Duttaphrynus+melanostictus


 * Asian Common Toad ** //Duttaphrynus melanostictus// (Schneider, 1799)


 *  Figure 1. ** Asian Common Toad (Source: Wikimedia . Photo taken by Lokionly. Creative Commons Attribution-Share Alike 3.0 Unported license)

1. INTRODUCTION
toc The Asian Common Toad (//Duttaphrynus melanostictus//) is the most common and well known native terrestrial amphibian in Singapore. They are so abundant and widespread (not just in Singapore but also across Asia) that you can find it across habitats ranging widely from forest margins, ponds and even in your own neighborhood. You might just catch a glimpse of it at night or after heavy rain, congregating under your street lamps to feed on the unsuspecting insects attracted to the light 1]. Although the Asian Common Toad may appear to be aesthetically unappealing due to its many warts and dry skin, a closer look reveals interesting details mentioned in this species page. media type="youtube" key="jg6oOFDa-cw" width="560" height="315" align="left"

**Video 1.** The call of the Asian Common Toad that can often be heard at night or after rain near grass lawns or under street lamps. (Source: Youtube by Leong Tzi Ming.) The Asian Common Toad was originally part of the large typical toad genus //Bufo// as //Bufo melanstictus// but as of 2006 has then been moved to a separate genus //Duttaphrynus// as //D. melanostictus// 2]. However, most available field guides may still list the Asian Common Toad as //B. melanostictus//. It is worth noting that whichever name you come across, both names still refer to the same species. The information you would find in this species page identifies the Asian Common Toad by its more updated name; //D. melanostictus//. This species page particularly aims to provide a broad range of information regarding the Asian Common Toad from a general description of its morphology, interesting behaviors, associations with humans and taxonomic details. The different page sections would appeal towards different visitors to this page:
 * If you happen to see a croaking lump and you are wondering what it is you just saw: || * **Morphology **
 * **Distribution ** ||
 * If you are an undergraduate or student: || * **Biology **
 * **Life Cycle ** ||
 * If you are a conservationist: || * **Conservation ** ||
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">If you are interested in the species’ phylogeny and taxonomic status: || * **<span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Taxonomy **
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Phylogeny ** ||
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">If you are really interested to learn more about the Asian Common Toad: || * **<span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Everything here! ** ||

2. TOADS VS FROGS
<span style="font-family: Arial,sans-serif; font-size: 13pt;">“//Are frogs and toads not the same?//” might just be the first question that would most likely pop up in your head upon reading this section. Although both amphibians do belong to the same order Anura, toads are actually a subset of frogs and belong to the families Bufonidae, Bombinatoridae, Discoglossidae, Pelobatidae, Rhinophrynidae, Scaphiopodidae, and Microhylidae. They differ mostly in their genetic sequences and skeletal structure but can also generally be distinguished by the distinct physical and behavioral characteristics (Figure 2): <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**Figure 2**. Morphological differences to distinguish between frogs (e.g. Marsh frog) and toads (e.g. Cane toad). (Source: The Earth Rangers Foundation. Adapted from Dorcas & Whitifield Gibbons, 2008. Permission granted by The Earth Rangers Foundation.) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Despite these physical differences, it is important to note that it is common to find toads that look like frogs and frogs that look like toads. These physical characteristics (figure 2) used to categorize a species into either a toad or a frog are merely generalizations of common characteristics. Therefore, it is not wise to deem an amphibian a toad simply based on how it looks. Instead, genetic sequences and skeletal structures provide a slightly more accurate classification. Luckily, the Asian Common Toad bears the characteristics of a general toad with its dry and warty skin, stumped body, short legs and inability to jump very high.

3.1 Identification
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian Common Toad that you might come across may be at different stages of its life history; be it at their adult stage or juvenile stage. Thus, the following are distinctive features can be accounted for when trying to identify the Asian Common Toad at its different life stages (Adult, Juvenile and Tadpole): __**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">ADULT **__



<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**Figure 3.** Distinctive features of an Asian Common Toad. (Source: Flickr. Photo taken by Thomas Brown. Adapted notes by Siti Maimon Hussin. Creative Commons Attribution-Share Alike 3.0 Unported license) <span style="font-family: Arial,sans-serif; font-size: 13pt;">These distinctive and highly prominent features greatly helps distinguish the Asian Common Toad from other similar looking toads. These features highlighted in Figure 3 are enough to aid identification if you are a novice explorer or manage to only catch a quick glimpse of this nocturnal amphibians. However, there are also other morphological features (Figure 4) that may not be as prominent but can be just as helpful if you manage to capture or come close enough to the Asian Common Toad. **<span style="font-family: Arial,sans-serif; line-height: 1.5;">Figure 4. **<span style="font-family: Arial,sans-serif; line-height: 1.5;"> Detailed features, habitat and call of the Asian Common Toad for identification. The Asian Black Spined Toad is another common name used for the Asian Common Toad (Source: Victoria State Government. Permission for usage still pending.)
 * Table 1.** Detailed description of the morphology of the Asian Common Toad in its adult stage to aid in identification.
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Color ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Colors are extremely variable throughout species.
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Colors range from plain brick red to almost fully black.
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Most common color seen is pale yellow-brown marked boldly with dark or reddish brown streaks and spots ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Head ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Moderately sized.
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Distinct pattern of bony ridges (cranial crests) on the head.
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Elevated ridges appear on head ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Eyelids ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Eyelids have a long dark crest around the boarder. ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Skin ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Thick, dry and warty skin
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Backs covered with warts of different sizes
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Warts are encircled with black or dark pigments and have spines protruding ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Snout ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Bony ridges along edge of the snout (canthal ridge)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Short and pointy snout ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Tympanum (external hearing structure) ** || * <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5; text-align: justify;">Distinct
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Oval or circular in shape
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">At least as wide as 2/3 the diameter of eye ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Parotid gland ** || * <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5; text-align: justify;">Prominent
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Kidney shaped or oval or elliptical and elongated ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Hindlimbs ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Short ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Fingers ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">First finger often longer than second.
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Blunt fingers ||
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Toes ** || * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Some are half webbed to the digits’ length ||

