#desert fish

To Live with the Death Valley Pupfish

The Death Valley Pupfish, or Salt Creek Pupfish (Cyprinodon salinus) is a species of pupfish found only in the Death Valley region of the Mojave Desert; within this region there are populations in Salt Creek, Cottonball Marsh, River Springs and Soda Lake. These locations are characterized by shallow water four times the salinity of the ocean, with temperatures regularly reaching peaks of 46 °C (116°F) and lows of 0 °C (32 °F), and limited vegetation.

Like other pupfish, Death Valley pupfish are quite small. Most adults are about 3.7 cm (1.5 in) in length. Females are rather drab, typically tan or brown with darker mottling. Males are larger than females, and turn bright blue and yellow during the breeding season. They also have larger dorsal and anal fins, which are used for display.

Salt Creek pupfish can reproduce several times a year, although their peak season is in the spring and the fall. When they're ready to mate, males will claim a small territory and vigorously defend it against rival males. Little is known about the physical aspects of their reproduction, but individuals typically live only a year or so.

C. salinus feed primarily on cyanobacteria and algae, and supplement their diets with available aquatic arthropods. Their only predator is the diving beetle Neoclypeodytes cinctellus, but their populations are also highly influenced by flooding and drought cycles. At the peak the rainy season, when flooding has increased habitat availability, the population of C. salinus can explode into the millions, but that number is then cut down to only several thousand when subsequent droughts dry up most pools and streams.

Conservation status: The Death Valley pupfish is considered Endangered by the IUCN. It has an extremely limited distribution, which is under threat from excessive draining of the aquifer that feeds their habitat.

Dr. Cynthia S. Shroba

Michael Hawk

I am transgender, and I am aware that Death Valley, a desert in the southwestern part of the USA, used to be one big ocean. Now there are tiny pockets of water here and there, each with its own unique attributes. Some are salty, some are fresh. Some are acidic, some are neutral, some are basic. The decedents of one kind of fish has evolved into several different species of Pupfish, each of which is suited to the particular conditions of its unique spring.

They are very smol fish. When it rains and the springs overflow briefly into little streams, the pupfish go downstream, mate, and leave eggs that survive in mud under a dry crust all the way until the next year’s brief rainy season, when they hatch and swim back up to live in their lil spring hole.

This little fish is in addition to the Death Valley pupfish, which is critically endangered. Seems that we ought to be protecting fish that live in a desert. The part “fish that live in a desert” ought to be enough to warrant our attention and protection.

Excerpt from this story from the Desert Sun:

Environmentalists are pressing forward with a fight to protect a small fish that inhabits desert springs and streams in California’s Death Valley region.

The Center for Biological Diversity on Friday announced it has filed a notice of intent to sue the U.S. Fish and Wildlife Service to seek Endangered Species Act protection for three populations of speckled dace, a minnow-like species that evolved to live in dry areas. The fish is threatened by excessive groundwater pumping for farms and residential development and geothermal energy development, they say.

“Our native freshwater fish deserve a break, and (federal) protections could provide some salvation to the speckled dace,” said Jeff Miller, a senior conservation advocate at the Center for Biological Diversity. “The Death Valley region is at the epicenter of the mega-drought that’s frying the West, and the speckled dace inhabit fragile desert springs and rivers suffering from the driest year on record. Unsustainable and reckless water-extraction policies piled on top of the drought could drive these unique desert fish to extinction.”

The center petitioned for Endangered Species Act protection for three populations of speckled dace in the region in June 2020. The tiny fish live in freshwater streams and springs in the desert and dry environments of Amargosa Canyon, Long Valley and Owens Valley.

Down Under with the Desert Goby

Desert gobies (Chlamydogobius eremius) are a species of goby found only in the middle of the desert, in the Lake Eyre drainage basin of South Australia. The permanent pools they reside in are fed by underwater springs, and during the rainy season they may also reside in rivers and streams formed by rainfall.

As a result of living in such a harsh environment, desert gobies are capable of tolerating temperatures as low as 5°C (41°F) and as high as 41°C (105°F), as well as salinity as high as 60 ppt-- twice the salinity of the ocean. To cope with the heat, adults are often observed sticking their heads out of the water and 'gulping' air to facilitate evaporative cooling. Otherwise, individuals spend the bulk of the day hiding under rocks and in submerged vegetation that provides shade and protection from predators.

Although C. eremius can swim, individuals tend to spend most of their time on the bottom of the pond or river in which they reside, and move around using their pectoral fins in a hopping motion. They are omnivorous, consuming whatever food is available. This can include small crustaceans, insects, algae, fish eggs, and detritus. The desert goby's main predator is the spangled perch.

Desert gobies are rather unremarkable in appearance. Both sexes are mottled brown, to better blend in with their environment. In general, males are larger than females, although they don't exceed 6cm (2.36 in) in length. Males also tend have a larger dorsal fin than females. This fin is black, with a white ridge and yellow and blue splotches, and serves to attract potential mates by signalling the male's fitness.

C. eremius mate in the summer, from November to March. Males attract females by constructing nest sites and performing courtship displays. After mating, the female deposits up to 300 eggs in the male's nest, and then leaves to seek out a new mate. The male then cares intensively for the eggs, guarding them and fanning them with his tail to keep them oxygenated. The eggs take anywhere from 10 to 17 days to hatch, at which time they become completely independent. In fact, offspring may travel many hundreds of kilometers from their parents via established waterways and temporary channels formed by rainfall. The average lifespan of desert gobies is one year.

Conservation status: The desert goby has not been evaluated by the IUCN. However, several other closely-related desert goby species are classified as Endangered. Their primary threats come from habitat destruction caused by excessive water draining, and by disruption from cattle and feral pigs.

Photos

Klaus Stiefel

Andreas Svensson