''Maritigrella crozierae'', the tiger flatworm, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine polyclad

flatworm Platyhelminthes (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") is a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Euryleptidae Euryleptidae is a family of marine polyclad flatworms. Genera The following genera are listed by the World Register of Marine Species: *'' Acerotisa'' Strand, 1928 *'' Anciliplana'' Heath & McGregor, 1912 *'' Ascidiophilla'' Newman, 2002 *'' C ...

. It is found on the eastern coasts of North America and the Caribbean Sea where it feeds on colonial

sea squirts Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer test or "tunic" made of the polysaccharid ...

. ''Maritigrella crozieri'' are also able to reproduce asexually through fission. When it divides into two or more parts, either on its own terms or due to predator influence, it can restore the lost part. If a considerable amount of each part remains undamaged, more than one tiger flatworm can grow back.

Description

''Maritigrella''Maritigrella'': "little tiger of the sea". crozierae'' is a large flatworm. The upper side of its body is boldly striped in yellow and black. The underside is creamy white with a sucker near the centre. The margin is ruffled, rimmed with orange and fringed with small orange tentacles. It has a tubular pharynx and two tentacles at the front of its head, formed from folds of parts of the front of its body. Just behind these is its brain, with two elongated clusters of ocelli (eyespots) on either side. It usually grows to about in length and occasional individuals may reach twice this size.

Distribution

''Maritigrella crozierae'' is found in shallow water in the western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

and the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

. Its

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

extends from

South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

and includes the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and

Bermuda Bermuda is a British Overseas Territories, British Overseas Territory in the Atlantic Ocean, North Atlantic Ocean. The closest land outside the territory is in the American state of North Carolina, about to the west-northwest. Bermuda is an ...

Biology

''Maritigrella crozierae'' is common in the

Indian River Lagoon The Indian River Lagoon is a grouping of three lagoons: the Mosquito Lagoon, the Banana River, and the Indian River, on the Atlantic Coast of Florida; one of the most biodiverse estuaries in the Northern Hemisphere and is home to more than 4, ...

where it feeds exclusively on the mangrove tunicate, ''

Ecteinascidia turbinata ''Ecteinascidia turbinata'', commonly known as the mangrove tunicate, is a species of tunicate in the family Perophoridae. It was described to science in 1880 by William Abbott Herdman. The cancer drug trabectedin can be isolated from this spec ...

''. In other parts of its range it feeds on other sea squirts but seems to become habituated to the species it first ate. It everts its pharynx into a

zooid A zooid or zoöid is an animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooids can ...

and sucks out the interior tissues. A colony of mangrove tunicates is often home to two flatworms, each eating about 19 zooids a day. The tunicate produces a

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

called

trabectedin Trabectedin, sold under the brand name Yondelis, is an antitumor chemotherapy medication for the treatment of advanced soft-tissue sarcoma and ovarian cancer. The most common adverse reactions include nausea, fatigue, vomiting, constipation, de ...

which has been shown to have anti-tumour properties. As it feeds, the flatworm gradually builds up the concentration of this chemical in its body. For this reason, it may be of interest to the

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

industry as a source of this compound which has been approved for medical use in the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

. ''Maritigrella crozierae'' is a simultaneous

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

, which means that an individual has both male and female gonads at the same time. Fertilisation is internal by hypodermic copulation. One individual approaches another from behind, rears up and falls forward, piercing the other with a fine stylet and inserting white bundles of sperm. Often the second individual reciprocates and both are inseminated at the same time. About 48 hours later, several clumps of cream coloured eggs are laid. These later hatch into larvae known as Muller's larvae which are

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic.

References

{{Taxonbar, from=Q2781707 Turbellaria Animals described in 1939