• Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

Loading content - please wait...

Yearly Archives: 2015

Gymnodoris ceylonica nudibranchs in Gorontalo

Gymnodoris ceylonica were everywhere! Pearly white nudibranchs with orange spots were crawling along the ocean floor. What was going on?

Watching a Rare Event

The dive site was Tambo’o Fish House. It is a favorite muck diving site in Gorontalo. No nudibranchs were seen the previous day. Then suddenly one day in November, there were dozens and dozens of Gymnodoris ceylonica nudibranchs. Most were about five centimeters in length.

Gymnodoris ceylonica laying eggs
Gymnodoris ceylonica laying eggs

Upon closer inspection, those Gymnodoris ceylonica nudibranchs were mating. Then they were laying eggs on various kinds of algae. A few were laying eggs on the sand. Miguel’s Diving staff had never seen this happen. So, we came back on the two following days to film this rare event. By the third day, all the nudibranchs had disappeared. Only their eggs were left.

Watch this amazing video, shot by Mr Yunis Amu of Miguel’s Diving. Notice the translucent body of this nudibranch. Sometimes, the yellow eggs still inside the nudibranch are visible from the outside!

The Ceylonese Nudibranch

The common name for Gymnodoris ceylonica is Ceylonese nudibranch. It was first discovered in 1858 off the coast of Sri Lanka. That island was a British Crown colony at the time marine researchers were working there. The British called their colony Ceylon, hence the name of this nudibranch.

The Life of Gymnodoris ceylonica

Ceylonese nudibranch eggs on algae
Eggs of Ceylonese nudibranch on algae

This lovely nudibranch prefers open grass beds. Plenty of algae live in that marine environment. Ceylonese nudibranchs are not vegetarian, however. They are carnivores. They eat other nudibranchs. Pictures of one eating a sea hare are available here.

Mr. Bill Rudman of Sea Slug Forum has several observations about the eggs of Gymnodoris ceylonica. Most noticeably, the eggs are not in the classic, smooth ribbon like other nudibranchs. These egg masses are almost messy in comparison. Missing are the pretty spirals that divers expect to see. Johnson & Boucher studied the eggs of this nudibranch in 1983. They discovered that the eggs are arranged in clusters of 20 to 40 eggs. Each yellow dot visible in the video and photo is actually a cluster of eggs.

Divers never know what to expect here because of the incredible variety of marine life. For your chance to watch Gorontalo marine life, please book your dive trip with us.

Sea Sapphires Mysteriously Disappear

Sea sapphires are flashy planktonic crustaceans that appear and disappear. No one knew how they did it – until now.

Suddenly Visible

In Gorontalo waters on certain days, divers are ready to descend. They notice tiny flashes of color in the water column. The flashes look like chips of iridescent blue paint. Sometimes the color is yellow. Occasionally, it is golden red. Upon closer inspection, those tiny ovals of blue are plankton floating in the water. Approach one with your finger. It will swim away and disappear. They are commonly called sea sapphires.

In the early mornings Gorontalo fishermen report seeing the ocean shimmer with these iridescent flashes. An old expression used by Japanese fishermen is tama-mizu. This means “jeweled water.”

The Life of Sea Sapphires

a male sea sapphires
A male sapphirina copepod

These brilliant and mysterious creatures are actually sapphirinid copepods. Copepods are a subclass of tiny crustaceans. They have elongated bodies and forked tails. Their scientific names reflect their jewel-like appearance.

Only male sea sapphires flash brilliant colors. They are carried by ocean currents, along with other planktonic life, to the coral walls of Gorontalo. Sea sapphires are an important part of the food chain. When we see them collecting off a dive site, we look out for whale sharks.

Female sea sapphires do not float the oceans with the free-swimming males. Instead, they congregate inside certain kinds of transparent jellys. Females have much larger eyes than males. Perhaps this allows them to scan the vast ocean for flashy boyfriends. Watch them in incredible Kaj Maney’s video.

