Sponge spawning of a Salvador Dali sponge gave divers a glimpse of a rarely witnessed event. Occasionally, Miguel’s Diving staff witness a large sponge releasing sperm into the current. This video records the only time we have witnessed spawning of a Salvador Dali sponge.

Salvador Dali Sponge Spawning

Most sponges are hermaphrodites, having both male and female reproduction capacity. Other sponges, like Barrel sponges, reproduce by spawning. Males release clouds of sperm into the current. Since the sperm is buoyant, the event looks like the sponge is smoking.

A female sponge will release eggs into the current. However, eggs are negatively buoyant, so the eggs sink to the ocean bottom. Some eggs may remain inside the ex-current opening of large vase and barrel sponges. When a female sponge releases her eggs, the nearby area of ocean bottom will look as if snow has fallen there. Miguel’s Diving staff have never seen a female sponge releasing eggs.

In the video of a Salvador Dali sponge spawning, notice the clouds of sperm into the current. This indicates that the sponge is male. No one knows how often a particular sponge will spawn. Miguel’s Diving staff have witnessed simultaneous sponge spawning among numerous sponges over a certain area of reef.

Gorontalo’s Surreal Sponge

When Miguel’s Diving first opened diving in Gorontalo, we discovered a strange and giant sponge. No one had seen this morphology before, although they were quite common on Gorontalo’s deep walls.

The surreal surfaces of this sponge reminded us of the Spanish painter Salvador Dali. So, we began calling it the Salvador Dali sponge.  

A Local Morphology of Petrosia lignosa

In order to discover the identity of this unusual sponge, we sent two samples to Nicole J. de Voogd. She was studying sponges at the Institute for Biodiversity and Ecosystem Dynamics, Zoological Museum, University of Amsterdam. The interior bodies of sponges are composed of mazes of microscopic spicules. Each sponge species has a unique pattern. After looking at the two samples we sent under a microscope, Nicole could identify our Salvador Dali sponge. It is Petrosia lignosa.

The genus name Petrosia actually means “stony hard.” When compared with other sponges, all Petrosid sponges are hard and rock-like. So far, Petrosia lignosa is known only from vertical walls in eastern Indonesia. It was first described in 1925 from the Togian Islands, south of Gorontalo. However, in other locations this sponge lacks the distinctive swirls found on our Salvador Dali sponges.

No one knows why this sponge looks so different here in Gorontalo. According to Nicole, the “Salvador Dali sponge” would be a locally unique morphology of Petrosia lignosa. 

Although divers cannot expect to witness sponge spawning, Salvador Dali sponges are common in Gorontalo. For your chance to see some for yourself, please make your dive reservations and join us for some great diving.

Galaxy coral forms the largest hard coral colonies in Gorontalo. Massive mounds and columns of this spiky coral astound passing divers.

Stars of the Reef

A colony of Galaxy coral is made up of countless individual corallites. A single Galaxy corallite measures between three and four millimeters. A corallite is composed of a circular polyp, which is living. Surrounding the polyp are ridges that radiate from its center. These radiating ridges serve to protect the polyp from predators. These radiating ridges give each individual polyp the appearance of a star. A colony composed of countless stars gives rise to a galaxy of coral.

However, divers should be careful when approaching Galaxy coral. Those radiating ridges are extremely sharp and can easily cut one’s skin. Moreover, the scientific term for radiating ridges is septa.

Galaxea astreata

The most common Galaxy coral in Indo-Pacific waters is Galaxea astreata. Usually, its colonies are low and encrust the substrate. At other times, it forms upright columns. For Galaxea astreata, its septa count is eight to twelve. Usually, it does not fully extend its polyps during the day. This helps protect it from daytime predators. In the closeup shot from Gorontalo, note the white-tipped polyps in this daytime photo.

Galaxy coral in Gorontalo

The large and notable Galaxy colonies of Gorontalo are most likely Galaxea astreata. In total, there are ten species of Galaxy corals. Possibly, Galaxea fasicularis is the coral found at dive sites here because it forms the largest known colonies. In Gorontalo, Galaxy corals form colonies larger than a city bus. This colony size is far larger than any described in scientific literature. In the wide angle shot from Gorontalo, note that the corals far in the background are still part of this massive colony of Galaxy coral.    

Two factors contribute to the giant size of Galaxy colonies in Gorontalo. The marine environment here is extremely healthy. Also, Galaxy corals possess special sweeper tentacles. These are a defensive organ tipped with powerful stings. Those stings keep other corals from living close by. That makes room for the colony to expand.

Galaxy corals not only feed on plankton caught with the polyp’s tentacles. Inside its body live zooxanthella. These convert sunlight into food. Notably, Gorontalo lies slightly north of the equator, so sunlight is abundant.

For your chance to marvel at the Galaxy coral found in Gorontalo, please book your dive trip with us.

White ribbon eel glides across the sandy bottom in shallow water. It undulates in effortless motions.

An Unexpected Sighting

During daylight hours, white ribbon eels usually stay hidden in their sandy dens. They live in shallow lagoons, preferring areas with white sand. At night, they emerge in search of food. They prefer to eat small crustaceans and molluscs. Sometimes, they will eat nudibranchs.

