• Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

Loading content - please wait...

Bodianus dictynna thrives in Gorontalo

Posted on by • 0 Comments

Bodianus dictynna is commonly found in Gorontalo’s coral rich reefs. This species was scientifically described in 2006. Since it is only found in the Pacific Ocean, the common name is Pacific Diana hogfish.

One Goddess, Two Species

For decades, divers and fish enthusiasts thought that there was only a single species of Diana hogfish. However, based on Dr. Martin F. Gomon’s extensive research, populations were separated in 2006. The Diana hogfish in the Indian Ocean remain Bodianus diana, whereas the newly named Bodianus dictynna lives in the Pacific Ocean. Both are very similar in appearance. So, the best way to recognize the species is simply by location.

Bodianus dictynna
Bodianus dictynna with a Salvador Dali sponge

Both Latin word diana and dictynna refer to the Roman goddess Diana. She was the moon goddess and famous huntress. The genus name Bodianus comes from a Portuguese word that means modesty. As a result of Gomon’s research, scientists now recognize 45 species of Bodianus. These are found in the Atlantic, Indian, and Pacific oceans.

Bodianus dictynna in Gorontalo

The Pacific Diana hogfish lives in warm, tropical waters. It lives as far north and south as Japan and Australia. Its eastern boundary is Tonga. No one knows yet how the recent volcanic explosion there will affect fish life. For unknown reasons, this hogfish species is rare in the central Pacific plate.

As to habitat, Bodianus dictynna prefers coral reefs. Juveniles frequent black corals and gorgonians. The juveniles also like the ceilings of underwater caverns. So, Gorontalo’s Jinn Caves dive site is a great place to search for this fish.

Divers should note that juveniles have a color pattern distinct from adults. Juveniles have a maroon and white maze pattern with distinctive black spots. These spots are on both ventral and dorsal fins as well as on the tail’s end. A terminal phase male sports a large black spot on the end of his dorsal fin. Also, he will have a black spot on mid anal and pelvic fins.

Adults eat molluscs and crustaceans. Juveniles eat parasites off the skin of other fish. Adults mate in pairs.

For your chance to see a Pacific Diana hogfish in Gorontalo, please make your dive reservations directly with Miguel’s Diving.  

    

Entoprocta on solitary tunicates in Gorontalo

Posted on by • 0 Comments

Entroprocta is a division of extremely small aquatic animals that mostly live in colonies. Their body shapes look like tasseled tulips on long stalks. Miguel’s Diving staff often find them.

A Speckled, White Halo  

Entoprocta colony on a tunicate
Entoprocta colony on a yellow tunicate

In Gorontalo, Miguel’s Diving staff see colonies of Entoprocta growing on the surface of certain solidary tunicates. Tunicates are actually animals, as well. We do not know which genus or species we most common here. These colonies look like a transparent forest sprouting from the tunicates surface. Individual entoprocts appear to have a dark spot. Sharp focus with a good lens is required to see the colony and its individuals.

Not a Flower, but an Animal

Entoprocta is a phylum of animals. All but two of 150 species are found in the world’s oceans. The other two live in fresh water. As adults, they cannot relocate, so they are sessile. An individual measures between 0.1 and 7 millimeters tall. An adult appears to be a tall stalk with a tulip on top. The top is ringed with solid tentacles. Moving their microscopic hairs or cilia creates a current that draws plankton into their mouths.

Both the mouth and anus lie inside this tentacle-ringed tulip. In fact, the name Entoprocta means inside anus.

Scientists call these critters zooids because they are not fully independent animals. In many ways they resemble bryozoans. However, anatomy and feeding are different.

Stalks of colonial Entoprocta rise from a shared foundation. This can be a plate or a network of tubes, which are called stolon. Solitary entoprocts are firmly anchored with a muscular foot. They will exhibit a nodding motion. Remarkably, some solitary species can move by creeping or by doing somersaults.

Entoprocta sketch from Wikimedia Commons

Reproduction of Entoprocta species

Both colonical and solitary entoprocts can reproduce sexually or by cloning. Depending on the species, unfertilized eggs are released into the water column. Other species have a pouch where the eggs mature then hatch. Some species even have an organ like a placenta to nourish the developing young.

Upon hatching, the larvae swim until they attach to a suitable surface. There, they will change into the adult form as described above. Moreover, the larvae will move its gut from pointing down to facing up. In this way, both mouth and anus face upwards. That is the most distinctive characteristic of Entoprocta.

All species can reproduce by budding. New zooids form from the network of stolon. Or, they can grow from a stalk. These will be clones of the parent. In this way, large colonies can form. Perhaps that is what we commonly see in Gorontalo.

As for entoprocts in Gorontalo, only Miguel’s Diving staff know about this marine animal. For your chance to see a colony of them, please make your dive reservations with us.

Green turtle pays a visit to Gorontalo reefs

Posted on by • 0 Comments

Green turtle is a species only occasionally seen along Gorontalo’s dense coral reefs. Adult green turtles are strictly vegetarian and so live near sea grass flats. Those seen at Gorontalo dive sites are migrating between sea grass areas in western Gorontalo to those in North Sulawesi Province. Divers will usually see Hawksbill turtles here.

Green Turtle Identification

green turtle on reef
The beautiful shell pattern of Green turtle

Both Green and Hawksbill turtles have similar appearances. However, certain features help identify both species. Green turtles have a single pair of large scales between their eyes. These are called prefrontal scales. Hawksbills have two pairs of small scales. Also, a hawksbill turtle has a distinctive hook on its beak, whereas a green turtle will have a rounded beak. Green turtles have smooth shells with smooth edges, whereas a hawksbill’s shell edges will be clearly serrated, especially towards the tail. Lastly, an adult Green turtle has a single claw on each front flipper, whereas a Hawksbill turtle will have two. Oftentimes, the shell of a green turtle will be highly polished with visible patterning.

Worldwide, Green turtles can grow up to a meter and a half in length. Also, they can weigh up to 400 kilograms. Those found in Indonesia are usually no longer than one meter.

Although baby green turtles eat a variety of things, adults shift to a plant diet. That means they eat mainly sea grass and marine algae. The common name green turtle comes from the fact that the fat found under this turtle’s shell is distinctively green in color. Scientists suspect the color is a result of the vegetarian diet. Also, this turtle’s scientific name is Chelonia mydas.

Moreover, should a diver notice the tail of a Green turtle, that turtle will be male. Only a male’s tail is long enough to protrude from under its shell.  

Breathing in Sea Turtles

Divers know that sea turtles spend most of their lives underwater. However, they must breathe oxygen from the air. While traveling to dive sites in Gorontalo, guests might notice when a turtle’s head breaks the surface. One breath is enough to exhale stale air and replace it with fresh air. A green turtle will dive for about four to five minutes. Then it will surface for a couple of seconds to catch a breath. Divers should never interfere with sea turtles while trying to breathe. Sea turtles will sleep in a safe place. During sleep, respiration slows considerably.

Nesting Sea Turtles

turtle on the reef
Pausing on a Gorontalo reef

A female sea turtle will reach forty to sixty years in age before laying her first eggs. Breeding females will lay eggs every two years. They will lay these every two to three weeks. They lay 50 to 150 eggs each time.

The temperature of the sand determines the sex of the hatchlings. Research on green turtles find that higher temperatures produce males, whereas lower temperatures produce females. Scientists worry that rising ocean temperatures from climate change will result in too few female green turtles.

A female sea turtle will crawl onto a sandy beach at night. Then she will dig a hole to lay eggs and recover them. Scientists believe they return to the beach of their birth to lay eggs.

Baby turtles will hatch about two months of incubation. They will usually hatch about the same time. Then they crawl as quickly as possible to the sea. Many predators from birds to large fish eat baby sea turtles. The chances of surviving to adulthood are very small. Humans still collect eggs and hunt sea turtles. This is illegal in Indonesia.

