Juvenile to Adult – the Amazing Transformations of Fish

Adult barramundi cod with corals with Coralia Liveaboard in Triton Bay in Indonesia

Juvenile to Adult – the Amazing Transformations of Fish

There are so many fascinating things to see in the ocean. One of the most intriguing is the difference between the adult and juvenile stages of some fish. There are some fish who completely transform and you wouldn’t believe that it is the same fish!

In this blog we will show you some great examples of the most often encountered fish with the most outstanding transformations.

Juvenile pinnate batfish with Coralia Liveaboard in Raja Ampat in Indonesia
Adult pinnate batfish with Coralia Liveaboard in Raja Ampat in Indonesia

Pinnate Batfish

Juvenile pinnate batfish look nothing like their adult version! This little juvenile is an exciting discovery during a scuba dive. They are usually hiding in hard coral areas. For example, try looking under ledges and inside crevices. Much easier to find during a night dive, they are fascinating to watch. They slowly jiggle their whole body.

The body of this juvenile is completely black with a bright orange outline. The juvenile pinnate batfish are thought to mimic flatworms to keep them out of harm’s way from their predators. As they get older they stretch out and begin to form a lighter line in their midsection. Eventually they elongate into their adult form.

Juvenile emperor angel fish with Coralia Liveaboard in Raja Ampat in Indonesia
Adult emperor angelfish with Coralia Liveaboard in Raja Ampat in Indonesia

Emperor Angelfish

Adult emperor angelfish are very beautiful but they look nothing like their juvenile version! The juvenile is also very beautiful. It has striking blue colours in a fabulous pattern. With some imagination you can see that the circular pattern of the juvenile stretches out into the stripes of the adult.

Like many juvenile fish, the baby emperor angelfish can be found lurking inside cracks and crevices. They are quite shy but sometimes their curiosity gets the better of them and they will come out and peer at you!

Juvenile barramundi cod with Coralia Liveaboard in Triton Bay in Indonesia
Adult barramundi cod with Coralia Liveaboard in Triton Bay in Indonesia

Barramundi Cod

Adult barramundi cods, also known as humpback groupers, are quite common on the reefs of Indonesia. They are very easy to distinguish from other fish due to their elongated snout. Like the adult, the juvenile is spotty.

A juvenile barramundi cod is certainly a treat to see while diving. They are super cute! The juvenile is usually found wiggling erratically, with its head down. Muck dives are a great place to see these adorable juveniles. Look in rocky areas where they have a place to hide. We have even seen one living in a discarded paint tin!

Juvenile harlequin sweetlips with Coralia Liveaboard in Raja Ampat in Indonesia
Adult harlequin sweetlips with Coralia Liveaboard in Raja Ampat in Indonesia

Harlequin Sweetlips

Our final amazing fish transformation is the harlequin sweetlips. This fish is also known as the spotted sweetlips. You can see why in both the adult and juvenile! All kinds of sweetlips are a regular on the reefs in Indonesia.

The baby harlequin sweetlips is another wiggly juvenile. Much like the juvenile barramundi cod it also spends a lot of its time head down and jiggling around! It is very hard to believe that this little fish turns into the grumpy looking, spotted adult!

Have a look at this video to see a juvenile harlequin sweetlips in action!

Juvenile Fish – See them Live!

Join Coralia Liveaboard for a luxurious cruise in Indonesia. Our experienced dive guides will show you some of these wonderous juvenile and adult fish!

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