Species account

Description
Slender, large-bodied newt. Head flattened, longer than wide. Snout rounded. Paratoids not prominent; gular fold present. Trunk almost round, rather slender, without dorsal ridge, but with slight vertebral depression. Tail almost as long as snout-vent length, rounded at the base, compressed laterally toward the tip (Schmidtler & Schmidtler, 1970). The tail is relatively shorter in the male than in the female (Pasmans et al., 2006). Tail-tip blunt. Moderately developed tail fins on dorsal and ventral sides; dorsal tail fin a little higher, especially in the breeding season. Limbs well developed and only just touching when laid against the body (Schmidtler & Schmidtler, 1970).

Skin of dorsal side granular and wrinkled, with scattered small warts. In terrestrial phase, the skin is dry and rough, not shiny as in Salamandra. Ventral side smooth.

Lungs reduced.

Dorsal colour dark brown to black with many small yellow-orange, rounded, irregular spots. Similar spots on the sides of the tail. Black colour of the sides partly extends onto the belly, reducing the orange-red colouration of the vent to a narrow line. Throat black with orange lining and often yellow spots. Ventral surface of the limbs grey-black.

Cloaca half rounded in the male, swollen in the breeding season, with a longitudinal slit. Cloaca slightly conical in the female with a rounded opening, less protruding than in N. crocatus (Schmidtler & Schmidtler, 1975). Unlike N. crocatus, male N. strauchii develop silver-blue spots along the tail, sometimes forming a stripe.

Total length between 16 and 19 cm (Schmidtler & Schmidtler, 1975). Neurergus strauchii is represented by two subspecies: N. s. strauchii (Steindachner, 1887) from the Lake Van area (Schmidtler & Schmidtler, 1970) and N. s. barani Öz, 1994, described from the mountains near the city of Malatya (Öz, 1994). This subspecies is characterized by having a lower number of dorsal yellow spots. The number of spots in N. strauchii follows a west-east cline, with specimens from populations of N. s. barani presenting the lowest number of spots, followed by a steady increase in the more eastern populations of N. s. strauchii. The subspecific status of N. s. barani is ratified by genetic analyses; no differences were noted in belly patterns between the two subspecies: both subspecies show a continuous or an interrupted orange ventral line (Pasmans et al., 2006).

Diagnosis
Smaller and more numerous yellow dorsal spots than in N. crocatus; on ventral side a continuous or interrupted orange line. Male with silver-blue spots along the tail in breeding season.

Eggs and larvae
Oviposition starting end April and continuing until May, sometimes later (Schmidtler, 1994; Steinfartz & Schultschik, 1997; Pasmans et al., 2006). 70 to 110 eggs are laid in clutches on the lower surface of stones in mountain streams. Jelly capsule 5-6 mm in diameter, embryo diameter 2.5 mm (Schmidtler & Schmidtler, 1970). Eggs are joined by a jelly string. At water temperatures between 12 and 18º C, larvae hatch after approx. one month, at a length of 13-15 mm (Fleck, 1984). Metamorphosis takes place after seven to eight months at a length of 60-70 mm (Steinfartz, 1995) or after four to five months at a length of 50-55 mm (Fleck, 1984). Metamorphosis may be postponed till after winter (Schmidtler, 1994). Sexual maturity is reached after two to four years (in captive bred animals, Haker, 1986; Macke, 2006).

Larvae have a slender body-form, but are stockier than larvae of N. crocatus. The dorsal tail-fin almost reaches onto the middle of the body. Tail-tip rounded. Short gills. Younger larvae grey with a dense cover of tiny black dots, older larvae have light spots in two rows along the back and two irregular rows of black-grey spots on the belly. Tail of older larvae densely pigmented black-brown (Schmidtler & Schmidtler, 1975). For comparative larval morphology of N. crocatus and N. strauchii, see Schmidtler & Schmidtler (1975) and Steinfartz (1995). 

Distribution
Neurergus s. strauchii is known from the Lake Van area and localities west of Lake Van, Turkey (Pasmans et al., 2006), N. s. barani is only known from the Kubbe mountains near the city of Malatya (Öz, 1994).

Habitat
Perennial, rocky mountain streams, with some calmer parts, at altitudes between 1,500 to 2,000 m. The borders of the streams may or may not have some vegetation. Terrestrial habitat is always situated in rocky areas with a scarce shrub layer and few trees (Bogaerts et al., 2006).

Behaviour
Animals spend the winter months on land under stones and in burrows (Schmidtler & Schmidtler, 1970), probably from October to end March. Breeding takes place in mountain streams, starting end April when snow is melting (Steinfartz & Schultschik, 1997).

Food consists of soft-bodied invertebrates, aquatic and terrestrial insects (Baran & Atatür, 1998).

Reproductive behaviour was studied in captive specimens of N. s. barani, originating from the type locality near Malatya, central Anatolia. The male takes up a position in front of the female, from where he starts a tail-fanning display, fanning his tail in the direction of her snout. By moving forward towards the male the female signals that she is responsive. The male makes a few steps backward, then turns away from the female and creeps ahead of her, his tail making undulating movements. The female follows him, touching his tail. The male deposits a spermatophore, moves forward and makes a 90º turn, bringing him back into a position perpendicular to the female’s body. He stops (brakes) the female in her progress at a point when her cloaca is situated above the place where the spermatophore was deposited. This behaviour was found to be similar in N. strauchii, N. crocatus and N. kaiseri. For N. microspilotus observations are uncertain. In its general pattern, this courtship behaviour is similar to that of small European pond breeding newts and of Asian Cynops, Pachytriton and Paramesotriton (Sparreboom et al., 2000).

Threats and conservation
The species may be locally common, provided suitable habitat is present. It is considered to be relatively susceptible to habitat change, habitat loss, pollution, drought and collection for the pet trade. Although strictly protected by the Convention on the Conservation of European Wildlife and Natural Habitats (the Bern Convention), the status of N. strauchii in Turkey is not clear (Bogaerts et al., 2006; Pasmans et al., 2006).

Observations in captivity
Neurergus strauchii has been bred in captivity on several occasions and in at least two generations (Fleck, 1984; Haker, 1986; Steinfartz, 1995). The newts should be kept in tanks with cool (12 to 16º C in egg-laying season) and running water, providing enough hiding places with flat stones. In captivity the animals can be kept aquatic all year round, but a terrestrial phase may be more natural. For breeding, both strategies have been successful (Macke, 2006). The data on eggs and larvae, and the observations on courtship and oviposition reported above have been obtained mainly from captive animals.

Comments
For earlier literature see Freytag (1957) and Schmidtler & Schmidtler (1970).

Neurergus strauchii
© 2007 Max Sparreboom

 
© 2004 IUCN, Conservation International and NatureServe. The gap between the two disconnected, marked areas has now been bridged by several further localities (Pasmans et al., 2006). (click on map to enlarge)