Although land turtles can pull head and flippers inside the shell, sea turtles cannot.

For your chance to see a green turtle in Gorontalo, please make your dive reservations directly with Miguel’s Diving.  

Covid vaccination complete for Miguel’s Diving staff

Posted on by • 0 Comments

Covid vaccination is complete for all Miguel’s Diving staff. Our local dive masters completed both doses of Sinovac by mid-2021.

Ministry of Health Covid Vaccination Program

Covid vaccination for staff
Our staff display proof of vaccination

Organization for the covid vaccination program in Gorontalo was very professional. Health care workers registered residents according to national identity card. Results were sent to each person’s cell phone. This also provided proof of vaccination. After the first dosage, a reminder for the second dosage arrived to the registered cell phone number. After the second dosage, the Ministry of Health provided a vaccination certificate. This certificate can be printed as a card.

Covid vaccination helps protect the individual dive master from severe covid-19. It also provides confidence to our guests that our staff is protected to the extent possible.

Entry Requirements for Travelers

In order to enter Gorontalo, travelers must show a negative COVID-19 test result. This is in effect for arrivals by air, land, or sea at the time this blog was written. Also required is proof of covid vaccination. As a result, Miguel’s Diving does not ask to see a guest’s health records.

Olele vaccination program
Vaccination at Olele Village

Since entry requirements from the Indonesian government frequently change, please check before leaving home. The information could have changed since we published this blog post. Garuda Indonesia provides a good summary of these requirements.

Additional Safety Measures

We at Miguel’s Diving take additional measures to lower the risk of transmitting the Covid-19 virus among guests and to our staff. In addition to new normal precautions, we have special protocols designed for our divers. 

In general, health officials encourage handwashing with soap & water for at least 20 seconds. When social distancing of 1.5 meters is not possible, we encourage people to wear a health mask. Also, avoid touching eyes, nose, and mouth. And please cough away from others and into the elbow.

We encourage divers to bring only necessary personal items on board. We are asked to check body temperature prior to leaving the dock. Also, please clean the dive mask with baby shampoo or cleaner rather than spit. Divers should clear sinuses in the ocean away from others and maintain social distancing when waiting to ascend the ladder.

In addition, Miguel’s Diving soaks each regulator and mask set for a minute in 22ml Clorox/L water. We provide a disposable health mask if guests forget to bring. After each trip, staff clean and disinfect our vehicle. In these ways, we follow protocol advised by PADI and DAN.

Guests of Miguel’s Diving can feel confident that we are doing our utmost to provide a healthy dive experience. So, please make dive reservations with us.

Jungle trekking in Gorontalo leads to hot spring caves

Posted on by • 0 Comments

Jungle trekking in Gorontalo is a great addition to a diving holiday. Any easy-to-access half day trip leads through primary jungle to caves formed by hot springs.

Bogani Nani Wartabone National Park

Gorontalo and North Sulawesi provinces contain a significant national park. Its new name is Bogani Nani Wartabone. Previously, its name was Dumoga Bone National Park. Nani Wartabone was a native Gorontalo freedom fighter. He led the successful resistance against the Imperial Japanese occupation during the Second World War. Visitors to the Gorontalo side of this park can visit a house museum dedicated to him.

The park comprises over 2,800 square kilometers. According to conservationists, this national park is the most important conservation area on Sulawesi. The park provides refuge for many of Sulawesi’s endemic species. A Maleo hatchery is located a couple hours’ hike into the park.

Caves and Hot Springs

Jungle trekking into Bogani Nani Wartabone National Park gives visitors access to two small caves. Seepage from underground hot springs formed both caves. These caves are in their natural state with no human development.

