Thursday, July 28, 2011


Hi Sea Fans!

Nope, not sharks this time, but a pretty little fish called a Jawfish.  I got to see a brooding male when we went on a collecting trip so I thought I'd share this cute character with you:

Photo: Wikipedia
Male mouth brooding (the male fish actually keep their eggs in their mouths), burrow-building, and passionate courtship displays are a few of the interesting behaviours that make jawfishes so fascinating to watch. These little blunt-headed, big-mouthed fish inhabit the sandy seafloor where they build rock-lined burrows which take nearly 8 hours to complete! These burrows are where they spend most of their day, grabbing zooplankton from the current just above their burrow entrance and clearing away rubble that may have fallen into the chamber. From early spring to autumn, males incubate clutches of eggs inside their mouths. An easy way to spot a brooding male is to look for those fish that have bloated cheeks, hanging around at the entrance of their burrow. These little guys are not keen on diver spectators so the chances are very good that they will hide away the entire time that you are around, but if you’re patient, you may catch a glimpse of one little guy coming out and churning his mouthful of eggs. (This is when the eggs are spit out of the mouth and quickly sucked back in). Churning removes waste, aerates the eggs and allows the embryos to mix, so that all of them will have the chance to develop equally. What leads to these clutches of eggs, of course, is romance.  Jawfishes only take one partner (they’re monogamous) and the partners live in separate burrows very close to each other, with a third “Honeymoon Suite”.   Unlike most reef fish spawns that are very short-lived, the Yellowhead Jawfishes take their time. The male approaches the female many times, swooping down to her and arching his back whilst flaring his beautiful fins and opening his mouth like an opera singer – a real show-off! They then enter their third burrow together and a few seconds later, the ritual starts all over again.   These behaviours can keep divers fascinated for ages!  (and aquarists distracted on a collection trip!) : )

A lot of people don't realise how much they can see when they visit an aquarium - you could spend an hour at just one tank watching how the fish go about their business and if you see those fish every day like we do, it's very easy to pick up when something is wrong like a sick fish.  It's just like knowing your puppy really well.
Have a great week Sea Fans and enjoy watching fish behaviour next time you visit your aquarium.
}( *)8

No comments:

Post a Comment