Featured Research

from universities, journals, and other organizations

Family tree of fish yields surprises

Date:
July 17, 2013
Source:
University of California Davis (UCD)
Summary:
The mighty tuna is more closely related to the dainty seahorse than to a marlin or sailfish. That is one of the surprises from the first comprehensive family tree, or phylogeny, of the "spiny-rayed fish," a group that includes about a third of all living vertebrate species.

The mighty tuna is more closely related to the dainty seahorse than to a marlin or sailfish. That is one of the surprises from the first comprehensive family tree, or phylogeny, of the "spiny-rayed fish," a group that includes about a third of all living vertebrate species.
Credit: Melissa Fiene / Fotolia

The mighty tuna is more closely related to the dainty seahorse than to a marlin or sailfish. That is one of the surprises from the first comprehensive family tree, or phylogeny, of the "spiny-rayed fish," a group that includes about a third of all living vertebrate species.

The work is published July 15 in the journal Proceedings of the National Academy of Sciences.

The spiny-rayed fish are an incredibly diverse group, including tuna and billfish, tiny gobies and seahorses, and oddities such as pufferfish and anglerfish. The fish occupy every aquatic environment from coral reefs and open oceans to lakes and ponds. It includes all the major commercially fished species -- all of which are threatened. But until now, no one has had any idea exactly how more than 18,000 species in 650 families are related to each other, said Peter Wainwright, professor and chair of evolution and ecology at the University of California, Davis and senior author on the paper.

"There has been a 'bush' at the top of the family tree leading to the rest of the vertebrates," Wainwright said. "Now we have this beautiful phylogeny of one-third of all vertebrates."

The study also shows that after roaring along for their first 100 million years, the pace of evolution of the spiny-rayed fish downshifted about 50 million years ago.

Some groups of fish have gone along steadily for millennia; others have gone through bursts of rapid evolution. Overall, the researchers found that the rate at which new species formed was fairly constant across the group from their origin to about 50 million years ago, then dropped about five-fold and has remained at that level since.

That might mean that these fish have essentially filled the available spaces, Wainwright said.

"It's not uncommon in evolution to see a rapid diversification followed by a slowdown, but it's never been seen on such a scale before," he said.

Wainwright's laboratory worked with the lab of Tom Near, a former postdoctoral scholar at UC Davis now at Yale University, and colleagues at the University of Tennessee, The Field Museum in Chicago, Florida Atlantic University and CUNY Staten Island to construct the family tree. Matt Friedman, a paleontologist at the University of Oxford, England, added fossils that helped set dates for branches of the tree.

The researchers looked at 10 genes in more than 500 fish species representing most of the families of spiny-rayed fish. They used the genetic data to construct a tree, grouping related families together. They also looked at the pace of evolution -- the rate at which new species formed -- in different branches, and across the group as a whole.

The spiny-rayed fish originated about 150 million years ago, separating from more primitive fish, such as lampreys, sharks and sturgeon, and from the ancestors of salmon and trout. Since then, they have spread into every aquatic habitat on Earth.

The tree shows some interesting relationships. For example, tuna are more closely related to seahorses than to swordfish or barracuda. The oddly shaped pufferfishes are related to anglerfish, the only fishes whose bodies are wider than they are deep.

Cichlids, a family that includes about 2,000 species of freshwater fish known for brooding their young in their mouths and a favorite for studies of evolution, are related to the engineer gobies, an obscure family of just two species that live on coral reefs and raise their young in a nest.

Wainwright's special interest is in the evolution of fish jaws. Fish have two sets of jawbones, an outer jaw and "pharyngeal jaws" in the throat that adapted to different functions. In some fish, the lower pharyngeal jaw is fused into a single solid bone that can be used to crush prey such as shellfish.

Biologists had assumed that this fused jaw had evolved once and then spread into different groups of fish. Instead, the new tree shows that this structure evolved at least six times in different groups of fish.

Additional collaborators on the project were: Samantha Price at UC Davis; Alex Dornburg, Ron Eytan and Kristen Kuhn at Yale University; Leo Smith at the Field Museum; Jon Moore, Florida Atlantic University; and Frank Burbrink, College of Staten Island/CUNY, Staten Island. Funding was provided by the National Science Foundation.


Story Source:

The above story is based on materials provided by University of California Davis (UCD). Note: Materials may be edited for content and length.


Journal Reference:

  1. T. J. Near, A. Dornburg, R. I. Eytan, B. P. Keck, W. L. Smith, K. L. Kuhn, J. A. Moore, S. A. Price, F. T. Burbrink, M. Friedman, P. C. Wainwright. Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1304661110

Cite This Page:

University of California Davis (UCD). "Family tree of fish yields surprises." ScienceDaily. ScienceDaily, 17 July 2013. <www.sciencedaily.com/releases/2013/07/130717051730.htm>.
University of California Davis (UCD). (2013, July 17). Family tree of fish yields surprises. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2013/07/130717051730.htm
University of California Davis (UCD). "Family tree of fish yields surprises." ScienceDaily. www.sciencedaily.com/releases/2013/07/130717051730.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins