Sunday, 9 July 2017

California Sheephead: Beautiful, Impressive, and Vulnerable Fish

                                      A male California sheephead

                                    Ed Bierman, CC BY 2.0 License

I think that California sheephead are beautiful and impressive fish. They have some unusual characteristics. They are colourful animals—especially the males—that can grow up to three feet long and weigh up to thirty-six pounds. They have white chins and large, protruding canines. The fish above also has red eyes, a fleshy bump on its forehead, a black head and tail, and red on its middle section. This indicates that it's a male. Females are light pink in colour. All California sheephead start their life as females. Many change to males years later and are therefore said to be protogynous (capable of changing from female to male). 

The scientific name of the California sheephead is Semicossyphus pulcher. Pulcher is the Latin word for beautiful, so it seems that the namer of the fish agrees with my opinion about its appearance. The fish can be found from Monterey Bay in California to the Gulf of California in Mexico. It usually lives around reefs and in kelp beds. It's carnivorous and prefers to eat animals with hard shells, including crabs, lobsters, mussels, and sea urchins. Its large and sharp teeth and its powerful jaws are useful for crushing its prey. A bony plate in its throat is used to grind shells.

                    This male has paler colouration than the one above.
                                   Its canine teeth can be seen.
                               Kristin Riser, public domain license

The fish are diurnal, which means that they hunt during the day and sleep at night. They enter a cave or a crevice to sleep and secrete a protective mucus cocoon around their body. Potential predators are unable to smell the fish through the mucus.

The fish live in a harem-like structure during the breeding season, which lasts from July to September. A dominant male travels with a group of females and fertilizes their eggs. He drives away any other other males that approach. The age at which a female changes to a male varies considerably. It seems to depend on both environmental and social cues. Some fish change genders as early as five years of age while others don't change until they are thirteen. The fish have been known to live for as long as fifty years, but most are thought to live around twenty years.

Unfortunately, the California sheephead is classified in the Vulnerable category of the Red List established by the IUCN, or International Union for Conservation of Nature. The animal is vulnerable due to its popularity as a food fish. The larger fish are often considered to be the prime catch, but these are generally males. This means that the ratio of males to females is altered, which can have a negative effect on the population. Regulations have been put into effect to improve the situation. Hopefully they are successful.


California sheephead information from the Monterey Bay Aquarium

Sheephead facts from fishbase (an online fish database)
Information about the sheephead fish from the IUCN

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