Spare this tree some mercy

Currently, there are five Bodhi Trees (Ficus Religiosa) in Singapore registered under the list of Singapore’s heritage tree register. However, one that is especially worth mentioning is the latest addition to the list, and that would be the Bodhi tree located within the premise of a temple located off Bartley road.

JLS_Bodhi_Tree

The tree is over 120 years old and has a height of approximately 30 metres, girth of 8.5 metres, which is considered to be ” the most ancient and largest Bodhi tree in Singapore according to the NSS (Nature Society Singapore) and Nparks.” (Wikipedia.com, 2007)

The Bodhi tree has a symbiotic relationship with the temple as its roots are deeply intertwined with the building’s foundation. Hence, development of the land at the proximity of the tree’s location will have an adverse effect on the tree, thus causing soil movement and stresses to the roots.

Alas, as part of the plan for redevelopment, the temple was acquired to make way for the construction of Circle line despite the immense effort and appeals from the public though the tree was conserved as in response to the public’s petition.

However, it looks like this is not the end to the tree’s sufferings. In 2009, URA has put up a site for application for likely development of homes on the land where the tree is occupying. Although it is under the protection of heritage trees, one can wonder what sort damage will be caused onto the tree when the land is developed for the building of fancy condominiums?bartley_landparcel02

References:

1. Wikipedia.com. Singapore oldest Bodhi Tree estimated at 120 year old at Jin Long Si Temple on 21 Jan, 2007. Credits: Aldwin Teo. Retrieved April 16, 2010, from http://en.wikipedia.org/wiki/File:JLS_Bodhi_Tree.jpg

2. H88.com.sg (n.d). The Bartley Road land parcel and a Bodhi tree. The homepage for homes. Retrieved April 16, 2010, from http://www.h88.com.sg/article/The+Bartley+Road+land+parcel+and+a+Bodhi+tree/

3. Singapore’s Heritage Tree Register (January, 2010). Retrieved April 16, 2010, from http://www.nparks.gov.sg/cms/docs/CIB/Heritage_Tree_Register_NOV2009.pdf

Being Upside down isn’t bad all the time.

As i walked along the intertidal zones of Pulau Semakua, many forms of  ecological relationships can be identified on the shore and these interactions  includes competition, exploitative interaction, commensalism, herbivory and symbiosis. However , out of all the organism i saw during that trip, a weirdly oriented organism that seemed like a flower anemone caught my attention.

Upside down jelly fish taken on semakua island

Picture 1: Upside down jelly fish taken on semakua island

Although the Upside-down jellyfish, Cassiopea sp., had been observed many times on the shore of Pulau semakua , that was my very first encounter with one.  Many non-biologists will either often mistake the jelly fish as a sea anemone or will try to flip the jellyfish around (picture 2) thinking that is it not in the correct orientation. Actually, the Upside-down jelly fish is in the correct orientation. The reason the jellyfish has such an orientation is due to is symbiotic relationship with unicellular algae called zooxanthella (Karla C. arcia). Such an orientation allows and promote  the growth of the algae.(picture 1)

upperside of an upside down jelly fish taken from semakua

picture 2 :upperside of an upside down jelly fish taken from semakua

The zooxanthella resides in the bell of the jellyfish and provides the jellyfish with an important carbon source through photosynthesis (Edward A. Drew). To enable the algae to access sunlight, the jellyfish usually floats upside down in shallow water so that they can settle upside down on the sand bed, while providing sufficient sunlight to the algae. The algae also provide the jellyfish with oxygen in oxygen poor waters while photosynthesizing (David et al, 2009).

The algae benefits from this relationship as the jellyfish not only ensure the algae stays in a photic zone, it also provide protection with the numerous nematocysts in its tentacles. These nematocysts help the jellyfish not only in paralyzing the planktons and zoo plankton for food; it also stings any organism that tries to eat the algae, protecting the algae from its potential herbivores. The jellyfish also provide the algae with an abundance of carbon dioxide as it respires.

Since both organism benefits from this relationship while either is alive, it is a mutualistic relationship. However, so as long as either ones dies, the other will likely to be affected and leads to death eventually. With such a relationship ,  being upside-down isn’t that bad after all.

