The Hogsback Frog or Rattray's forest frog (Anhydrophryne rattrayi) is a species of frog

Frog

Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

 in the Pyxicephalidae

Pyxicephalidae

Pyxicephalidae is a family of frogs.-Classification:Pyxicephalidae contains two subfamilies, with a total of 13 genera. This family was formerly considered part of the family Ranidae.Family PYXICEPHALIDAE* Subfamily Cacosterninae...

 family. It is one of three species within the genus Anhydrophryne.
It is endemic to South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

.

Discovery

This frog was initially discovered and described in 1919 by Dr. Rattray in the Hogsback Mountain region of the Eastern Cape

Eastern Cape

The Eastern Cape is a province of South Africa. Its capital is Bhisho, but its two largest cities are Port Elizabeth and East London. It was formed in 1994 out of the "independent" Xhosa homelands of Transkei and Ciskei, together with the eastern portion of the Cape Province...

, South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

.

Range

In addition to the Hogsback region, the frog is also found in the nearby Katberg, Stutterheim, Keiskamahoek and Peddie Mountain forests as well. Habitat is floor of forest and temperate grassland at an altitude greater than 1100 meters.

Biology

These small frogs are light-grey to dark-brown (sometimes coppery) in colour. Adults often have a thin pale line over the head and back, with two darker bands alongeither side. The belly is marbled (white and dark brown to black.)
The female of the species is approximately 21 mm long. The male is considerably smaller and may be distinguished by a horny tip on their snout. The males have a short ‘ping’ call with up to 15 repeats in rapid succession though single ‘pings’ may also be heard. These calls are typically heard at night though the males are also active on rainy days.

The frogs live on the forest

Forest

A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

 floor among damp vegetable debris, particularly near open water. Diet is principally composed of small arthropods e.g. forest flea

Flea

Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...

s and woodlice.

Eggs

Egg (biology)

An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...

 are large (approximately 2.6 mm in diameter), white and enclosed in a jelly capsule about 6 mm in size. Up to 20 such eggs are laid in a nest

Nest

A nest is a place of refuge to hold an animal's eggs or provide a place to live or raise offspring. They are usually made of some organic material such as twigs, grass, and leaves; or may simply be a depression in the ground, or a hole in a tree, rock or building...

 chamber, the diameter of which is approximately 20 mm, with a 10 mm opening to the surface. The opening is covered with leaves

Leaves

-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...

. It is believed that the male digs the nest.

Unusual amongst amphibians, the tadpole

Tadpole

A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...

s mature out of water and indeed drown (they do not have gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s) if they are transferred to a wholly aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 environment. Nevertheless, the nest needs to remain moist for successful development. The tadpoles take twenty-six days to mature, at which stage they leave the nest as 4 mm ‘froglets.’

Conservation

Due to its declining natural habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

, the Hogsback Frog is currently classified as endangered.

Source

• Minter, L., Channing, A. & Harrison, J. 2004. Anhydrophryne rattrayi. 2006 IUCN Red List of Threatened Species. Downloaded on 23 July 2007.
• Wager, V. A. "Frogs of South Africa: Their Fascinating Life Stories." Delta Books, 1986.