• Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

  • Photo by William Tan

  • Photo by Rantje Allen

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Yearly Archives: 2024

Funnelweed pass unnoticed

Funnelweed, though found worldwide, lives in limited locations in Gorontalo. Divers certainly pass by without noticing. But scientists are researching it.

Delicate scalloped algae

Although funnelweed is a member of the brown algae family, its color here in Gorontalo is not brown. It grows in some sandy patches or substrate among other algae. Its color is pale cream. Sometimes, it has tinges of light green.

funnelweed
Beautiful white funnelweed in Gorontalo

It grows in beautiful, radiating ribbons. Opaque bands alternate with more transparent ones. Often, this algae forms scallops that curve inwards. On the outer edges and surface sprout almost transparent filaments.

Divers, who take the time to notice funnelweed, quickly appreciate its unique beauty. However, they should not brush against it with unprotected skin. Something about these algae here leaves itchy stings.

Funnelweed around the World

 In Gorontalo, this beautiful plant only grows in a few small areas. A few sandy patches are full of these algae. In a couple of other sites, it grows among other algae.

However, it is found worldwide. This includes the Caribbean and Atlantic oceans, as well as the Indian and Pacific ones. The detailed list of locations is quite long. The scientific name for funnelweed is Padina gymnospora. Since it lives in so many oceans, scientist the world over are researching its potential value.

Scientific Research on Padina gymnospora

One group has extracted sulfated polysaccharides from it. Their research indicates anti-inflammatory properties. They used mice in their studies prior to potential use on humans.

Padina gymnospora
Padina gymnospora clings to a wall

Other researchers discovered anti-amyloidogenic agents in funnelweed. This extract in an important component in drugs that combat Alzheimer’s disease.

Field research on Padina gymnospora has found significant absorbent properties in the algae. A synthesized compound from it is over 80% effective in absorbing industrial dyes. Removing these dyes from industrial waste is a priority to build a cleaner world. Using this extract is clean and green solution in reusing industrial wastewater.

Padina gymnospora produces an aragonite calcium carbonate compound as well as phlorotannins. These are found on the algae surfaces. These compounds play an important role in defending the algae from worms and snails.

That chemical protection has no effect on Green turtles, which are herbivores. Padina gymnospora is actually edible. Naturally, it contains no heavy metals or toxins. Although no one really uses funnelweed for human food, it has potential for as a natural fertilizer.

In Gorontalo, only staff of Miguel’s Diving will know where to find these beautiful algae. To see for yourself, please make your dive reservations directly with us.

Duncanopsammia peltata forms pagodas in Gorontalo

Duncanopsammia peltata or pagoda coral form immense colonies in Gorontalo’s healthy waters.

Stunning Pagoda Coral Colonies

One of Gorontalo’s ancient and stunning coral formations is pagoda coral. Giant plates form spirals, hence the common name denoting pagodas. The colonies featured in this video measure over four meters across. The video is courtesy of @jhonheriano of Pertamina Dive Club.

Other colonies of this distinctive coral form single plates. Additional plates may take several centuries to form. In other coral reefs of the Indo-Pacific region, this coral forms pillars. That morphology has yet to appear in Gorontalo.

Descriptions of Duncanopsammia peltata

Duncanopsammia peltata
Corallites of Duncanopsammia peltata

The scientific name for pagoda coral is Duncanopsammia peltata. When we consulted coral experts, they asked for a detailed photograph of the polyps. These are distinctive in determining the species. Usually, corallites measure between three and five millimeters in diameters. However, those of the giant colony featured here measure almost one centimeter!

As with other corals, polyps are only found on the upper surfaces of the colony. They need sunlight and easy access to plankton brought by passing ocean currents. Sometimes, the corallites are embedded flush with the coral plate. However, other times they protrude above the plate like little bumps. Typically, the polyps are extended during daylight hours, ready to sunbathe and catch plankton. Their many arms can measure up to one centimeter in length.  

pagoda coral
Photo courtesy of @jhonheriano

Tiny single-cell organisms called zooxanthellae live inside Duncanopsammia peltata. They turn sunlight into food that they share with their host coral.

Colonies of Duncanopsammia peltata live in coral reefs throughout the Indo-Pacific region. They thrive just below the surface, down to a depth of about forty meters. The color is grey to light brown.

Ask us to show you Gorontalo’s pagoda corals when you make your dive reservations directly with Miguel’s Diving. 

Dendrodoris tuberculosa inhabits Gorontalo reefs

Dendrodoris tuberculosa rarely appears on Gorontalo’s coral rich dive sites, despite its very large size. After years of absence, in late 2023 divers saw three in the same week!

The Frilly Dendrodoris tuberculosa

Dendrodoris tuberculosa
The first Dendrodoris tuberculosa

Sometimes called the Tuberculate Dendrodoris nudibranch, it can grow to twenty centimeters in length. Colors range from brown to green to pink. Most distinctive about this giant nudibranch are its numerous tubercules. These almost entirely cover its upper body. Among the masses of tubercules, two rhinophores emerge. Perhaps because of its large size, it crawls quite fast. Despite its size, divers can easily miss seeing it.

Three in One Week

The first of three we spotted recently looked like a scrap of old carpet flowing over the substrate. It easily blended in and quickly disappeared under some coral. This sighting was at a depth of two meters. Its length was twenty centimeters.

The second Tuberculate Dendrodoris

The second Dendrodoris tuberculosa sighted was at twelve meters. It was crawling on top of plate coral that projected from one of Gorontalo’s spectacular walls. Its pinkish color contrasted nicely with the coral. Much smaller than the first, it measured about twelve centimeters in length. After crawling across the coral, it turned upside down and disappeared underneath the coral.

The third Tuberculate Dendrodoris had beautiful bluish tips on its tubercules. It was still on the small side, measuring about ten centimeters.

Discovery during Around-the-World Expedition

This enormous nudibranch was first discovered during a scientific voyage around the world. Commissioned by the French king, the voyage departed the port city of Toulon on 22 April 1826. The name of the ship was Astrolabe, after an instrument used in marine navigation. Scientists on board collected samples of animals and plants from the coasts of Chile and Peru, Australia, New Zealand, New Guinea, and various Pacific islands. They also surveyed the Molucca islands of Indonesia.

Dendrodoris tuberculosa
The third sighting

Two French naturalists Quoy and Gaimard named one discovery Doris tuberculosa. The genus name later changed to Dendrodoris.

The expedition returned to France in March 1825.

For your chance to enjoy a dive expedition in Gorontalo, please make your dive reservations directly with Miguel’s Diving.  

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