References:

1.  Upside-down jelly fish ,http://www.jellyfishfacts.net/upside-down-jellyfish.html

2.  A Symbiotic Lifestyle: C. xamachana and Zooxanthellae FINAL by Karla C. arcia. Http://jrscience.wcp.muohio.edu/fieldcourses05/PapersMarineEcologyArticles/ASymbioticLifestyle.C.xam.html

3.   Edward A. Drew, The biology and physiology of alga-invertebrate symbioses. I. Carbon fixation in Cassiopea sp. at aldabra atoll, J. exp. mar. Biol. EcoL, 1972, Vol. 9, pp. 65-69

4.  David T. Welsh , Ryan J. K. Dunn & Tarik Meziane, Oxygen and nutrient dynamics of the upside down jellyfish(Cassiopea sp.) and its influence on benthic nutrient exchanges and primary production, 2 February 2009

5.  Verde, E. A. & L. R. McCloskey. Production, respiration,and photophysiology of the mangrove jellyfish Cassiopea xamachana symbiotic with zooxanthellae: effect of jellyfish size and season. Marine Ecology ProgressSeries 168: 147–162, 1998

6. Picture 1 & 2 above are self taken on Pulau Semakua.

Microhabitat and Relationships: Mushrooms

Ever thought of something growing right beside your steps? This is noticed when I hopped down the slope at King Edward VII Hall in NUS. It is a mushroom. It seems that it is most probably under the Order Agaricales, Family Psathyrellaceae. During observation, the bunch of mushroom was among piles of dead leaves. After a few days, the mushroom started to die out and some cleaner came to ‘blow’ all the dead leaves away. On the ground, I could see nothing but soil and busy ants. Since it died naturally, I assumed there will be more ‘little’ mushroom shooting out soon. However, it didn’t happen.

Mysterious Mushroom

Mysterious Mushroom

Here, we forgot about something, the micro-habitat (Molles, 2010). The habitat the mushroom grows in is a micro-habitat, but any changes to it, will actually decide its survival. The dead leaves were actually decomposing on the ground providing nutrient to the ground. This is the decomposed nutrient that is needed by fungus like mushroom that can’t undergo photosynthesis. The moment the leaves were blown away, not only does the mushroom loss its nutrient source, it has lost its protection and camouflage from the mushroom. Hence, it is not suitable for new generation of mushroom to grow on. Hence, from here, we could roughly draft the relationship between organisms in a microhabitat.

Relationship in Within

Relationship in Within

Besides, the event of ant staying with the mushroom has strike my interest. I looked through some journals to understand that there is Ant-Fungus mutualism whereby Attini (such as leaf-cutter ants) will be responsible in nurturing and protecting fungus like mushroom from mould while mushroom provides a resting place for them (Nash, 2007). This is a symbiosis relationship between mushroom and ants but parasitism between ants and the tree, interesting huh? In this case, it is very hard to deduce whether the phenomenon I saw was on the same relationship due to insufficient observation data.
References:


Garling, L. (1979). Origin of Ant-Fungus Mutualism: A New Hypothesis. Biotropica , 284 – 291.

Molles, M. C. (2010). Ecology: Concepts and Applications. New York: McGraw-Hill .

Nash, D. (2007, March 30). The Attini. Retrieved April 15, 2010, from Ants and their interactions with other organisms: http://www.zi.ku.dk/personal/drnash/atta/Pages/attini.html

Ulrich G. Mueller, T. R. (2001). The Origin of the Attine Ant-Fungus Mutualism. The Quarterly Review of Biology , 169 – 197.

Wade, N. (2003, January 28). Ants, Mushroom and Mold: An Evolutionary Arms Race. Retrieved April 14, 2010, from New York Times: http://www.nytimes.com/2003/01/28/science/life/28ANTS.html?pagewanted=1

“Solar-powered” Sea Slugs

Sea slugs which belong to Phylum Mollusca and Class Gastropoda appears like snails but without shells. You will be almost certain to see a sea slug on a visit to any of Singapore’s shores. These sea slugs are interesting invertebrates as some being highly toxic whereas others used for behavioral and neurological research medically important to humans. One particular group of sea slugs that spark my interest is the “Solar-powered” Sea Slugs. Two quite different groups of sea slugs have evolved ways of using the ability of plants to convert the sun’s energy into sugar and other nutrient. In layman’s term, they have become solar-powered. How fascinating, an animal becoming solar-powered?!

