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We have been seeing loads of Blue Ring Octopus recently in Lembeh so we thought we would tell you a bit about them!

Ecology
There are possibly 10 different species of blue-ringed octopus but only 4 have been formally names and all are inhabitants of asian-pacific waters:

• Greater Blue-ringed Octopus (Hapalochlaena lunulata)
• Lesser Blue-ringed Octopus or Southern Blue-ringed Octopus (Hapalochlaena maculosa)
• Blue-lined Octopus (Hapalochlaena fasciata)
• Hapalochlaena nierstraszi

They are one of the jewels of the ocean, with vivid blue rings visible over the body when hunting, courting or alarmed. The are only 12 to 20 cm (5 to 8 inches) long but are considered as one of the world’s most venomous marine animals. When the octopus is agitated, the brown patches darken dramatically, and iridescent blue rings or clumps of rings appear and pulsate within the maculae. Typically 50-60 blue rings cover the dorsal and lateral surfaces of the mantle. They hunt small crabs, hermit crabs, and shrimp, and may bite attackers, including humans, if provoked.

Behaviour
The blue-ringed octopus spends much of its life hiding in crevices. Like all octopuses, it can change its shape easily, which helps it to squeeze into crevices much smaller than itself. This helps safeguard the octopus from predators and it may even pile up rocks outside the entrance to its lair. In common with other octopuses, the blue-ringed octopus swims by expelling water from its hyponome (funnel) in a form of jet propulsion. If the blue-ringed octopus loses an arm, it can regenerate it within six weeks.

Life-cycle
Blue-ringed octopus females lay only one clutch of about 50-100 eggs in their lifetime. The eggs are laid then incubated underneath the female’s arms for approximately six months, and during this process she will not eat.

After the eggs hatch, the female dies, and the young larval octopuses will then feed off of copepods, larval crabs and larval starfish until they are ready to move deeper into the ocean then reaching maturity and will be able to mate by the next year.
Once the larval octopuses grow to be one to two years old they produce eggs and continue the cycle. Like most octopuses, they have a lifespan of approximately 1-2 years

Venom
Despite this small size and relatively docile nature, its venom is powerful enough to kill humans. The venom is a neurotoxin called tetrodotoxin, it is also found in pufferfish and is 10,000 times more toxic than cyanide. The toxin is injected using the octopus’ beak and causes motor paralysis and respiratory arrest within minutes, leading to cardiac arrest due to a lack of oxygen.

It carries enough venom to kill 26 adult humans within minutes. Their bites are tiny and often painless, with many victims not realizing they have been envenomated until respiratory depression and paralysis start to set in.

Symptoms
Respiratory arrest can occur within minutes as the toxin blocks nerve transmission. Other symptoms include vomiting, muscle weakness and paralysis of respiratory muscles. Victims are fully awake until lack of oxygen, from the inability to breathe, leads to unconsciousness.

Treatment
Tetrodotoxin causes severe and often total body paralysis; the victim remains conscious and alert, but this effect is temporary and will fade over a period of hours as the tetrodotoxin is metabolized and excreted by the body.

There is currently no anti-venom available, and victims are frequently saved if artificial respiration is started and maintained before marked cyanosis and hypotension develop. First aid treatment is therefore pressure on the wound and artificial respiration once the paralysis has disabled the victim’s respiratory muscles. Victims who live through the first 24 hours generally go on to make a complete recovery.

It is essential that rescue breathing be continued without pause until the paralysis subsides and the victim regains the ability to breathe on their own. This is a daunting physical prospect for a single individual, but use of a bag valve mask respirator reduces fatigue to sustainable levels until help can arrive.

Definitive hospital treatment involves placing the patient on a medical ventilator until the toxin is neutralized by the body.

It is essential that efforts continue even if the victim appears not to be responding. Tetrodotoxin poisoning can result in the victim being fully aware of their surroundings but unable to breathe. Because of the paralysis that occurs they have no way of signaling for help or any way of indicating distress. Respiratory support, together with reassurance, until medical assistance arrives ensures that the victim will generally recover well.

