Science & Environment

By: Dian Puspitarini

Seafood is an important source of protein in many diets around the world, especially in coastal areas.  Shrimp are probably one of the most popular and most consumed types of seafood in many countries. They have a buttery texture with a slightly sweet taste and they can be cooked in so many different ways. They are nutritious and good for heart and brain health.

The term shrimp is used to refer to some decapod crustaceans. Decapod comes from Greek words deka means ‘ten’ and pous, pod means ‘foot’ (Oxforddictionaries definition). Crustaceans comes from a Neo-Latin word crustacea that means hard-shelled (Thefreedictionary). So, a shrimp is a ten footed animal with a hard exoskeleton (shell). Shrimp live on the river beds and ocean floors around the world, filtering sand and particles in the water. There are thousands of different species of shrimp but most are tiny in size, with some species of shrimp being so small that many animals cannot see them.

So, what kind of shrimp do we have out here at Telunas? While there are various species, the most common shrimp you can find are the Tiger Shrimp and Sand Shrimp.


Tiger shrimp (Penaeus monodon)
Tiger shrimp got its name from the stripes on the shell. This species occurs mainly in Southeast Asian waters, eats mainly of small crustacea, mollusks, and annelids (worms). The life span may be one and a half to two years, and the female may live for a longer period than the male. In general, the female is larger than the male (Motoh, 1985). Females can reach approximately 33 centimetres (13 in) long, but are typically 25–30 cm (10–12 in) long and weigh 200–320 grams (7–11 oz); males are slightly smaller at 20–25 cm or 8–10 in long and weighing 100–170 g or 3.5–6.0 oz (wikipedia.org).


Sand Shrimp or Greasyback Shrimp (Metapenaeus ensis)
The Sand Shrimp, also called the greasyback shrimp, is usually around 7 to 14 centimeters (3-5.5 in) long. Females can reach approximately to 19  centimeters (7.4 in) and male to 15.4 centimeters (6 in) long (Holthuis, 1980: in Palomares and Pauly, 2012). The color is sand color, that is why the local people call them sand shrimp. Just like Tiger Shrimp, Greasyback Shrimp have fan-like tails (uropod) with reddish, bluish, and purplish color.


You’ve tried fishing, but have you tried shrimping? If you are interested in catching these tasty animals, you can always go shrimping at Telunas during low tide. Shrimp have big eyes that reflect lights and they are most likely nocturnal. That means that the best time to go shrimping is at night. The shrimp are quite easy to spot once you know how they look, but they can be pretty hard to catch because they can jump quite far and fast. Are you up for it?

Sources:
http://en.wikipedia.org/wiki/Penaeus_monodon
http://www.oxforddictionaries.com/definition/english/Decapoda
http://www.thefreedictionary.com/crustacean

Motoh, Hiroshi. “Biology and ecology of Penaeus monodon.” In Taki Y., J. H. Primavera and J. A. Llobrera (Eds.). Proceedings of the First International Conference on the Culture of Penaeid Prawns/Shrimps. Iloilo City, Philippines: Aquaculture Department, Southeast Asian Fisheries Development Center, 1985. 27-36. Web. 28 Nov. 2013. <http://hdl.handle.net/10862/874>

Palomares, M.L.D., and D. Pauly. “Metapenaeus ensis: Greasyback shrimp.” SeaLifeBase. UBC Fisheries Centre & The FishBase Information and Research Group, Inc., 19 Jul 2012. Web. 28 Nov. 2013. <http://sealifebase.org/summary/Metapenaeus-ensis.html>.

By: Nikarta Jana Barus

When we walk on Telunas Beach at low tide we can feel an unusual softness of the sand on our feet. This is because the beach is covered with millions of tiny spheres of sand. Who made these tiny balls? The answer is the Sand Bubbler Crab. At low tide the crabs emerge looking for food stored in the sand, in doing so they create the tiny balls of sand that look like bubbles. The crabs are often clustered in large numbers that can look like soldiers marching. If you approach them they may bury themselves in the sand (which they commonly do when they feel threatened).

The Sand Bubbler Crab is relative of the Soldier Crab (Dotilla) and prefers sandy areas. They have numerous stiff hairs on their legs, and lack the transverse row of abdominal hairs. Their hairs are instead located at the base of their legs, and are used for the same purpose as Dotilla’s.