**__<span style="font-family: Arial,sans-serif; font-size: 13pt;">JUVENILES __**

**Figure 5.** Juvenile of Asian Common Toad from Bangkok (Source: Reptiles and Amphibians of Bangkok. Photo taken by Jonathan Hakim. Creative Commons Attribution-Non Commercial-Share Alike 3.0 Unported) <span style="font-family: Arial,sans-serif; font-size: 13pt;">There are slight differences between juvenile Asian Common Toads to their adult counterparts. Juveniles possess a black band around their throat that runs between the chin and the breast. Juveniles also do not have the distinct warts seen in adults. Their tympanum (external hearing structure) is much smaller than the adults. <span style="font-family: Arial,sans-serif; font-size: 13pt;">The differences in morphology between the juveniles and adults makes identification of the Asian Common Toad difficult if we only characterize them by their morphology. Instead, looking at their genetic sequences (which is the **same** as the adult!) is more helpful in identification.
 * __<span style="font-family: Arial,sans-serif; font-size: 13pt;">TADPOLES __**

**Figure 6.** Tadpole stage of Asian Common Toad from Hong Kong (Source: The University of Hong Kong School of Biological Sciences. Photo taken by Teresa Ma.) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Tadpoles are often found in groups at slow and still moving water such as the side pools along hilly torrents, marginal waters of ponds and puddles. They can be characterized by the following details 3]: <span style="font-family: Arial,sans-serif; font-size: 13pt;">Interested to learn more about the tadpoles of Asian Common Toad, then jump straight to: **__Life history: Growth and metamorphosis__** for further information regarding this fascinating stage in the Asian Common Toad’s life history.
 * Table 2.** Description of the Asian Common Toad at its tadpole stage
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Size ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Total length of 26 - 27 mm ||
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Color ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Uniform black in color for some ||
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Shape ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Globular shape ||
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Beak ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Finely serrated and sharp ||
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Fin ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Broad dorsal fin ||
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Tail ** || * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Weak short tail
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Tail length of 19 - 20 mm ||

3.2 Determining gender
<span style="font-family: Arial,sans-serif; font-size: 13pt;">After successfully identifying the Asian Common Toad, it is also possible to determine its gender based on the few distinct differences in morphological features mentioned below 4]:
 * Table 3.** Detailed differences in morphology between male and female Asian Common Toad at its adult stage
 * **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Morphology ** ||  **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Male **  ||  **<span style="font-family: Arial,sans-serif; font-size: 13pt;">Female **  ||
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt;">Size (From snout to vent) // || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">57 – 83 mm  || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">65 – 85 mm  ||
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt;">Subgular vocal sac // || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Black pigmented subgular vocal sac which opens into the pharynx by a single asymmetrically located slit.  || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Absent  ||
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt;">Throat region // || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Dull copper yellow/ bright yellow orange throat region  || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Light gray or gray buff  ||
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt;">Fingers // || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Inner side of first and second fingers have pale grey to intense black nuptial pads  || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Absent  ||
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt;">Bidder’s organ // || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Remains throughout life in males  || <span style="display: block; font-family: Arial,sans-serif; font-size: 13pt; text-align: center;">Has a tendency to disappear in majority of females after maturity  ||

4.1 Global distribution
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian Common Toads have a wide distribution across Asia. The native distribution extends north Pakistan through Nepal, Bangladesh, India, Sri Lanka, Southern China, Myanmar, Lao, Vietnam, Thailand, Cambodia, Malaysia, Singapore, and Indonesia (Sumatra, Java, Borneo and Natuna Islands). <span style="font-family: Arial,sans-serif; font-size: 13pt;">They were introduced to the islands of Bali, Sulawesi, Ambon and Manokwari, and the northeastern portion of the Vogelkop Peninsula in New Guinea 5] media type="custom" key="28019203" width="588" height="454" align="center"

**<span style="font-family: Arial,sans-serif; font-size: 11pt;">Figure 7 **<span style="font-family: Arial,sans-serif; font-size: 11pt;">. Global distribution of Asian Common Toad (Green placemarkers - Native; Red placemarkers - Naturalized or Invasive)

