The red-necked pond turtle (''Mauremys nigricans'') is a species of

turtle Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...

s in the family

Geoemydidae The Geoemydidae (formerly known as Bataguridae) are one of the largest and most diverse families in the order Testudines (turtles), with about 70 species A species () is often defined as the largest group of organisms in which any two in ...

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It is most likely restricted to

Guangxi Guangxi,; officially the Guangxi Zhuang Autonomous Region, is an Autonomous regions of China, autonomous region of the China, People's Republic of China, located in South China and bordering Vietnam (Hà Giang Province, Hà Giang, Cao Bằn ...

and

Guangdong ) means "wide" or "vast", and has been associated with the region since the creation of Guang Prefecture in AD 226. The name "''Guang''" ultimately came from Guangxin ( zh, labels=no, first=t, t= , s=广信), an outpost established in Han dynasty ...

provinces, although pre-historic skull remains have been found in northern

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

and

Hainan Hainan is an island provinces of China, province and the southernmost province of China. It consists of the eponymous Hainan Island and various smaller islands in the South China Sea under the province's administration. The name literally mean ...

. Other common names include Kwangtung river turtle and black-necked pond turtle.

Anatomy and morphology

A megacephalic form of the red-necked pond turtle exists, commonly called 'dumb-head'. This form is rarer than the smaller headed individuals. This species has strong

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

with a significant size difference between males and females. The largest recorded male's carapace measured 185mm (7.2 in) in length whereas females with a size up to 298 mm (11.7 in) have been found.

References

* Asian Turtle Trade Working Group 2000.
''Chinemys nigricans''

2006 IUCN Red List of Threatened Species.
Downloaded on 29 July 2007. ;Bibliography * {{Taxonbar, from=Q305926 Reptiles of China Chinemys Reptiles described in 1834 Taxonomy articles created by Polbot Endangered Fauna of China