Tuesday, June 25, 2024

[Arachnida • 2024] Typhlonesticus angelicus & T. santinellii • Two New Subterranean Typhlonesticus (Araneae: Nesticidae) from the Alps with Notes on their Ecology, Distribution and Conservation

[A, D] Typhlonesticus angelicus sp. nov., [B, F] T. morisii (Brignoli) and [C, H] T. santinellii sp. nov. 

in Isaia, Nicolosi, Infuso et Ribera, 2024.


The spider genus Typhlonesticus Kulczyński, 1914 (Araneae: Nesticidae) includes seven species, most of which exhibiting strict preference for caves, abandoned mines and other subterranean habitats. In Italy the genus is represented by two species: T. morisii (Brignoli, 1975), an extremely narrow endemic species from SW-Alps with a very high level of subterranean adaptation and T. idriacus (Roewer, 1931), showing a much wider distribution in NE-Italy and poor adaptations to subterranean life. Our recent biospeleological surveys in the Alps lead to the discovery of new populations of highly troglomorphic Typhlonesticus that proved to belong to two new species based on morphological and molecular data. Considering the rarity of these new species, we provide general information on their ecology and distribution, including a comparative analysis of troglomorphic traits in Typhlonesticus in relation to biogeographic factors. Information on the conservation status, useful for assessing their extinction risk based on International Union for Conservation of Nature (IUCN) guidelines, is also provided.

Keywords: Alpine subterranean fauna, Biogeography, Endemic species, Extinction risk, Systematics, Troglomorphism

Live specimens of Typhlonesticus angelicus sp. nov. (A male), T. morisii (Brignoli) (B female) and T. santinellii sp. nov. (C female) in their natural habitats.
The entrance of Grotta superiore delle Camoscere [Pi 250], type locality of T. angelicus sp. nov. (D), the military bunker of Sotterranei di Vernante, type locality of T. morisii (Brignoli) (E, F);
the walls of “Galleria del Pozzo’’ within the mining complex of Gorno, type locality of T. santinellii sp. nov. (G); the entrance of Murdosso cave [Lo BG 7407], where the first female of T. santinellii sp. nov. was collected during the unblocking operations of the cave conducted by the local speleological groups “Underland” and “I Tassi” (H).

Family Nesticidae Simon, 1894

Genus Typhlonesticus Kulczyński, 1914

 Typhlonesticus angelicus Isaia and Ribera, sp. nov.

Etymology: The species is dedicated to Angelo Morisi (1943–2016) beloved Piedmontese natural scientist, expert in reptiles, amphibians, cave-dwelling invertebrates, freshwater macroinvertebrates, fishes and lichens. Angelo was a kind-hearted, altruist and caring natural scientist, pioneer of the biospeleological research in Piedmont, and first collector of several rare troglobiont species that still carry his name, including Typhlonesticus morisii, sister species of T. angelicus sp. nov. The specific epithet is in form of adjective and conjugates the name of Angelo and the features of benevolent immortal beings with a translucent body of light, barely visible to the human eye.

  Typhlonesticus santinellii Isaia and Ribera, sp. nov.

Etymology: The species is dedicated to the speleologist Roberto “Robertone” Santinelli, who first collected the female specimen in Murdosso cave, allowing the diagnosis of the new species. Noun in genitive.

Combining morphological and genetic evidence, we revealed the existence of two new species of Typhlonesticus, the oldest evolutionary lineage of Nesticid spiders in Europe. The new species are characterised by a high level of adaptation to the subterranean environment, confirming the extraordinary richness of subterranean diversity in the Alps. Using a trait-based approach, we inferred how highly troglomorphic Typhlonesticus are particularly vulnerable to environmental changes, and in particular we interpreted their isolation and their small distribution ranges as critical conditions amplifying their extinction risk, especially from a global warming perspective. We particularly address this issue by recommending further studies focusing on the thermal tolerance of these species, aiming at understanding their possible response to increasing global temperatures.

  Marco Isaia, Giuseppe Nicolosi, Alessandro Infuso and Carles Ribera. 2024. Two New Subterranean Typhlonesticus (Araneae: Nesticidae) from the Alps with Notes on their Ecology, Distribution and Conservation. Arthropod Systematics & Phylogeny. 81: 801-818. DOI:  10.3897/asp.81.e106948