4.2 Local distribution
<span style="font-family: Arial,sans-serif; font-size: 13pt;">In Singapore itself, the Asian Common Toad has been recorded in various parks in Singapore such as West Coast Park, Chinese Garden, Singapore Botanic Gardens, East Coast Park, Pasir Ris Park, Sungei Wetland Nature Reserve, MacRitchie Resevoir and even Pulau Ubin (Figure 8). media type="custom" key="28019211" align="center" width="566" height="454"

**<span style="font-family: Arial,sans-serif;">Figure 8. **<span style="font-family: Arial,sans-serif;"> Distribution of the Asian Common Toad in Singapore. (Source: The DNA <span style="color: windowtext; font-family: Arial,sans-serif;">of Singapore, RMBR)

4.3 Habitat
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian Common Toads are ** generalists. **<span style="font-family: Arial,sans-serif; font-size: 13pt;">They can be found in a widespread range of habitats such as in our urban areas, under ground cover (e.g. rocks, leaf litter and logs), in human dominated agricultural land, in water bodies like upper beaches, riverbanks, ponds and lakes, and in disturbed lowland forests and edges of these forest. As it is a nocturnal amphibian, it can be found in open areas at night to feed on insects but later hides under rocks, leaf litter and man-made structures for shelter during the day. It can also be found in more aquatic biomes as the Asian Common Toad breeds particularly in still and slow-moving waterbodies, rivers, ponds and pools 6].

**<span style="font-family: Arial,sans-serif;">Figure 9. **<span style="font-family: Arial,sans-serif;"> This Asian Common Toad from Singapore is a common sight particularly at night or after a heavy rain (Source: Wildlife Singapore//.// Photo by Nick Baker and Kelvin Lim) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">In Singapore, this very common Asian Common Toad can be found among vegetation, roads and jungle paths, and in bodies of water throughout Singapore. Its commonality in Singapore is not simply just due to its wide range of habitat but also due to its availability throughout the year, regardless of dry or wet conditions 7].

5.1 Toxicity
<span style="font-family: Arial,sans-serif; font-size: 13pt;">True toads are defined by the parotid glands behind their eyes that secrete powerful toxins that can be deadly to their enemies. No doubt the Asian Common Toads also share this distinctive feature that has been beneficial in deterring many predators. This has allowed the Asian Common Toad to successfully breed without a fear of predation. Their oval or elliptical parotid glands secretes a milky and pungent substance (called **Bufotoxin**) that have been recorded to be fairly toxic. On top of that, their skin also excretes several bioactive compounds with lethal, hypotensive, hypertensive, neurotoxic, cardiotoxic, haemolytic and sleep inducing factors 8]. The toxin from the parotid glands and secretions from the skin of the Asian Common Toad has driven countless of scientific studies on discovering and further understanding these interesting properties for possible drug discovery against cancer. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">There has been records of the Asian Common Toad causing skin irritations, illnesses and even deaths to humans particularly in Laos and Taiwan where these toxic toads were consumed 9] 10]. Yikes! Seems like the best option is to stay away from the Asian Common Toad. However, there is no need to be //too// alarmed as its toxicity level (only when physically touched) is relatively too low to be directly life threatening to humans 11]. Only consumption of the Asian Common Toad has shown adverse health effects. ** Physical handling of the Asian Common Toad is still relatively safe for humans. However, it is still advisable to practice good hygiene after handling them. **

5.2 Adaptations to urban landscape
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The urban landscape can be particularly challenging for some wildlife species. However, the ability for a species to successfully adjust and adapt to the urban environment and its harsh anthropogenic pressures demonstrates the specie's fascinating ecological and behavioral **plasticity** 12]. For the Asian Common Toad, it has been extremely successful in adapting to the urban Singapore landscape as observed by its great abundance even in grassy lawns and drains 13].

**<span style="font-family: Arial,sans-serif; line-height: 1.5;">Figure 10. **<span style="font-family: Arial,sans-serif; line-height: 1.5;"> Dry, thick and relatively impermeable skin of the Asian Common Toad allows it to tolerate the drier and harsher urban conditions (Photo taken by . <span style="font-family: Arial,sans-serif; text-align: center;">Creative Commons Attribution-Share Alike 3.0 Unported license ) <span style="font-family: Arial,sans-serif; font-size: 13pt;">This feature of being highly adaptable and tolerant to disturbance and severe habitat alteration is due to its thick and relatively impermeable skin. Their skin allows the Asian Common Toad to be less susceptible to drying and helps increase its ability to survive even in dry urban microhabitats 14]. <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Its toxic skin secretion and parotid gland are poisonous to predators and enemies from the urban environment. This has given the Asian Common Toad the added advantage to expand its population number without facing the **risk of predation**. Even during its tadpole stage, the Asian Common Toad has been recorded to be toxic thus reducing predation risks. The tadpoles are also noted to be capable of assessing predatory risk and reducing its time in feeding and delaying metamorphosis to avoid predators 14]. Studies have shown that tadpoles reared with a predator that fed on other tadpole species were able to develop these capabilities (assess predatory risk; reduce feeding time; delay metamorphosis) compared to tadpoles that were grown in a predator-free environment. These abilities allow the Asian Common Toad to thrive even better in the urban landscape. <span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian Common Toads are also great generalists in their habitats and feeding habits. Their ability to thrive in a range of habitats and feed on a variety of food allows the Asian Common Toad to survive and reproduce better than other species that has a narrower environmental tolerance and lower resilience to the urban landscape.