Source:

Tan, L. W. H. and P. K. L. Ng. ” Sand Bubbler Crab: Scopimera.” A Guide to Seashore Life in Singapore. Singapore Science Centre. n.d. Web. 11 Feb 2014. <http://mangrove.nus.edu.sg/pub/seashore/text/193.htm>

By: Bramantya Widiantoro

The first time I heard the word venomous cat, I think about a four-legged mammal that has fur all over the body and says “meow”. Wait, cats in Sugi Island are venomous?!! What a dangerous place! Well, if that were true, it would definitely shock the world. However, this is no ordinary cat. This is a Gold-ringed cat snake (Boiga dendrophila).

This snake belongs to the Colubridae family which is the largest variant of snake family. Among cat-snakes, Boiga dendrophila is considered big as it can grow up to 2.5 meters (8.2 feet) long. This particular snake is a opisthoglyphous, or rear-fanged, snake. It has a specific pattern which is defined by golden/yellow rings on the body. However, some of the golden parts are small and not connected. This snake can be found in Riau Archipelago including Sugi Island. The common species found in the region is Boiga dendrophila melanota.

The Boiga dendrophila can be found in mangrove areas. For that reason some people simply call it a “mangrove snake” because of its habitat. This snake is mostly nocturnal. It preys on small animal like birds, bats, rats, etc. During daylight hours, it just hangs in trees and appears to be sleeping. Although it seems quiet, the snake is mildly venomous and naturally aggressive which can be dangerous recipe if someone inexperienced attempts to play with it.

Note: Thanks to Nick Baker and Ecology Asia for the great pictures.  

Sources:

http://en.wikipedia.org/wiki/Colubrid 

http://en.wikipedia.org/wiki/Boiga_dendrophila

Baker, N. “Gold Ringed Cat Snake.” Snakes of Southeast Asia. Ecology Asia. Web. 11 Feb 2014. <http://www.ecologyasia.com/verts/snakes/gold-ringed_cat-snake.htm>

By: Elsa Siahaan

Picture taken by Telunas staff on the Jungle hike, Sugi Island.

This plant has several names. It’s scientific name in Latin is Nepenthes and also is known as Tropical Pitcher Plant. In Bahasa Indonesia it is known as Kantong Semar. In Malay, this plant called periuk kera or cawan monyet. This plant can be found in some tropical areas such as Southern China, Indochina, Malaysia, The Philippines, Western Madagascar, Seychelles, New Caledonia,, India, Sri Lanka, Australia, and Indonesia. The habitat is most widely found in Borneo and Sumatra. Not to be forgotten, these pitcher plants can be found growing vigorously in the jungle in Sugi Island on the way to the black pool.

Carnivorous plant, really?

Pitcher plants are called carnivorous plants because this plant eats prey such as bugs, insects, or even small animals like rats. On the contrary there are some reports of the species becoming a vegetarian.

How do we tell if it is pitcher plant?

This plant has some characteristics. This plant has more than 100 species in the world that can live both mountainous and lowland areas (i.e, beach area).  It contains sword-shaped leaves entirely. It can grow either propagating like climbing stem in between 15-20 cm or has a shallow root system which makes it stay close to the ground. This plant has 3 different kind of shape, the top, bottom, and rosette types.

Is there any trap inside the plant?

Yes. This plant has a trap inside it. The trap contains a fluid of the plant’s own production which is used to trap the prey.

“The Research has shown this fluid contains viscoelastic biopolymers that may be crucial to the retention of insects within the traps of many species. The lower part of the trap contains glands which absorb nutrients from captured prey. Along the upper inside part of the trap is a slick, waxy coating which makes the escape of its prey nearly impossible. Surrounding the entrance to the trap is a structure called the peristome (the “lip”) which is slippery and often quite colorful, attracting prey, but offering an unsure footing. Above the peristome is a lid (the operculum); in many species, this keeps rain from diluting the fluid within the pitcher, the underside of which may contain nectar glands which attract prey.”

Wikipedia (Botanical History, Ecological Relationships)

How useful is this plant?

• It is very helpful as a climate indicator. If in one location that has the kind of Nepenthes gymnamphora, it means that location has high percentage of rainfall rate, humidity up to 75%, and the soil is low in nutrients.

