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
T. K. Lehtonen
