| Euphrates softshell turtle | |
|---|---|
.jpg) | |
 | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Family: | Trionychidae |
| Genus: | Rafetus |
| Species: | R. euphraticus |
| Binomial name | |
| Rafetus euphraticus (Daudin, 1801) | |
| Synonyms[3] | |
List
| |
TheEuphrates softshell turtle (Rafetus euphraticus), also known as theMesopotamian softshell turtle,[4] is a species ofsoftshell turtle in the familyTrionychidae. It is found throughout much of theEuphrates–Tigris river basin inIraq,Syria,Turkey andKhūzestān Province ofIran. Historically it has also been reported fromIsrael, but this likely involves confusion with the very similarTrionyx triunguis (the two typically require in-hand examination to be separated).[5]
The Euphrates softshell turtle is anendangered species that primarily is threatened by habitat loss and alteration, especially the building ofdams,[5] but to lesser extent alsopollution and killing by fishermen.[6]
The Euphrates softshell turtle became known to western science when the French naturalistGuillaume-Antoine Olivier shot a specimen while crossing theEuphrates nearAnah in June 1797.[7] The local residents told him that the meat of this animal was not good to eat, but its fat was considered an excellent medication for a variety of skin diseases. Olivier named the speciesTestudo rafcht, because, as he said "the Arabs called itrafcht".[8]
Olivier's book did not explain what the name meant inArabic; however a number of modern Arabic web pages say that the turtle is known locally asal-rafš (الرفش), which is translated in standard dictionaries as "the spade" or "the shovel", and perhaps refers to the shape of the creature'scarapace.[9] Olivier passed the information about the creature toFrançois Marie Daudin, who described it in hisHistoire des reptiles (1801).[8][10]
Later naturalists apparently often misread Olivier'srafcht asrafeht.[11] The nameRafetus euphraticus, and the genusRafetus itself, were proposed byJohn Edward Gray in 1864, who mentions in his work that the species had been variously known asTrionyx euphraticus,Testudo euphraticus,Trionyx rafeht,Tyrse rafeht, orTestudo rafeht.[12]
This freshwater turtle can weigh up to 20 kg (44 lb),[4] and it has a smooth leathery shell that can reach up to 68 cm (2.2 ft) in length.[5] The sexes are apparently alike in size and general appearance.[5] The upperparts are typically dullolive in colour, sometimes with an indistinct spotted pattern, especially on the head.[5] There are some minor variations in the colour pattern,[4] and rarely individuals may be dark brown or even black above.[5]
.png)
_(18197407012).jpg)
_(18197410952).jpg)
The Euphrates softshell turtle has been found in a wide range of freshwater habitats such as rivers, streams, lakes, ponds, reservoirs and marshlands.[5] It prefers areas with shallow and calm water, sandy banks and many fish (especiallycyprinids).[13] Although it mainly resides in shallow calm water, this is often adjacent to deep fast-flowing water.[5] In the fast-flowing Euphrates it generally avoids themain stem, instead occurring in side-branches or backwaters. In parts of theTigris River with a slower flow, it occurs even in the main stem.[5] They bask on or at the banks of rivers, with some remaining in shallow water to avoid being on land.[4] They sometimes bury themselves into the bottom.[4]
The Euphrates softshell turtle is mainly active during the day, but some night-activity also occurs.[5] In parts of its range it is infrequently seen during the winter, likely due to the lower temperature.[5][13]
Little is known about its feeding preference, but the species has generally been considered acarnivore. It is sometimes seen feeding on carcasses, is easily attracted by lowering a nylon bag filled with lamb blood into the water and fishermen often complain about it taking fish from their nets.[5] However, it has also been caught on lines baited withwatermelon, an individual defecated a partially digestedtomato and local farmers claim their crops sometimes are eaten by the species.[5] A fecal analysis of 30 individuals mostly revealed remains of crabs and plants, but also insects, birds, fish, river-bed material and debris, leading to the conclusion that the Euphrates softshell turtle is an opportunisticomnivore.[5]
Nesting in this species is seasonal, but exact timing depends on the region.[13] The nest is dug by the female in a bank of a river and it can be up to 50 cm (1.6 ft) deep.[14] The site can be bare sand or a sand-soil mix with vegetation.[13] In one case a nest was placed about 4.1 m (13 ft) from the water's edge, in a sand bank with an incline of almost 15°.[14] Each nest can contain up to 32 eggs.[14] The eggs are white,[14] and have a diameter of 2.3–3.0 cm (0.9–1.2 in).[13] When hatching the young have a carapace length of 3.9–5.5 cm (1.5–2.2 in).[5] In some regions a female may nest twice in a season.[5] Adults and sub-adults often have claw or bite marks, indicating frequent aggression between individuals.[5]
The Euphrates softshell turtle is anendangered species.[1] The primary threats arehabitat loss and alterations,[5] but to lesser extent alsopollution and killing by fishermen.[6] A major threat isdams, which alter levels of sediment and water temperature, and may flood areas. For example, the population in theHalfeti region disappeared entirely following the construction of theAtatürk Dam, possibly due to colder water, and theIlısu Dam flooded some known nesting sites of the species.[14] Numerous other dams are planned in the Euphrates-Tigris drainage.[5] Nevertheless, there are indications that they are able to use nesting sites near human and are not particularly vulnerable to general disturbance.[13] When basking on land they are very shy, retreating to water at the slightest hint of danger.[4] It has been reported from man-made habitats such as reservoirs and artificial canals near cities.[5] Despite its endangered status there are no specific conservation projects aimed at this species in most of its range, except one underway in Iran'sKhuzestan Province.[5]
Trionychidae family | ||||
|---|---|---|---|---|
| ||||
| Genera |
|  | ||
| Amyda | ||||
| Apalone | ||||
| †Axestemys | ||||
| Chitra | ||||
| Cyclanorbis | ||||
| Cycloderma | ||||
| Dogania | ||||
| †Gilmoremys | ||||
| †Hutchemys | ||||
| †Khunnuchelys | ||||
| Lissemys | ||||
| Nilssonia | ||||
| †Palaeoamyda | ||||
| Palea | ||||
| Pelochelys | ||||
| Pelodiscus | ||||
| Rafetus | ||||
| Trionyx | ||||
Phylogenetic arrangement of turtles based onturtles of the world 2017 update: Annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. †=extinct. | ||||
