Caspian Turtle
Encyclopedia
The Caspian turtle or Striped-neck terrapin (Mauremys caspica) is a species
of turtle
in the family
Geoemydidae
(=Bataguridae), living of the eastern Mediterranean region. It ranges from southwestern former USSR and central Iran
to Saudi Arabia
, Bahrain
, Israel
and Lebanon
, northward through Turkey
to Bulgaria
, and through Cyprus
, Crete
, and the Ionian Peninsula to former Yugoslavia.
has a slight medial keel (better developed in juveniles) and a smooth unserrated marginal border, which is slightly upturned and tapered above the tail. A pair of low lateral keels are present on the pleural scute
s of hatchlings but these become lower with age and disappear completely in adults. The carapace is tan to olive or black with yellow to cream-colored reticulations patterning the scutes, and some individuals have yellow vertebral stripes. These light lines fade with age but the pleural seam borders become darker. The well-developed plastron is notched posteriorly. The plastral formulae are given in the subspecies descriptions under Geographic Variation. The plastron is either yellow with variable reddish to dark-brown blotches, or dark brown or black with a yellow blotch along the lateral scute borders. The bridge is either yellow with dark seam borders and dark spots on the corresponding marginals, or almost totally black with a few small yellow marks. The head is not enlarged, and is olive to dark brown with yellow or pale cream-colored stripes. Some stripes extend anteriorly from the neck onto the head. One of these on each side passes above the eye and onto the snout where it meets the stripe from the other side. Several others extend across the tympanum
to contact the posterior rim of the orbit, and two additional stripes continue across the snout and pass ventral to the orbit. Neck, limbs, and tail are tan gray to olive or black with yellow, cream, or gray stripes or reticulations.
M. caspica has 52 chromosomes; (Killebrew, 1977a; Bickham and Carr, 1983).
Females are generally larger than males, have flat plastra and shorter tails with the vent under the rim of the carapace. The smaller males have concave plastra and longer, thicker tails with the vent beyond the rim of the carapace.
are recognized: The eastern Caspian turtle, Siebenrock's Caspian turtle, the spotted-bellied Caspian turtle, and the western Caspian turtle.
The eastern Caspian turtle (Mauremys caspica caspica) was recently split into three forms. The nominate subspecies occurs in central Turkey
and northern Iran
, northward to the Republic of Georgia and eastward to southwestern Turkmenistan
. It has wider reticulations on its carapace
than M. c. rivulata, and a yellow-to-tan plastron with a regularly shaped large dark blotch on each scute. These more or less symmetrically arranged plastral spots may merge to one dark central spot, but a yellow border to the plastron often remains. The soft parts are mainly dark, and the bridge is mainly yellow with some dark lines or spots (but may be dark in old melanistic individuals ). Its plastral formula is fem > abd > pect > gul > hum > an for males, and abd > fem > pect > gul > hum > an for females.
Siebenrock's Caspian turtle (M. c. siebenrocki ), occurs in Iran and Iraq, with relict
populations in Saudi Arabia and on the island of Bahrain; it intergrades with M. c. caspica in Mesopotamia
. This light form with contrasting colors resembles M. c. caspica but has a yellow-to-orange plastron with a small to medium-sized regularly shaped dark blotch on each scute
. The soft parts are lighter than in M. c. caspica, and, unlike in this subspecies, age-related melanism does not occur.
The spotted-bellied Caspian turtle (M. c. ventrimaculata is endemic to the highlands of the Kor and Maharloo basins in southern Iran. It is distinguished from the caspica and siebenrocki subspecies by a yellow plastron with one or several irregularly shaped black spots on each scute. In older individuals this results in a complex plastral pattern of irregular dark markings.
The western Caspian turtle (M. c. rivulata) ranges throughout southeastern Europe (former Yugoslavia
to Greece
, the Ionian Islands
, Crete
, and Cyprus
), Bulgaria
, eastern to south-central Turkey, coastal Syria
, Lebanon
, and Israel
; records from the vicinity of Ankara
and from Lake Emir are questioned by Fritz ). This subspecies has narrow or fine reticulations on its carapace (which may be lost with age ), and a totally black plastron and bridge. Age-related flavism may occur, resulting in a mainly yellow plastron with black reduced to the seams. This subspecies can be separated from melanistic M. c. caspica by differences in head, neck and foreleg pattern. Its plastral formula usually is abd > fem > pect > gul > an > hum in both sexes, but variations of this have been described in Izmir
populations.
