Monsoon has ended very early this year, and we’ve already started diving on the south ‘clear water’ sites. We are lucky to have renowned photographer Wolfgang Poelzer and his wife Barbara diving with us. They’ve been to Ambon before, but have never dived anywhere but Ambon Bay. The muck dives have, as always, been fantastic, but they’ve also enjoyed immensely the south and east coast dives they’ve never done before. So much so, that when we dived Pintu Kota, they wanted to do it again for the very next dive!!!
When we were diving there, under the magnificent and beautiful archway, we saw a huge school of what turned out to be juvenile Convict Blennies. They were a mesmerizing sight to see, forming tight balls in the blue water, then flowing like a river and waterfall over the coral. And when we investigated after the dive, we found them to be a very strange and unique fish.
The first thing is that they are not Blennies (or Gobies), but in fact one of two species of the family Pholidichthyidae. The juveniles look nothing like the adults. It’s thought that the juveniles mimic Catfish, as Catfish are poisonous.
Researchers found juveniles emerging from holes in the seafloor and adjoining coral reefs. By day, these juveniles swim up to 50 m (55 yd) from their home burrows to feed on plankton. At the end of the day, all returned to the burrows, remarkable and unique behaviour for larval fish.
While their young are out feeding, the parents eject mouthfuls of debris from the burrows. In a single day as much as 3 kilos (6.6 pounds) of sand might be collected and spat out of the hole by the parents. Research has revealed a maze of tunnels and chambers totaling a length of some six meters. At night, young fish dangle by their mouths from the roof of the tunnels by thin mucous threads.
Adults may grow to almost 60 cm (24 in), but never leave the tunnels to feed. They frequently take in mouthfuls of juveniles and spit them out again. An inspection of adult stomachs showed only a green slime.
So, there you go…every day we learn something new and wonderful about our bizarre underwater world.