Photo of the Week: February 13, 2012

Hi Gang!

This week's POTW is a picture form Maui that I captured on a dive with Captain Steve. It is a shot of a relatively small fish that looked more like a leaf being blown around by the wind than a fish when I first saw it than any kind of living creature. The species is commonly known as the rock mover wrasse, and the one pictured in this week's POTW is definitely a juvenile. Ichthyologists know rock movers as Novaculichthys taeniourus. The species is also commonly referred to as dragon wrasse, a name that is likely derived from the facial appendages and other facial features of the juveniles.

Rock mover wrasse get this common name from a behavior that is commonly seen in the adults. When hunting for food, adult rock mover wrasse flip over, turn, push, and otherwise move large pieces of rubble and other debris to see what they can scare up. The highly territorial adults grab, push and pull the debris with their mouth or snout in order to get the job done as the scour the sea floor for a variety of mollusks, sea urchins, brittle stars, crabs and polychaete worms.

But that description is all about the adults. The rock mover wrasse in this week's POTW is a juvenile. Young rock mover wrasse drift and flit about like a clump of algae that is alternately caught in an irregularly flowing current and dumped into the quiet of an eddy. Juveniles are usually encountered as they "bounce" their way around coral heads and open patches of reef that offer some protection. The juveniles constantly start, stop and drift in a manner that makes it appear that they are completely at the mercy of the current and surge, and upon first sighting them the young fish appear as if they might be injured or sick. But just when you think you have it all figured out they suddenly appear perfectly normal. However, that appearance doesn't last very long as they soon start flitting their way across the bottom once again.

Adult rock mover wrasse attain a maximum length of approximately one foot. I estimated the juvenile pictured here to be roughly half that length.

The range of rock mover wrasse extends from the Red Sea to South Africa, and the Tuamoto Islands northward to Ryuku, throughout the Hawaiian Islands, and south to Lord Howe Island. The species is also known to occur from Mexico's Sea of Cortez southward to Panama and in Ecuador's Galapagos Islands. Within their range rock mover wrasse tend to be found in reef areas and rubble zones between 10 and 80 feet deep.   

By far and away the most challenging aspect of photographing a juvenile rock mover is to find that one precious moment in which the fish poses in a pleasing way, is facing you, allows you to get close enough to fill a pleasing percentage of your frame with your subject, and slows down long enough for you to focus and frame. It might be easy to write about all of those factors, but it can be a real challenge to make all of those factors come together especially when you are also having to deal with current and surge. But, as frustrating as underwater photography can sometimes be, giving it a go sure beats sitting at a keyboard at the office!

I used a Nikon D300 camera (cropped sensor) with a Nikon 105 mm lens behind a flat port along with a pair of Ikelite DS to strobes to light the scene.

I used the auto-focusing capabilities of the camera and lens, and did my best to get the rock mover wrasse's eye in razor sharp focus. I don't really know the exact numbers, but I feel confident that I deleted a lot more images than I kept. Like I said, they can be a challenging subject. Of course, that makes getting a shot you are happy with more satisfying than a lot of shots that are considerably easier to get.

In any case, the shot seen here represents my best effort during the dive. 

I hope you enjoy this week's POTW and the accompanying background information.

See you next week!

Marty