Hairy Squat Lobster

The Pink Hairy Squat Lobster or fairy crab, Lauriea siagiani, is closely related to a hermit crab. Although they are fairly common in the Philippines and Indonesia, they are rarely seen by divers partly because they are very small (less than half an inch in length). They also blend in really well with the textured ridges of the giant barrel sponge, Xestospongia testudinaria, on which they live.

Hairy Squat Lobster

Experienced dive guides will usually be able to help find you a subject if you tell them what you are looking for.

Getting good images or video also requires plenty of patience, a steady hand and a good macro lens that will let you get as close as possible. Camera Equipment: Nikon D7100, 105mm macro lens, Sea & Sea Strobes. Images taken at ISO 200, F/11, 1/200.

The Smooth Trunkfish

TTrunkfishhere are a number of very interesting fishes in the Caribbean. One of my favorites is certainly the Smooth Trunkfish, Rhimesomus triqueter, a member of the family of fishes called boxfish. These slow-moving reef fish can be one of the most entertaining fish to watch on a dive. They are easily recognizable by their shape, coloration and their unique means of propulsion.Trunkfish
They have short triangular bodies enclosed in a boney covering, which has the appearance of stretched canvass. When viewed from the front, the body is triangular in shape with a wide base and a narrow pointed top. Only the jaw, bases of the fins and the tail protrude from this carapace, and the locomotion of these fish is unusual if not peculiar. The dorsal and anal fins propel the fish with a rotary motion, while the tail acts as a rudder. The ventral fins move continually, forcing air through the narrow, constricted gill openings. They have a pointed snout with bulging lips encircling its small mouth.

The general background color is dark shades of black to brown, with a pattern of small white spots. If you look closely, you will see that it has hexagonal patterns giving a honeycomb-like appearance in the middle area of the body. The Smooth Trunkfish may have gotten its name because it is the only member of the boxfish family that has no spines above its eyes or by the anal fin.

They appear clumsy or sluggish at first, but if you try to approach them too quickly, you will be surprised at how fast they can accelerate using their tails. They normally frequent shallow water, in sandy or strip reef areas. They don’t seem to mind the presence of divers, especially if you hang around, keeping your movements to a minimum. When you observe them for a while, they take on an almost coquettish personality, displaying a bashful, timid side and yet curious and carefree at other times.

Its normal adult size is about 7 to 8 inches in length, although it can get much larger. The smooth trunkfish is normally solitary but sometimes moves around in small groups. In fact, the male trunkfish is thought to have a harem of females in its large territory. I was recently lucky enough to observe some very interesting mating displays within such a group, including dramatic color changes. The scientific names Lactophrys triqueter and Rhimesomus triqueter are synonymous.

I often find myself watching in amazement as they blow water at the sand in an attempt to uncover food. It uses its protruding lips to expel a jet of water, to prey items such as which disturbs the sandy seabed and reveals any shallowly buried benthic invertebrates, such as tiny mollusks, crustaceans, worms, and sponges.

The (Not So) Terrifying Tiger Shark

Although tiger sharks, Galeocerdo cuvier, have long been considered dangerous to humans, today there are a growing number of dive operations worldwide that focus on putting divers and the sharks in the water together. While some shark experts assert that these encounters are just an accident waiting to happen, it is interesting to note that despite baiting, close proximity and almost daily interactions over the course of more than 10 years, there have been no reported attacks specifically involving tiger sharks and divers.

Partially to thank for that record are reputable dive operations that set up strict guidelines for these interactions, and which require all of their divers to adhere to a strict set of rules. When these big predators show up, divers are required to continuously track them, maintain eye contact and point them out to the rest of the group.

Up-close, personal encounters have taught me that tiger sharks generally swim slowly and deliberately. When there are bait boxes in the water, other sharks, such as lemons and bulls, will swim directly to the bait. The tigers, however, approach warily, with their noses to the sand as if following a scent like a bloodhound. Ordinarily they don’t immediately compete with the other sharks, instead taking their time to investigate the smell. Despite their sluggish behavior, tiger sharks are very strong swimmers and extremely fast when they want to be. Their high back and dorsal fin can be used as a pivot, allowing them to spin quickly on their axis. This is why dive operations insist that divers maintain eye contact and keep track of the sharks as they pass, especially when they are nearby.