Avoidance
It may come as a surprise to divers but blue-ringed octopuses are common in very shallow water. As a result, children are probably most at risk as they are attracted to the vivid blue rings displayed by the octopus when threatened: the octopus is small and so is often picked up by inquisitive children. For divers, as always, great care should be taken when touching the reef as, when not threatened, the octopus’ camouflage can be very effective. They are not aggressive and their first form of defence is to flee.

The mandarin fish is one of the most beautiful fish in the ocean and their special mating display can be seen right here in both Bunaken and Lembeh waters!

• Scientific Name: Synchiropus Splendidus
• Found: Indo-Pacific Ocean (Philippines, Indonesia, Malaysia, Australia)
• Size: 1 -2 Inches
• Diet: Carnivore – feed on small worms, protozoans and small crustaceans
• Habitat: Broken coral rubble beds or under dead coral
• Depth: 1 – 18 metres

Features
• The name comes from its fantastic colouration which resembles the robes of an imperial Chinese officer (Mandarin)
• They live in pairs and groups of up to 5
• Males have more orange colouration in their face and are larger in size with an elongated first dorsal spine. Females have smaller dorsal fins.
• Mandarin fish are distinctive due to their unusual shape and broad, depressed head
• One of its most remarkable features is their big outward-set eyes. This is an ideal adaptation for food hunting and feeding in the dim light environments underwater
• They swim with a rapid pulsating of their fins which tends to make them look like they are hovering, like a humming bird
• The mandarin fish is one of the few marine fish which does not have scales. As a protective compensation it is protected by a mucous-coated slimy and smelly skin, which not only protects them from most parasitic skin diseases, but also discourages predators due to its horrible taste. Their bright vivid coloration also serves to give out warning to predators of their nasty smell and taste.
• There is little information on specific predators of this species, although scorpionfish are known to lie in wait to attack an unsuspecting mandarin fish, normally during the mating ritual.

Reproduction
The mating of mandarin fish by spawning is something you HAVE to witness before leaving Bunaken!! Just before the sun sets, 3 to 5 females will make their way to a particular region of reef (“street corner”!) and gather where males visit and display courtship behaviour, hoping to attract the females. The visiting males may tour around various sites in one evening spreading their sperm among a number of different females!

A successful male will be joined by a female that will rest on his pelvic fin. The male and female mandarin fish align themselves belly-to-belly and together, slowly rise about 1 metre above the reef. Once they are at the peak of their ascent, they will release sperm and a cloud of eggs (usually up to 200 eggs). The fish then disappear in a flash. The fertilized eggs are from that point at the mercy of the current and normally take around 18-24 hours to hatch into 1 mm long larvae. For a period of up to 2 weeks they will remain plankton with no parental involvement before finally settling on the reef and choosing an appropriate habitat where they will live for the next 10 to 15 years.

With only a small number of active females in a group’s population, competition among the males is high. In the world of mandarin fish, size does matter! The bigger and stronger males tend to be favoured by females and mate more often than smaller males. Due to the lower chances of mating, the smaller males have developed a rather desperate compensating measure where they rush up to mating pairs and release sperm with the hope of random fertilization!

This is a ritual you can witness most nights here in Bunaken & Lembeh, and is a must for any diving enthusiast – ask your guide for more information!
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We are seeing alot of Robust ghost pipefish in Lembeh at the moment so we thought that we would tell you what they are.

Family Solenostomidae
Ghost pipefish belong to the family Solenostomidae. They are closely related to Seahorses and Pipefish, are from the same order and share the long tube like snout. They live in tropical, subtropical and warm temperate waters from Indian to Western Pacific oceans.

Spending most of its time in a head down position, they tend to make their homes in shallow areas or close to coastal reefs that are current swept and therefore have a steady stream of food. In many regions Ghostpipefish are only seasonal visitors, settling on the reef for only a few months each year to breed.

