What the Fish? Episode 13: Exploring Fish Evolution on the Tree of Life
Piecing Together the Mysteries of the Fish Tree of Life
One of the primary reasons that we here at What the Fish? are fascinated with the evolutionary history of life on Earth is that it provides a context and scientific hypothesis from which we can further study the wonderful biodiversity of fishes. For example, if we have a working scientific hypothesis of how different species of clownfishes are related to one another, we can address questions surronding the number of times clownfishes have formed symbiotic relationships with anemones. But how do we build these evolutionary trees of fishes, such as the one seen below? Well there are various different kinds of scientific data that can be used to infer evolutionary relationships through time (e.g. variation in the sequence of DNA/genes, anatomical features, behavioral traits) that scientists around the world collect in order to support these hypotheses. Shared anatomical characteristics, such as the position of a spiny-rayed dorsal fin, may be indicative of common evolutionary ancestry, and scientists use this evidence to produce hypotheses regarding the evolution of life on Earth.
Fish of the Week: Velvet Whalefish (Barbourisia rufa)
Distribution: Found across all of the worlds oceans in predominantly deep-sea environments.
Size: Can reach lengths of nearly 40 cm long.
Fun Fact: Because many deep-sea organisms have difficulty seeing the color red, the red coloration of this velvetfish helps it hide in its deep sea environment.
The Velvet Whalefish is an enigmatic deep-sea species that possess a striking red coloration that allows it to be camoflauged in the open ocean. They have enlarged lateral-line canals that helps them sense motion in their environment at a greater distance and with more sensitivity. Further, they have a gaping mouth for swallowing prey. Velvet whalefishes are found in open-ocean habitats and are often characterized by their remarkably flabby bodies.
So long, and thanks for all the fish!