Galemys pyrenaicus (E. Geoffroy Saint-Hilaire, 1811)
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publication ID |
https://doi.org/ 10.5281/zenodo.6678191 |
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DOI |
https://doi.org/10.5281/zenodo.6671954 |
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persistent identifier |
https://treatment.plazi.org/id/0380B547-B655-FF84-9FB5-FB8FF90CC404 |
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treatment provided by |
Valdenar |
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scientific name |
Galemys pyrenaicus |
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Pyrenean Desman
Galemys pyrenaicus View in CoL
French: Desman des Pyrénées / German: Pyrenaen-Desman / Spanish: Desman ibérico
Other common names: Iberian Desman
Taxonomy. Mygale [sic] pyrenaica E. Geof- froy Saint-Hilaire, 1811 ,
“centrale de Tarbes,”
Pyrenees, France.
Generic name Galemys View in CoL , although antedated by Mygale, is conserved because it has been in common use for so long. Galemys pyrenaicus View in CoL is the only extant species of Galemys View in CoL . Two subspecies ( pyrenaicus View in CoL and rufulus), based on size differences, have been recognized, but they do not match phylogenetic patterning and are invalid.
Phylogeographical analyses retrieved two parapatric lineages: one in the eastern Cantabrian Mountains and the Pyrenees and the other in the western Cantabrian Mountains, the Central System, and the Iberian System ranges. Both lineages are further substructured into population groups. The main lineages diverged 0-32 million years ago in glacial refugia and were evidently not influenced by topography of the main river systems. There is no exchange of mitochondrial haplotypes between these lineages. Monotypic.
Distribution. Northern Iberian Peninsula, discontinuously from Galicia and N Portugal (N of upper Mondego River) E to both sides of the Pyrenees, also in W Central System and N Iberian System Mts; two small isolated populations in Zézere River (Portugal) and Mayor River (Vizcaya, Spain). View Figure
Descriptive notes. Head-body 108-145 mm, tail 123-160 mm, hindfoot 31-38 mm; weight 44-3-80 g. Sexes are the same size. Head of the Pyrenean Desman is conical, with highly mobile, protracted, and flattened snout, which is 2 mm deep and c.7 mm wide at its middle. Vibrissae are numerous, long, strong, and immobile at their roots. Eyes are minute but not covered by skin. There are no external pinnae. Neck is as short as in fossorial moles, but limbs are longer. Forelegs are not particularly enlarged and have five sharp, long, curved claws. Much larger hindlegs have long claws with longitudinal grooves and sharp edges. Forefeet and hindfeet are webbed and have fringes of stiff hairs on external edges. Tail is longer than head-body length and cylindrical, except for flattened terminal section; it is covered with short hairs throughout and has mid-ventral ridge ofstiff hairs. Fur is coarser and less dense than in fossorial moles. Hairs are of two types: longer hairs are spearshaped andstiffer, and underfur is ¢.50% as long and softer. Dorsum and flanks are deep brown, shaded gray in some individuals, with brilliant metallic shines. Buffy gray to silvery venter is rather clearly demarcated. Area around eyes is light. Snout and feet are dark brown or almost blackish, and tail is whitish. Females have four pairs of mammae: one pectoral, one abdominal, and two inguinal. Skull is elongated, with narrow and tapering rostrum, truncated occipital region of braincase, and constricted interorbital region. Zygomatic arches are nearly parallel. Mandible is rather heavy, with high coronoid process and broad, blunt angular process. Dental formula: 13/3, C1/1,P 4/4, M 3/3 (x2) = 44. 1' is larger than canine. Karyotype is 2n = 42.
Habitat. Any type of riparian water body with cold well-oxygenated water, rich in macroinvertebrates, and with shelters along banks, from near sea level (15 m) up to elevations of ¢.2700 m in the Pyrenees. Preferred habitats of the Pyrenean Desman are fast running waters at elevations above 400 m, particularly river currents that have high invertebrate biomass and produce ample drift. Pyrenean streams occupied by the Pyrenean Desman have a current velocity of 0-2 m/s, discharges of 0-1-0-2 m?/s, and summer temperatures of 1-3°C. Characteristics of riverbeds and banks are equally important because these provide shelter like crevices and holes among stones. Most suitable are watercourses with high heterogeneity of substrates, high proportion of rocks, and low proportion of earth and fine sediment. Occasionally, Pyrenean Desmans occur in slow-moving water such as canals, lakes, and marshes. Several studies have emphasized close similarities of habitat preferences of the Pyrenean Desman and the white-throated dipper (Cinclus cinclus).
Food and Feeding. Wide variety of prey was identified in the diet of the Pyrenean Desman, belonging to 156 different invertebrate genera. Despite this heterogeneity, diet
mostly consists of abundant benthic invertebrates, specifically gammarids ( Gammaridae ) and larvae of mayflies (Ephemeroptera), caddisflies (Trichoptera), and stoneflies ( Plecoptera ). The Pyrenean Desman feeds on animals from the river bottom, on the water surface, and on land. In the water, the Pyrenean Desman actively explores sediment with forefeet, head, and snout. Captive Pyrenean Desmans readily eat mice, fish, other vertebrates, duck mussels (Anodonta), earthworms, and mealworms. Small prey is eaten underwater, and larger prey is taken out of water and consumed on the bank. While eating, a Pyrenean Desman stands erect, using forefeet and snout to manipulate prey. Reports on daily requirements vary between one-fifth (i.e. 14-21 g) to two-thirds of the body weight of a Pyrenean Desman.