These two groups of sea slugs are the herbivorous sacoglossans and the carnivorous nudibranchs. The herbivorous sacoglossans are suctorial feeders removing the cell sap from the algae on which they feed. In most, the cell contents are simply digested by the slug. Some species however have evolved branches of their gut which ramify throughout the body wall and contain plastids, which are the photosynthesizing  “factories” from the algae, alive and operating. In many cases these plastids are chloroplasts, but sacoglossans that feed on red and brown algae are also reported to keep the plastids from these algae alive as well.

Sea Slug 1

The sacoglossan Placida cf.dendritica showing the green network of ducts which contain the green chloroplast from its algal food. Photo by Bill Rudman

In nudibranchs , many have evolved similar ways of keeping whole single-celled plants (zooxanthellae) alive in their bodies. In most cases, the zooxanthellae are obtained from their food, often cnidarians, which already have symbiotic zooxanthellae in thier bodies.

Sea Slug 2

The aeolid nudibranch Pteraeolidia ianthina which "farms" colonies of brown single-celled algae (zooxanthellae) in its body. Photo by Bill Rudman

Phyllodesmium longicirrum is probably the most spectacular of the aeolids which have evolved a symbiotic relationship with single-celled plants (zooxanthellae). It is exceptionally large and the cerata have evolved into large flattened “solar paddles” to maximise the animal’s ability to “farm’ the plants in its body. It is known to feed on the soft-coral Sarcophyton trocheliophorium.

Sea Slug 3

At the right, shows Phyllodesmium longicirrum crawling over. Lower left, ceras showing the white ducts of the digestive gland radiating out to the brown "gardens" of symbiotic zooxanthellae. Lower right, section through the a ceras showing the ducts leading to the zooxanthellae "gardens" at the surface of the ceras. (zooxanthellae stained red). Photo by Bill Rudman

References

Tan R.(2008) Sea Slugs : Wildsingapore. Retrieved April 14, 2010 from http://www.wildsingapore.com/wildfacts/mollusca/slug.htm

Rudman, W.B., 1998 (October 11) Solar-powered sea slugs. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/solarpow

Rudman, W.B., 1998 (October 11) Phyllodesmium longicirrum (Bergh, 1905). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/phyllong

Johnson, S., 2000 (Feb 10) Hypselodoris bertschi from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Retrieved April 14, 2010 from http://www.seaslugforum.net/search_citation.cfm

Hoegh-Guldberg,I.O. & Hinde,R. (1986) Studies on a nudibranch that contains zooxanthellae 1. Photosynthesis, respiration and the translocation of newly fixed carbon by zooxanthellae inPteraeolidia ianthinaProceedings of the Royal Society, London B, 228: 493-509.

Rudman, W.B. (1981b) The anatomy and biology of alcyonarian feeding aeolid opisthobranch molluscs and their development of symbiosis with zooxanthellae. Zoological Journal of the Linnean Society 72: 219-262.

Rudman, W.B. (1987c) Solar-powered Animals. Natural History 96(10): 50-53.

Parasitic, Parasi-TICKS

Almo (left on 14 March 2010), the usual host for ticks when brought down for walks

Almo (passed on 14 March 2010), the usual host for ticks when brought down for walks

Having ticks was one major problem when I kept dogs as pets. Especially during humid and wet periods, they would always appear in numbers after I took my dogs for walks. They would leave bite sites and rashes on my dogs, which made me very worried for the dogs.

Though small, these parasites are smart! They detect body heat and carbon dioxide from the respiration of their hosts such as humans and dogs, and crawl onto them (Dantas-Torres, 2008; Swain, 2009). After a few days, you would notice some crawling on the floor and up at the walls, and one or two would appear engorged.

Engorged female ticks (Wikimedia, 2008)

These engorged ticks are the females, which will suck blood from the hosts. They swell up to 5 times of their original size. The engorgement process is necessary for obtaining nutrition for hatching. Thereafter, the tick falls off their host, hides to digest the blood meal and lay up to 4,000 eggs (Dantas-Torres, 2008; Health, 2010). Some species of ticks are also vectors for pathogens of arboviruses, protistans and bacteria (Kaufman, 2010). They are able to carry diseases such as Lyme disease and American Mountain fever.

Rhipicephalus sanguineus, also known as brown dog tick (Wikimedia, 2006)

Rhipicephalus sanguineus, also known as brown dog ticks (Wikimedia, 2006)

Luckily, the tick species found in Singapore is Rhipicephalus sanguineus, also known as Brown Dog tick. According to Illonois Department of Public Health, this species is not an important carrier of diseases to humans (Health, 2010) .