• It is useful as traditional medicine. The liquid that kept closed can be used as a cough medicine. Boiled water from the root and the liquid inside is also useful as stomach medicine, an aid in avoiding wetting your pants, a balm for soothing burns, and a remedy for eye problems. Also, this plant is another drinking source for thirsty hikers.

• Pitcher plant type N. gymnamphora is a drinkable water source with its neutral PH ( 6-7 ) with the condition if the plant’s skin is still closed. Opened ones will have already been contaminated by dead insects that went inside resulting in a PH of 3 and a sour taste as well.

• There are some local people using this plant as a substitute of rope. The stem of this plant can be used to tie goods.

Scientific classification: Kingdom Plantae, Division Magnolipophyta, Class Magnoliopsida, Order Caryophyllales, Family Nepenthaceae Dumort. (1829), Genus Nepenthes L. (1753).

Sources:

http://simple.wikipedia.org/wiki/Nepenthes

———–. “Kantung Semar.”Ndobos. n.p., 27 Feb 2008. Web. 11 Feb 2014. <http://ndobos.com/2008/02/27/kantung-semar/>

Endah, A. “Kantong Semar Tanaman Karnivora.”Alamendah. n.p., 08 Oct 2009. Web. 11 Feb 2014. <http://alamendah.org/2009/10/08/kantong-semar-tanaman-karnivora/>.

Saputra, G. A. “Kantong Semar – Ciri-ciri, Manfaat dan Jenis Kantong Semar.” Satwa: Flora dan Fauna Indonesia. 15 Sep 2013. Web. 11 Feb 2014. <http://www.satwa.net/542/kantong-semar-ciri-ciri-manfaat-dan-jenis-kantong-semar.html>

By: Santi Marina

The fiddler crab is an arthropod. Arthropod means jointed leg. Specifically, the fiddler crab is under the subphylum of crustacean which includes familiar animals such as lobsters, crayfish, shrimp, krill and barnacles. At Telunas Beach Resort, you will find the fiddler crab in the mangroves or along the shore.

The fiddler crab is small in size, even the largest being slightly over two inches across. Like all crabs, fiddler crabs shed their shells as they grow. So, where did this little crab get its name? The answer is the movement of the smaller claw from the ground to mouth during feeding. It looks as if the animal is playing the larger claw like a fiddle.

Males are characterized by a greatly enlarged claw while the other is small with spoon-tipped fingers. The large claw is used to court females as well as fend off male rivals. The smaller claw is used for feeding. The female fiddler carries her eggs in a mass on the underside of her body. She remains in her burrow during a two week gestation period, after which she ventures out to release her eggs into the receding tide.

Porcelain Fiddler – Uca annulipes found at Telunas Beach Resort

Fiddler crabs prefer to live out of the water on damp ground, even when they are sealed in their burrows during high tide, they maintain a bubble of air underground. They have tufts of hair at the base of their legs which they use to absorb water into their gill chamber through capillary action (Ng and Sivasothi, 2001).

Source:

Ng, P.K.L. and N. Sivasothi (eds.). “Fiddler Crab.” A guide to the mangroves of Singapore II: Animal diversity. Singapore Science Centre, 2001. Web. 6 Nov 2013. <http://mangrove.nus.edu.sg/guidebooks/text/2053.htm>.

By: Santi Marina

What are these shy creatures and fast moving hoppers? They look like fish, but how can they spend their time out of water?

Mudskippers (Vertebrates: Fish – Family Gobiidae)

Here is what I learned from an expert and a friend, Ms. Wang Luan Keng, the Nature Workshop Singapore and from a book “A Guide to Mangroves of Singapore” by Peter K.L. Ng and N. Sivasothi (editors).

These creatures are mudskippers. Mudskippers are uniquely adapted because they breathe by holding water in their mouth and gill chamber, replacing it with fresh water when it becomes deoxygenated. They can also breathe through their wet skin. These mudskippers look more comfortable crawling around and hopping on the mud than submerged in water.