Breeding. Spermatogenesis takes place in winter and spring (November—May), and estrus starts in January. Female Pyrenean Desmans are polyestrous. During pregnancy between the beginning of February and late June, proportion of gravid females peaks in February, March, and May. Numbers of embryos are 1-5/female (mean 3-6), and gestation lasts ¢.30 days. There is a postpartum estrus. First young are weaned in late March and reproductively mature in the following year. Between May and July, ¢.18% of a population is juveniles. Females lactate until late August. Young Pyrenean Desmans differ from adults in body weight (less than 45 g) and tooth wear. Maximum life expectancy is more than five years, but proportion of individuals in a population of five years or olderis only 6%.
Activity patterns. The Pyrenean Desman is powerful swimmer and partially adapted to subterranean life. It climbs well, but it has a cumbersome walk and is a poor runner in open spaces. Most obvious external adaptations for aquatic existence are webbed feet, fringed tail, and pelage providing insulation in water. Articulation of femur allows sufficient leg movement for rapid swimming. Hindfeet provide propulsion by strong alternating strokes at 2-5 strokes/second. Forefeet are inactive and directed forward. About ¢.25% of activity in water is on the bottom. Claws on forelegs enable gripping of rocks to resist currents in fast-moving water and facilitate climbing of steep banks. Pyrenean Desmans can remain submerged for c.1 minute, exceptionally up to four minutes. After leaving the water,they first energetically shake their bodies and then groom their fur with hindfeet. The only respiratory adaptation to swimming and diving is laryngeal velum that allows water to enter nasal passages but prevents it from entering respiratory tract. Although olfactory orientation is not inhibited underwater,it is of lesser importance, and olfactory centers in the brain are regressed. The Pyrenean Desman has poor vison but can distinguish between light and dark. Tactile senses are of prime importance in orientation. Long and highly mobile snout lacks chemoreceptors but is rich in vibrissae and mechanical sensory receptors, particularly Eimer’s organs that are restricted to the rhinarium. Eimer’s organs are involved in discrimination of small particles and probably also detect obstacles in water. The Pyrenean Desman is primarily nocturnal with one (spring) to 2—4 (autumn) peaks of activity. Main peak is.23:00 h, and another less pronounced one is between 04:00 h and 05:00 h. Bouts of
activity outside the nest during daylight were longest in autumn (mean 73-7 minutes). Pyrenean Desmans are active for 9-10 hours/day, longer in spring than autumn. Active periods have an average duration of 2-5 hours, and average distance traveled is 268-5 m. They usually find shelter in rocky crevices and cavities with entrances partially or fully underwater. Resting sites are 30-110 cm (mean 64-4 cm) from the shore. Each individual uses 1-7 resting sites (mean 2-3) that average 248-3 m apart. Pyrenean Desmans reportedly modify and use burrows of Water Voles (Arvicola sapidus). Captive Pyrenean Desmans constructed a simple nest using grass and leaves that are carried by snout.
Movements, Home range and Social organization. Linear home ranges of Pyrenean Desmans cover 350-2300 m of watercourse (mean 523 m). Males occupy, on average, larger home ranges (429 m) than females (391 m). Home ranges are used more extensively in autumn (76%) than spring (58:6%). An individual takes c.2 days to exploreits entire home range. During the daytime, an individual use 6-2% (spring) to 11-6% (autumn) of its home range. Densities in optimal habitats in Spain were 2-8-7-3 ind/km, but because no individuals were found on 30-50% of the sampled rivers, adjustment yielded higher densities of 4-1-14-6 ind/km. Average densities (4-7 ind/ km) were similar in France. Early studies portrayed the Pyrenean Desman as strictly territorial, with aggressive behavior toward other individuals. Captive Pyrenean Desmans were extremely aggressive toward conspecifics. New observations suggest that wild Pyrenean Desmans are not territorial or aggressive. Furthermore, they evidently do not alter their activity and spatial behavior to avoid conspecifics. They might be semi-nomadic and possibly change home range between seasons. Pairs of the same or opposite sex share space and resting sites. Encounters last from ten seconds to ten minutes. Captive Pyrenean Desmans displayed scent marking behavior with their scent glands at bases of their tails. Scent has a strong odor, but it is less conspicuous than in the Russian Desman ( Desmana moschatai). Although Pyrenean Desmans are mainly silent, captive individuals produced various sounds when handled or confronting unfamiliar conspecifics.
Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Pyrenean Desman is protected under the Bern Convention (Appendix II) and the EU Habitats and Species Directive (Annexes II and IV). It has suffered substantial decline in the last two decades, and Portugal and France have implemented action plans targeting the Pyrenean Desman. Proper water management is crucial for long-term survival. Warming climate will presumably shrink suitable habitat and fragment populations.
Bibliography. Aymerich & Gosélbez (2015), Biffi, Charbonnel et al. (2016), Biff, Gillet et al. (2017), Fernandes et al. (2008), Gonzalez-Esteban, Castién & Goséalbez (1999), Gonzéalez-Esteban, Villate & Castién (2003), Gonzalez-Esteban, Villate, Castién, Rey & Gosélbez (2002), Igea et al. (2013), Juckwer (1990), Melero, Aymerich, Luque-Larena & Gosélbez (2012), Melero, Aymerich, Santulli & Gosélbez (2014), Morueta-Holme et al. (2010), Némoz et al. (2011), Niethammer (1970), Nores (2012), Nores et al. (1998), Palmeirim & Hoffmann (1983), Queiroz (1999), Richard (1985).
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