Life of A Mudskipper

Mudskippers live in self made burrows by digging the ground up with their mouths and spitting out of it. They use these burrows to hide from predators, temperature regulation, and to guard their eggs/larvae, these burrows can also reach around 1.5 meters in the ground. Females have a high fecundity and lay nearly 2,000 eggs per gram of body mass in their partners burrows during courtship. Spawning happens potentially across the year but usually during spawning seasons of Feburary and May. These eggs are on the ceiling of a specialized air-filled chamber created by gulping air from the surface and bringing it in their chamber which is how they keep themselves and their eggs oxygenated while submerged in water especially useful during high tide in a typically hypoxic environment such as mudflats.

After mating the female leaves the male’s burrow and the male safeguards the eggs until they develop for hatching. When the eggs hatch the father removes all the air from the chamber being gulping it up and spitting it back towards the surface letting the larvae swim out from the water and drift into the surface where a majority succumb to predation. Male mudskipper tend to help the larvae with different strategies reach the surface by creating some kind of current with tale undulation, turbulence by swimming towards the burrow, or relocation by transporting the larvae in the mouth. Species demonstrate one or multiple of these behaviors yet the exact behavior of Atlantic Mudskipper remains to be found.

After around 1 to 2 months the larvae are able to defend themselves by burrowing in the mud and once they reach sexual maturity around the size of 10.8cm (males) and 11.8cm (females) on average though they can reach that point as early as 7cm (males) and 9cm (females). At maturity they’ll defend their territory aggressively, this territorial behavior is very pronounced in the Atlantic Mudskipper even for their species. When Mudskippers show off aggression against intruders they signal it by raising their first dorsal fin. If that signal doesn’t scare off the predators they battle each other by, biting, leaping and opening their mouths.

Atlantic Mudskippers have a max growth of 25 centimeters and a life expectancy of 5 years.

Osmoregulation and Thirst

The Atlantic Mudskipper is a diurnal species, their genera like to spends most of its time on land than in water. Its ability to spend all this time on land by breathing in the air with a newt word of blood vessels in the surface of its skin, where they’re respiratory gasses are exchanged with the surrounding atmosphere. However there are behavioral patterns and motivators for it to migrate from land back to the water. One vital need for water being that its skin needs to be moist for it to respirate properly out of water, usually to prevent its skin from drying Mudskippers would roll on its side to absorb the moisture from the ground to its body. Another vital prompt for it to is that its constantly regulating itself both osmotically and ionically, a unique way it keeps up this regulation is by the hormone found in mammals: Angiotensin II. This hormone contracts the blood vessels to maintain blood pressure, as well as stimulating thirst for the animal to manipulate its behavior to ‘drink’ water in events of dehydration. Other fish marine saltwater fish regulate by drinking to, but since they’re constantly in the ionized water they don’t need to stimulate thirst.

Social stimulus can motivate mudskippers as well, whenever mudskippers would make some form of communication exerted high numbers of neurohypophysial hormones particularly vasotocin these types of hormones play a key role in osmoregulation and as a result when these hormones are activated by the social behavior it also stimulated thirst in the mudskippers. These specific behaviors that involved migrated back into the ocean were categorized as reproductive with them heading back to their burrows to spawn eggs/reproduce and submission to avoid stronger competitors.

Another behavioral hormone tied to osmoregulation are corticosteroids which contain other hormone receptors such as glucocorticoid receptor. Under stressful situations these triggers regulate their mood and increase these hormones create another connection in how its behavior plays into its important function to osmoregulate and by extent its migration habits between aquatic and terrestrial environments.

Click here to find out more