Conch Wall in Upper Keys provides a viewing variety

A gray angelfish swims near the Conch Wall.
A gray angelfish swims near the Conch Wall.

As I reached the base of the mooring-ball line secured in about 50 feet of water, I was greeted by an 18-inch long curious and brave fish.

It hung around while I adjusted the controls on my underwater camera. I finished the adjusting and started kicking down the reef; my new buddy decided to follow along.I had just made friends with, or at least become a curiosity for, a gray angelfish.

My friend the fish and I were at one of my favorite spots to dive in the Upper Keys — Conch Wall, which slopes down to over 100 feet deep, is filled with all manner of marine life, barrel sponges, conch shells and pelagic (open water) fish.

The wall is part of the part of the Conch Reef system that includes a Sanctuary Preservation Area (SPA) and is home to the Aquarius Reef Base, an underwater laboratory.

The base has been the site of marine ecosystem science, coral observation, undersea equipment testing and training and for NASA and the U.S. Navy. Ocean explorer and documentary filmmaker Fabien Cousteau, first grandson of famed ocean researcher Jacques Cousteau, conducted a 31-day expedition at the base from June 1 to July 2, 2014.

After a few minutes of admiring the sights, it occurred to me that I had a perfect subject for a photo op -- the gray angelfish escorting me on my dive. The fish did a great job of posing — no contract or residual fees, no temperamental outbursts, great profile images and no skin blemishes requiring extensive post production touchup.

The gray angelfish, often confused with the French angelfish or the spadefish, can be found at depths from approximately 7-100 feet on reefs in the western Atlantic Ocean, ranging from New England south to Rio de Janeiro, the West Indies and the Gulf of Mexico. It also now can be found in Bermuda.

Carl Linnaeus (a Swedish botanist, physician, and zoologist) first described the gray angelfish as Pomacanthus arcuatus in 1758. English language common names include angelfish, gray angelfish, and pot cover.

The gray angelfish has a small mouth containing comb-like teeth and a thin, discus-shaped body. Its lower jaw protrudes past the upper jaw. All its vertical fins are scaled and its dorsal fin is continuous, helping to distinguish it from the closely related spadefish, which has two separate dorsal fins.

Juvenile gray angelfish are black with five yellow bands on the head and body, extending onto the fins.

When juvenile gray angelfish grow into adults, they become a uniform gray to grayish-brown. The scales develop a large gray or brown spot in the center and are edged in pale gray. The head, chest, pelvic, and pectoral fins become dark brown and the chin and mouth area turns white.

Gray angelfish mature when they are about 9 inches long. They can grow to a length of 24 inches and weight up to 4 pounds. Most of the fish are from 17 to 19 inches long.

They usually travel alone or in pairs. Males form territories to defend their mates from other males. The fish make a sound like a moan in recognition of each other. (The literature doesn’t say if the moan means “glad to see you,” “oh no, not you again” or “I’m having a really good time.”)

Gray angelfish feed throughout the day eating sponges (about 70 percent of their diet), seagrasses, algae and invertebrates (creatures with no internal skeleton). Their strong mouths help them to tear off pieces of sponges and they secrete mucous to protect their stomachs from the sponges’ spiny spicules (tiny sharp-pointed objects).

Conch wall is an ideal place to see gray angelfish because of the large number of giant barrel sponges that live there. Juvenile gray angelfish act as cleaners, feeding on parasites they clean from other fish including jacks, snappers, morays, grunts, surgeonfishes and wrasses.

Gray angelfish have been reported to reproduce year around, but it is believed that most spawning occurs from April through September. Many of the fish form monogamous pairs that may result in long-term bonds, but some are promiscuous. Spawning usually occurs at sunset and early morning hours.

A mating pair of gray angelfish swims slowly, rising in the water and bringing their vents close together. The female releases from 25,000 to 75,000 eggs while the male releases sperm. The pair then returns to the bottom and repeats the spawning dance numerous times. If a solitary unlucky fish approaches the spawning pair too closely, it is quickly chased away.

The fertilized spherical and transparent eggs (about one-thirty-second of an inch in diameter) hatch in 15 to 20 hours into larvae that live in beds of floating plankton until they reach a little over half an inch when the larvae settle onto the coral reef.

Large marine animals including octopuses, groupers and some sea anemones are predators of gray angelfish. Larvae and juveniles are prey for invertebrate predators.