At other times, they will move from one den to another. This means they will swim across the sandy bottom. One day, Miguel’s Diving staff observed a White ribbon eel doing just that. However, this one did not move quickly from one hole to another. It spent fifteen minutes swimming across the bottom. Occasionally, it stuck its head into goby holes. Perhaps it was searching for a shrimp to eat.

Once, it swam underneath some cloth lost by a fisherman. The cloth was half buried in the sand. Soon, the White ribbon eel emerged from the other side. After crossing back and forth, it finally disappeared head first into a hole.   

Elegance in Motion

This ribbon eel has a pale body color. Its dorsal fin is continuous and edged in brilliant white. Its face is peppered with small spots. When swimming, its motion in indeed like a sensuous ribbon.

The Truly Unique White Ribbon Eel

White ribbon eels belong to its own genus of which it is the only species. That means its morphology is truly unique. As with other eels, it does not have scales. Instead, slime covers its body. This mucous coating allows it to enter and exist holes in sand and gravel without getting scratches. Also, the slime repels parasites.

The eyesight of this unique eel is not as good as its sense of smell. That sense is well developed. Moreover, it has not two nostrils but four. The first pair lie on the tip of its nose. The second pair are barely visible and lie level with its eyes. Its sense of smell leads the White ribbon eel to its prey. In fact, during the long interval with our dive staff, the ribbon eel totally ignored the diver and camera. Nothing good to eat there!

As with many eels, the branchial openings are small holes. They are found behind the head, one on each side.

The maximum length of this beautiful ribbon eel is about one meter. However, most measure between fifty and eighty centimeters in length.

Its Scientific Name

Pseudechidna brummeri is the official name of the White Ribbon eel. Its genus name consists of two Greek words. Pseudes means false and echidna means viper. This name is meant to describe the pointed feature of its long snout.

Pieter Bleeker was a Dutch doctor who lived in Indonesia for eighteen years. During that time, he collected over twelve thousand specimens of marine life. He published extensive studies in his two work classic Atlas Ichthyologique des Indes Orientales Néêrlandaises. One of the species he discovered and named was the White ribbon eel, Pseudechidna brummeri. The species name honors Lieutenant Medical Colonel Brummer. Brummer was a colleague, friend and fellow collector.

For your chance to dive with beautiful marine life, please make your dive reservations and perhaps you will sight a ribbon eel.

A pilot whale beached itself close to Olele Marine Park in Gorontalo on 3 January 2020.

Too Big to Help

A local fisherman named Iwan Adam discovered the large pilot whale on the beach near his house in Tolotio Village. The time was 0530 hours. According to Iwan, the cetacean was still breathing and alive when he found it. So, he called nine friends to discuss options for saving the whale. Unfortunately, the discovery coincided with low tide.  Also, the pilot whale weighed almost two tons. Dragging the whale over the rocks and coral proved impossible, given the conditions. Although they poured water on it to keep it cool, the whale died twenty minutes later and before the tide rose again.

Government officials arrived to assess the situation. According to their notes, the whale measured 482 centimetres long. Its girth was 220 centimetres. Moreover, it was male. In order to avoid contamination, the villagers buried the carcass.

Sightings of Pilot Whales in Gorontalo

Miguel’s Diving staff have observed pilot whales on other occasions. Although these cetaceans are famous for traveling in pods, we have only observed single pilot whales near diving areas. Pods of pilot whales occasionally pass Gorontalo fishermen, who are handlining yellowfin tuna farther from shore. The dorsal fin of a pilot whale tends to fold back a bit. Thus, with this observation, visual identification is possible.

The Short-Finned Pilot Whale

The unfortunate whale that beached itself was a Short-finned Pilot Whale. Globicephala macrorhynchus is its scientific name. Distinguishing features include a rounded, bulbous head. Its fins are set forward on its body and point sharply back. The mouth slants upward. Mostly, its color is uniformly black. Some individuals exhibit a diagonal stripe from eye to dorsal fin and a cape. Sometimes, a lighter belly patch is visible. The body is slender but robust. In death all color will be lost.

The Short-finned Pilot Whale is among a group of marine life called blackfish. These cetaceans are mostly jet black in color. The Long-finned Pilot Whale is not found in our area, as it prefers the cold waters of the northern and southern oceans. In Gorontalo, Miguel’s Diving staff have seen other blackfish species. This includes Pygmy Killer Whale, Melon-Headed Whale and False Killer Whale. Surprisingly, the most common blackfish we see are Killer Whales or Orca.

Behavioral Characteristics

Short-finned Pilot Whales usually travels in pods but rarely breaches. Feeding mostly at night, they love deep-sea squid. These whales have no fixed migration routes, but they often follow squid spawning. Also, they prefer the edges of continental shelves and deep underwater canyons. This perfectly describes the marine substrate along the southern shores of Gorontalo in Tomini Bay.

For your chance to see one of Gorontalo’s blackfish, please book your dive trip with us.