Species

BackPseudoblothrus vulcanus Mahnert, 1990

Pseudoblothrus vulcanus Mahnert, 1990

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Pseudoscorpiones
  • Family: Syarinidae
EN Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores

Archipelago(s):
Azores

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Assessment Rationale:

Pseudoblothrus vulcanus is an Azorean-endemic, cave-adapted species from the islands of Pico and Terceira (Azores, Portugal). It has a small extent of occurrence (EOO = 1,525 km²) and a small area of occupancy (AOO = 20 km²). The species is relatively common and known from eight isolated subpopulations in lava tubes. However, the area surrounding the caves is heavily impacted by human activities. Further research is needed into its population, ecology and life history. A habitat management plan is needed and one is anticipated to be developed during the coming years. We also suggest as future measures of conservation the regular monitoring of the species (every ten years) and limiting access to the caves. The fact that the species is a cave-adapted species and occurs on two islands may imply that there are two cryptic species, so there is the urgent need of a taxonomic revision of this taxon. The species is assessed as Endangered (EN), mostly due to its small range, population fragmentation and decline in its habitat quality. 

Geographic Range:

Pseudoblothrus vulcanus is an Azorean-endemic cave adapted pseudoscorpion species known from Pico and Terceira islands (Azores, Portugal) (Borges et al. 2010). Originally described from Gruta das Agulhas (Terceira), it is present in a total of eight caves and lava tubes in both islands; Furna da Baliza, Furna do Frei Matias and Furna Nova (Pico); Gruta das Agulhas, Gruta do Coelho, Gruta da Malha, Gruta dos Principiantes and Gruta de Santa Maria (Terceira). The extent of occurrence (EOO) is 1,525 km² and the maximum estimated area of occupancy (AOO) is 20 km². 

Regions:
Portugal - Azores
Extent of Occurrence (EOO):
1,525 (km2)
Area of Occupancy (AOO):
20 (km2)
Elevation Lower Limit:
(m)
Elevation Upper Limit:
(m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Azores
Seasonality:
Resident

Population:

This species is apparently quite common (Borges et al. 2015), occurring in eight volcanic caves in Pico (Furna da Baliza, Furna do Frei Matias and Furna Nova) and Terceira (Gruta das Agulhas, Gruta do Coelho, Gruta da Malha, Gruta dos Principiantes and Gruta de Santa Maria) islands. This species is assessed here as severely fragmented as at least 50% of its population can be found in subpopulations/in habitat patches that are 1) smaller than would be required to support a viable population, and 2) separated from other habitat patches by a large distance, with many of the caves being surrounded by highly degraded habitats, agricultural land and urban areas. Current Population Trend:  Decreasing

Habitat and Ecology

There is limited information regarding this species' ecology and life-history. It occurs in eight lava tubes, some in protected areas (Natural parks of Pico and Terceira), others are surrounded by highly disturbed or urbanized areas, and two are coastal caves. The genus Pseudoblothrus is exclusively cave-dwelling (Mahnert 1990). Specimens have been found near the entrance of the caves, under rotting wood and other organic litter. It is a cavernicolous (i.e. a troglobitic species) predator and/or saprophagous species. Its eyes are more developed than those of P. oromii (Mahnert 1990). Systems:  Terrestrial

Major Threat(s):

The main current threats to this species are the degradation of habitat quality due to the impact of agricultural activities and livestock raising, agricultural and domestic pollution and recreational cave visitation. Additionally, invasive plant species altering the habitat at the entrance of the caves might also impact the overall habitat quality in the caves. There are also several future potential threats: climatic changes (see Ferreira et al. 2016) that can change the conditions inside the cave; changes in the road infrastructure around the cave; potential human recreational activities with cave visitation; and geological events (volcanic activity and earthquakes). 

Conservation Actions

The species is protected by regional law (RAA 2012), as are some of the caves where it occurs (Natural Parks of Pico and Terceira). Land-use changes are one of the main current and future threats, and conservation and restoration measures should be extended beyond the caves. Further research is needed into its population, ecology and life history. The fact that the species is a cave adapted species and occurs on two islands may imply that we are in the presence of two cryptic species; therefore, there is the urgent need of a taxonomic revision of this taxon. A monitoring plan for the invertebrate community is necessary in order to contribute to the conservation of this species. As a future conservation measure, the restriction of visits to the caves could be considered. A habitat management plan is needed and one is anticipated to be developed during the coming years.