The Arts of Reflection and Disappearance

A team of scientists from the Weizmann Institute of Science just discovered how male sea sapphires appear and disappear. Their study was published in June 2015. Males have alternating layers of hexagonal-shaped crystals. These are imbedded in their backs. Sea sapphires are only a few millimeters in length. But researchers managed to measure the distance between those reflective crystals found in sea sapphires. They used live males. The distance between crystals was only about 1/10000 mm. This measure is about the same as a wavelength of blue light. When sunlight hits male sea sapphires, only one color is reflected by the crystals. Usually, it is blue. Differences in color depend on the distance those layers of crystals are from one another. That is why some sea sapphires appear yellow or golden. This type of coloration is called structural coloration.

 tiny male sea sapphires
A tiny male sea sapphire reflects blue

Male sea sapphires swim freely in the open ocean. However, they do not swim in straight lines. They swim in spirals. Researchers also discovered how these sea sapphires disappear so quickly. As they turn, the angle of reflected light changes. When light hits them at a 45-degree angle, the reflection shifts out of the visible light range. Only ultraviolet light is reflected. Since humans cannot see ultraviolet light, male sea sapphires seem to disappear. They do this by merely turning their bodies. Although how they appear and disappear is now known, no one knows why.

Fimbriated Moray Eel Cruises Gorontalo

Fimbriated moray eels are seldom seen during daylight hours. Usually, they are hiding. Even more rare is a video of one swimming in its natural environment.

Captured Live on Video

During a dive in July 2015 a Fimbriated moray made a dash from one hiding place to another. This happened at Sand Castle dive site in Gorontalo. Many types of moray eels love this dive site. Usually, only their heads are visible. Their bodies are hidden inside holes and crevasses. Notice that the Fimbriated moray eel in this video swims with its mouth open. It does not feel threatened by the divers who were watching it. But what does that behavior indicate?

Moray Eels

Like other eels, Fimbriated moray eels breathe by opening and closing their mouths. This helps pump oxygen-rich water through its gills. A small opening behind an eel’s head is where water exits the gills. Perhaps the eel in the video is out of breath from its unexpected daylight swim.

A distinctive of all morays is the single, continuous fin. It begins behind the head, encircles the tail, and then reaches midway under the belly. Unlike snakes, morays lack scales. Instead, their muscular bodies are covered with a protective coating of mucous.

Fimbriated Moray Eels

The scientific name of this eel is Gymnothorax fimbriatus. Perhaps the finger-like patterns of black spots are the reason it was named fimbriated. Morays of the Gymnothorax genus have long, pointed teeth. They use these to catch fish and octopi to eat. In fact, if divers see an octopus with a missing arm, the culprit is probably a moray eel that attacked unsuccessfully. Moray eels typically hunt at night.

Fimbriated moray eel in Gorontalo
A Fimbriated moray eel pauses during a swim

Fimbriated moray eels are medium in size. They reach a maximum of 80 centimeters in length. One such eel living in an aquarium for 18 years has grown to 100 cm. The pattern of dark spots are distinctive of this species. However, since it rarely ventures from its hiding place, divers will rarely see that pattern. An easier way to identify this moray is to notice its tapered snout. Most importantly, the corners of its mouth are distinctively white.

This moray eel is found throughout Indo-Pacific waters. It prefers coastal reef of oceanic islands but is also found in lagoons and harbors. It is only common in Bali. To glimpse one of Gorontalo’s moray eels, please book your dive trip with us.

Bokeh Effect in Underwater Photography

Bokeh can help underwater photographers achieve dramatic effects.

The Blur Effect

bumblebee shrimp in Gorontalo
A Bumblebee shrimp with eye in sharp focus

The term bokeh comes from the Japanese word meaning blur. In ordinary photographs both object and background are in focus. The bokeh effect relies on blurred background. Only the object is in sharp focus.

Beginning underwater photographers are happy when everything in a photo is in focus. They are happier still if the color is good. Bokeh is an advanced technique. It concentrates on having only the foreground object in focus. The background is deliberately blurred. With this technique a simple id shot becomes dramatic.

