This video says about itself:
California Wildlife — Tidewater Goby
3 November 2013
Classified as a Protected (Vulnerable) species by the IUCN.
From Science News in the USA:
California’s goby is actually two different fish
Southern version gets its own name
By Amy McDermott
6:00am, September 6, 2016
It’s official: The southern tidewater goby is a thing. And it’s chubbier and nubbier than its northern cousin.
Endangered tidewater gobies live in California’s seaside lagoons. Ranging roughly the entire length of the state, the fish used to be considered one species. But a new study confirms that gobies living in Northern and Southern California are physically different, and now the southern swimmer has its own name: Eucyclogobius kristinae.
The northern goby, E. newberryi, is sleeker and longer than its southern counterpart. The southern fish has more girth and more nubby sensory organs exposed atop its head, researchers report July 27 in PLOS ONE.
Differences in DNA, found in earlier studies, suggest that the fish separated over a million years ago, probably because of geology. Tidewater gobies can dart from pool to pool in the rainy season but can become isolated by outcrops of rock or kelp. Today, the southern goby is found only in three coastal pools in San Diego’s Camp Pendleton. The fish used to range north from San Diego County about 200 kilometers, says geobiologist David Jacobs of UCLA, who codiscovered the new species. As coastal cities grew, the goby lost habitat. Now that the southern species has its own name, Jacobs says, California is more likely to give it extra protection.