Usually, I would squash the engorged females with a tissue paper, and yes, it gets messy after that. However, because the male ticks are flat, they are harder to be squash under my fingers. Hence i would flick them into the toilet bowl and let them drown to their death!  =) *peace* These ticks are just horrible parasites to many animals. Won’t it be best if they can go extinct? I guess dog owners will raise their hands and feet up to agree.

References:

– Ben J. Mans, Albert W.H Neitz (2004). Adaptation of ticks to a blood feeding environment: evolution from a functional perspective . Insect Biochemistry and Molecular Biology , Volume 34, Issue 1, pg 1-17.

– Dantas-Torres, F. (2008). The brown dog tick, Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae): From taxonomy to control. Veterinary Parasitology , 152 (3-4), 173-185.

– Health, I. D. (2010). “Common Ticks”, by Illinois Department of Public Health: Prevention and Control. Hosted on : http://www.idph.state.il.us/envhealth/pccommonticks.htm (assessed on 10 April 2010)

– Kaufman, W. R. (2010). Ticks: Physiological aspects with implications for pathogen transmission . Ticks and Tick-borne Diseases , 1(1), 11-22 .

– Swain, J. (2009). “How do ticks get onto people” by Boston.com. Hosted on: http://www.boston.com/news/science/articles/2009/06/01/how_do_ticks_get_onto_people/ (assessed on 10 April 2010)

- “Rhipicephalus sanguineus” by Wikimedia. Wikipedia, 07 April 2006.  URL: http://en.wikipedia.org/wiki/File:Rhipicephalus_sanguineus.jpg (accessed on 17 April 2010)

-” Tick engorged with thumb” by Wikimedia. Wikipedia, 21 April 2008. URL: http://upload.wikimedia.org/wikipedia/commons/9/9b/Tick_engorged_with_thumb.jpg (accessed on 17 April 2010)

A mother’s blind love? Bird brood parasitism

I came across this picture where it shows a picture of a Common Myna (Acridotheres tristis), feeding a Asian Koel (Eudynamys scolopaceus) .

2734767424_c329ebdb72_t 

2733935115_0f7f60eb51_t

( from Z.Faisal, Flickr)

 I find it interesting that the myna mum is rearing a child that is not of its own species. This behavior is usually noted in bird-brood parasitism.

Birds as brood parasites lay their eggs in the nest of other birds and these “hosts” would help them to feed and rear the young of the brood-parasites. There are two types of brood parasitism mainly intraspecific brood parasitism (hosts are of the same species as the parasites) or interspecific brood parasitism ( hosts are of different species) .

Parasitic birds exploit mainly the parental care of altricial birds whereby their nestlings depend on the parents for food (R.B.Payne, 1977).  It ensures that the young of the brood parasites would be fed. In such cases, it relives the parasitic parent from building nests and rearing the young, they can spend more time foraging or producing more offspring.

It has often been questioned why majority of the hosts care for the nestlings of brood parasites as these brood parasites usually differ in appearance and size from the hosts. The presence of brood parasites may also reduce the survival rates of the hosts’ nestlings.

One of the probable answers would be the “Mafia hypothesis”. Upon detection and rehect of a brood parasite’s egg,the host’s nest would be depredated on, its nest destroyed and nestlings injured or killed, this threatening response enhances selective pressure favouring aggressive parasite behavior (M.Soler et al, 1995).

The other would be that hosts are unable to distinguish between her offspring and that of others (Tomas Roslin,2001).

Several factors are needed for successful parasitism. Firstly, compatible parental behavior of the hosts is needed such as the type of food provided by the host to the brood parasites (R.B.Payne, 1977). It can be fruits, seeds or insects.

The second factor is the size of the egg of the brood parasite. Eggs are incubated by contact hence the contact might be poor if the parasites eggs are larger than the host (R.B.Payne, 1977).

 

Other pictures of bird brood parasitism.

3641171283_a079f90840_t

Song sparrow, Melospiza melodia (host) feeding Baby Cowbird.( from Muskrat55, Flickr)

cuckoo

A common cuckoo raised by a reed warbler. ( From brood parasitism, wikipedia)

References

1) R B Payne The Ecology of Brood Parasitism in Birds, November 1977.Annual Review of Ecology and Systematics Vol. 8: 1-28

http://arjournals.annualreviews.org.libproxy1.nus.edu.sg/doi/pdf/10.1146/annurev.es.08.110177.000245?cookieSet=1

2) Soler, M., J. J. Soler, J. G. Martinez, A. P. Moller (1995). Magpie host manipulation by great spotted cuckoos: Evidence for an avian mafia? Evolution. 49, 770–775

3) Tomas Roslin,2001.Other mothers’ ducklings–why look after them.Trends in Ecology & Evolution Volume 16, Issue 2, 1 February 2001, Pages 73-74

4) Photos 1 and 2 : Common myna feeding asian koel by Z.Faisal ,4 August 2008.

