A Rare Sighting!

Photo Copyright 2011 by Barry Fackler

 Last weekend Betty and I were diving at Honaunau when we happened upon a male 
Whitley's Boxfish. These are seldom seen in Hawai'i although the females are quite common.

Photo Copyright 2011 by Barry Fackler

According to the book The Ultimate Guide to Hawaiian Reef Fishes, the large, blue males are most abundant in the Marquesa Islands. Females of this species are golden brown with cream-colored markings and have none of the vibrant blue coloration of the males.

We found this fish on a small coral head on the sand bottom beyond the reef drop-off at a depth of around 80'. We returned to the coral head on our next dive but he was gone. I made another dive to the coral head this past weekend but, again, no male Whitley's was there. This is only the third instance in eleven years and around 1200 dives on the Big Island that I have seen a male Whitley's Boxfish.


 

Whitley's Boxfish and Sexual Dimorphism

Photos Copyright 2010 by Barry Fackler

A couple of weeks ago I posted a photo of a female Whitley's Boxfish. At the time, I mentioned that the male of the species was rarely seen but had beautiful blue coloration. For you, dear reader, I went through my slides and found an ancient photo of a male Whitley's that we saw years ago. The quality of the photo is poor due to the scanning process.

As you can see, the sexes differ drastically in appearance. This is an example of sexual dimorphism which Wikipedia describes as "the systematic difference in form between individuals of different sex in the same species". In many fish, the sexes are almost indistinguishable from one another. In some reef fish, though, the difference is spectacular. Examples include many species of wrasse and parrotfish.

The rationale for sexual dimorphism is a subject of debate but the leading theory is that it aids the male in attracting mates. A flashy, brightly- colored male will attract more mates than a dull, drab one. However, it seems that a flashy, brightly-colored male would also attract more predators too! Not a good scenario for propagating a species like the Whitley's Boxfish where males are already in short supply. The boxfish has an adaptation to deal with this as well - a strong toxin secreted through the skin which acts as an effective deterrent.

Happy New Year! Dive Report for Friday, 01/01/10

Happy New Year to you all!  Let's all hope for a better year and a happier world in 2010.

I had hoped to get another diving day in before the year ended but a combination of poor surf conditions and holiday festivities kept me on dry land. 

This morning, I watched the blue moon set behind a bank of ominous clouds that hung over the Pacific. To the east, the sun had not quite cleared the summit of Mauna Loa. The tide was high and the lava rock beach was partly awash. The shoreline was deserted and I realized that I was making the first dive of the new decade from the Two-Step. I thought about all the thousands of divers and countless adventures that would start from this spot over the next ten years.

There was considerable surge today and visibility was pretty lackluster with a lot of planktonic detritus hanging in the water column. The vis wasn't much improved down at 82 feet where I bottomed out for this dive. I initially headed south but encountered surge when I came up to around 35 feet. Figuring that things weren't likely to improve, I swung around and headed north. 

Photo Copyright 2010 by Barry Fackler

I found my little school of Pyramid Butterflyfish in good shape today. They seem to be growing and thriving. The area of coral rubble they inhabit seems like an underwater nursery with juvenile tropicals all about.

Photo Copyright 2010 by Barry Fackler

I spied this pair of tiny Moorish Idols peeking from the coral. They were very shy and wouldn't let me get a photo without one of them hidden by the coral. I don't see Idols this small usually.

Photo Copyright 2010 by Barry Fackler

This large pair of Reef Lizardfish was being groomed by a Hawaiian Cleaner Wrasse. This is a little unusual to me as I usually see swimming fish hovering at cleaning stations for servicing. It's not often that the wrasse ventures away to clean a bottom-dwelling fish.

Photo Copyright 2010 by Barry Fackler

This photo gives a little insight into the occupational hazard of being a cleaner wrasse. The Reef Lizardfish has a mouth bristling with fine, sharp teeth. It is capable of snatching and devouring whole a fish 3 or 4 times larger than the wrasse.

When I surfaced, I found the beach crowded with at least a hundred people. A good-sized pod of Spinner Dolphins was in the deep waters of the northern side of the bay. This is certain to draw a crowd in this age of cell-phones. After a surface interval, I geared up and swam out to see if they would approach me.

Photo Copyright 2010 by Barry Fackler

The Nai'a were very sociable this day and approached closely on multiple occasions. Even when not visible to the eye, they made their presence know with their squeals, clicks and whistles.

 

All photos Copyright 2010 by Barry Fackler

A really outstanding time with the dolphins today. The photos show how close they chose to approach. When my air supply was about half gone, I headed back to the reef to finish my dive in shallower water.

Photo Copyright 2010 by Barry Fackler

I saw a pair of female Whitley's Boxfish flitting along the reef. Despite their awkward shape, they are quite agile and surprisingly fast. The males are bigger and have beautiful dark blue markings. Males are seldom seen and, personally, I haven't seen one in a couple of years.

 

Photo Copyright 2010 by Barry Fackler

Sometimes Cornetfish, like this one, will follow a diver for a little while. Betty and I once saw one swimming along above a Green Sea Turtle with it's body arched to match the contour of the turtle's shell.

SCUBA diving provides little miracles every now and then. As I was finishing up my dive in just 17 feet of water, I looked to my right to see around 20 more dolphins swimming right past me. They pulled ahead, and then turned around and spiraled all about me. A really magical moment.

All Photos Copyright 2010 by Barry Fackler

Many of you have probably already surmised that the dolphins swimming upside down are engaging in sexual intercourse with the ones immediately above them. Dolphins have no need for prudishness and this behavior is seen every time dolphins are observed underwater.

I left the water today feeling tired but exhilarated by the wonders I had seen. While sitting on the beach, I saw Humpback Whales spouting and surfacing near the entrance of the bay. It was quite a scene with the dolphins still frolicking in the foreground and the beach crowd was very appreciative. After an hour of sunning, I gathered my wetsuit and folded my beach chair and started for my Jeep. Then I heard someone say "There they are again". I turned to see a puff of vapor and the black, shiny back of a whale sliding beneath the surface. I paused to see if it would re-surface. To the astonishment of all, the mighty form of a Humpback Whale shot skyward. It spun in a three-quarter turn to it's right, hung in the air for a second and then crashed back into the sea in an explosive cloud of foam. It was close enough that the grooves on it's ventral side could be plainly seen. What a fantastic sight!

It was a great day at the beach and I believe that all these wonderful occurences on New Years Day bode well for 2010!