Family- Dicroglossidae

Frogs of the family Dicroglossidae were previously placed in the subfamily Dicroglossinae under the family Ranidae. But recent molecular phylogenetic analyses have shown that these frogs deserve to be in a separate family (Frost et al., 2006). There are very few external features that unites them. They have a free living tadpole stage which possesses keratinous mouth parts. Thirteen species in five genera (Euphlyctis, Hoplobatrachus, Minervarya, Nannophrys, Sphaerotheca) are recorded from Sri Lanka. Most of the Sri Lankan species are associated with aquatic environments except the species of the genus Sphaerotheca. The genus Nannophrys is endemic to Sri Lanka.

Genus - Euphlyctis Fitzinger, 1843

These are medium to large (40-70 mm) entirely aquatic frogs. They have well developed webbing in their hind feet. Species of Euphlyctis can be differentiated by all other Sri Lankan dicroglossids by the presence of fully webbed toes and by the absence of longitudinal ridges on the back. Two species are known from Sri Lanka.

Species of Euphlyctis in Sri Lanka

Euphlyctis cyanophlyctis (Schneider, 1799)
Euphlyctis hexadactylus (Lesson, 1834)

Euphlyctis cyanophlytis can be diagnosed from E. hexadactylus by the presence of a smooth gular area (vs rough warty gular region in E. hexadactylus). Further, E. hexadactylus is usually greenish in colour while E. cyanophlytis has a spotted dorsum. Both species prefer still waters but E. cyanophlyctis is also seen in flowing waters. Euphlyctis cyanophlytis is distributed throughout Sri Lanka up to an elevation of 1800m above msl. This frog has the ability to skip over the surface of water and has earned the name 'Skipper frog'. Euphlyctis hexadactylus is distributed in the lowlands of Sri Lanka. It is the only known frog to supplement its diet from plant matter.

Genus - Hoplobatrachus Peters, 1863

These are large frogs that usually attain a snout to vent length of 60 mm and hence are the largest frogs in Sri Lanka. They differ from all other Sri Lankan dicroglossids by the presence of fully webbed feet and prominent longitudinal ridges on the skin of back (Dutta & Manamendraarachchi, 1996). Tadpoles of Hoplobatrachus are carnivores and they often prey on other tadpoles (Grosjean et al., 2004). They are well adapted to this mode of life by having needle like mouth parts (Grosjean et al., 2004). Two species are recorded from Sri Lanka.

Species of Hoplobatrachus in Sri Lanka

Hoplobatrachus crassus (Jerdon, 1854)
Hoplobatrachus tigerinus (Daudin, 1802)

The occurrence of H. tigerinus in Sri Lanka is however doubted due to the very few authentic reports in Sri Lanka. Hoplobatrachus crassus can be diagnosed from H. tigerinus by the presence of a shovel shaped or crescentic inner meta-tarsal tubercle (vs elongate inner meta-tarsal tubercle in H. tigerinus). Hoplobatrachus crassus is known to reach about 100mm from snout to vent and thus considered to be the largest species of frog in Sri Lanka. Hoplobatrachus tigerinus was previously reported from the coastal regions of the dry zone of Sri Lanka while H. crassus is distributed throughout lowlands of Sri Lanka up to about 700m above msl.

Genus - Minervarya Dubois, Ohler & Biju 2001

These are relatively small frogs that grow up to a maximum of 40mm. Species of Minervarya can be distinguished by other dicroglossid genera by the presence of incomplete webbing on feet and the presence of uninterrupted longitudinal ridges or rounded tubercles on the skin of mid-back. Three species are known from Sri Lanka of which two are endemic to Sri Lanka. All Sri Lankan species of Minervarya were formally placed in the genus Fejervarya. However, recent molecular phylogenetic analyses (Sanchez et al., 2018) suggests that they be placed in the genus Minervarya. The members of the genus Fejervarya is currently considered be restricted in distribution to Southeast Asia and Northeastern India (Sanchez et al., 2018) .

