed by the crabs presence, that is whether the relationship is commensal
Commensalism
In ecology, commensalism is a class of relationship between two organisms where one organism benefits but the other is neutral...
or parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
. It is associated with a wide range of mollusc hosts, most of which are bivalves
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
. They include Argopecten irradians
Argopecten irradians
Argopecten irradians, formerly classified as Aequipecten irradians, common names the "Atlantic bay scallop" or "bay scallop", is an edible species of saltwater clam, a scallop, a marine bivalve mollusk in the family Pectinidae, the scallops....
, Atrina rigida
Atrina rigida
Atrina rigida, commonly known as the rigid pen shell, is a bivalve mollusc found from the North Carolina coast through the West Indies and to Brazil...
, Modiolus americanus
Modiolus americanus
Modiolus americanus, or the tulip mussel, is a species of bivalve mollusc in the family Mytilidae. It can be found along the Atlantic coast of North America, ranging from North Carolina to the West Indies....
, Mytilus edulis and Flexopecten felipponei
Flexopecten felipponei
Flexopecten felipponei is a species of saltwater clam, a scallop, a marine bivalve mollusk in the family Pectinidae, the scallops.- Original description :...
. It has also been found in a tunicate
Tunicate
Tunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...
of the genus Molgula
Molgula
Sea Grapes or Molgula sp. are very common, globular, individual marine tunicates roughly the size of grapes. They are translucent with two protruding siphons. They are found subtidally, attached to slow-moving submerged objects or organisms....
, in the tubes of the tubeworm Chaetopterus variopedatus
Chaetopterus variopedatus
Chaetopterus variopedatus is a species of parchment worm, a marine polychaete in the family Chaetopteridae. It is found worldwide.Polychaetes, or marine bristle worms, have elongated bodies divided into many segments. Each segment may bear setae and parapodia...
and on the asteroid (starfish) Asterias vulgaris.
In molluscan hosts, T. maculatus uses its legs to cling to the gills of its host, and feeds on strands of food aggregated by the host. Reported rates of infestation of T. maculatus on mollusc hosts vary widely, from 0%–20% on Argopecten irradians
Argopecten irradians
Argopecten irradians, formerly classified as Aequipecten irradians, common names the "Atlantic bay scallop" or "bay scallop", is an edible species of saltwater clam, a scallop, a marine bivalve mollusk in the family Pectinidae, the scallops....
at St. Joseph Bay
St. Joseph Bay
St. Joseph Bay is a bay on the Gulf Coast of the U.S. state of Florida, located in Gulf County between Apalachicola and Panama City. Port St. Joe is located on St. Joseph Bay....
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, to 97.6% on Mytilus edulis at Quicks Hole, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
.
Taxonomy
Tumidotheres maculatus was first describedAlpha taxonomy
Alpha taxonomy is the discipline concerned with finding, describing and naming species of living or fossil organisms. This field is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and...
by 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, under the name Pinnotheres maculatus. It was transferred to the new genus Tumidotheres, alongisde T. margarita by Ernesto Campos in 1989. It may be the species referred to by Carl Linnaeus as Cancer parasiticus in his 1763 work Centuria Insectorum
Centuria Insectorum
is a 1763 taxonomic work by Carl Linnaeus, and defended as a thesis by Boas Johansson; which of the two men should be credited with its authorship has been the subject of some controversy. It includes descriptions of 102 new insect and crustacean species that had been sent to Linnaeus from...
, and the one he called Cancer pinnophylax in the 1767 12th edition
12th edition of Systema Naturae
The 12th edition of was the last edition of to be overseen by its author, Carl Linnaeus. It was published in three volumes, with parts appearing from 1766 to 1768...
of Systema Naturae
Systema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
.