According to Fritz and Wischuf, M. c. caspica sensu lato (caspica, siebenrocki and ventrimaculata) and M. c. rivulata only intergrade in two populations near the Turkish-Syrian border; no wide intergradation belt between these two forms exists. Therefore they propose rivulata to be separated as a "monotypic semi-species". Rivulata and members of the main caspica group are known to produce (presumably fertile) hybrids, so they should never be housed together in captivity
The Spanish pond turtle (Mauremys leprosa) was formerly considered a subspecies of M. caspica, but studies of the electrophoretic properties of its proteins, and studies of its morphology have shown it to be a separate species.
body within its range. It also lives in irrigation canals and is quite tolerant of brackish
situations. Reed (1957) reported that the turtles at one Iraq site lacked the ability to swim. Instead, they would crawl out of the water periodically to breathe and then slide back in again. A captive from there could not be induced to swim. Reed thought this behavior to be an adaptation to the extreme variability in the supply of surface water in the area.
Breeding usually takes place in early spring, but may also occur in the fall (Anderson, 1979). The courtship behavior has not been described, but must be similar to that of captivity. Nesting occurs in June and July. A typical clutch is four to six, elongated (20-30 x 35–40 mm), brittle-shelled, white eggs. Hatchlings have round carapaces about 33 mm in length, and are brighter colored than the adults.
Mauremys caspica may occur in large populations in certain areas, especially in permanent water bodies. In temporary waters it is forced to aestivate in the mud in summer, and the more northern populations hibernate during winter. It is very fond of basking, but disappears at the least disturbance. Anderson (1979) reported that many are killed each year by humans who obtain their eggs to use in treating ubiquitous eye ailments. Storks and vultures also take a heavy toll of juveniles and adults, respectively.
M. caspica is carnivorous, feeding on small invertebrates, aquatic insects, amphibians, and carrion
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of turtle
Turtle
Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Geoemydidae
Geoemydidae
Geoemydidae is the largest and most diverse family in the order Testudines with about 70 species. It includes the Eurasian pond and river turtles and Neotropical wood turtles.-Characteristics:...
(=Bataguridae), living of the eastern Mediterranean region. It ranges from southwestern former USSR and central Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
to Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...
, Bahrain
Bahrain
' , officially the Kingdom of Bahrain , is a small island state near the western shores of the Persian Gulf. It is ruled by the Al Khalifa royal family. The population in 2010 stood at 1,214,705, including 235,108 non-nationals. Formerly an emirate, Bahrain was declared a kingdom in 2002.Bahrain is...
, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
and Lebanon
Lebanon
Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
, northward through Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
to Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...
, and through Cyprus
Cyprus
Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...
, Crete
Crete
Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...
, and the Ionian Peninsula to former Yugoslavia.
Description
This is a tan to blackish, medium-sized (to 25 cm), semi-aquatic turtle. Its low, oval carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
has a slight medial keel (better developed in juveniles) and a smooth unserrated marginal border, which is slightly upturned and tapered above the tail. A pair of low lateral keels are present on the pleural scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
s of hatchlings but these become lower with age and disappear completely in adults. The carapace is tan to olive or black with yellow to cream-colored reticulations patterning the scutes, and some individuals have yellow vertebral stripes. These light lines fade with age but the pleural seam borders become darker. The well-developed plastron is notched posteriorly. The plastral formulae are given in the subspecies descriptions under Geographic Variation. The plastron is either yellow with variable reddish to dark-brown blotches, or dark brown or black with a yellow blotch along the lateral scute borders. The bridge is either yellow with dark seam borders and dark spots on the corresponding marginals, or almost totally black with a few small yellow marks. The head is not enlarged, and is olive to dark brown with yellow or pale cream-colored stripes. Some stripes extend anteriorly from the neck onto the head. One of these on each side passes above the eye and onto the snout where it meets the stripe from the other side. Several others extend across the tympanum
Tympanum (zoology)
The tympanum is an external hearing structure in animals such as frogs, toads, insects, and mammals, to name a few.-Anurans:In frogs and toads, it is located just behind the eye. It does not actually process sound waves; it simply transmits them to the amphibian's inner ear, which is protected...
to contact the posterior rim of the orbit, and two additional stripes continue across the snout and pass ventral to the orbit. Neck, limbs, and tail are tan gray to olive or black with yellow, cream, or gray stripes or reticulations.
M. caspica has 52 chromosomes; (Killebrew, 1977a; Bickham and Carr, 1983).
Females are generally larger than males, have flat plastra and shorter tails with the vent under the rim of the carapace. The smaller males have concave plastra and longer, thicker tails with the vent beyond the rim of the carapace.
Systematics
Four subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are recognized: The eastern Caspian turtle, Siebenrock's Caspian turtle, the spotted-bellied Caspian turtle, and the western Caspian turtle.
The eastern Caspian turtle (Mauremys caspica caspica) was recently split into three forms. The nominate subspecies occurs in central Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
and northern Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, northward to the Republic of Georgia and eastward to southwestern Turkmenistan
Turkmenistan
Turkmenistan , formerly also known as Turkmenia is one of the Turkic states in Central Asia. Until 1991, it was a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Republic . Turkmenistan is one of the six independent Turkic states...
