Fejervarya cancrivora
Common name: Mangrove Frog or Crab Eating Frog
Fejervarya cancrivora is a medium sized frog with a SVL of 40 to 60mm. It has a long snout and its tympanum is prominent with tympanumic folds. This frog is grayish brown in color and has dark marking throughout the body. Continuous ridges can be found on the back which runs ventrally. It has strong, well-built hind limbs with toes three-quarterly webbed. The tips of the toes and fingers are pointed.
Just as the name suggested, F. cancrivora can eat crabs which dwell in the mangroves or near the coast where F. cancrivora can be found. This is a human commensal and is often found in disturbed areas all over SE Asia. Singapore is no different, with populations of these frogs being found in many unusual locations
Common name: Field Frog or Grass Frog
Fejervarya limnocharis is a small to medium frog of SVL of 30 to 60mm. It has a long, narrow head. It is morphological very similar to F. cancrivora with prominent tympanum with tympanumic fold, toes and fingers with pointed tips and dark marking over the grayish brown colored body. The main differences are the disrupted ridges found on the back of the body, the toes less than half webbed, and its smaller overall size.
F. limnocharis are common and found on the edges of all nature reserves and nature parks. Due to its size and its powerful hind limbs, it is one of the most difficult frogs to handle.
R. chalconota is a medium size frog which grows up to over 60mm in SVL. It has a long and pointed snout with distinct tympanum which is mostly dark colored. The slender body is accompanied by two hind legs which are relatively long. The tips of the fingers and toes are expanded into round discs which are adhesive. Its toes are fully webbed.
R. chalconota is bright green in the day but turns to brownish green on the back at night. Like what the name suggest, it has lips which are white in color. R. chalconota is uncommon and is found only in relatively good secondary to primary forests but is abundant in such habitat.
Rana erythraea
Common name: Common Greenback or Green Paddy Frog
Rana erythraea is another medium-sized green frog around 40 to 80mm in SVL. It has a long and pointed snout with distinct tympanum. It has strong and long hind limbs with toes half webbed. R. erythraea is green in color and has two bleach colored strips which run dorsa-laterally from each eye, above the tympanum to the end of the body.
R. erythraea are commonly found in and around ponds in urbanized disturbed parks, although it is very difficult to catch. The call can be described as a series of soft squeaky warbles, giggles and ‘pips’.
Rana baramica
Common name: Brown Marsh Frog or Golden-eared Rough-sided Frog
Rana baramica is a small to medium sized frog 30 to 70mm in SVL. The brown and spotted body is slender and the snout is pointed. The tympanum is gold in color. Both the fingers and toes are long with the tips slightly enlarged and toes mildly webbed. R. baramica has small bumps and ridges on the sides of the back that makes it appear rough. The upper lip is white and interrupted with dark bars and patches.
Although it is only found in the nature reserves locally, the distribution is very abundant in these areas. It has a high pitch giggling call that sounds like ‘yip-yip-yip’.
Rana laterimaculata
Common name: Masked Rough-sided Frog
Rana laterimaculata is morphologically very similar to R. baramica except that the tympanum is darker instead of golden. In addition, the upper lip is continuously white in color. The dorsum aspect of R. laterimaculata is also not as distinctly spotted as R. baramica.
Rana laterimaculata is also only found in nature reserves where it can also be quite locally abundant in the right habitats. To complicate things, its call is also a very high pitch giggling and is very much like R. baramica. Even expertd have difficulty in differentiating these frogs from their very similar congeners, R. baramica.
Rana catesbiana
Common name: American Bullfrog
Rana catesbiana is a large, squat frog with large and distinct tympanum. It stocky hind legs have toes which are fully webbed. The tips of the toes and fingers are swollen. The belly of it is distinctly white with the rest of the body is green in color. Dark patches are spotted over the body.
R. catesbiana was imported from America and has been bred locally for food as in the famous “frog leg porridge”.
Limnonectes blythii
Common name: Malayan Giant Frog or Blyth’s Frog
Limnonectes blythii is a one of the largest frog in Southeast Asia with a SVL up to 150mm. It is morphologically very similar to L. malesiana. Its tympanum is distinct with a tympanumic fold (a layer of skin) above it. On the lower lip of the frog, there is also a pair of fang-like structures. The tips of both finger and toes are swollen and the toes are fully webbed except for the fourth toe. In addition, in some adult individuals, there are two humps on the back, located behind each of the eyes.
L. blythii is common and abundant in the nature reserves in Singapore. Due to the size and its stocky legs, it was commonly captured for food. L. blythii could be a cryptic species with at least two distinct forms just in Singapore. While coloration is one obvious difference, some of these individuals have smooth backs compared to others with rough ridges on either side of the back.
Limnonectes malesiana
Common name: Malesian Frog
Limnonectes malesiana is a large, stout frog with a SVL of up to 130mm. It has a broad, large head which is angular in shape, a differentiating characteristic from L. blythi. The tympanum is distinct with a tympanumic fold above it – always lined in black, making a slight black mask for the frog.. The hind legs are stocky with toes more than three-quarterly webbed. The tips of both fingers and toes are swollen. In some individuals of this species, there is a very thin, white stripe between the eyes and run vertebrally down the back. The back is smooth.
L. malesiana is uncommon and found only in the nature reserves of Singapore. It resides in shallow streams and due to its large size, its pair of eyes can be seen very distinctly just above the surface of the water.
Limnonectes plicatella
Common name: Rhinoceros Frog
Limnonectes plicatella is a small frog of SVL of around 30 to 40mm. It has a short snout but its head is broad and large. The tympanum is not very obvious but the tympanumic fold is present. It has relatively short fore-limbs and the toes are half webbed with swollen tips of the toes and fingers. There are continuous ridges that run ventrally along the back. L. plicatella is yellowish brown in color with a bright yellow belly. Perhaps, the most distinct morphological characteristic is the presence of a horn like structure found in many males on the top of the head.
L. plicatella is rare and found only in good forest.
Occidozyga laevis
Common name: Yellow-bellied Puddle Frog
Occidozyga laevis is a small, stocky frog which ranges from around 30 to 50m in SVL. The distance between its eyes is very small and it is decidedly slick. Its stocky, strong legs are accompanied by fully webbed toes where the tips are rounded. Some individuals of this species have a tan colored line down the middle of the back while others have a cauliflower liked tan colored patch on the forehead. The belly of this frog is, of course as suggested by its name, yellow in color.
O. laevis inhabits water puddles with only the eyes protruding from the surface. It is not common and can only be found in nature reserves of Singapore.