A Mudskipper in the mangrove area at Telunas Beach Resort

Mudskippers have interesting features designed to help them rule the mud. When we observe closely, we can see that the mudskipper has a pair of muscular leg-like pectoral fins that enable them to crawl over the mud, and even climb trees. They have eyes at the top of their head for an all-around view. The eyes on the top of their heads provide excellent eyesight that allows them to spot prey and predators from afar. Mudskippers avoid marine predators by digging deep burrows in soft sediment during the high tide. They submerge and burrow for lying as well. Also their mouth faces downwards to feed on the mud surface. Mudskippers are predatory, feeding on small crabs, worms and insects. They emerge when the tide recedes to graze on algae and detritus by moving their mouth sideways over mud.

Source:

Ng, P.K.L. & N. Sivasothi (eds.). A guide to the mangroves of Singapore II: Animal diversity. 2nd ed. Singapore: Singapore Science Centre, 2002. Print.

Wang, Luan-Keng. Personal Communication. 2012

This post marks the launch of a series of posts we’re calling “The Real Residents of Telunas Beach”.  Many guests inquire about who lives at Telunas Beach. While there are no permanent human inhabitants, there are some small villages on other parts of spacious Sugi Island. The real residents of the beach are a variety of creatures and plant life that make Telunas such an interesting place. Through this series of posts, we will introduce you to the ecosystems that are found around Telunas Beach and the animal and plant varieties that they are composed of.

We’re thankful to have an expert guest and friend of Telunas, Wang Laun Keng, introduce the series.

Ecosystems at Telunas Beach

By Wang Luan Keng, The Nature Workshop, Singapore

Telunas Beach, situated at Sugi Island, part of the Riau Islands, is home to many ecosystems. The shore comprises both rocky and sandy habitats. As the tide recedes, meadows of seagrass are partially exposed. Mature stands of mangrove forests and coastal forests cover the coastline of the island. As one moves inland, the habitat becomes drier, allowing open country or secondary forests to establish.

I shall introduce three main ecosystems at Telunas Beach.

Intertidal

The rocky shore and sandy beach form the intertidal zone. This is the area which is submerged during high tide and exposed during low tide. Marine organisms living in the intertidal area are challenged by extreme environmental conditions. High tides bring in aquatic predators. During low tides, most parts of the intertidal area are exposed to the sun—organisms are faced with dangers from aerial and terrestrial predators as well as desiccation. Intertidal organisms have developed various strategies to cope with these challenges. Those that are mobile will run and find shelter in shadier areas, such as under rocks, or in burrows which they dig. Slow-moving or soft-bodied animals may protect themselves with a thick shell or are masters of camouflage. Some are brightly-coloured or have striking patterns to warn predators of their venom. Others develop defensive mechanisms, such as sharp spines, teeth or claws. Some animals exhibit behavioural adaptations and move in troops, thus seeking safety in numbers. Some sessile animals are able to tolerate the high temperatures.

Sandy and rocky habitats of the intertidal area, with the chalets of Telunas Beach Resort in the background.

The Onch Slug (family Onchidiidae) is well camouflaged against the rocks which they graze algae from.

The Cryptic Rock Star (Cryptasterina sp.) is usually found underneath rocks.

The Black Sea Cucumber (Holothuria leucospilota) hides under rocks. When threatened, it secretes white sticky threadlike substance to repel potential predators.

Mangrove Forests

The mangrove forest is situated between land and sea. Organisms living in this special habitat have to cope with daily fluctuations in salinity and temperatures with the rising and ebbing of the tides, as well as low oxygen levels in the soft and unstable substrate. Special adaptations allow a small group of plants to live in the mangrove forests. Mangrove plants have aerial roots to cope with living in unstable, water-logged and oxygen-poor muddy substrate. To deal with the salt in the water, some mangrove plants are able to prevent salt from entering the roots or have the ability to ‘sweat’ out the salt through the leaves.

Mangroves near Telunas Beach.

Mangrove trees with extensive breathing root systems, exposed as the tide recedes.

Coastal Forests

Fringing the coastline is a group of plants that have adapted the tough conditions by the sea. These plants tolerate strong winds conditions, high temperatures and salty sea sprays.

They adapt to the harsh environment by developing thick and leathery leaves to reduce water loss.

Coastal forests at the resort.

A pioneer species of the coastal forest, the Rhu Tree (Causarurina equisetifolia) has needle-like leaves to minimize water loss. The cone-like fruits are often found littered on the beach.

The sea Luttuce (Scaevola taccada), a common coastal plant, has thick, waxy leaves to reduce water loss.