Photo of the Week: November 2009 Week 5

Hi Gang!

For this week’s POTW I have yet another image from the reefs of Indonesia. It is an image of a pair of cuttlefish in an almost synchronized pose. The cuttlefish are probably needle cuttlefish (Sepia aculeate), but I am not certain.

Of all of the animals in the sea, cephalopod mollusks reign supreme when it comes to altering their colors and shapes. The abilities of octopuses, squids and cuttlefishes seem to know no bounds when it comes to quickly changing their shape, color and texture of their skin. Specialized cells in the nerves and muscles in the skin, and cells in the skin as well, give these invertebrates their amazing talents.

The ability to alter skin color and texture as well as overall body shape provides a way for cuttlefishes and other cephalopods to disguise themselves in an effort to avoid predation. This skill is also used to enable cephalopods to communicate with other members of their own species. Specialists that are studying communications in cephalopods have made great strides in their ability to understand what the various poses and colors are intended to communicate in recent years, but much still remains to be learned.

It is known that cuttlefishes uses their ability to change their shape, color and texture when courting and mating. I suppose there is no end to what animals will do- especially us males- to gain the favors of their desired mates!

I was watching this pair of cuttlefish swim together for several minutes before I took this week’s POTW. What caught my eye was that they appeared to be twins, and when one changed color and shape the other quickly did the same almost perfectly matching its partner. Then the cuttlefish began to hunt. Several times I watched one cuttlefish strike out at potential prey. During this period of time they sometimes looked like twins, and at other times they did not, but for at least ten minutes they stayed within a foot of each other.

As I continued to watch they once again changed their pose extending their tentacles into the shapes you see here. Exactly what the nearly perfectly matched poses meant, I have no idea, but from a photographic perspective, I had quite a good opportunity to create a special image  The challenge was to get myself into position without disrupting the behavior while getting the tentacles, faces, and especially the eyes of both cuttlefish to face my camera and be in focus.

As my good luck would have it the cuttlefish turned toward me and remained in virtually the same plane long enough for me to capture five images. In each one they appear to be swimming in synchronized fashion.

I captured this image with a Nikon 60 mm lens on a D300 camera. With a cropped sensor camera such as the D300, I think this lens is a great choice for most macro, or “critter” dives on Indo-Pacific reefs. If I were using a full-frame sensor I think I would opt for a 100 mm or 105 mm lens depending on what the camera manufacturer offered.

The reason for my lens selection came from studying the photographs I acquired during the first half of my recent trip to Indonesia. On the first leg I used my 105 mm lens quite a bit. With a cropped sensor that lens essentially becomes a 150 mm lens, and that means that many subjects are too large to be photographed from close range. Backing up means shooting through more water column and dealing with more suspended particles than desired. I studied my results between trip legs and opted to use the 60 mm lens much more often during the second leg, and I was much happier with my results.

But no matter what lens you use, the reefs of Indonesia are very likely to provide some terrific photographic opportunities.

I hope you enjoy this moment shared with a pair of cuttlefish.

See you next week!
Marty