5.3 Diet
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**<span style="font-family: Arial,sans-serif;">Video 2 **<span style="font-family: Arial,sans-serif;">. Asian Common Toad feeding on winged termites (Source: [|Youtube]. From Wild Angles.) <span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian Common Toads are mostly insectivorous that feed on wasps, bees and ants but are also known to be opportunist that can also feed on a variety of arthropods and mollusks. Arthropods such as earwigs, grasshoppers, crickets, true bugs, moths and butterflies, beetles, typical bugs, termites, cockroaches, mantids, true flies, centipedes and millipedes have also been recorded in the stomach of some Asian Common Toads 10] 11]. This **opportunistic feeding** is particularly observed by some Asian Common Toads from the Singapore Botanic Gardens. They were found to feed dominantly on the ants and termites, along with centipedes, millipedes and beetles. Ants and termites are the typical litter fauna found in the grass areas and secondary forest of the Singapore Botanic Gardens 15].

6.1 Life history
|| ** Time length ** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Throughout the year (In Singapore) || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">10 years (captivity) || (Source: 16]17])
 * Table 4.** Summary of the time length during the different life stages of the Asian Common Toad
 * ** Life stage **
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Breeding season || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Breed during wet season (In geographic areas with distinct wet and dry seasons)
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Call || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Heard throughout the year (In Singapore) ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Oviposition frequency || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Can possibly breed twice per year ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Average number of offspring || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">40, 000 eggs per clutch ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Hatching of eggs || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">24 – 48 hours ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Tadpole stage || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">34 – 90 days ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Metamorphosis || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">25 – 30 days ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Life expectancy || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">4 years (wild)



<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**Figure 11.** Life cycle of toad (Source: National Geographic Society. Drawing courtesy of Jane Kim. Adapted notes from Siti Maimon Hussin)

6.2 Breeding season
<span style="font-family: Arial,sans-serif; font-size: 13pt;">Breeding of the Asian Common Toad has been observed to be dependent on rainfall. In areas outside of Singapore where there are distinct differences in rainfall and temperature during the wet and dry seasons (e.g India, Pakistan and China), breeding occurs more prominently during the wetter seasons. However, Singapore’s high rainfall and temperature throughout the year encourages the Asian Common Toad to persist breeding all year round 7].

<span style="font-family: Arial,sans-serif; font-size: 13pt;">This is further supported by the observation of mature sex characteristics in both males and females throughout the year in Singapore. Mature adult males in Singapore were observed to have nuptial pads and comparable secondary sexual characters while its female counterparts were found to have enlarged oviducts in all months. Male Asian Common Toads are also noted to have a continuous **spermatogenic cycle** whereby sperm cells are produced year round 18]. These ‘reproductive ripeness’ indicates the readiness of the Asian Common Toad to breed throughout the year. The male Asian Common Toad were also observed to have enlarged vocal sacs in most months. This feature is important for males to vocalize their calls to attract potential mates throughout the year 7].

6.3 Call
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**<span style="font-family: Arial,sans-serif;">Video 3. **<span style="font-family: Arial,sans-serif;"> Call of Asian Common Toad in Singapore by Leong Tzi Ming. (Source:[| Youtube]) <span style="font-family: Arial,sans-serif; font-size: 13pt;">The call of the male Asian Common Toads has been noted to sound like “curr-curr-curr”. The Asian Common Toad are not recorded to make any other vocalizations except for the calls (Video 3) observed only during mating. 10]. Calls were heard throughout the year in Singapore indicating all year round breeding 7].

6.4 Mating


**<span style="font-family: Arial,sans-serif;">Figure 12. **<span style="font-family: Arial,sans-serif;"> A mating male (on top and smaller in size) and a female (below and larger in size) Asian Common Toad in the standard **amplexus** mating position. (Source: Flickr. Photo taken by Thomas Brown. <span style="font-family: Arial,sans-serif; line-height: 1.5;">Creative Commons Attribution-Share Alike 3.0 Unported license.) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian Common Toads can breed opportunistically in small natural and man-made water bodies including gutters, puddles, and cement cisterns in parks. Males would congregate at these breeding sites and call to attract the females 10]11]. These calling males can become quite aggressive as they tug and jump over each other to secure a nuptial hold on the females. As males often largely exceed females in their numbers, the Asian Common Toad practices **polygynandry** mating system//.// This is typically observed in large populations such as the Asian Common Toad. The male and female then shakes off other suitors and move to a quieter place away from the breeding site to mate 19].

6.5 Reproduction
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The female will lay a long string of black eggs in generally deep and quiet waters or pools, which are then externally fertilized by the male. Eggs are enclosed in a thick mucus membrane and deposited on submerged vegetation 20]. Average number of 40, 000 eggs per clutch were observed.

