Crustaceans in bar codes

BIOTA-FAPESP Thematic Project studies ten-footed crustaceans on the São Paulo State coast to put together a catalog with DNA barcoding

By Fabio Reynol

Agência FAPESP – It is estimated that over 17,000 species of ten-footed crustaceans, or decapods, exist including shrimp, crab from the Portunidae family, lobster, hermit crabs and other crab species. Of this group, it is believed that over 600 can be found along the Brazilian coast, but only about 350 species are known along the São Paulo State coast.

The Thematic Project Decapod crustaceans: multi-disciplinary characterization of the sea biodiversity of the State of São Paulo, was kicked off at the beginning of 2011 through the BIOTA-FAPESP Program with the objective of increasing the paulista inventory.

“We hope to increase the number of known decapods by 20% over the next five years,” said the project’s coordinator, Fernando Luis Medina Mantelatto, full professor at the Biology Department of the University of São Paulo’s Ribeirão Preto College of Philosophy, Sciences and Letters (FFCLRP-USP).

The seed for the project came about in 2001 when Mantelatto did a post-doctorate in molecular phylogenetics in the United States. He then got the idea of applying this knowledge to solve taxonomic problems among decapod crustaceans, his focus of study.

The second step came when the Crustacean Bioecology and Taxonomy Laboratory was created at USP Ribeirão Preto. Both the post-doctorate and the laboratory received FAPESP funding.

Two other factors were also important: advances in molecular biology and the advent of DNA barcoding.

It was then a question of bringing these elements together to focus on a common goal: to gain knowledge about the decapod crustacean fauna that inhabit the São Paulo coastline and map them genetically.

“There are many species of taxonomic importance and which play key roles in the evolution of some groups, aside from others with much commercial importance like the white, pink and ‘seven-bearded’ [sete barbas] shrimp,” said Mantelatto.

On the first expedition alone, the researchers found marked populational differences in these species in relation to the areas in which they were found along the São Paulo coastline as well as five species of yet-unregistered decapods. “The broad biodiversity along the paulista coast is result of the fact that it is a transitional faunistic zone with representatives of tropical and cold waters,” he said.

In the first two years of the project, efforts will be aimed at bringing together a collection of species from regions along the entire coast including samples from mangrove forests, beaches, unprotected coastlines, islands and even deep water areas.

Periodic expeditions with some 20 researchers and students of different levels will be carried out in these areas to collect the animals and preserve them in ice or 80% alcohol so they can be analyzed.

“The animals will be collected manually through the use of traps, trawlers, free diving and scuba. Aside from the collections, we expect to visit different institutions and museums in Brazil and abroad to identify the species,” told Mantelatto.

Once they are in the laboratory, the species will be identified and DNA extracted from their musculature for sequencing and formation of the barcode for each species. This code will be deposited at GenBank, a databank holding the genetic code of species the world over that is maintained by the National Center for Biotechnology Information in the United States.

Aside from Mantelatto, Unesp professors from the Assis, Bauru and Jaboticabal campuses along with another ten researchers from Brazil, Germany, Chile, Costa Rica, Spain, Mexico and the United States are involved.