Bokeh in Underwater Photographs

Bokeh effect highlights goby's eyes
Whip coral goby with bokeh effect

Many shrimps, crabs and fish rely on camouflage. Others have transparent bodies. Both of these help blend the creature into its environment. Being unseen means safety. However, the underwater photographer wishes to shoot those creatures in ways that they can be seen. Their unseen beauty is better recognized using the bokeh technique. Otherwise, the creature still remains obscured by its environment. Typically, only the eye or the face of a marine creature is in focus. The rest of its body remains out of focus. Its living space, whether crinoid or coral, is also blurred.

Three among Miguel’s Diving staff have placed in international underwater photo competitions. That means we know how to help guests get better photos. Underwater bokeh photos for this blog are courtesy of Mr. Digant Desai of Bombay, a repeat guest of Miguel’s Diving. All photos were shot in Gorontalo.

Technical Tips

The bokeh effect relies on a sharp foreground object and blurred background. Here are several tips. Manual settings must be used, not automatic ones. First, select the smallest F-number available. This will decrease the depth of field and isolate focus on only a small part of the frame. Take a shot to check results.

Second, use the zoom feature on your camera. This will further isolate the focus on the desired object. Take another shot and adjust.

coral background in blur
White dots of blurred coral unify this shot of a White-marked shrimp

Third, move as close as possible to the object. When shooting underwater, this can be challenging. Some marine creatures think their camouflage is working. They will not move. Others can become afraid and flee when a photographer gets too close. That is why the zoom should be used before getting closer. Moving closer also requires patience. Once marine life discovers that you mean no harm, approach is easier.

Fourth, certain macro lenses can achieve better bokeh effects. This will depend on the make and model of the camera used. There is one caution to note. Simply using a computer program to make a close crop of an object will not achieve the bokeh effect. The background must be blurred at the time the photo is taken.
For your chance to shoot pictures using the bokeh effect in Gorontalo, please book your dive trip with us.

Indonesia Visa Free Travel

Indonesia visa free travel regulation was just expanded to citizens of 45 countries.

Visa Free Travel to Indonesia

On 9 June 2015 Indonesian President Joko Widodo signed a new law. Presidential Directive No. 69/2015 expands the list of countries whose citizens can enter Indonesia visa free. This marks an effort to boost tourism from those countries. It also aims an improving relations. Citizens of those countries can receive an Indonesia visa for free upon arrival. The new Indonesia visa provides a 30 day stay. The new free visa cannot be extended. This visa is for visit purposes only and not for study or business.

Ports of Entry

The free Indonesia visa is only available at certain ports of entry. These are Soekarno Hatta Airport (Jakarta), Ngurah Rai Airport (Bali), Kuala Namu Airport (Medan), Juanda Airport (Surabaya), Hang Nadim Airport (Batam), Seaport Sri Bintan, Seaports Sekupang, Batam Center Seaports and Seaport of Tanjung Uban (Riau).

Citizens Receiving Indonesia Visa Free

Citizens from countries of the Association of Southeast Asian Nations (ASEAN) have long enjoyed visa free visits to Indonesia. The new list includes many western nationals. Although Australians comprise the third largest group to visit Indonesia, they will still need to purchase a visa on arrival. The current list for the free visa is:

Indonesia visa free for divers
Dive gear arriving in Gorontalo

Austria, Bahrain, Belgium, Brunei, Cambodia, Canada, Chile, China, Czech Republic, Denmark, Ecuador, Finland, France, Germany, Hong Kong, Hungary, Italy, Japan, Kuwait, Laos, Macau, Malaysia, Mexico, Morocco, Myanmar, the Netherlands, New Zealand, Norway, Oman, Peru, Philippines, Poland, Qatar, Russia, Singapore, South Africa, South Korea, Spain, Sweden, Switzerland, Thailand, United Arab Emirates, United Kingdom, United States, and Vietnam.
This is great news for divers from those countries. Divers from other countries or those entering Indonesia at a different port will need to purchase an arrival visa. To arrange your dive trip to Gorontalo, please book your dive trip with us.

Thysanostoma thysanura Jellyfish in Gorontalo

Thysanostoma thysanura is a large jellyfish rarely seen in Gorontalo waters.

