Smithsonian finds color patterns in fish larvae may reveal relationships among species

July 24, 2013

Similarities in how different organisms look can indicate a close evolutionary relationship. Conversely, great differences in appearance can suggest a very distant relationship, as in many adult marine fish species. For the first time, however, a Smithsonian scientist has found that color patterns of different fish species in the larval stage can be very similar, revealing a closer evolutionary relationship than their adult forms would suggest. The research is published in the July issue of the Zoological Journal of the Linnean Society.

Many marine fish species spend their larval stage near the ocean's surface―an environment completely different than the one they are in as adults. Two different environments often require two different body shapes and appearances, resulting in fish in their larval stage that bear little to no resemblance to their adult counterparts. Carole Baldwin, a zoologist at the Smithsonian's National Museum of Natural History, examined more than 200 species of marine fishes in their larval stage, primarily from the western Caribbean. She found that in many cases larval color patterns of different species were very similar, contributing evidence to a phylogenic relationship.

"Biologists, artists and tropical fish aquarists have described, illustrated or photographed color patterns in adult marine fishes for centuries, but color patterns in marine fish larvae have largely been neglected," said Baldwin. "Yet the larval stages of many marine fishes have subtle to striking, ephemeral color patterns that can potentially tell us a lot about a species' place on the taxonomic family tree."

Adult mullets, for instance, are very different in appearance than adult flying fish, yet when Baldwin examined these fishes in the larval stage she noticed that they share a unique transformation of color pattern that supports the idea that they could be closely related. Larvae of some species in the order Tetraodontiforme, like the pufferfish, and those in the order Lophiiforme, like the anglerfish, are strikingly similar in having the trunks of their bodies enclosed in an inflated yellow sac. Their appearance as adults, however, would not hint at a close relationship.

"More investigation of larval color patterns in marine fish is needed to fully assess their value in phylogenic reconstruction," said Baldwin. "But the evidence I've found so far is promising that this will be an important taxonomic resource in the future."

Color information on many more marine fish larvae is needed to fully use this new suite of evolutionary information, and Baldwin will encourage colleagues to obtain color photographs of larvae when possible. And studies on the formation of pigment, such as those conducted on the model freshwater zebrafish (Danio species), are needed.
-end-


Smithsonian

Related Fish Articles from Brightsurf:

Fish banks
Society will require more food in the coming years to feed a growing population, and seafood will likely make up a significant portion of it.

More than 'just a fish' story
For recreational fishing enthusiasts, the thrill of snagging their next catch comes with discovering what's hooked on the end of the line.

Fish evolution in action: Land fish forced to adapt after leap out of water
Many blennies - a remarkable family of fishes - evolved from an aquatic 'jack of all trades' to a 'master of one' upon the invasion of land, a new study led by UNSW scientists has shown.

How fish got onto land, and stayed there
Research on blennies, a family of fish that have repeatedly left the sea for land, suggests that being a 'jack of all trades' allows species to make the dramatic transition onto land but adapting into a 'master of one' allows them to stay there.

Fish feed foresight
As the world increasingly turns to aqua farming to feed its growing population, there's no better time than now to design an aquaculture system that is sustainable and efficient.

Robo-turtles in fish farms reduce fish stress
Robotic turtles used for salmon farm surveillance could help prevent fish escapes.

Heatwaves risky for fish
A world-first study using sophisticated genetic analysis techniques have found that some fish are better than others at coping with heatwaves.

A new use for museum fish specimens
This paper suggests using museum specimens to estimate the length-weight relationships of fish that are hard to find alive in their natural environment.

Reef fish caring for their young are taken advantage of by other fish
Among birds, the practice of laying eggs in other birds' nests is surprisingly common.

Anemones are friends to fish
Any port in a storm, any anemone for a small fish trying to avoid being a predator's dinner.

Read More: Fish News and Fish Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.