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Over 1000 fish species can be legally sold in the United States, a challenge for accurate labelling. Many fish products such as fillets cannot be identified to species, even by experts. DNA surveys suggest that at least for some expensive species, most fish products are mislabelled. In 2004 Nature 430:309, scientists at University of North Carolina analyzed mtDNA of fish labelled as red snapper, which by US law can only be applied to a Caribbean snapper species, Lutjanus campechanus. 77% (17/22) fish purchased from 9 vendors in eight states were not L. campechanus, and most were species from other regions of the world, or could not be identified to species due to lack of reference sequences.

More recently, the availability of commercial DNA testing has enabled enterprising news stations to do their own research. Last year a Florida television station found that 6 of 11 restaurant entrees labeled as local grouper were other species, including Asian catfish and tilapia, and last month a Los Angeles television station reported that red snapper entrees at 4 local restaurants were either tilapia, catfish, or mahi mahi.  Following up on the news media, the Florida Attorney General’s office did their own testing, found 17 of 24 restaurants sold entrees mislabeled as grouper, and made legal settlements. What is needed is needed is a widely available method backed up by a reliable reference library that can be routinely applied to identification of fish and fish products in the marketplace. DNA barcoding is designed to be just that. 

The Food and Drug Adminstration (FDA) Regulatory Fish Encyclopedia (RFE) aims “to assist with the accurate identification of species and help federal, state, and local officials and purchasers of seafood identify species substitution and economic deception in the marketplace.”

The species pages include scientific and common names, pictures of whole fish and fish products, analytic gels of fish proteins, and excitingly, an empty space for reference DNA sequence information. For reliable identification, the fish reference library needs comprehensive taxonomic coverage and adequate sampling of variation within species, ie DNA barcoding. I believe the Fish Barcode of Life Initiative (Fish-BoL), which has already collected barcodes from over 16,000 specimens representing more than 3500 species, will provide a widely used tool that will benefit consumers and the many species of fish that require management or protection.  

A dozen articles in current issue of Nature examine the legacy of Carl Linnaeus, born 300 years ago this May. The wonderful cover illustration shows Carl Linnaeus as a modern field biologist in blue jeans and down vest, holding up a DNA barcode.  I am particularly struck by Charles Godfray’s “Linnaeus in the information age,” a wide-ranging, thoughtful, visionary and practical look at how taxonomy might evolve so as to provide the widest benefit to society. His near-term wish list includes “a comprehensive web-based taxonomic and identification resource (morphology plus DNA barcodes) for the world’s macrolepidoptera”, which “would be a wonderful lever for bringing new resources into the field.”  A central theme echoed in many of the pieces is the need for taxonomists to join together and create “big science” projects that benefit the many end-users of taxonomic knowledge.

A flock of 22 scientists converged on National University of Singapore on March 8-9, 2007 for a 2-day Indomalayan Organizational Meeting for All Birds Barcoding Initiative (ABBI), including representatives from India, Indonesia, Malaysia, Philippines, Singapore, Sri Lanka, Thailand, and individuals from European and North American museums with active collaborative research programs in this region.

The Indomalayan biogeographic region spans a vast area of tropical biodiversity and includes inumerable islands with high numbers of endemic species. A large scale genetic survey with DNA barcoding is likely to help lead to dramatic increases in species counts in particular and better understanding of biodiversity in general.  Additional collecting may be particuarly important in this region, as it is at present the least well-represented in frozen tissue collections. There was strong enthusiasm among regional participants, and recognition the initiative has public appeal and the potential to engage new sources governmental support.

I look forward to organizational and scientific progress in this exciting region. 

Two papers in early online Mol Ecol Notes report large scale COI surveys of tropical bats and North American birds. In the first paper, Clare et al examined 840 specimens representing 87 (72%) of 121 known bat species in Guyana, each derived from vouchered specimens held at Royal Ontario Museum, including multiple individuals (range 2-74) from 73 (84%) of species. 81 of 87 species had distinct COI barcodes with average intraspecific variation of 0.6%. In the remaining 6 species, 15 distinct mitochondrial lineages were found which likely represent overlooked cryptic species. 

As most bats are small brown animals that fly around at night emitting noises that humans cannot hear, it is not surprising that some have been overlooked, and it seems probable many new species will be found lurking in museum drawers. Even in relatively bat-poor temperate regions there may be hidden diversity. It was not until 1997 that Europe’s most abundant and best studied bat, the Pipistrelle (Pipistrellus pipistrellus, Schreber 1774) was suggested to be 2 species through DNA analysis, a hypothesis confirmed by biological covariants and official species designation in 1999. 

In the second paper, Kerr et al (I am a co-author) report a continental-scale survey of mtCOI sequences in North American birds, including 2590 individuals from 643 species, representing 93% of the breeding avifauna of Canada and the United States. 94% of species had distinct barcodes, and in the remaining 6%, barcode clusters corresponded to small sets of closely-related species, most of which hybridize regularly. Fifteen (2%) of currently-recognized species were comprised of two distinct barcode clusters, many of which may represent cryptic species.

Birds being conspicuous, vocal, diurnal animals it is surprising that there are what appear to be overlooked species, even in an intensively-studied temperate region with relatively few species.  Of course barcode clusters are not proof of species status, but to my knowledge all such divergent lineages either correspond to recognized species, or have subsequently been found to show biological covariants and have ultimately been granted species status.

Sequencing of large tissue collections housed in museums can be done relatively rapidly and inexpensively. It is a challenge on how to report results in a way that communicates the genetic findings in a timely fashion without trampling on the careful procedures designed to maintain order in taxonomy.

By using tissues derived from vouchered museum specimens, these barcoding studies lay the groundwork for subsequent taxonomic study. By analyzing a standardized region, DNA barcoding studies can be stitched together to create a large-scale map of biodiversity, a horizontal genomics approach mapping leaves on the tree of life.

I see the “barcode map of genetic diversity” as analogous to an astronomical sky map that uses just a slice of the electromagnetic spectrum. It does not contain all the information necessary to understand the universe, but by focusing on one part of the spectrum it enables results from various studies to be seamlessly combined and allows both large and small scale comparisions.