Bushy Oral Arms

Thysanostoma thysanura in Gorontalo
Thysanostoma thysanura surface swimming

This large jellyfish lives in warm waters from the central Indo-Pacific to Japan. It was named in 1880. The Latin word thysanura means “bristle tails.” This name refers to the large, bushy oral arms that hang from the jellyfish’s central bell. Modern researchers have gathered specimens from Sulawesi, the northern Philippines and the Great Barrier Reef in Australia. Thysanostoma thysanura has been seen at depths reaching 24 meters. In Gorontalo, however, it has only been observed at the surface.

Encounter with Thysanostoma thysanura

Although Miguel’s Diving has been operating in Gorontalo since 2003, we have only encountered Thysanostoma thysanura a few times. After a dive in April 2015, one was swimming around the dive boat. Jellyfish of any kind are usually not present in areas where we dive. Imagine the excitement to see this large and beautiful jellyfish. In our experience, this jellyfish is a very active swimmer. It pumps water with its bell to move. Its oral arms drag along behind it. Taking photographs was a challenge because it never stayed still. Watch our video!

Jellyfish Facts

Adult jellyfish are called medusa. They have a soft body consisting of a bell with tentacles or oral arms surrounding a central mouth. Solitary medusa, like Thysanostoma thysanura, swim freely in the open ocean.

 

a rare Thysanostoma thysanura
A rare encounter in Gorontalo

Jellyfish are most famous for the stinging cells contained in their tentacles. The stinging cells are called nematocysts. They are microscopic and sensitive to pressure. Even a causal touch triggers hundreds or thousands of nematocysts. They fire like darts. Jellyfish use them to immobilize prey like small fish.

Some jellyfish are considered dangerous to humans. We have never seen any of these in Gorontalo. Since Thysanostoma thysanura is so large, avoiding it is quite easy. Since this jellyfish is so rare, only a few lucky divers will ever see it. Our jellyfish was kindly identified by Wyatt Patry of Monterrey Bay Aquarium.

Diving in Gorontalo is exciting because of the unusual marine life found here. For your chance to experience the beauty of Gorontalo, please book your dive trip with us.

Porcupine Fish of Gorontalo

Porcupine fish add to the diversity of marine life in Gorontalo. About twenty species of this unusual fish are found worldwide. Divers are most likely to encounter three of them in Gorontalo.

Prickly Balls

Porcupinefishes are similar to puffers. They have distinctive body spines. When threatened, they will ingest water. This dramatically increases their body size and causes their spines to protrude. It is consider bad manners for divers to provoke this defensive behavior. The fish is terrified that it will be eaten.

Black-blotched porcupine fish

Blotched porcupine fish in cave
A Blotched porcupinefish scurries into a cave

The most common porcupine fish found in Gorontalo is the Black-blotched porcupine fish (Diodon liturosus). It is found in tropical waters of the Indo-Pacific region. It is usually about 45 cm in length. Like other porcupinefishes, it eats sea urchins, gastropods and crustaceans. If divers see more than one, it is mating season. Usually, porcupinefishes are solitary. They are also nocturnal. During the day, they prefer caves and sheltered crevasses.

Similar to the Black-blotched porcupine fish is the Long-spined porcupine fish. The only visible difference is that it lacks dark spots on its fins. It is found in warm tropical waters worldwide. Its official name is Diodon holocanthus.

Spot-fin porcupine fish

Spot-fin porcupine fish hides
A Spot-fin porcupinefish hides under a rock

The Spot-fin is the largest porcupine fish found in Gorontalo. Its scientific name is Diodon hystrix. It grows up to 91 cm and is covered with black spots. It is found worldwide. Like other porcupinefishes, certain of its glands contain tetrodotoxin. This is a powerful neurotoxin.

Orbicular burrfish

Orbicular burrfish eye
The eye of an Orbicular burrfish

This small type of porcupine fish grows to only 30 cm. Its official name is Cyclichthys orbicularis. Unlike the others, it is found on sandy or mud bottoms. Divers will see it while muck diving. It prefers hiding in sponges during the day. The iridescent eye of this fish graces the back cover of the book Gorontalo: Hidden Paradise.

Diving in Gorontalo is exciting because of the incredible variety of marine life. To glimpse one of Gorontalo’s porcupinefishes, please book your dive trip with us.

