Fossil fishes challenge an evolutionary ‘urban legend’
Genome duplications, thought to power evolutionary radiations, can’t explain the explosion of fish diversity

Imagine a half-ton tuna laid out on a dock next to a seahorse, a minnow, and a moray eel.

That’s just a snapshot of the astonishing diversity found in the group of fishes called teleosts, or ray-finned fish, which today have 30,000 species—more than all living mammals, birds, reptiles, and amphibians combined. For more than a decade, many researchers have assumed that teleosts’ dizzying array of body types evolved because their immediate ancestor somehow duplicated its entire genome, leaving whole sets of genes free to take on other functions.

Now, an examination of the fish fossil record challenges that view. Despite duplicating their genome about 160 million years ago, teleost fish hewed to a few conventional body types for their first 150 million years. Meanwhile, the holostean fishes, a related group with genomes that never underwent a doubling, evolved a stunning diversity of body plans…

The Armhook Squid and the Owlfish

In the deep sea, when an animal comes across a potential meal, it has to take advantage of the opportunity, regardless of how daunting a task it may seem. This image shows a deep-sea armhook squid Gonatus onyx fighting to eat an owlfish Pseudobathylagus milleri. It was recorded using remotely operated vehicle Doc Ricketts in the Monterey Bay.

You can watch a video of this amazing encounter on our YouTube channel:

(via: Monterey Bay Aquarium Research Institute)

2.5 hour cleaning job and rearrangement done

you can’t see what i did very well because of the bubbles so i’ll have to post later but

i uprooted all the plants again and bombed them with hydrogen peroxide because i was too lazy to rub off the diatoms and i wanted to do a thorough cleaning job. h2o2 got most of the diatoms off the plants without any effort from me and im super happy about that. i ran out of it though so next time i do a wc im gonna bomb the substrate.

ALSO!! IM GETTING A PYTHON WATER CHANGER!!!!!!!!!!!!!!!!! omg im so happy my next water change is probably gonna be with a python