URL : http://www.flickr.com/photos/zfaisal/2734767424/ ( accessed on 13 April 2010)

5) Photo 3 : Song sparrow feeding Baby Cowbird byMuskrat55, 19 June 2009.

URL : http://www.flickr.com/photos/robinarnold/3641171283/ ( accessed on 13 April 2010)

6) Photo 4 : A common cuckoo raised by a reed warbler, Wikipedia.

URL : http://en.wikipedia.org/wiki/Brood_parasitism ( accessed on 13 April 2010)

Ecology in a tank: rams horn snails (Gastropoda: Planorbidae)

I started my freshwater aquarium in January. Desiring it to be self-cleaning, I added dwarf suckers (a.k.a. otos) and snails, along with other species that lived in peace for weeks. Unfortunately, due to a Chinese New Year holiday, custody of my tank went to my room-mate. An economist desiring to decrease opportunity cost, he threw in three weeks worth of food, and placed an opaque cover over the tank to prevent ‘mosquito breeding’.

My prized cherry shrimp before the massacre

My prized cherry shrimp before the massacre


Before this event, I had:
2 genera of aquatic plants
1 driftwood log of Java moss
25 neon tetras
10 cherry shrimps
3 otos
2 rams horn snails
the 6 remaining commandos

the 6 remaining commandos


After:
1 plant
1 java moss
6 neon tetras
No cherry shrimp
2 otos
200-300 rams horn snails

The water was suffering from eutrophication, there was algal bloom, and excessive nitrates led to extreme growth in the remaining plant (with emergent leaves sprouting out of water). The two hundred snails became the talk of the block, and everyone took turns visiting to see the spectacle. Two weeks later, with me back in charge, and the original feeding regime, the snails finished their buffet, and most perished (only twenty surviving today).

This is after the population decline for the rams horn snails

This is after the population decline for the rams horn snails


In brief, El-Emam and Madsen (1982) suggest that starvation affects survival and darkness slowed reproduction of Helisoma duryi. My tank clearly supports the ‘starvation affects survival’ notion, but the snails in my tank reproduced explosively in near complete darkness. Perhaps, distance chemoreception, rapid aggregation and efficient food utilization (Madsen, 1992) was more important for reproduction in Helisoma sp.
I started with only 2 of these!

I started with only 2 of these!


some of these learnt to feed on floating food on the surface

some of these learnt to feed on floating food on the surface


note the remaining plant was really FLOURISHING

note the remaining plant was really FLOURISHING

It is interesting that while otos and the snails overlapped in resource utilization, the high fecundity of snails caused a population explosion and subsequent decline. Much to elaborate, too little words, hence concluding, ecological principles apply everywhere, even in an environment as small as a fish-tank.

pls dont tell RVR management about the tank!

pls dont tell RVR management about the tank!

Word count: 300 words

References

El-Emam, M.A., Madsen, H. (1982). The effect of temperature, darkness, starvation and various food types on growth, survival and reproduction of Helisoma duryi, Biomphalaria alexandrina and Bulinus truncates (Gastropoda: Planorbidae). Hydrobiologia 88, 265-275.

Madsen, H. (1992). A comparative study of the food-locating ability of Helisoma duryi, Biomphalaria camerunensis, Bulinus truncates (Pulmonata: Planorbidae). Journal of Applied Ecology 29, 70-78.

P.S. Pictures speak a thousand words. Hence for those interested, the following is a series of photos of the stuff that was in my tank at one point or another, along with their scientific names for your information.

Hot Weather? Plants Feel It Too!

Few days before Pulau Ubin trip, after a few days of extreme hot weather, a tree was observed outside Lecture Theatre 32, NUS. It was a Sea Almond tree (Terminalia catappa). The tree was spotted to be almost bald and only a few red unshed leaves were left on those nearly-naked twigs. There were several holes on the unshed leaves too. Hence, two guesses were made: it has disease or the weather has an impact on it.

