Tubby toad

Asiatic Common Toad (Duttaphrynus melanostictus)
Asiatic Common Toad (Duttaphrynus melanostictus)

Duttaphrynus melanostictus is called the Asian common toad, Indian toad or Black-Spined Toad.  It occurs very widely in south and south-east Asia, from Pakistan all the way to Indonesia.  These toads occur in a variety of habitats, including forests, gardens and urban areas where they can enter homes.  I took these photos in a restaurant in southern Thailand; the toad was under the table!  They feed on a wide range of invertebrates, even consuming scorpions, and can grown quite large (up to 8 inches).  They breed during the rainy season, and the females produce a huge number of eggs (e.g. 40,000) which are laid in ponds of streams.

Asian common toad (Duttaphrynus melanostictus)
Asian common toad (Duttaphrynus melanostictus)

The colours of this toad seem to be highly variable (brown, grey, reddish or yellow), but it is probably a species complex, or a group consisting of more than one species.  Despite the variation however, there are a number of characteristic features.  Firstly, a series of bony ridges: along the edge of the snout; in front of, above and behind the eye, and between the eye and ear.  Secondly, the parotoid glands – kidney-shaped swellings behind the eyes have a network of characteristic black markings (see below).  Thirdly, one or more black spots on the prominent warts which occur all over the body. The ear drum is also very distinctive and in size, is always least as wide as two-thirds of the diameter of the eye.

Duttaphrynus melanostictus parotid gland
Duttaphrynus melanostictus parotoid gland

This species is a typical Bufo type toad (Anura : Bufonidae) containing poisonous secretion both in large parotoid gland as well as in numerous warts on the skin.  The milky white secretions of the parotoid glands of some toads – particularly the cane toad – can produce seizures and death, for example in dogs or cats which have tried to bite or swallow them. Humans should wash their hands after handling toads!  The toxins themselves are called bufadienolides (bufogenins and bufotoxins) and their effects are not pleasant but are used to protect the toad from predators and infections.

This toad is a potentially invasive species and can become a pest if introduced into areas outside of its natural range (2).

1) http://animaldiversity.org/accounts/Duttaphrynus_melanostictus/

2) https://www.daff.qld.gov.au/plants/weeds-pest-animals-ants/pest-animals/a-z-listing-of-pest-animals/photo-guide-to-pest-animals/asian-spined-toad/?a=56658

Rocky Rococo the pebbly toad!

The Rococo toad, Rhinella schneideri, Argentina.
The Rococo toad, Rhinella schneideri, Argentina.

This huge toad, Rhinella schneideri – over 20 cm in length – lives in South America: throughout North and Central Argentina, central Bolivia, the Atlantic coast of Brazil, Paraguay and Uruguay (1). It occurs in a wide variety of habitats, from urban areas to the Chaco, Cerrado and Atlantic Forest regions. Fortunately, it is not threatened – listed as being of Least Concern by the IUCN – and is common throughout its range; it is said to adapt well to anthropogenic disturbance, which perhaps explains why it is increasing in numbers, and bodes well for its future. (2)

It is called the Cururu Toad, or the Rococo Toad.  Cururu is a river in the Pará state of north-central Brazil; presumably a lot of these toads live there!  Rococo is however, a very good alternative name for this toad; the word was derived from the French word “rocaille”, which means pebbles and refers to the stones and shells use to decorate the interiors of caves.  The toad looks very much like it is covered with small pebbles.

The Rococo toad, Rhinella schneideri, Argentina.
The Rococo toad, Rhinella schneideri, Argentina.

It is not too fussy about what it eats, as long as it is insect-like and crunchy!  Beetles, insect larvae and ants are the mainstay of its diet, but it has even been seen swallowing  bees at hives, so bee-keepers consider it a pest! (1)

Don’t try eating this toad!  It has poison glands on its back legs, as well as on either side of its head, which can squirt a poison, which causes eyes or mucous membranes to  burn painfully. According to one report, ‘a dog that has taken such a toad in its mouth will immediately and yowling release it’! (3)  But the interesting thing is that some of the complex organic compounds found in the skin secretions from this toad – at least 10 different compounds have been isolated –  are highly active against human cancer cells (4).  So who knows, perhaps it contains a cure for cancer?

Rhinella schneideri,Argentina

Rhinella schneideri,Argentina

I took these photographs in March 2012, at a ranch in Corrientes Province, northern Argentina.  The frog was obviously feeding on insects attracted to the lights on the buildings at night.  I did not notice it at the time, but there is a red and white beetle on the back of the toad.  What is it doing?  In may be a prey item that just made a lucky escape, or perhaps there is some other sort of relationship occurring?  Is it feeding on something on the toad?  Who knows?  There is also a mosquito feeding on the toad (just behind the right eye), sucking the blood no doubt – see below.

Beetle and mosquito seen on back of Rhinella schneideri
Beetle and mosquito seen on back of Rhinella schneideri

This blog has reminded me once again, that once you start looking closely at an animal, all sorts of interesting – and sometimes unexplained things – pop up!

1) http://amphibiaweb.org/cgi/amphib_query?where-genus=Rhinella&where-species=schneideri

2)  Lucy Aquino, Steffen Reichle, Guarino Colli, Norman Scott, Esteban Lavilla, Jose Langone 2004. Rhinella schneideri. The IUCN Red List of Threatened Species. Version 2014.3. http://www.iucnredlist.org/details/54755/0

3) http://www.waza.org/en/zoo/choose-a-species/amphibians/frogs-and-toads/rhinella-schneideri

4)  Cunha-Filho, Geraldino A., et al. (2010). Cytotoxic profile of natural and some modified bufadienolides from toad Rhinella schneideri parotoid gland secretion. Toxicon 56(3): 339-348.