Marbled Rubber Frog (Phrynomantis annectens)

View the above photo record (by Cornelia Rautenbach) in FrogMAP here.

Find the Marbled Rubber Frog in the FBIS database (Freshwater Biodiversity Information System) here.

Family Microhylidae

MARBLED RUBBER FROG – Phrynomantis annectens

(Werner, 1910)



In the atlas region, P. annectens occurs in the far-northern parts of the Succulent Karoo and Nama Karoo biomes where it is associated with inselbergs and other rock exposures. The pools of rainwater trapped in these outcrops provide breeding habitat. The average annual rainfall in this region is <60 mm, falling mainly in winter in the west (Richtersveld) and in summer in the east (Bushmanland).


Breeding takes place immediately after the first rains of spring or summer. Males call from the edges of small pools formed by the runoff from sheets of rock, or in the deeper rock pools remaining in drainages after the rains. Females lay 80–100 eggs in groups of 2–8 and attach them to submerged rock surfaces or vegetation (Channing 1976, 2001). These develop quickly and free-swimming tadpoles hatch within 18–36 hours. Older tadpoles are large and transparent with flattened heads and conspicuous fins, flecked with silver and gold. They are gregarious, forming schools that hang in the water column and filter out unicellular algae and diatoms (Channing 2001). The tadpole stage lasts at least eight weeks before metamorphosis is completed. During the dry season the adults aestivate in deep rock cracks.

Predators of the adults have not been recorded, but dragonfly nymphs are known to prey on the tadpoles.

Status and Conservation

The distribution of P. annectens is mainly extralimital and it occurs in many protected areas in Namibia and Angola. In South Africa, it occurs in Richtersveld and Augrabies Falls national parks, and is protected by provincial (Northern Cape) conservation regulations. In the atlas region, the habitat occupied by P. annectens is not heavily exploited, hence the species is not classified as threatened. However, quarrying and mining lead to the pollution of surface water by fuels and lubricants used to run and maintain heavy machinery, and this will affect local populations.


P. annectens is endemic to the larger Namib region, from Angola southward through western Namibia, reaching South Africa in the extreme northern parts of Northern Cape Province. In the atlas region, it is known from the Augrabies Falls, the Richtersveld around the Vandersterrberg Mountains, and the rocky areas between Aggenys/Pofadder and the Gariep (Orange) River. These areas range from 600 to 1200 m in altitude.

The atlas survey added several new Bushmanland localities for P. annectens. The species probably occurs in other localities with suitable habitat in the Richtersveld and in Bushmanland south of the Gariep (Orange) River. The atlas data are reliable but likely to be incomplete.

Further Resources

Virtual Museum (FrogMAP > Search VM > By Scientific or Common Name)

More common names: Marmerrubberpadda (Afrikaans)

Recommended citation format for this species text:

Channing A, Tippett RM.  Marbled Rubber Frog Phrynomantis annectens. BDI, Cape Town.
Available online at

Recommended citation format: 

This species text has been updated and expanded from the text in the
2004 frog atlas. The reference to the text and the book are as follows:

Channing A 2004 Phrynomantis annectens Marbled Rubber Frog. In Minter LR
et al 2004.

Minter LR, Burger M, Harrison JA, Braack HH, Bishop PJ, Kloepfer D (eds)
2004. Atlas and Red Data Book of  the Frogs of South Africa, Lesotho and
Swaziland. Smithsonian Institution, Washington, and Avian Demography
Unit, Cape Town.

Ryan Tippett
Ryan Tippett
Ryan is an enthusiastic contributor to Citizen Science and has added many important and interesting records of fauna and flora. He has been a member of the Virtual Museum since 2014 and has currently submitted over 12,000 records. He is on the expert identification panel for the OdonataMAP project. Ryan is a well-qualified and experienced Field Guide, and Guide Training Instructor. He has spent the last 18 years in the guiding and tourism industries. Ryan loves imparting his passion and knowledge onto others, and it is this that drew him into guide training in particular. Something that he finds incredibly rewarding is seeing how people he's had the privilege of teaching have developed and gone on to greater things. His interests are diverse and include Dragonflies, Birding, Arachnids, Amphibians, wild flowers and succulents, free diving and experiencing big game on foot. With this range of interests, there is always likely be something special just around the corner!