6.6 Growth & Metamorphosis
<span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian common toads have a typical Anuran development which is indirect with an aquatic tadpole stage. Tadpoles then hatch form their eggs within 24 and 48 hours, depending on the water conditions. Increase in reproductive success of the tadpoles of the Asian Common Toad were sometimes observed during their tadpole stage. This reproductive success has been studied to be partly dependent on kinship and evasion from predators. <span style="font-family: Arial,sans-serif; font-size: 13pt;"> Tadpoles that were reared with their sibling groups grew at a higher rate and developed faster compared to those that were reared in mixed groups 19]. The high number of eggs produced by the females results in intra-specific competition among tadpoles. These tadpoles also showed the ability to evade predators by emerging at different times and sizes in the presence of predators. A decrease in body mass of up to 46% and a delayed **metamorphosis** are also behaviors that the Asian Common Toad tadpole has adapted against predators allowing successful growth of the Asian Common Toad species to huge population numbers 21]. <span style="font-family: Arial,sans-serif; font-size: 13pt;">The tadpoles then undergo metamorphosis to become a toadlet where they start to lose their tail and become less dependent on the aquatic environment. Metamorphosis to the toadlet stage can take up 25 - 30 days. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**Figure 13.** Metamorphosed toadlet of Asian Common Toad that usually takes up 25 – 30 days but can be delayed upon presence of predators (Source: Reptiles and Amphibians of Bangkok. Photo taken by Jonathan Hakim. Creative Commons Attribution-Non Commercial-Share Alike 3.0 Unported)

7.1 Singapore
<span style="font-family: Arial,sans-serif; font-size: 13pt;">The Asian common toads are listed on the International Union for Conservation of Nature (IUCN) Red list as “Least Concern”. Their high reproductive success, adaptability to the urban environment and widespread distribution allows the Asian Common Toad to have a high population in Singapore 6].

7.2 Outside of Singapore
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">In the regions of the world that these toads have become naturalized, populations are on the rise. These toads are becoming increasingly common and a cause of concern 1]7]11]. The Asian Common Toad is regarded as a significant invasive pest in Queensland, Australia and is predicted to possibly overtake Australia's infamous native pest, the Cane Toad (//Rhinella marina//). Similar to Cane toads, the Asian Common Toad has been reviewed to be a threat to the native Anuran and invertebrate communities in Australia through predation and competition for food and shelter. They have the potential to carry exotic parasites and diseases that can cause severe impacts to the native population 25]. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">The Asian Common Toad was also first detected in Bali in 1958 which then spread throughout Indonesia to Papua New Guinea. Their ecological impact in Papua remains unknown due to lack of assessment and study. They were also observed recently in East Timor and are suspected to cause serious ecological problems, comparable to the impact of Cane Toads in Australia. To date, no quantitative assessment has been carried out to measure their impacts in East Timor 11].

8.1 Taxonavigation
<span style="font-family: Arial,sans-serif; font-size: 13pt;">(Source: ITIS)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Animalia (kingdom)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Chordata (phylum)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Tetrapoda (superclass)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Amphibia (class)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Anura (order)
 * <span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Bufonidae (family)
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Duttaphrynus //<span style="font-family: Arial,sans-serif; font-size: 13pt;"> (genus)
 * //<span style="font-family: Arial,sans-serif; font-size: 13pt; line-height: 1.5;">Duttaphrynus melanostictus //<span style="font-family: Arial,sans-serif; font-size: 13pt;"> (species)

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">The Asian Common Toad was previously placed in the genus //Bufo// as //Bufo melanostictus// by Schneider in 1799 10]. However, its taxonomic hierarchy has recently been revised in 2006 under the genus //Duttaphrynus// as //Duttaphrynus melanostictus// by Frost as he concluded that //Duttaphryunus// is only distantly related to other Asiatic bufonids 2].

8.2 Synonyms

 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo melanostictus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> (Schneider, 1799)
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo chlorogaster //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Daudin, 1802
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Rana dubia //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Shaw, 1802
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo scaber //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Daudin, 1802
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo bengalensis //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Daudin, 1802
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo flaviventris //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Daudin, 1802
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo carinatus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Gray, 1833
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo isos //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Lesson, 1834
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo gymnauchen //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Bleeker, 1858
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Docidophryne isos //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Fitzinger, 1861
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Docidophryne spinipes //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Fitzinger, 1861
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Phrynoidis melanostictus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Cope, 1862
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo spinipes //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Steindachner, 1867
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo longecristatus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Werner, 1903
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo tienhoensis //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Bourret, 1937
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Docidophryne melanostictus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Bourret, 1942
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo camortensis //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Mansukhani and Sarkar, 1980
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Ansonia kamblei //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Ravichandran and Pillai, 1990
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo melanostictus melanostictus //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Khan, 2001
 * //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">Bufo melanostictus hazarensis //<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;"> Khan, 2015

<span style="color: #252525; font-family: Arial,sans-serif; font-size: 13pt;">(Source: NCBI)

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Synonyms tend to arise whenever an existing taxa is changed or moved to a different genus. This is observed by the original name of the Asian Common Toad, //Bufo melanostictus// being a synonym after Frost, et. al. (2006) transferred it to the genus //Duttaphrynus//. Synonyms can also arise when the same species is described and named more than once. This error in nomenclature can possibly occur due to:
 * 1) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Lack of highly connected and updated databases in the past,
 * 2) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Subjectivity in morphology (e.g. cane toads look almost similar to the Asian Common Toad with the only difference being its smaller size),
 * 3) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">Lack of accurate morphological detail of the **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;">holotype **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt; line-height: 1.5;"> noted by Schneider (1799) allows variations (vary mostly in morphology) of the Asian Common Toad to be deemed as a different species instead of one species.