Species of Minervarya in Sri Lanka

Minervarya greenii (Boulenger, 1905)^E
Minervarya kirtisinghei (Manamendra-Arachchi and Gabadage, 1996)^E
Minervarya agricola (Jerdon, 1853)

Minervarya agricola (previously known as Fejervarya limnocharis) can be distinguished from both M. kirtisinghei and M. greenii by the presence of rounded tubercles on the skin of mid-back (vs uninterrupted longitudinal ridges). Minervarya greenii can be differentiated from M. kirtisinghei by the presence of prominent cutaneous fringe along the inner side of the first toe in M. greenii (vs no prominent cutaneous fringe along the inner side of the first toe in M. kirtisinghei). Minervarya kirtisinghei is distributed in the wet and intermediate zones of Sri Lanka up to about 1500m above msl. Minervarya greenii is distributed in the regions above 1500m above m.s.l. in the central hills of Sri Lanka. Minervarya syhadrensis is a very common species distributed throughout the island up to about 1500m above msl. It is commonly seen in paddy fields, home gardens and also close to water bodies.

Genus - Nannophrys Gunther, 1869

Nannophrys are medium sized frogs that grow usually to a maximum size of 60 mm. They can be distinguished by rest of the Sri Lankan dicroglossids by the the presence of dorso-ventrally flattened bodies, horizontal pupils, blunt finger tips and partially webbed toes (Clarke, 1983; Dutta and Manamendra-Arachchi, 1996). These frogs are always found on wet rock surfaces or rock crevices close to streams. Their flattened bodies allow them to live easily inside crevices or under boulders (Senevirathne & Meegaskumbura, 2015). These interesting frogs have semi-terrestrial tadpoles that live on wet rock surfaces (Wickramasinghe et al., 2004a; Wickramasinghe et al., 2004b; Wickramasinghe et al., 2007). The mating frogs attach their eggs under wet rock surfaces and the eggs hatch in to a developed tadpole stage than other aquatic tadpoles (Wickramasinghe et al., 2004b). The frogs are then known to gaurd the eggs until they hatch (Wickramasinghe et al., 2004b).The genus is endemic to the island. Four species are known from Sri Lanka.

Species of Nannophrys in Sri Lanka

Nannophrys ceylonensis Gunther, 1869^E
Nannophrys guentheri Boulenger, 1882^E,Ex
Nannophrys marmorata Kirtisinghe, 1946^E,CR
Nannophrys naeyakai Fernando, Wickramasingha, and Rodrigo, 2007^E,En

Nannophrys ceylonensis can be distinguished from rest of the Nannophrys species by the truncate snout when viewed laterally. Nannophrys guentheri differs from all other Nannophrys species by the presence of a slightly truncate snout and by the lack of white tipped tubercles on the surface of head. Nannophrys marmorata differs from N. ceylonensis and N. guentheri by the presence of a smoothly rounded snout when viewed laterally and scattered white tipped tubercles on head and marbled markings on legs. Nannophrys naeyakai closely resembles N. marmorata, but it can be differentiated from it by the presence of well separated subarticular tubercle and penultimate subarticular tubercles on the 4th toe (vs. closely placed distal subarticular tubercle and penultimate subarticular tubercles on the 4th toe in N. marmorata). Nannophrys guentheri is considered to be extinct. Nannophrys marmorata is a critically endangered species that is restricted in distribution to the Knuckles mountain range in Sri Lanka. Nannophrys

ceylonensis is distributed in the lowland wet zone of Sri Lanka up to about 1000m above msl. Nannophrys naeyakai is restricted in distribution to the Uva and Eastern provinces of Sri Lanka (Fernando et al., 2007).

Genus - Sphaerotheca Gunther, 1859

Sphaerotheca are medium sized frogs that grow up to a snout to vent length of 55mm. They are characterized by their globular shaped bodies and short limbs. They can be distinguished from other Sri Lankan dicroglossids by the presence of partially webbed toes and an elongate compressed shovel shaped inner meta-tarsal tubercle on feet. They are burrowing species and their shovel shaped inner meta-tarsal tubercles on feet aid in burrowing. Two species are known from Sri Lanka. Sphaerotheca rolandae is endemic to Sri Lanka (Deepak et al. 2020).

Species of Sphaerotheca in Sri Lanka
Sphaerotheca pluvialis (Schneider, 1799)
Sphaerotheca rolandae (Dubois, 1983)^E

Sphaerotheca breviceps can be distinguished from S. rolandae by the presence of a truncate snout when viewed laterally (vs snout rounded when viewed laterally in S. rolandae) and by the absence of a tubercle at the tibio-tarsal articulation (vs the presence of a tubercle at the tibio-tarsal articulation in S. rolandae) (Dutta & Manamendraarachchi, 1996). Both are restricted to the lowland intermediate and dry zones of Sri Lanka.