. It has wider reticulations on its carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
than M. c. rivulata, and a yellow-to-tan plastron with a regularly shaped large dark blotch on each scute. These more or less symmetrically arranged plastral spots may merge to one dark central spot, but a yellow border to the plastron often remains. The soft parts are mainly dark, and the bridge is mainly yellow with some dark lines or spots (but may be dark in old melanistic individuals ). Its plastral formula is fem > abd > pect > gul > hum > an for males, and abd > fem > pect > gul > hum > an for females.
Siebenrock's Caspian turtle (M. c. siebenrocki ), occurs in Iran and Iraq, with relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
populations in Saudi Arabia and on the island of Bahrain; it intergrades with M. c. caspica in Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
. This light form with contrasting colors resembles M. c. caspica but has a yellow-to-orange plastron with a small to medium-sized regularly shaped dark blotch on each scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
. The soft parts are lighter than in M. c. caspica, and, unlike in this subspecies, age-related melanism does not occur.
The spotted-bellied Caspian turtle (M. c. ventrimaculata is endemic to the highlands of the Kor and Maharloo basins in southern Iran. It is distinguished from the caspica and siebenrocki subspecies by a yellow plastron with one or several irregularly shaped black spots on each scute. In older individuals this results in a complex plastral pattern of irregular dark markings.
The western Caspian turtle (M. c. rivulata) ranges throughout southeastern Europe (former Yugoslavia
Yugoslavia
Yugoslavia refers to three political entities that existed successively on the western part of the Balkans during most of the 20th century....
to Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, the Ionian Islands
Ionian Islands
The Ionian Islands are a group of islands in Greece. They are traditionally called the Heptanese, i.e...
, Crete
Crete
Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...
, and Cyprus
Cyprus
Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...
), Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...
, eastern to south-central Turkey, coastal Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
, Lebanon
Lebanon
Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
, and Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
; records from the vicinity of Ankara
Ankara
Ankara is the capital of Turkey and the country's second largest city after Istanbul. The city has a mean elevation of , and as of 2010 the metropolitan area in the entire Ankara Province had a population of 4.4 million....
and from Lake Emir are questioned by Fritz ). This subspecies has narrow or fine reticulations on its carapace (which may be lost with age ), and a totally black plastron and bridge. Age-related flavism may occur, resulting in a mainly yellow plastron with black reduced to the seams. This subspecies can be separated from melanistic M. c. caspica by differences in head, neck and foreleg pattern. Its plastral formula usually is abd > fem > pect > gul > an > hum in both sexes, but variations of this have been described in Izmir
Izmir
Izmir is a large metropolis in the western extremity of Anatolia. The metropolitan area in the entire Izmir Province had a population of 3.35 million as of 2010, making the city third most populous in Turkey...
populations.
According to Fritz and Wischuf, M. c. caspica sensu lato (caspica, siebenrocki and ventrimaculata) and M. c. rivulata only intergrade in two populations near the Turkish-Syrian border; no wide intergradation belt between these two forms exists. Therefore they propose rivulata to be separated as a "monotypic semi-species". Rivulata and members of the main caspica group are known to produce (presumably fertile) hybrids, so they should never be housed together in captivity
The Spanish pond turtle (Mauremys leprosa) was formerly considered a subspecies of M. caspica, but studies of the electrophoretic properties of its proteins, and studies of its morphology have shown it to be a separate species.
Ecology
Mauremys caspica occurs in large numbers in almost any permanent freshwaterFreshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
body within its range. It also lives in irrigation canals and is quite tolerant of brackish
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
situations. Reed (1957) reported that the turtles at one Iraq site lacked the ability to swim. Instead, they would crawl out of the water periodically to breathe and then slide back in again. A captive from there could not be induced to swim. Reed thought this behavior to be an adaptation to the extreme variability in the supply of surface water in the area.
Breeding usually takes place in early spring, but may also occur in the fall (Anderson, 1979). The courtship behavior has not been described, but must be similar to that of captivity. Nesting occurs in June and July. A typical clutch is four to six, elongated (20-30 x 35–40 mm), brittle-shelled, white eggs. Hatchlings have round carapaces about 33 mm in length, and are brighter colored than the adults.
Mauremys caspica may occur in large populations in certain areas, especially in permanent water bodies. In temporary waters it is forced to aestivate in the mud in summer, and the more northern populations hibernate during winter. It is very fond of basking, but disappears at the least disturbance. Anderson (1979) reported that many are killed each year by humans who obtain their eggs to use in treating ubiquitous eye ailments. Storks and vultures also take a heavy toll of juveniles and adults, respectively.
M. caspica is carnivorous, feeding on small invertebrates, aquatic insects, amphibians, and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
.