8.3 Common Names

 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian spined toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Southeast Asian toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian common toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Spectacled toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Common Indian toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Black-spined toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Common Sunda toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Black-lipped toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Keeled-nosed toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">South Asian garden toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Black-spectacled toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">House toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asiatic toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian eyebrowridge toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Asian black-spotted toad
 * <span style="font-family: Arial,sans-serif; font-size: 13pt;">Javanese toad.

<span style="font-family: Arial,sans-serif; font-size: 13pt;">(Source: EOL)

8.4 Original description
**<span style="font-family: Arial,sans-serif;">Figure 14. **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt; line-height: 1.5;">Original description of the Asian Common Toad as described by Schneider in 1799. Asian Common Toad was filed under the section x. Melanotietus in the original description. (Source: Schneider, 1799) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">The original description of the Asian Common Toad was by Schneider in 1799 (Figure 14) who filed the species under the name //Bufo melanostictus.// Certain details regarding his description is summarized as followed (words that could not be translated by Google Translate remain in its original latin form and is italicized): <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11pt; text-align: justify;">"Warts top //dorfiet// joints of body gray color, //atropunetatae//, //limbus// side of the head jaw //fuperioris// black, plants //femipalmatae//, the tips of the fingers black. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11pt; text-align: justify;">From 'India orientali' Museum Blochianum, gray color, warts capital, //artuumque denfae//, most //planiusculae//, black dot, //er// against both sides of colors, gray, the distance between the eyes //depreffum//, smooth, //exftantis// orbital margins, edging back toward the black tympanum until it runs out, //antrorfum defeendens// on both sides of the nose //coit//. //Idom// is surrounded by a fringe cheek //fuperiorem//, Likewise tips of the fingers and palm calluses two black //plantarumque//. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11pt; text-align: justify;">Another example of the //Mufei//, where under his name //Chinenfis bufunis proftabat// color //fundum// had to //fufeum// more inclining, //Derfor// tiny black spots and unaffected." (translated using Google translate) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Schneider's original description lacks accurate morphological details needed to properly determine the Asian Common Toad. This can pose potential problems in identification from other similar looking cryptic species.

8.5 Type series
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Having both the original description and the physical specimen (or an illustration of the specimen) of the species when it was being described provides useful information and details for other taxonomists and users to identify the Asian Common Toad. The following are the type specimens that has been used to construct the morphological details used for the identification of the Asian Common Toad. Unfortunately, for unknown reasons, there is no information accessible regarding the holotype of the Asian Common Toad. Thus, other type series used are listed instead:
 * Table 5.** Type series of the Asian Common Toad and important details (i.e location found, location of storage, etc.) regarding the type.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">**Type** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">**Image** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">**Details** ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Holotype || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Not available || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Not available ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Syntypes ZMB 3462-63 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Not available || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">In the Museum für Naturkunde, Universität Humboldt, in Berlin, Germany. The type locality was listed from “India orientali”. ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Lectotype ZMB 3462

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">(Note: Lectotypes have no 'legal' standing and so they are often not listed) || **Figure 15.** Lectotype of //D. melanostictus// (Source: SysTax databse system. Photo taken by Kwet.) || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Re-described by Dubois & Ohler in 1999 is found in the Museum für Naturkunde, Universität Humboldt, in Berlin, Germany. The type locality was listed from “India orientali” ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Paratype ZMB 3463

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">(Note: Paratypes have no 'legal' standing and so they are often not listed) || **Figure 16**. Paratype of //D. melanostictus// (Source: SysTax databse system. Photo taken by Kwet.) || <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: center;">Described by Bloch and is found in the Museum für Naturkunde, in Berlin, Germany. The type locality was listed to be from India. ||

** 9.1 Gene Sequence **
<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">As scientific knowledge and technology continue to advance, we are able to better identify species based not just entirely on morphological differences (which can be relatively incomplete or subjective) but also based on their molecular data (e.g. DNA, nucleotide sequences, protein sequences) and phylogenetic information. These additional details are of great help when identifying the Asian Common Toad from other morphologically similar looking species. The following is the complete genomic sequence of the Asian Common Toad which can be used for identification: <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">//Bufo melanostictus//, mitochondrion, complete genome <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Accession: Locus AY458592.1 <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Base pair length: 17374 bp

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**Table 6**. Genomic sequence of the Asian Common Toad (Source: Gen Bank AY458592.1)

media type="custom" key="28021931" align="left" width="250" height="250"

**Figure 17.** Illustration of the DNA barcoding of the complete genomic sequence of Asian Common Toad when processed by the BOLD database. (Source: BOLD) <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">Certain nucleotide sequences in the genome are also particularly helpful in determining phylogenetic relationships of the Asian Common Toad with other closely related species. We can achieve this by looking at the cytochrome oxidase I (COI) gene -- a gene sequence that codes for an essential protein in the cellular respiration pathway in the mitochondria. Any gene sequence from the genome of the Asian Common Toad can actually be used for sequencing however, the COI is the more preferred sequence as it generally meets the following requirements important for sequencing:
 * 1) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;"> Must be //**widely present**// in most organisms so that it can be compared across species.
 * 2) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Must be //**highly conserved**// whereby the gene sequence changed slow enough that it remains the same throughout all individuals of the same species but fast enough that it varies between different species.
 * 3) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Have //**many copies**// so that there is a high likelihood of extracting sufficient amount of DNA for analysis.

