One Dedicated Dad: A Glimpse into the Jawfish Gestation Cycle
A male banded jawfish, carefully tending to its clutch of eggs. This clutch is roughly mid-way through the gestation cycle, which lasts from 7-10 days.
We are so fortunate here in south Florida to have easy access to a common breeding ground for many aquatic species. Over my years of diving at Blue Heron Bridge I have witnessed and photographed the next generation of octopus, seahorses and several tropical fish species. However, these past couple months have been filled with another fascination for local underwater photographers and curious divers - a banded male jawfish, who has hosted 8 separate clutches of eggs in its mouth.
Clutch #5: new bundle of eggs for papa jawfish. As you can see, the eyes within these eggs are not well developed yet. They will remain in this opaque state for several days while dad takes good care them, aerating them and keeping them safe from predators.
Being able to return to this special dive site week after week not only affords me the opportunity to work on different photography techniques, but it also allows me to witness some pretty incredible animal behavior. These past couple months I was fortunate to be able to see and photograph several clutches of eggs, all at different phases.
The 7th clutch of eggs from this magnificent papa jawfish are almost ready to hatch. This dedicated dad has worked hard to protect the eggs from predators and environmental hazards.
Naturally, seeing this behavior in the wild makes one curious to learn more. Prior to this experience, I was not aware that a single jawfish couple could have so many separate clutches of eggs during one breeding season. It was a beautiful and intriguing process to witness, one I am very grateful I was able to experience.
Now that’s a mouthful. . .
This dad’s level of commitment is admirable.
Jawfish are a mouthbrooding species - meaning they protect their eggs in their mouth. It is actually the male that performs this behavior, not the female. After courtship, the female lays fertilized eggs, which are immediately taken into the male’s mouth. The male then carries the eggs in his mouth—not swallowing them, but gently holding them for around 7-10 days until they are ready to hatch. During this timeframe, the male does not eat and focuses solely on incubating the eggs.
Aerating the eggs
Papa jawfish takes good care of his young by aerating them. He does this by dropping them down his throat, then pushing them out of his mouth, only to very quickly snatch them back again. He is essentially flushing them with fresh seawater to avoid any fungal growth or egg clumping. It takes an impressive amount of skill!
Being mouthbrooders, proper oxygenation and cleanliness of the eggs is essential for proper embryo development - this is why you can at times see the male “aerating” the eggs. It can be a challenge to capture the exact moment with the camera, since it happens very quickly. This shot certainly takes much patience, and whole lot of luck, to get just right.
Witnessing this ritual not only gave me some pretty amazing opportunities to document animal behavior, but is also gave me a far greater appreciation for this species. Father’s Day is a time when we acknowledge the hard work and contribution of dads everywhere - and I am so glad I could share the amazing efforts made by this dedicated underwater dad.
Happy Father’s Day to all the dads out there, and as always, happy diving!
-Grace
Mama jawfish keeping a close watch on me with my camera! While the jawfish dad was very tolerant of my presence, his female mate watched me closely to ensure I didn’t cause any harm.
Just a couple feet away in his own hole, papa jawfish was very generous with sharing his clutch of eggs. At times, it was almost as if he was offering them up for the camera!
Tools for capturing the jawfish with eggs include a macro set-up (90mm), close-up lens (+12.5 diopter), beam restrictors on my strobes and an optical snoot.
A close-up lens, also known as a diopter, can be helpful to capture details of the eggs with a shallow depth of field effect.
Here you can better see the environment the jawfish lives in. Nestled into a solitary burrow with only it’s head protruding from the muck, it can be challenging to spot these small fish.