Sauna cave Gorontalo
Ceiling of the Sauna Cave

One tiny cave is called the Sauna cave. Only the slim and agile trekker can climb into it. Inside it indeed feels like a sauna, complete with steam and dripping hot water. Flow stones and dramatic stalactites grow from its ceiling. High on a cliff is the Fairy cave. Locals call it Goa Bidadari. Access to this cave requires scrambling up a steep and barren slope where mineral waters leach over the surface. Only fit and agile trekkers should attempt the brief ascent. They do so at their own risk without any recommendation from Miguel’s Diving. These caves are located in the Hungayono area.

Jungle Trekking to Waterfalls and the one River

jungle trekking to water fall
Newly-formed waterfall

Jungle trekking in the national park can lead to two waterfalls. One falls dropping one hundred meters is accessed via Lombongo Hot Springs. Another falls formed during the COVID-19 pandemic after an earthquake. This waterfall is in the Hungayono area near to the Maleo hatchery. Its waters descend into the Bone River, which flows through the national park. These two falls cannot be accessed on the same trip. So, those seeking jungle trekking to a waterfall must choose. Be warned that scalding hot, underground water pours into the Bone River.

Wildlife Sightings

Trekkers should be on the lookout for various wildlife. Officially, the national park has identified 125 bird species, 24 mammals, 23 amphibians and reptiles. Moreover, tree species number 289. Often, trekkers can see or hear the endemic Gorontalo macque (Macaca nigrescens). This is actually a different species from the Sulawesi macaque (Macaca nigra) found in North Sulawesi’s Tangkoko Reserve. Neither of these primates are monkeys because they lack tails.

Mostly likely, trekkers will glimpse endemic kingfishers. The Green-backed kingfisher (Actenoides monachus) sports a brilliant blue head and orange beak. They live only in north and central Sulawesi. Additionally, lucky visitors can see the Sulawesi dwarf kingfisher (Ceyx fallax), which is distinctly red and found only on Sulawesi.

Other Sulawesi endemic birds include the Grey-sided flowerpecker (Dicaeum celebicum) with its brilliant red breast or the Sulawesi scops owl (Otus manadensis). Watch for green parrots with red heads. These are endemic Sulawesi hanging parrots (Loriculus stigmatus). Other endemics include hornbills, woodpeckers, rails, goshawks, pigeons, other parrots.  

If you would like a jungle trek on a free day or after a short diving day, please let us know when you make dive reservations.

Cuvier’s beaked whales dive deep off Gorontalo

Posted on by • 0 Comments

Cuvier’s beaked whales often swim past locals fishing for Yellowfin tuna. Known for their diving ability, this medium-sized whale loves Gorontalo’s four-kilometer-deep waters.

A Pair of Cuvier’s Beaked Whales Caught on Video

Video of Cuvier’s beaked whales by Miguel’s Diving staff

Since Miguel’s Diving staff are all local fishermen, they will often take their small outrigger canoes into the deep ocean. There, they will handline Yellowfin tuna. One day, Boka noticed two Cuvier’s beaked whales swimming far offshore. He captured their passing using his cell phone. Local fishermen in Gorontalo are familiar with many cetacean species, including this one. The very small dorsal fin is one clue. Another is their brownish coloration.

These whales usually swim in small pods of two to seven individuals. However, males can be solitary. As seen in the video, the body and head emerge from the water while swimming. However, they do little breaching. Before taking a deep dive to feed, they will arch their backs.  

A Living Fossil Gets a Name

French naturalist Georges Cuvier was analyzing a skull fragment for his research. He mistakenly concluded that it was a fossil from an extinct species. That was in 1823. However, several decades after his death, other researchers discovered the skull belonged to a living whale. Moreover, it lives worldwide in temperate, tropical, and subtropical oceans. That is where the Cuvier’s beaked whale gets its name. Its scientific name is Ziphius cavirostris.