The following is the COI sequence of the Asian Common Toad: <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">//Bufo melanostictus//, mitochondrion, CO1 sequence <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Accession: Locus NC_005794.2 <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Base pair length: 1542 bp

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11pt; text-align: justify;">**Table 7**. CO1 sequence of the Asian Common Toad (Source: Gen Bank NC_005794.2) media type="custom" key="28021895" align="left" width="711" height="513"

9.2 Phylogentic Tree
<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">The COI gene sequence of the Asian Comm on Toad can be compared with the COI sequences from other species to determine how different the sequences are from each other. It is in these differences that we can determine how much evolutionary time has passed since the Asian Common Toad distinguished itself from other species and how distantly related the Asian Common Toad is from other species. From this information, we are able to construct phylogentic trees to determine evolutionary relationships.

**Figure 18.** Phylogenetic relationship of the Asian Common Toad (listed as //Bufo melanostictus// in this tree) in the family Bufonidae. A general phylogenetic tree constructed from the consensus of four most parsimonious trees. (Source: Frost, et.,al., 2006. Copyright from the American Museum National History 2006.) <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Other sequences like 12S rRNA and 16S rRNA are also often used to construct phylogenetic trees like the ones in Figure 19. Studies have shown that both the Asian Common Toad from West Bengal in India and in China are very closely related despite being separated geographically by the Himalayas for a considerable amount of time 24]. **<span style="font-family: Arial,sans-serif;">Figure 19. **<span style="font-family: Arial,sans-serif;"> Maximum Parsimony tree derived from 3080 mt DNA bp having 12S rRNA and 16S rRNA sequences from different Bufo species, number at the nodes represent percentage replicate trees in whih the associated taxa clustered together in bootstrap test (Source: Dutta & Das, 2013)

10. GLOSSARY

 * **Generalist** - Species that are able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Bufotoxin** - Moderately potent poison secreted in the skin of many anuran amphibians, especially in the typical toads (genus Bufo)
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Plasticity** - Adaptability of an organism to changes in its environment or differences between its various habitats.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Predation risk** - The effect of the absence or presence of predators that feed on its prey
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Opportunistic feeding** - Species that are able to sustain itself on different food sources
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Spermatogenic cycle** - Process of the production of sperms; the male reproductive cell.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Amplexus** - A type of mating behavior in which males grasps a female with his front legs during which the male fertilizes the female eggs as they are released from the body
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Polygynandry** - Reproductive strategy that occurs when two or more males have an exclusive sexual relationship with two or more females.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Metamorphosis** - biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Holotype** - single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described.
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13pt; text-align: justify;">**Maximum parsimony tree** - has an optimality criterion whereby the phylogenetic tree that minimizes the total number of character-state changes is chosen.

11. USEFUL LINKS

 * 1)  Nick Baker's page on Amphibians of South-east Asia <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">- This website highlights some of the common amphibians found in Southeast Asia according to their family. Take a look at the true toads under the family Bufonidae to find the Asian Common Toad!
 * 2)  Wild Singapore's page on Amphibians in Singapore: A blog on Singapore's Wildlife. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">- This website showcases the frogs and toads commonly found here in Singapore, including the Asian Common Toad which is listed as 'Asian Toad' in this website.
 * 3)  IUCN Red List - Duttaphrynus melanostictus <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">- The IUCN provides an interesting evaluation regarding the Asian Common Toad to assess its conservation status.

