Let’s talk about scientific classification for a second. Every species is identified by a scientific name that is designated by two names, also known as the binomial nomenclature (Solomon, Berg, & Martin, 2005). The first part of the name identifies the genus the species belongs to, and the second part of the name is specific species. For example: Carcharodon carcharias (the great white shark) is in the genus Carcharodon and caracharias is specific species name (Parker, 2008). And the names are not randomly assigned because scientists wanted to make it as hard as possible to remember these names. Each part of the name describes characteristics of the species with Latin or Greek origin. This system was first devised way back in 1753 when Carl Linnaeus began his work Species Plantarum (Linnaeus, 1753).
So why does this matter? Why do we have this system at all? Why can’t we just refer to every species by their common name? It’s easier than remembering some goofy Latin, right? Because not every species is referred to by the same common name throughout every part of the world. Prime example is the headline out of an Australian Aquarium in January of this year that surprised some readers from out of town:
If you are at all familiar with either the leopard shark (Triakis semifasciata), a species endemic to the Pacific coast of the United States, or the zebra shark (Stegostoma fasciatum), a species found in the Indo-Pacific, you’ll know that the species featured in the article is the zebra shark (Stegostoma fasciatum), however in Australia and other regions of the Southern hemisphere they are referred to as the leopard shark because of the spots they display in their adult stage, instead of referring to the zebra stripes they display in their juvenile stage. So referring to a species by its common name can get confusing in scientific writing because it can vary greatly depending on the region you reside in.
So why am I discussing this in a blog about elasmobranchii conservation? Well because on Sunday (June 24, 2017) an article was published in the Zoological Journal of the Linnean Society that actually renamed the Giant Manta Ray and the Reef Manta Ray. When scientists, like Linnaeus, began classifying and cataloging species all the way back in 1753, DNA sequencing did not exist, so species were classified based on how closely they resembled another species physically. However DNA sequencing technology over the last 30 years has begun to challenge our understanding of evolutionary biology and as a result, several species have been reclassified including the two extant species of Manta Rays! The research team concluded from DNA sequencing from mitochondrial genomes of manta and devil rays within the Mobulidae family that only a single genus within the family actually exists (White et al., 2017).
Prior to the White et al. study, the Mobulidae family was comprised of two genus’s
- Mobula, comprised of 9 species of devil rays
- Manta, comprised of 2 species
- the Reef Manta ray (Manta alfredi)
- the Giant Manta ray (Manta birostris)
However the DNA showed conclusively that those with genus Manta consistently nest within the Mobula genus. This means that Manta rays, once named Manta birostris and Manta alfredi, will be reclassified to Mobula birostris and Mobula alfredi.
While the scientific names will be changing, don’t fret, the common name Manta Ray is most likely here to stay! Based on this exciting news this week I have decided to featured the Giant Manta Ray as the Featured Species for this coming Friday. Learn more about this amazing species in Friday’s blog post! If you missed last Friday’s Featured Species, be sure to check it out and learn all about the Longnose Sawshark (Pristiophorus cirratus)
Until next time, feel free to share your thoughts on anything going on the elasmobranchii world! And remember you can make a difference for marine ecosystems by calling your Congress man or woman and tell them that you care about the quality of our waters! Sharks, rays, and other marine organisms cannot speak or be represented in Congress. They need your voice. Get involved and stand up for sharks.
Featured Image Source
Inoue et al. (14 June 2010). Phyolgenetic Tree [Figure 1]. Retrieved from Evolutionary origin and phylogeny of the modern holocephalans (Chondrichthyes: Chimaeriformes): A mitogenomic perspective.
Inoue, J. G., Miya, M., Lam, K., Tay, B. H., Danks, J. A., Bell, J., … & Venkatesh, B. (2010). Evolutionary origin and phylogeny of the modern holocephalans (Chondrichthyes: Chimaeriformes): a mitogenomic perspective. Molecular biology and evolution, 27(11), 2576-2586.
Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.
Solomon, E. P., Berg, L. R., Martin, D. W., & Villee, C. A. (2005). Biology. Belmont, CA: Thomson-Brooks/Cole.
White, W. T., Corrigan, S., Yang, L., Henderson, A. C., Bazinet, A. L., Swofford, D. L., & Naylor, G. J. P. (2017). Phylogeny of the manta and devilrays (Chondrichthyes: mobulidae), with an updated taxonomic arrangement for the family. Zoological Journal of the Linnean Society, 82, 65–73. http://doi.org/10.1093/zoolinnean/zlx018