Cuvier’s beaked whales
Sketch of Cuvier’s Beaked Whale by NOAA Fisheries

The body color of this whale varies from dark gray to rusty brown. Individual whales can have very different appearances. As the whale ages, its head grows whiter. This is more pronounced in males. Moreover, adult males possess two large, cylindrical teeth. These protrude from the lower jaw. As observable in the video, these whales keep their distance from boats and humans. For anyone lucky enough to see a Cuvier’s beaked whale close up, most noticeable will be the smiling appearance of its jaw. Also, many scars will be visible. Bites from cookie-cutter sharks, lampreys, and deep-squid are the cause of this scarring.

Deep Dive Record Holders

Cuvier’s beaked whales are famous deep divers. For that reason, they normally inhabit waters deeper than one kilometer. The ocean depths of Tomini Bay along Gorontalo’s southern coastline plunge more than four times that depth. These whales dive deep for squid. They will also eat fish and crustaceans. Hunting at such extreme depths requires the use of echolocation to find squid to eat.

The Cuvier’s beaked whale is the deepest diving mammal in the world. Its deepest recorded depth for diving is around three kilometers. In order to dive that deeply, this whale must have incredible breath-holding ability.

In fact, in a 2020 study from Duke University USA analyzed around 3,700 deep dives by Cuvier’s beaked whales. The research team placed satellite tags on 23 whales. The study lasted five years. The median time spent diving for food lasted about one hour. After that, the whale surfaced to breathe. However, one male shattered old records with two extreme dives. One dive lasted almost three hours. His longest dive lasted three hours and forty-two minutes. 

Cuvier’s beaked whales can live up to sixty years. An adult whale measures between five and seven meters in length.

For your chance to watch passing cetaceans from our dive boat, please make your dive reservations with us.

Zosterops chloris nests at Miguel’s Diving dive center

Posted on by • 0 Comments

Zosterops chloris is a small lemon colored bird with a beautiful ring of tiny white feathers around its eyes. Commonly called Lemon-bellied white-eye, it is endemic to Indonesia. Here its name is burung katamata laut.

Regular Nesters in Miguel’s Diving Green Zone

Lemon-bellied white-eye
Lemon-bellied white-eye, an endemic

At our dive center, we seek to maintain green zones, even though our property is small. In front we maintain a grassy area edged in flowers. In the back are clusters of bamboo and trees. These are commonly used as green fencing locally. Also, we have climbing, flowering vines.

With branches towering far above the ground, a pair of Zosterops chloris have built their nest for several years in a row. After raising their young, all the birds leave until next nesting time. As of this blog posting, they are nesting again and sing twice a day.

Rescuing Fallen Juvenile Birds

Zosterops chloris juveniles
Rescued juvenile White-eyes

One year when the juvenile birds were learning to fly, both fell to the ground. Fortunately, our dive staff were working on the speed boats that day. Boka, a dive master, noticed a large rat quietly approaching the helpless birds. He quickly scared the rat away and picked up the baby birds. Then, he placed each one on a low branch.

The parent birds quickly flew down. They made much chirping sounds to encourage their babies to try to fly up the tree in a series of short flights. One baby made a return to the nest high in the tree. Its sibling was too afraid to try. So, one parent bird perched next to it and they both slept there through the night.

Naturally, our dive staff stayed away from the baby and parent. We only checked on them occasionally during the night. However, by dawn both were gone. In the following days, we saw all four birds. After that incident, the adults seem to know Boca and start chirping if he is working at the dock.

Zosterops chloris, Exclusive to Indonesia

Zosterops chloris is found from the Sunda Strait west to the Aru Islands. However, it is said to be missing from the Indonesian archipelago’s large islands of Borneo, Java, Sumatra, and Timor. Based on small color variations, research in 2017 states that there are five sub-species. We are not sure which one of those nests on our property. The geographic complexity of Indonesia has created genetically isolated populations.

This small bird measures about 11 centimeters. It has a lovely, high-pitched song. Dive staff hear the nesting pair sing in the early morning. Also, they sing in the late afternoon. Recordings of their song are available at this link.

For your chance to see one of these delightful birds while waiting to board one of our speed boats, please make your dive reservations with us.