Situation after few days of extreme hot weather

Situation after few days of extreme hot weather

After doing some research of information on the internet of the tree’s behaviour, I found an interesting interaction between Sea Almond Tree and weather. Terminalia catappa are dry-season deciduous plants. They shed their leaves during dry season with red leaves.

Leaves used for identification

Leaves used for identification

This season is when water availability to the plant is low, for example during draught or winter (Macmillan Science Library: Plant Sciences, 2006). Water stress causes the tree to shed their leaves in order to reduce the evaporation of water from the surface of leaves. This is considered one of the adaptations of plants towards climate. For Terminalia catappa, this strategy will be worth since its broad leaves will cost it a large amount of water loss through leaves surface. After shedding, the tree usually went into dormant state since it can’t undergo any photosynthesis process (Missouri Botanical Garden, 2002).

After few days of wet weather

After few days of wet weather

To check with my hypothesis, I went back around two weeks after the observation. Throughout the two weeks, the weather was wetter with rain and cooler climate. The hypothesis of weather’s impact on Sea Almond tree was quite difficult to reject when the tree was then observed to be growing new shoots with new green leaves. According to Ria Tan, Terminalia Catappa shed its leaves twice a year, around February and August, after it reaches 3-4 years old (Tan, 2001). Hence, the shedding of the leaves observed might be connected to the local weather pattern such as rainy seasons and dryer seasons.
More Photos available here.

References:

Macmillan Science Library: Plant Sciences. (2006). Deciduous Plants. Retrieved April 13, 2010, from BookRags: http://www.bookrags.com/research/deciduous-plants-plsc-02/

Missouri Botanical Garden. (2002). Temperate Deciduous Forest: What’s A Temperate Deciduous Forest Like? Retrieved April 13, 2010, from Missouri Botanical Garden: http://www.mbgnet.net/sets/temp/whats.htm

Tan, R. (2001). Sea Almond Tree. Retrieved April 13, 2010, from Print to Web, Convert to Conserve: http://www.naturia.per.sg/buloh/plants/sea_almond.htm

Tropilab Inc. (n.d.). Terminalia Catappa – Tropical Almond. Retrieved April 13, 2010, from Tropilab Inc: http://www.tropilab.com/terminalia-cat.html

Cauliflory: That’s just one part of me.

Have you ever walked around Singapore and observe the many unusual growths on large trees? Bird nest ferns, dragon scales and many other epiphytes can be found on many roadside trees. Amidst all the creeper plants overtaking its host tree, it is likely that you would have observed this particular tree and thought that it has been overgrown with epiphytes.

Unusual growth on tree

Unusual growth on tree (Photo taken on 14 April 2010)

But wait! Is there really an epiphyte growing on it? Let’s take a closer look.

Close up look at the unusual growth

Close up look at the unusual growth (Photo taken on 14 April 2010)

Closer investigation shows that all the hanging stems that produce flowers and fruits originate from the trunk of the tree, a condition known as cauliflory (Shimonski, 2009).

Cauliflory is frequent among smaller trees of the rainforest, such that flowering may take place on the trunk and the upper branches remain leafy to compete for the limited amount of light (Bakers, 1970).  It also allows for trees to target other pollinators such as insects that lived near the ground or on the tree trunk (Armstrong, 1999). Cauliflory allows for stout attachments of large and heavy fruits, which attracts larger animals for seed dispersal (Armstrong, 1999; Butler, 2006; Stebbins, 1974).

The tree in question is Couroupita guianensis, or more commonly known as Cannonball tree from the distinct fruits it bears, which has the shape and size of a cannon ball.

Flowers and fruit of Couroupita guianensis

Flowers and fruit of Couroupita guianensis (Photo taken on 14 April 2010)

Because Couroupita guianensis exhibits cauliflory, large numbers of woody stems cascade down the tree, causing the tree to look as if some other plant is overtaking it. The large, beautiful and pleasantly aromatic flowers also seem out of place on the tree trunk. These visual factors combined made it easy to mistake the flowering and fruiting branches for an epiphyte growth, instead of a part of a single cauliflorous tree.

So take a second look the next time you spot unusual growth on the trees. If it is attached to the tree, it might just be cauliflory, a part of the tree.

