A study published in the July issue of the Zoological Journal of the Linnean Society details how scientists have found that color patterns of different species of fish in the larval stage can be similar, showing a closer evolutionary relationship than what the adult forms of the same species of fish would suggest.
Carole Baldwin, a zoologist at the Smithsonian’s National Museum of Natural History took a look at more than 200 species of primarily Western Caribbean marine fishes in their larval stage and found that in many instances, the larval color patterns of different species were similar, which showed evidence of a phylogenic relationship.
Baldwin said that while the adult versions of these fishes have been described by biologists, artists and tropical fish hobbyists for centuries, the larval versions of many of these fishes have so far been neglected, with many of their color patterns unknown at the larval stage. Baldwin said that the larval stages of many marine fishes have subtle to striking color patterns that can tell scientists much about a species place on the taxonomic family tree.
For example, Baldwin examined the larval stage of adult mullet to that of flying fish and found that they share a transformation of color patterns that support a notion that the two species are closely related. She also calls out the larval stage of the puffer fish and those of the anglerfish, two distinct species from different orders, yet they both retain similarities in how the trunks of their bodies are encased in an inflated yellow sac. These fish in adult form look nothing like each other.
“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.”