Healthy Coral Growth Evident in Gorontalo’s Reefs

Posted on by • 0 Comments

Healthy coral growth is a notable characteristic of Gorontalo’s pristine reefs. Hard corals, known as scleractinians, dominate the marine environment here. Situated in the center of the Indo-Pacific’s Coral Triangle, Gorontalo displays highly diverse and dense corals.  

Diverse Acropora coral colonies

One genus of Gorontalo’s hard corals is Acropora. Acropora coral colonies can form tables or branches, depending on the species. In fact, there are over 140 species of Acropora.

healthy coral with polyps
Acropora with coral polyp tentacles protruding

Scleractinian corals are actually animals that live in a surrounding calcium structure. The animal is a a coral polyp. It is shaped like a tube with a single opening at one end. Tentacles usually ring this opening and function to gather plankton for food. Waste is expelled through the same opening. These tentacles can protrude or retract from the surrounding structure. Moreover, these tentacles gather passing plankton to eat. The embedded end of a coral polyp is connected to the entire coral colony via shared tissue and a nerve net. Moreover, all Acropora species are colonial.

Most Acropora species share a common distinction. The individual coral polyp is encased in a small tube that projects from the common substructure. This is true whether the Acropora forms a flat table or forms branches. Upon close inspection, divers can observe this distinction. However, determining the species of an Acropora colony requires microscopic analysis of its calcium skeleton.

Ringed in White

For the most part, the coloration of Acropora colonies comes from algae living inside the tissue of coal polyps. These algae are symbiotic. By process of photosynthesis, they convert sunlight into energy. This energy is more than the algae needs, so the surplus is passed to the coral polyp host. Scientists suspect that algae provides up to 98% of the nutrients health coral colonies need to survive.

Most divers know that rising ocean temperatures can cause the algae to vacate its coral host. If the algae does not return, within a matter of weeks the coral starves to death.

healthy coral
Acropora table corals with healthy white edges

Some divers are shocked to see Acropora colonies in Gorontalo ringed in white. They conclude that the coral is experiencing dangerous bleaching. However, this white edging is actually indicates rapid coral growth. In fact, the colony edges represent new coral growth. Algae has not yet had time to assimilate into the new coral polyps on the edge of the healthy coral colony.

Healthy Coral Environmental Conditions

Gorontalo Province is free from chemical producing factories. This means water contamination is very low. Also, frequent wave action creates high amounts of oxygenation. Located just north of the equator, Gorontalo enjoys an abundance of sunlight. All these elements are necessary for healthy coral growth.

Gorontalo’s health coral reefs are waiting for you to enjoy. So, please make your dive reservations directly with Miguel’s Diving.

Reticulated puffers delight divers in Gorontalo

Posted on by • 0 Comments

Reticulated puffer is a clumsy, clownish swimmer that delights divers who chance to see it. This puffer lives throughout the Indo-Pacific tropics, including Gorontalo.

A Distinctive Network of Lines

reticulated puffer
Arothron reticularis in Gorontalo

The scientific name for this fish is Arothron reticularis, which is a fitting name. Reticulated means arranged like a net or marked like a network. Only the Reticulated puffer has the network of white lines around its face and belly. It sports white spots on its body. But so too does Arothron hispidus, another puffer species that lacks the network of lines. The body color for Arothron reticularis range from brown to grey.  

Puffer fish have quite distinctive bodies. This includes tough skin and a dental plate in their beak-like mouth. What they lack is more notable. They lack fin spines and ribs. As a result, they can inflate their stomachs with water when afraid. Moreover, their skin, gonads, and liver contain two toxins. These are tetrodotoxin and saxitoxin. Some species are more toxic than others. Because different puffer species have similar body shapes, identification is most accurate when using color patterns.

So, the reticulated pattern makes the Reticulated puffer easy to identify.