References:

Armstrong, Wayne P. 1999. “The Truth About Cauliflory.” Retrieved April 12, 2010 from http://waynesword.palomar.edu/plmay99.htm

Bakers, Herbert G. 1970. “Evolution in the Tropics.” Biotropica, Vol. 2, No. 2 (Dec., 1970), pp. 101-111

Butler, Rhett A (2006). “Seeds and Fruits” Retrieved April 12, 2010 from Mongabay.com / A Place Out of Time: Tropical Rainforests and the Perils They Face. Web site: http://rainforests.mongabay.com/0503.htm

Shimonski, Jeff. 2009. “Cauliflory: Flowers that Bloom on Tree Trunks.” Retrieved April 12, 2010 from http://www.malaysiaflora.com/Articles/tabid/55/articleType/ArticleView/articleId/15/Cauliflory-Flowers-that-Bloom-on-Tree-Trunks.aspx

Stebbins, G.L. 1974. “Flowering Plants: Evolution Above The Species Level.” The Belknap Press of Harvard University Press, Cambridge, Massachusetts.

If you don’t get your end of the deal, get even.

Pollination, which is a term for sexual reproduction process in plants, is a common and ubiquitous form of mutualism between flowers and their pollinators. According to Poole (2004), the use of a pollinator can be much more exact if the plant species can attract a pollinator, attach its pollen to it, and then get the pollinator to go to another individual of the same plant species. This is especially true for figs and their pollinators, fig wasps, which are interdependent on each other for propagation. Their relation is strictly specific – each fig species has its own associated species of pollinator wasp which co-evolved with it (Wiebes, 1979).

This type of mutualism can be seen in Kent Ridge Park, behind NUS campus. The most common fig found there is Ficus grossularioides, also known as the White-leaved fig. Other species such as Ficus fistulosa, Ficus fulva and Ficus microcarpa can also be found growing at the edges of the Park (Tan et al, 2002).

White-leaved fig which shows green unripe figs with some yellow orange ripe figs on fruiting branch

White-leaved fig which shows green unripe figs with some yellow orange ripe figs on fruiting branch. Photo taken from Tan et al, 2003.

How this mutualistic relationship works: The figs, Ficus spp., offer protection for the safe development of the wasp larvae  after fig wasps lay their eggs inside the fruit. In return, the wasps pollinate the figs (Kelly, 2010). In the figs, the wasps mate after hatching and the males die while the females squeeze out of the fig to lay their eggs, and in the process pick up pollen (Seah, 2004). The fig ripens once the female fig wasps have left the fig, changing colour and smell which becomes attractive to seed or fruit-eating birds, bats, and monkeys (Noort, 2009). Female fig wasps deposit the pollen they carry when they enter other figs to lay their eggs, thus pollinating the figs.

A female fig wasp laying eggs in a split open fig. Photo taken by Simon van Noort.

A female fig wasp laying eggs in a split open fig. Photo taken by Simon van Noort, 2009.

 

Females and males emerging from their galls in a split open fig. Photo taken by Simon van Noort.

Females and males emerging from their galls in a split open fig. Photo taken by Simon van Noort, 2009.

However, if a wasp lays its eggs but fails to pollinate the fig, the trees will drop those figs to the ground, killing the baby wasps inside.

A learning point to take away from nature: If you can’t get your end of the deal, get even.

References:

“Mutualism” by Robert W. Poole. Nearctica, 2004.  URL: http://www.nearctica.com/ecology/pops/mutual.htm#aphid (accessed 11 April 2010)

Wiebes, J. T., 1979. Co-Evolution of Figs and their Insect Pollinators. Annual Review of Ecology and Systematics, Vol 10: 1-12

“The History and Biology of Kent Ridge Park” by H.T.W. Tan, T. Morgany and Tan Kai-Xin. Robocat, 2003. URL: http://zeta.robotcat.org/wh/KRP-history-biology.pdf (accessed 11 April 2010)

“Figs and Fig Wasps” by Kelly. Biology-blog, 2010. URL: http://www.biology-blog.com/blogs/permalinks/1-2010/figs-and-fig-wasps.html (accessed 12 April 2010)

“Introduction to Plant Life on Kent Ridge” by Brandon Seah. Habitatnews, 2004. URL: http://habitatnews.nus.edu.sg/heritage/pasirpanjang/articles/kentridgeplants-brandonseah.pdf (accessed 12 April 2010)

“How Fig Trees are Pollinated” by Simon van Noort. Figweb, 2009. URL: http://www.figweb.org/Interaction/How_do_fig_wasps_pollinate/index.htm (accessed 12 April 2010)

Weaver Ants: Friend or Foe?

