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Amphibians

> Iberian Newt

Lissotriton boscai


This newt is small in size, usually between 6.5 and 9 cm in total length. The head has rounded contours, slightly wider and taller. The eyes are small, prominent and in a lateral position.

The parotid glands are small but visible on the back of the head. The body is of round or quadrangular section with the tail very flattened laterally being the crest reduced or absent.

The limbs are thin with 4 toes on the front legs and 5 on the hind legs. The skin is smooth during the aquatic phase, but somewhat rough in the terrestrial phase. The dorsal colouration is variable, predominating the brown, olive-green or yellow tones, dotted with some black spots. Sometimes a clearer vertebral line is evident.

In the terrestrial stage,
has a darker and more uniform colouration. The ventral region is typically orange in colour with round dark spots that may form irregular rows in the lateral areas.

Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Sexual Dimorphism

Females reach a larger size (7-9 cm) than males (6.5 - 7.5 cm) and their body has a cylindrical section, more uniform dorsal drawing with reduced dark spots, hind limbs are more developed and cloaca smaller. The males have the thinnest body, quadrangular section, usually with dark patches clearly evident. During the breeding period, they have a white long band that extends across the tail, more visible in its terminal part. At this point, they also develop a low caudal crest and a small terminal filament (0.5-2 mm).

Behaviour

This newt has an aquatic phase, which coincides with the time of reproduction, and a terrestrial phase. During the terrestrial phase, its activity is predominantly nocturnal and during the aquatic phase it is both daytime and nocturnal. However, it may go through a period of winter or summer inactivity, during which it takes shelter under the rocks or in the bottom of the aquatic habitats.

Reproduction

In the south-west region of Portugal, adults migrate to the bodies of water to reproduce in the autumn. Adults show activity at dusk, but with the advancement of the mating season and oviposition during the winter, their activity also covers the daytime period. Mating occurs within water, and is preceded by a complex courtship behaviour.

At an early stage, the male is placed in front of the female, folds the tail forward so as to be parallel to the body, performing regular wave movements, which are intended to disperse odoriferous particles. In case the female is not attracted, the male can make new movements, among which stands out the "flamenco", where it loops the tail and slowly oscillates its tip to one side and the other. Frequently, the male repeats and alternates the different movements until the female moves against its flank. At this point, the male releases the spermatophore and moves away a little. The female, when moving towards the male, is left with the cloaca above the spermatophore, which is then absorbed.

Posture sites are usually aquatic environments with weak or no current, and some vegetation, such as temporary ponds. The postures occur over several days and consist of 100 to 250 eggs, which adhere individually to aquatic plants, leaves or other materials present in the bottom of the bodies of water chosen for reproduction.

Eggs of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Eggs of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Eggs of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Eggs of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Egg hatch occurs 10 to 20 days after laying. The duration of the larval period is quite variable, depending on factors such as water temperature and food availability for the larvae.

Larvae of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

However, the larvae of the newts are much more developed than the tadpoles so when they hatch they are already born with the previous paws and are able to swim quickly to escape to possible predators and to take shelter next to the aquatic vegetation. The larvae can be observed from February to June, with the first juveniles completing the metamorphosis in May.

Juvenile of Lissotriton boscai. Photo of Vasco Flores Cruz in Anfíbios e Répteis de Portugal

Juveniles have a dark dorsal colouration and an intense yellow or red colouration. The known longevity of this species is six years for males and nine for females.

Feeding

Feeding of adults during the aquatic phase, as well as that of larvae, consists of small aquatic invertebrates. During the terrestrial phase, adults feed primarily on soft-bodied invertebrates, such as earthworms or slugs.

Adults of these newts can be caught by water snakes and larvae are prey to dragonfly larvae, aquatic insects, salamanders larvae, and adults of marble newts. The main defence mechanisms are the escape and the toxic secretions in cutaneous glands.

They live in very diverse places like meadows, woods and agricultural zones. They can use very diverse water bodies to reproduce, namely, streams with abundant aquatic vegetation with weak or no current, such as temporary ponds, wells, tanks, dams and reservoirs.

It is an Iberian endemism distributed in the western half of the Iberian Peninsula to the line of the Guadalquivir river. The climate that characterizes its area of distribution and the majority of its habitats always has some Atlantic influence, even when it is on the Mediterranean mainland.

Jan Willem Arntzen, Pedro Beja, Robert Jehle, Jaime Bosch, Miguel Tejedo, Miguel Lizana, Iñigo Martínez-Solano, Alfredo Salvador, Mario García-París, Ernesto Recuero Gil, Paulo Sá-Sousa, Rafael Marquez. 2009. Lissotriton boscai. The IUCN Red List of Threatened Species 2009: e.T59473A11947331. http://dx.doi.org/10.2305/IUCN.UK.2009.RLTS.T59473A11947331.en. Downloaded on 05 December 2016.

A more differentiated genetic lineage was found to live in this region of the Southwest of Portugal, between the Caldeirão's Algarve mountain range and that later extends from the western Lusitanian to almost Figueira da Foz (Martinez-Solano et al. 2006). It is therefore one that gives rise to a slightly greater concern if it is to be confirmed as a distinct species.

It shares the main threats of the generality of amphibians.

In the IUCN red list it has the status of Least Concern (LC). However, this species is an Iberian endemism, legally protected by the Habitats Directive 92/43 / EEC (Annex IV).

Jan Willem Arntzen, Pedro Beja, Robert Jehle, Jaime Bosch, Miguel Tejedo, Miguel Lizana, Iñigo Martínez-Solano, Alfredo Salvador, Mario García-París, Ernesto Recuero Gil, Paulo Sá-Sousa, Rafael Marquez. 2009. Lissotriton boscai. The IUCN Red List of Threatened Species 2009: e.T59473A11947331. http://dx.doi.org/10.2305/IUCN.UK.2009.RLTS.T59473A11947331.en. Downloaded on 05 December 2016.


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