Hoplobatrachus tigerinus (Daudin, 1802)

Taxonomy and Naming

The Indian bullfrog, scientifically named Hoplobatrachus tigerinus (Daudin, 1802), is a large frog species.

Adult Body Size

Adults can reach up to 170 millimetres (6.7 in) in length.

Head Morphology

Their heads are generally longer than they are wide, though older individuals tend to develop wider heads.

Adult Coloration

Their base coloration is normally green or brown with dark spots, and males turn yellow during the breeding season. Most individuals have a yellow streak running along the spinal region of the back.

Population Variation

Substantial variation in both color and size occurs between different populations, even populations that are geographically close. A 2012 study found that frogs from different villages in Jamshoro District, Sindh, Pakistan were consistently different in size and coloration from other nearby populations; the study suggested these differences were caused by variation in food availability, water quality, and age distributions.

Limb and Webbing Structure

This species has unwebbed front hands, while its hind feet are almost fully webbed.

Male Secondary Sexual Characteristics

Males have nuptial pads (swellings on the forearms of some male amphibians that help grasp females during mating) on the first finger, and two blue-colored vocal sacs, one on each side of the throat.

Tadpole Morphology

Tadpoles have black speckles across their tails and fins, with dark-colored tail tips.

Tympanum Sexual Dimorphism

In males, the tympanum (eardrum) is wider than the eye, while in females the eye is wider than the tympanum.

Body Size Sexual Dimorphism

Females are also heavier and longer than males.

Native Distribution

The Indian bullfrog is native to mainland Afghanistan, Bangladesh, India, Myanmar, Nepal, and Pakistan. Its presence in Bhutan and China is possible but has not been confirmed.

Introduced Distribution

It has been introduced to the Maldives, Madagascar, and India's Andaman Islands, where it is now a widespread invasive species.

Future Invasion Risk

Areas that are considered likely to be invaded by this species in the future include the Mascarene Islands, Malaysia, Indonesia, and East Africa.

Habitat Preferences

Hoplobatrachus tigerinus typically inhabits freshwater environments, especially wetlands like paddy fields. It is not generally found in other types of ecosystems, such as forests or coastal areas.

Reproduction

Indian bullfrogs reproduce during the monsoon season, in pools of rainwater. They lay many eggs in a single reproductive event, though most tadpoles die before reaching adulthood.

Lifespan

Individuals can live for more than seven years in the wild.