They are usually seen in pairs. Female Ghostpipefish have much larger ventral fins, as they double in purpose for storing eggs. Male Ghostpipefish are generally smaller than the females.

Usually they are seen hovering next to their matching host, perfectly camouflaged. These hosts depend on the type of Ghostpipefish and include gorgonians, corals, crinoids, hydroids, algae substrata and seagrass beds. 

Feeding - They often hang upside down while feeding. They feed mainly on crustaceans and small fish, the unassuming prey is sucked up at the last minute through the specially adapted snout. 

Reproduction - It is the female Ghost Pipefish who incubates the eggs in a pouch created by hooking together their ventral fins. In both Seahorses and Pipefish, which are closely related, it is the male who performs this role. After incubation, the eggs are released into the water column and are planktonic, travelling with the currents until they find a suitable reef to inhabit.

Robust Ghostpipefish (Solenostomus cyanopterus)
Simulating rotting sea grass, Robust Ghostpipefish is a rare find due to being hard to spot.

Often seen floating upside down on a sand or rubble bottom mimicking sea grass or weeds. They are usually brown, green or dark red, with darker spots and markings.

Unlike the other types of Ghostpipefish, Robust Ghostpipefish are fairly mobile and revisiting them is not usually possible.

This is the largest type of Ghostpipe, growing to approx 15cm in size.

Ornate or Harlequin Ghostpipefish (Solenostomus paradoxus)
These are easily identified and the most elaborate type of Ghostpipefish, and are much photographed. They are found near overhangs and crevices, mimicking crinoids or soft corals. They can sometimes be spotted hanging in the current to feed. They come in a wide variety of colours including, black, white, red, yellow, brown and green.

The fins of the Ornate Ghostpipefish are well developed, large and, as the name suggests, ornately decorated.

If undisturbed they will remain in the same host fauna for many weeks.

Halimeda Ghostpipefish (Solenostomus halimeda)
This type of Ghostpipefish looks exactly like the green algae Halimeda, and it is amongst this algae where is normally found. It is green or green with white patches, just like those seen on the host algae.

There are sometimes short filaments on the snout, body and fins that look like the filaments that are also sometimes found on the Halimeda algae. All in all, this species is an outstanding mimic of its botanical namesake!

Rough or Hairy or Filamented Ghostpipefish (Solenostomus paegnius)
The colour can vary from green to reddish brown, and it is covered with many small skin filaments, giving it a hairy look.

It is often found in bay or lagoon, in sandy environments close to algae or hydrozoans.

We think thats all the types of Ghostpipefish, have you got another type? Which one is your favourite?

Coelecanth is a Devonian lobed fin fish that thrived in the oceans 450-500 million years ago. Its importance lies in the fact that it is considered the “missing link” between fish and animals, ie they were the ones that crawled from the waters to create life on land. It is also an inhabitant of Bunaken Marine Park, and probably one of the most unusual inhabitants at that!

DISCOVERY
It was thought that the Coelcanth disappeared along with the dinosaurs over 73 million years ago. Then one of the biggest scientific discoveries of the 20th century happened when Marjorie Latimer, who worked at the local museum in East London, South Africa found a Coelcanth on a local fishing boat. Later more were discovered in the Comoros Islands in the Indian Ocean, and they have since been have been found in the waters of Kenya, Tanzania, Mozambique, South Africa, and Madagascar.

DISCOVERED IN BUNAKEN!
The Coelecanth is nicknamed the “living fossil”, and in 1997 it was discovered in a local fish-market in Manado, and later in 2009 it was videoed by a japanese team of divers around Manado Tua in the Buaken Marine Park.

During the daytime, the Coelecanth rest in caves anywhere from 100–500 meters deep while others migrate to deeper waters. With steep underwater, eroded volcanic slopes covered in sand that also house an obscure system of caves and crevices, the topography of the Bunaken Marine Park is therefore an ideal habitat for the Coelecanth.

