The Sarcastic Fringehead (Neoclinus blanchardi)
The sarcastic fringehead is a small fish found along the Pacific Coast of North America, between northern California and Mexico. They are known best for being aggressively territorial and for the unusual way they defend themselves. Sarcastic fringeheads can grow up to 12 inches long, but most are between three and eight inches long.
Sarcastic fringeheads are solitary creatures and live in shells, holes and crevices in rocks, or even in empty cans and bottles if there is pollution. If an individual detects an intruder, it will try to intimidate it: sarcastic fringeheads have very large mouths that they snap open and shut in order to appear bigger to their rivals. If the intrusion leads to a fight, sarcastic fringeheads will wrestle with each other with their mouths open and pressed together. While this may look like the fish are kissing, they are in fact aggressively defending their territory from each other! The fish with the smaller mouth will usually lose this fight.
These fish are omnivores and seem to have been able to adapt to anthropogenic habitat changes (for example by living in empty cans and bottles) so they are not currently endangered.
For more on the sarcastic fringehead, take a look at the video below of two fringeheads battling it out for their home turf. For more on fish and weird and wonderful creatures, check out these resources from Science NetLinks: Introducing Biodiversity; The Fish Trade; and Disappearing Fish.
Image credit: James Martin (English Wikipedia) [Public domain], via Wikimedia Commons
Originally posted on AAAS Science NetLinks.