Canthigaster bennetti forms a Magic Carpet

Canthigaster bennetti flows in schools along Gorontalo reefs, forming a magic carpet.

A Magic Carpet

Canthigaster bennetti
A magic carpet of Bennett’s tobies

Canthigaster bennetti, commonly called Bennett’s toby, gather in Gorontalo in huge numbers. They gather to spawn. Swimming in coordinated streams, they fly along the reefs and walls like a magic carpet. Miguel’s Diving staff have observed this rare phenomenon many times. It can occur during any month but happens only once or twice a year. We call this event “magic carpet.”

The peak for gathering schools of Canthigaster bennetti lasts only a few days. Then the fish start rummaging in patches of coral rubble. Presumably, they are laying and fertilizing eggs. At this time, individual tobies can be found floundering in mid water. They are clearly malnourished and dying. A closer look reveals that their tails and pectoral fins are severely torn. Presumably, they have been fighting with each other. Within another day or so, thousands and thousands of dead tobies litter the reef.

End of the Phenomena

Canthigaster bennetti is a small puffer fish. When threatened, a Bennett’s toby can ingest water and puff itself to twice its normal size. As with other puffer fishes, certain tissues of Canthigaster bennetti contain poisons. Perhaps that is why other fish do not feed on the dead and dying Bennett’s tobies. Water motion eventually carries the dead tobies below diving limits.

Canthigaster bennetti in Gorontalo
One in a million

The mass spawning and dying of Canthigaster bennetti has been scientifically reported. The study comes from Una-una, a volcanic island in Tomini Bay. Gorontalo reports of the magic carpet phenomena occur on the north shores of Tomini Bay where Miguel’s Diving operates.

Daily Life of Canthigaster bennetti

Canthigaster bennetti usually occur in pairs or singly. Its cone-shaped nose earns it an alternate name, Bennett’s Sharpnose Puffer. It mainly feeds on filamentous green algae. Sometimes, it will eat coralline red algae and benthic invertebrates like tiny shrimps. This harder diet helps break down their ever-growing teeth.
This magic carpet is only one aspect that makes diving in Gorontalo so exciting. For your chance to experience the beauty of Gorontalo, please book your dive trip with us.

Simpang Siur Depan Kampung

Simpang Siur adalah salah satu dari beberapa tempat penyelaman yang terdapat di Cagar Alam Desa Olele di Gorontalo. Salah satu ciri khasnya adalah terumbu karang yang masih perawan justru di depan kampung.

Nama Tempat Penyelaman Simpang Siur

Tahukah anda mengapa dinamakan Simpang Siur? Karena pada saat kita melakukan penyelaman di situ, terkadang kita harus ikut arus dan terkadang harus menantang arus. Setiap penyelam yang melakukan penyelaman di situ dikenakan biaya, yaitu Rp. 10.000 per penyelam karena Simpang Siur terdapat di dalam kawasan konservasi Desa Olele.

Biota Lautnya

sponge salvador dali berbentuk bunga
Sponge Salvador Dali berbentuk bunga di Simpang Siur

Bicara tentang Simpang Siur, itu adalah salah satu tempat penyelaman yang para pengunjung sukai, karena bila pengunjung melakukan penyelaman di situ, pengunjung disuguhkan dengan berbagai macam biota laut dan terumbu karang yang sangat-sangat padat, seperti karang meja, terumbu karang keras dan lunak di antara lainnya.

Melakukan penyelaman di Simpang Siur, pengunjung bisa melihat keunikan biota laut yang ada di Gorontalo, yaitu Salvador Dali sponge yg hanya terdapat di Gorontalo. Di Kepulauan Togean pun yang hanya satu lautan dalam Teluk Tomini tidak mempunyai Salvador Dali sponge.

Tahukah anda mengapa dinamakan Salvador Dali? Salvador Dali adalah sponge yang permukaannya seperti terukir dan bentuk ukirannya, seperti lukisan seorang seniman yang berasal dari Spanyol, namannya Salvador Dali. Di Simpang Siur, ada Salvador berbentuk bunga dan sangat bagus untuk para pecinta foto bawah laut atau underwater photographer. Ada juga karang kipas yang sangat besar dan tidak mungkin ada pygmy seahorse di situ karena sea fannya terlalu besar.