SIZE & SHAPE
The word coelacanth literally means, “hollow spine,” because of its unique hollow spine fins. Coelacanths are large, plump, lobe-finned fish that grow up to 1.8 meters. They are nocturnal drift-hunters. The body is covered in cosmoid scales that act as armor. Coelacanths have 8 fins – 2 dorsal fins, 2 pectoral fins, 2 pelvic fins, 1 anal fin and 1 caudal fin.

Locomotion of the coelacanths is unique to their kind. To move around, coelacanths most commonly take advantage of up or downwellings of the current and drift. They use their paired fins to stabilize their movement through the water. While on the bottom of the ocean floor their paired fins are not used for any kind of movement. Coelacanths can create thrust for quick starts by using their caudal fins. Due to the high number of fins, the coelacanth has high maneuverability. Coelacanths can also orient their bodies in any direction in the water. They have been seen doing headstands and swimming belly up. It is thought that their rostral organ helps give the coelacanth electroperception, which aides in their movement around obstacles.

HOW THEY ARE CAUGHT
Coelacanths are usually caught when local fishermen are fishing for oilfish and sharks. Fishermen will sometimes snag a coelacanth instead of an oilfish because they usually fish at nighttime when the oilfish (and coelacanths) are feeding. The coelacanth has no real commercial value, and as a food it is almost worthless as its tissues exude oils that give the flesh a foul flavour. Before scientists became interested in coelacanths, they were therefore usually just thrown back into the water if caught. Now that there is an interest in them, fishermen trade them in to scientists or other officials once they have been caught.

LIVING FOSSIL EXPEDITIONS
Scuba Diving (open circuit and closed circuit) expeditions for the Coelacanth have been successful in South Africa where Coelacanths were identified off the continental shelf near Sodwana Bay at depths between 90-110m. These depths are with the limits of experienced technical divers either on open or closed circuit scuba. Rebreather diving would be optimal regarding gasses and bottom times.

Two Fish Divers are also offering similar expedition dives for Coelacanths in Bunaken Marine Park via our TEC diving services headed by Brendon. No one else has ever offered this kind of diving opportunity in this area that have the facilities, equipment and experience to pull it off… Until now!

In Bunaken Island, North Sulawesi the Whitetip reef shark is one of our regular encounters.

Despite having a face that looks strangely like that of a disgruntled weasel, the Whitetip Reef Shark (Triaenodon obesus) is generally unaggressive toward humans who invade its environment. Although it often rests in caves during daylight hours, this species is probably the most commonly-encountered shark of the tropical Pacific. Indeed, for many divers and snorkellers, the phlegmatic Reef Whitetip is their only ambassador to sharkdom.

Despite its formal species name, obesus, the Whitetip Reef Shark is rather slender and delicately built. This body form grants it the ability to slither, eel-like into crevices in the reef, where this species is an absolute master at extracting prey. Quiescent during the day, Whitetip Reef Sharks become active and determined hunters at night. Moving over the reef face in loosely organized packs, these sharks systematically poke their blunt heads into each crack and crevice in the reef face in search of prey. Known prey of the Whitetip Reef Shark includes sleeping diurnal teleosts or hiding nocturnal creatures such as octopuses, soldierfishes, wrasses, and trumpetfishes, which are grasped with its small, tricuspid teeth. Using its ampullae of Lorenzini and uniquely tube-flapped nares, the Whitetip Reef detects its prey primarily by bioelectrical cues and scent. When a hunting Whitetip Reef locates a prey animal within a hole in the reef face, it violently twists and turns to push itself deep into the crevice. Some sharks actually squirm into a hole in one side of a coral head and exit through an opening on the other. During these zealous foraging bouts, Whitetip Reef Sharks have been observed breaking off pieces of coral — sometimes tearing their skin and fins. Although they are primarily nocturnal, Whitetip Reef Sharks can and do feed opportunistically by day.