12. REFERENCES

 * 1) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Church, G. (1960). The invasion of Bali by //Bufo melanostictus//. //Herpetologica//, 16(1), 15-21.
 * 2) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Frost D, Grant T, Faivovich J, Bain R, Haas A,Haddad C, de Sá R, Channing A, Wilkinson M,Donnellan S, Raxworthy C, Campbell J, Blotto B, Moler P, Drewes R, Nussbaum R, Lynch J,Green D, Wheeler W. (2006). The amphibian tree of life. //Bulletin of the American Museum of Natural History.// 297: 1–370.
 * 3) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Khan, M.S. (1991). Unpublished Ph.D. dissertation, University of the Punjab, Lahore, Pakistan.
 * 4) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Alexander, G. (1933). Secondary Sexual Characters of //Bufo melanostictus// Schneider. //Copeia//, //1933//(4), 204–207.
 * 5) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Krysko, K.L. and 12 others. 2011. Verified non-indigenous amphibians and reptiles in Florida from 1863 through 2010: Outlining the invasion process and identifying invasion pathways and stages. Zootaxa 3028:1-64.
 * 6) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Paul van Dijk, P., Djoko Iskandar, Wai, M. N. L., Gu, H. Geng, B., Lue K., Chou, W, Yuan, Z. Bosco, C., Dutta, S., Inger, R., Manamendra-Arachchi, K.,Khan, M.S. (2004). //Duttaphrynus melanostictus//. In: IUCN 2014
 * 7) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Berry, P. Y. (1964). The breeding patterns of seven species of Singapore Anura. //The Journal of Animal Ecology//, 227-243.
 * 8) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Dutta, D., & Das, S. K. (2013). Phylogenetic Relationship of Duttaphrynus melanostictus From India and China as Revealed from the Study of 12S and 16S mtDNA Genes. //International Journal of Zoological Research//, //9//(2), 49.
 * 9) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Khan, M.S. (1982a). Collection, preservation and identification of amphibian eggs from the plains of Pakistan. //Pakistan Journal of Zoology//, 14, 241-243
 * 10) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Mercy, M. 1999. Studies on some aspects of the Biology and Ecology of the Common Indian Toad Bufo melanostictus Schneider (Class Amphibia; Order Anura). Mahatma Gandhi University Online Theses Library.
 * 11) <span style="font-family: Arial,sans-serif; font-size: 13pt;">The State of Queensland, Department of Employment, Economic Development and Innovation. (2010). Pest Risk Assessment: Asian spined toad (//Bufo melanostictus//). PR10_5469. Queensland, Australia: The State of Queensland. Accessed Nov 02, 2015 at <span style="color: windowtext; font-family: Arial,sans-serif; font-size: 13pt;">[] <span style="font-family: Arial,sans-serif; font-size: 13pt;">.
 * 12) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Luniak, M. (2004). Synurbization–adaptation of animal wildlife to urban development. In //Proc. 4th Int. Symposium Urban Wildl. Conserv. Tucson// (pp. 50-55).
 * 13) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Bickford, D., Ng, T. H., Qie, L., Kudavidanage, E. P., & Bradshaw, C. J. (2010). Forest fragment and breeding habitat characteristics explain frog diversity and abundance in Singapore. //Biotropica//, //42//(1), 119-125.
 * 14) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Inger, R. F. & Stuebing, R. F. (2005). A field guide to the frogs of Borneo. 2nd edition. Natural History Publication, Kota Kinabalu.
 * 15) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Berry, P. Y. & Bullock, J. A.. (1962). The Food of the Common Malayan Toad, Bufo melanostictus Schneider. //Copeia//, //1962//(4), 736–741.
 * 16) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Bartlett, R.D. & Griswold, B. (2001) Reptiles, amphibians, and invertebrates: an identification and care guide. Barron’s Educational Series.
 * 17) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Daniels, RJR (2005) Amphibians of peninsular India. Universities Press (India).
 * 18) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Huang, W. S., Cheng, Y. S., & Tu, H. Y. (2004). Reproductive patterns of two sympatric ranid frogs, Rana latouchii and R. sauteri, with comments on anuran breeding seasons in Taiwan. //Coll. Res//, //17//, 1-10
 * 19) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Saidapur, S. & Girish, S. (2001). Growth and Metamorphosis of Bufo melanostictus Tadpoles: Effects of Kinship and Density. //Journal of Herpetology.// 35 (2): 249- 254.
 * 20) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Khan, M.S. (1982b). Collection, preservation and identification of amphibian eggs from the plains of Pakistan. //Pakistan Journal of Zoology//, 14, 241-243
 * 21) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Mogali, S. M., Saidapur, S. K., & Shanbhag, B. A. (2011). Levels of predation modulate antipredator defense behavior and metamorphic traits in the toad Bufo melanostictus. //Journal of Herpetology//, //45//(4), 428-431.
 * 22) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Schneider, J. G. (1799). //Historia Amphibiorum Naturalis et Literarariae. Fasciculus Primus. Continens Ranas, Calamitas, Bufones, Salamandras et Hydros in Genera et Species Descriptos Notisque suis Distinctos//. Jena: Friederici Frommanni. 216
 * 23) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Che, J., Chen, H.M., Yang, J.X., Jin, J.Q., Jiang, K., Yuan, Z.Y., Murphy, R. W. and Zhang, Y.P. (2012), Universal COI primers for DNA barcoding amphibians. Molecular Ecology Resources, 12: 247–258. doi: 10.1111/j.1755-0998.2011.03090.x
 * 24) <span style="font-family: Arial,sans-serif; font-size: 13pt;">Dutta, D., & Das, S. K. (2013). Phylogenetic Relationship of Duttaphrynus melanostictus From India and China as Revealed from the Study of 12S and 16S mtDNA Genes. //International Journal of Zoological Research//, //9//(2), 49.
 * 25) <span style="font-family: Arial,sans-serif; font-size: 13pt;"> <span style="font-family: Arial,Helvetica,sans-serif; font-size: 13pt;">Shine, R. (2010). The ecological impact of invasive cane toads (//Bufo marinus//) in Australia. //The Quarterly Review of Biology.// 85(3), 253-291.

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