Often, concepts and lessons taught in class are thought to be something observed in the laboratory or in some jungle where students will never go. Yet a trip to one’s own backyard or park proves otherwise.

While taking a walk in a park (literally), a trail of Weaver Ants (Oecophylla smaragdina) on a tree trunk caught my eye.

A trail of weaver ants on a tree trunk which catch my eye.weaver ant

A trail of weaver ants on a tree trunk which caught my eye.

On further inspection, I noticed that the leaves on the tree were covered with holes but no animal was found to be feeding on the leaves. An interesting thing I observed was that holes were observed on only one particular species of trees and only on the mature leaves.

Leaves covered with holes

Leaves covered with holes

This is unusual as weaver ants were known to protect the host tree from herbivory to the extent that they are used as pest control in crops (Peng & Christian, 2004). This ant-plant interaction is known as myrmecophily a form of mutualism. The plant host, known as myrcophytes, often provides shelter (or the building materials, leaves in this case) or food for the ants, which in turn protect plant from herbivores.

A weaver ants' nest, observe how the leaves are folded to form a pocket to house the ants.

A weaver ants' nest, observe how the leaves are folded to form a pocket to house the ants.

As it turns out, ants have inter-species relationships with other animals such as homopterans and lycaenid butterflies (Family: Lycaenidae) (Tsuji at el, 2004). As homopterans adapted to feeding on plant fluids, they are not likely to cause these holes.

A lycaenid butterfly feeding on the flower

A lycaenid butterfly feeding on the flower

Licaenid butterflies are likely culprits as their caterpillars feed in the leaves and they have been spotted in the area. These butterflies also have a record of being myrmecophiles, which are animals form relationships with ants. The caterpillars use chemical and audio signals to interact with ants (Pierce at el, 2002). It seems that the weaver ants might have been harboring the caterpillars which feed on the leaves. Maybe they are not that helpful after all…

Reference:

Peng, R. K. & Christian, K. (2004) The weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), an effective biological control agent of the red-banded thrips, Selenothrips rubrocinctus (Thysanoptera: Thripidae) in mango crops in the Northern Territory of Australia. International Journal of Pest Management, 50(2): 107-114.

Pierce, N. E., Braby, M. F., Heath, A., Lohman, D. J., Mathew, J., Rand, D. B., and Travassos, M. A. (2002)The ecology and evolution of ant association in the Lycaenidae (Lepidoptera). Annual Review of Entomology, 47: 733-771

Tsuji, K., Hasyim, A., Harlion & Nakamura, K. (2004) Asian weaver ants, Oecophylla smaragdina, and their repelling of pollinators. Ecological Research, 19(6): 669-673

Images: All pictures were taken with a Canon PowerShot A1000 IS camera.

Acting stoned: Crypsis in a non-motile fish

stonefish

While reef walking along the shores of St John’s Island, a step on a soft “rock” turned out to be a near scare for an envenomation event. Further investigation of the “rock” while extricating it from my bootie led to the discovery of the estuarine stonefish, S. horrida, infamously known as the most venomous fish in the marine environment (Gwee et al. 1994). Besides their toxic venom, S. horrida also has evolved a specialized skin for trapping mucus and behavioural traits for sedentary life along the intertidal rocky shore.

The use of crypsis as a survival mechanism has been recorded in many different organisms, and it is used for both defensive and offensive strategies for protection and obtaining prey respectively (Starrett 1993). Though many organisms have evolved active camouflage with the use of specialized cells (e.g. chromatophores), S. horrida is unique as it relies on the mucus on its skin to pick up debris and sediment (Fisherson 1973).

With this passive camouflage and their modified swimming behaviour, S. horrida has not only evolved into the most venomous creatures in the sea but also one of the best camouflaged as well. However, in lieu of all this information, a question that begs asking is why such a well camouflaged animal would require such toxic venom?

References

Fisherson L, 1973. Observations on skin structure and sloughing in the stone fish Synanceia verrucosa and related fish species as a functional adaptation to their mode of life. Z. Zellforsch 140: 497-508.

Gwee MC, Gopalakrishnakone P, Yuen R, Khoo HE, Low KS, 1994. A review of stonefish venoms and toxins. Pharmacology & Therapeutics 64: 509-528.

Starrett A, 1993. Adaptive resemblance: a unifying concept for mimicry and crypsis. Biological Journal of the Linnean Society 48: 299-317.