In addition to electrical and olfactory cues, the Whitetip Reef Shark is also highly responsive to sounds and vibrations. In experiments conducted at the Marshall Islands and French Polynesia, Whitetip Reefs consistently responded to recorded sounds of struggling fish, feeding sharks, and even vocalizations of teleosts. At Eniwetok Atoll, Marshall Islands, artificially generated sounds were found to be most attractive to Whitetip Reef Sharks when they combined low frequency (25-100 Hertz) with varied intermittent pulses every 7.5 to 15 seconds. These sound characteristics correspond well to the irregular sounds and vibrations generated by a fish struggling on the end of a spear or on hook and line. In South Pacific areas where spearfishing is common, Whitetip Reef Sharks respond very rapidly to the sound of a speargun discharge, typically appearing within seconds. Although normally quite placid, this inquisitive species can become persistent and bold when faced with a diver playing or carrying a speared fish — sometimes dashing in to tear an impaled fish from the spear tip.

Due to the abundance of Whitetip Reef Sharks in coastal areas of the tropical Pacific and Indian Oceans, day-to-day life of this species is better known than that of most sharks. Whitetip Reefs are most often encountered during daylight hours while they rest quietly in underwater caves throughout much of the tropical Indo-Pacific or in lava tubes of Hawaiian reefs. But in some locations — such as at Cocos Island and near-shore waters off the Pacific coast of Costa Rica — this species is often seen lying stretched out on the sandy bottom, completely exposed in broad daylight. Sometimes, several of these gregarious sharks are seen lying side-by-side or even stacked on top of one another, like cord-wood. The significance of these diurnal al fresco gatherings is not known, but may have something to do with these sharks being cleaned by small wrasses and at least one species of goby.

The Reef Whitetip is one of the three most common sharks on Indo-Pacific coral reefs, the other two being the Blackfin Reef Shark (Carcharhinus melanopterus) and the Grey Reef Shark (Carcharhinus amblyrhynchos). Although these three sharks are widely distributed over the vast expanse of the tropical Pacific and Indian Oceans, their relative distribution over the reef profile is remarkably uniform from place to place. Blackfin Reef Sharks, especially juveniles, are typically found closest to shore, inhabiting the turbid lagoon shallows over sandy plains at depth from 0 to 50 feet (0 to 15 metres). Juvenile Grey Reef Sharks are found in the clearer, deeper waters of the back reef, while adults of this species typically patrol the reef crest and fore reef from the depth of about 65 feet (20 metres) down to a depth of about 330 feet (100 metres). Both species are most active at dawn and dusk, accomplishing most of their feeding during these twilight hours when schooling diurnal fishes are most vulnerable.

Neatly nestled between the crepuscular Blackfin Reef and Grey Reef sharks, Whitetip Reefs typically haunt the reef flats and shallower parts of the fore-reef at depths of 35 to 100 feet (10 to 30 metres). Although it can extend its range from the intertidal to at least 130 feet (40 metres), the Whitetip Reef manages to coexist with the Blackfin Reef and Grey Reef Shark by feeding primarily at night and specializing in extracting prey from cracks and crevices in the reef face that are all but inaccessible to these other sharks. By inhabiting different depths and ecological niches, the slender, weasel-faced Whitetip Reef Shark reduces competition for food resources with other sharks sharing its habitat.

SHARK FACTS

Size:
Birth: 20-24 in (52-60 cm)
Maturity:males 40-41in (104-105cm), females 41-43in (105-109 cm)
Maximum: 5.6 ft (1.7 m)

Reproduction:
Maturity: unknown; at least 5 years in both sexes
Mode: viviparous, with a yolk-sac placenta
Gestation: 13 months
Pups: 1-5 (usually 2-3), probably every two years

Diet:
Juvenile: small teleost fishes, crabs, octopuses
Adult: teleost fishes, crabs, octopuses
Habitat: Sandy Plains, Rocky Reefs, Coral Reefs, Deep Sea

Depth: 3-1080 ft (1-330 m), often at 26-130 ft (8-40 m)

Distribution: Central Pacific, South Pacific, Tropical Eastern Pacific, Southern African, Madagascaran, Arabian, Indian, South East Asian, Western Australian, Northern Australian, Japanese