As soon as the tiger figures out that the smell is coming from the bait box, it often becomes focused and determined. I have seen a shark suddenly swim directly to the crate and grab the whole box, or one of the tether ropes, in its mouth and then swim away with its prize in tow.

Formidable looking animals, these sharks are named for the dark, vertical stripes Tiger sharks are also recognizable by their wide, blunt nose. They have very large mouths, with rows of 18 to 26 sharp, serrated teeth. Their powerful jaws allow them to crack open the shells of sea turtles and large clams.

The stomach contents of captured tiger sharks have revealed almost anything you can imagine, including stingrays, sea snakes, seals, birds, squids, and even license plates and old tires. Large specimens can grow to 18 feet or more (5 meters) and weigh more than 1,900 pounds (900 kilograms). Tigers live up to 50 years in the wild. They have small pits on the snout, which hold electro-receptors called the ampullae of Lorenzini.

These enable them to detect electric fields, including the weak electrical impulses generated by potential prey. Tiger sharks also have a sensory organ called a lateral line on their flanks that allows them to detect minute vibrations in the water. These adaptations, their excellent eyesight and acute sense of smell make them fearsome nocturnal hunters, able to follow faint traces of blood in the water to their source, even in murky water. The tiger will circle its prey and study it by prodding it with its snout before doing a taste test. This is somewhat reassuring when it is bumping into my camera port. Tigers are not at all shy about coming in close to inspect your cameras and check you out.

Diving with tiger sharks at night is an incredible experience, albeit a daunting one, knowing that tigers had been present on the late afternoon dive. The night dives I have participated in have usually been in relatively shallow water, beginning at dusk to let the dive group form a close line on the bottom. Diving directly under the boat with lights mounted at the surface can add enough ambient light to allow divers to spot the sharks before they just appear in front of you.

These awesome predators are found in tropical and subtropical waters worldwide. Off the Atlantic coast of the United States, tiger sharks are found from Cape Cod, Massachusetts, to the Gulf of Mexico and Caribbean Sea. Off the Pacific coast, tiger sharks are found from Southern California southward. They’re found in the Hawaiian, Solomon, and Marshall Islands. In the western Pacific they are found from Australia and New Zealand, up through Indonesia, Fiji and Micronesia and as far north as Japan.

It is thought that tiger sharks bear offspring only every two to three years, usually two at a time. The tiger shark is the only species in its family that is ovoviviparous; its eggs hatch internally and the young are born live when fully developed.

Unfortunately, tiger sharks are considered a Near Threatened species by the International Union for the Conservation of Nature (IUCN) due to excessive finning and fishing. They are still killed by man for sport. Tigers are especially vulnerable because they grow slowly and take many years to mature. They are also hunted for their livers, which contain high levels of vitamin A that is processed into vitamin oil. This beautiful animal, often characterized as a man-eater, faces far more danger from men than it poses.

The Fascinating Coconut Octopus

During a recent trip to Lembeh Strait in Indonesia, I happened upon one of the most fascinating marine-life behaviors that I’ve ever observed. Diving along a fairly shallow, barren, sandy slope, I was searching for something really interesting to photograph. My dive buddy was busily taking pictures of porcelain crabs and ghost shrimps going about their daily lives among the tentacles of the occasional carpet anemone. As I scoured the sandy expanse ahead of me, I concentrated on controlling my fin kicks, trying not to lift clouds of fine silt.

Perhaps because there was a scarcity of potential subjects in the expanse of sand, a solitary clamshell drew my attention. The shell, perhaps 3 or 4 inches across, was clean and intact. It struck me as odd that it would be just sitting by itself, out in the open. As I continued to investigate, the shell opened a crack and then quickly closed. I thought then that the shell might contain an eight-legged resident, so I settled in for a closer look. I balanced my camera atop my reef stick, which I had gingerly pressed into the sand to form a makeshift mono-pod. My buddy noticed that I was “on point” and settled in next to me to see what had attracted my attention.

Octopuses will often use discarded objects for shelter. Empty containers, such as bottles, cans and clamshells afford excellent refuge for small octopuses. I’ve found they exhibit a remarkable sense of curiosity, even about intruders many times their size. Move slowly and patiently on your dive, and you will often discover they are as curious about us as we are about them.

In this case, the opening between the halves of the clamshell reappeared in less than a minute, and this time I could see two diminutive eyes staring back at me intently. The top shell continued to open very slowly as the octopus grew braver. At some point, I realized that the cephalopod I was observing might be the highly intelligent coconut octopus, Amphioctopus marginatus, which I have heard so much about.