Di Simpang Siur juga bila kita beruntung, terkadang pengunjung bisa melihat hiu paus atau whale shark, black manta, lumba-lumba dan tuna, tapi tidak bisa dijamin. Ada juga biota laut yang lainnya, seperti nudibranch, kepiting-kepiting seperti orangutan crab, soft coral crab. Juga ada udang-udang, seperti Coleman coral shrimp, Sarasvati shrimp dan itu bisa dijamin ditemukan di temapt penyelaman ini.

Lokasi Snorkeling

anak main air laut di Simpang Siur
Anak-anak Desa Olele main di Simpang Siur

Di Simpang Siur juga adalah favorit para pecinta snorkeling dan katamaran atau perahu kaca pada saat akhir pekan banyak turis lokal dan mancanegara yang datang ke Desa Olele hanya untuk menikmati keindahan taman laut Desa Olele yang salah satunya lokasinya di Simpang Siur. Rata-rata para pecinta snorkeling senang bila melakukan snorkeling di Simpang Siur. Mereka juga bisa memberi makanan pada ikan-ikan, seperti biscuit, roti-roti supaya ikan–ikan di situ berkumpul.

Penduduk Desa Olele kira-kira 80% adalah nelayan laut dalam. Mereka memancing ikan laut dalam seperti tuna, cakalang, cumi dan ikan kembung. Mereka tidak memancing di pinggiran karang sehingga mereka tidak merusak terumbu karang. Oleh karena itu, karang-karang di Desa Olele masih padat dan sehat termasuk di Simpang Siur. Datanglah ke Gorontalo dan menyelam di Simpang Siur. Tolong mengurus bookingan langsung dengan Miguel’s Diving.

Oleh: Undeng Amu[svpVideo v=1]

Crustacean Identification Guide for Divers

Crustacean identification guide Coral Reef Crustaceans is newly available at Apple’s iBooks Store.

By a Diver for Divers

crustacean identification guide by Andrey
Andrey views a Salvador Dali sponge in Gorontalo

Mr. Andrey Ryanskiy is the author of this interactive crustacean identification guide. He is a Moscow-based financial consultant. He and his wife Irina are avid underwater photographers. The book represents countless dives over six years. The goal for his crustacean identification guide is to educate, entertain and inspire.

Features of the Crustacean Identification Guide

Coral Reef Crustaceans contains more than 780 photographs. Of the 490 species covered in the book about 160 of them have never before appeared in other field guides. Leading marine specialists confirmed the scientific names of the critters contained in this crustacean identification guide. As its subtitle indicates, the region covered is from the Red Sea to Papua New Guinea. This guide is well organized and easy to use. Photos are high quality, full-screen shots.

It is a multi-touch book and best read with iBooks. Divers who have a Mac or iPad or use iTunes can download this crustacean identification guide for USD4.99. What a great bargain for 257 pages!

Unusual Species from Gorontalo

In December 2014 Andrey and Irina spent five days diving in Gorontalo. They returned for four more days in January 2015. Marine scientists consulted for the crustacean identification guide recommended diving in Gorontalo to them. The reason was the unique marine species available here. Andrey would often ascend from a dive to share something new or rare he had just seen or photographed. For him the most fascinating areas to search are below 40 meters and above three meters. He recommends Gorontalo for its combination of great wall dives and “pure blood” muck diving. He also notes that Gorontalo is one of the few regional destinations with good diving weather over the New Year period.

crustacean identification guide with crabs
The beautiful and rare Trizopagurus strigatus found in Gorontalo

Irina wishes the dive guides of Miguel’s Diving were available in other locations. On one diving day, Andrey opened his book on his iPad and showed Miguel’s Diving staff his favorite crab, Trizopagurus strigatus. It is rarely seen. During the next dive, his guide found one for him. And Irina’s guide found another one for her!

mgd-logo-block
Visit Us On FacebookVisit Us On YoutubeCheck Our Feed