Facing a Reticulated Puffer

Typically, puffer fishes are occasional in the marine environment. However, Miguel’s Diving staff know of one dive site in Gorontalo where Reticulated puffers are likely to be seen. Moreover, this species of puffer fish also exhibits the ability to recognize humans. Certain puffers at that dive site swim right to our dive masters.  

reticulated puffer smiles
A Reticulated puffer smiles for the camera

The face of a Reticulated puffer makes a delightful photo. Besides showing the distinctive reticulated pattern, the eyes are especially beautiful. Encircled with white rings, the eyes have brown irises and dark pupils. The eyes have great range of motion. This puffer fish smiles for the camera with its four teeth plates. These continually grow. The fish will keep them worn down by eating shrimps and crustaceans. On the snout and between the eyes are twin, forked tuffs. These are actually olfactory organs that allow the fish to smell its watery environment.

Divers will notice that the body of this fish is often sprinkled with sand. During the day, puffer fish often hide in sandy bottoms. They use their pectoral fins to throw sand onto their backs. Their maximum length is 45 centimeters.

Proper Behavior for Divers

Divers should never catch or grab puffer fish to make them inflate. This action frightens the fish, causing stress. Like many puffer species, the Reticulated puffer is covered with defensive spines. These short prickles are only visible when the fish is puffed up in a defensive posture.

Although our Reticulated puffers know some of our dive staff, they do not like to be pursued with cameras. Instead, for guests who want a souvenir photo of this cute fish, we recommend approaching patiently. If the fish starts to swim away, leave it alone. Given time, it will return. A photographer’s random behavior that ignores direct pursuit of the fish will calm it down, allowing a closer approach for a photograph.  

For your chance to see this delightful puffer fish in Gorontalo, please make your dive reservations directly with Miguel’s Diving.  

Bornella anguilla Spotted in Gorontalo

Posted on by • 0 Comments

Bornella anguilla is an unusual nudibranch that sports a mosaic pattern on it skin. Numerous branches grow from its body. Its colors include brown, orange, and tan.

A Rare Find

Bornella anguilla eating
Bornella anguilla ready to eat hydroids

At the end of a dive at Gorontalo’s Otje Garden dive site, a dive master showed guests a most unusual nudibranch. It was busy munching on hydroids, its mouth parts clearly open. Eager underwater photographers took their chance to take shots. Miguel’s Diving staff confess they see this nudibranch less than once a year.

Bornella anguilla, the Eel Bornella nudibranch  

In 1984, this unusual nudibranch received its official name when Johnson submitted his research. Its scientific name reflects its distinct ability to swim like an eel. Anguilla means eel in Latin. Other Bornella species of nudibranch can swim as well. However, they flex their bodies from side to side to generate motion. In this way, they swim sideways. Bornella anguilla creates a muscular wave that moves down its body. In this way, it swims head first in an eel-like manner. While swimming, its rhinophores and cerata lay down for better streamlining.

Bornella anguilla is found throughout the Indo-West Pacific region. However, divers have also seen it in the Indian Ocean. It can grow up to eight centimeters in length. That means it can be rather large for a nudibranch.

Unusual Body Structure

This species of nudibranch has an unusual body structure.

Below the twin rhinophores on its head are its eyes. Although the eyes of most nudibranchs are hard to see, those of this nudibranch are distinct. They look blue or black, depending on the angle. Can you spot the eye in the close-up photo? Rhinophores are sensory organs that detect chemical scents in the water. The eyes measure light and darkness.

Most remarkable are the numerous branches growing from the body. These are called cerata. A pair of them grow around the brown rhinophores. This helps protect the sense organs from predators that can nibble a replaceable cerata instead.

Bornella anguilla close up
Close-Up of Bornella anguilla

Another unusual feature of this nudibranch are its gills. Most nudibranchs sport a cluster of gills near its dorsal rear and look like a small tree. On this nudibranch, the gills are distributed along the dorsal side of the body and protrude from the various branches that grow there. They look like mostly transparent feathers that poke from a cerata. These are visible in the close-up photo.

To dive in Gorontalo with dive masters skilled at spotting unusual marine life, please make your dive reservations with Miguel’s Diving.

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