 

In some respects the coconut octopus is like any other octopus. It is normally found on sandy bottoms in bays or lagoons. It has four pairs of arms covered with suckers, two eyes and an uncanny ability to make itself invisible from potential predators. The main body of this octopus is smallish, typically around 3 inches in size, and has arms approximately 6 inches long. The coconut octopus displays a fairly typical color pattern with dark branching lines similar to veins, and usually displays a yellow siphon.

Marine biologists coined the name “coconut octopus” after observing the animals excavating coconut half shells from the ocean floor and carrying them for use as portable shelters — the first documented example of invertebrates using tools and carrying objects for future use. Although octopuses often use foreign objects as shelter, the sophisticated planning ahead of coconut octopuses, in selecting materials, carrying and then reassembling them, is considered far more complex. In recent studies, researchers have observed the animals carrying those half-shells up to 65 feet across the seafloor, where they reassembled them into a roughly spherical hiding place. Interestingly, while the octopuses are transporting the shells, they receive no protection from them, which is highly unusual behavior. It’s even more difficult to keep from laughing out loud and flooding your mask as you watch an octopus tiptoe awkwardly across the sand carrying its shells, and then reassemble them to create a protective shelter.

As we continued to watch, this particular octopus opened its clamshell a full 180 degrees, until the two halves lay flat on the sand. At this point we could clearly see that the two halves were no longer connected. We watched as the octopus maintained a firm grasp on both halves of the shell as it extended two of its arms out over the edges of the shell and onto the sand. Next, the octopus awkwardly lifted the shells off the bottom and actually stood up on the two arms. As it began shuffling across the sandy floor, it used the two arms for locomotion, sliding one arm at a time in a kind of walking motion. As it moved across the bottom, it used several of its arms to form an unrecognizable mass above the shell, apparently attempting to mask or camouflage its presence.

The octopus continued its navigation across the sand for about twenty feet and then suddenly stopped. It withdrew its “walking” arms and allowed the shell to settle on the sand. We watched with amazement as it deliberately lined up the edges of the shell-halves and pulled its top cover back down as if on a hinge, withdrawing back into the confines of its portable shelter.

 

 

 

 

 

 

Sea Kraits

The banded Sea Krait, Laticauda colubrina, is a species of sea snake that inhabits coral reefs throughout the Indo-Pacific region. They are usually found off the shore of small islands and they often hide in small crevices or under rocks. They are generally nocturnal hunters, but they are often found out during the day.

Sea Krait

Banded sea kraits are also called yellow-lipped sea kraits because of a characteristic yellow upper lip. Their heads are mostly black with a yellow band extending along the lip, underneath each eye. Their tails have a U-shaped yellow marking along the edge that borders a broad black band. They have a smooth, scaled body with a blue or gray base color. Twenty to sixty-five black bands form rings around the body. They frequently reach lengths of 1.5 meters or more.

Sea Krait

They spend much of their lives in the ocean, but also spend a great deal of time on rocky islets in order to court, mate, lay eggs, digest food, and shed their skins. They are air breathers, but they have many special adaptations for diving including a saccular lung allowing them to dive to depths up to 60 m in search of food.

Sea Krait

Sea kraits are oviparous and return to land to lay their eggs. They also digest their food on land, and they can actually climb trees. However, they hunt and catch prey in the ocean. They reportedly feed primarily on smaller eels that inhabit shallow water. The females are typically larger than the males and feed on larger species of eels that inhabit deeper water to eels.

DID YOU KNOW THAT female sea kraits rarely show any overt response during the courtship process, however when they are feeling “frisky,” they may signal potential males by waving their tails when they are ready to copulate.

Sea Krait

Cozumel – FPMC Turtle Protection Program

We were here in Cozumel finishing up research and images for the new eBook, Dive Cozumel. This green turtle hatchling was one of 88 baby turtles that we removed from one nest site. We were thrilled to see them all make it safely into the ocean to begin their lives. This is a terrific program conducted by the FPMC, Foundation for Parks and Museums of ‪‎Cozumel‬.

Video of Cozumel Turtle Release

During our research visit to Cozumel, we also took video. Here is a 60 second clip of our visit including the release of the 88 turtles. The volunteer groups invest a tremendous amount of time and deserve our thanks.