The European Zoological Journal ISSN: (Print) 2475-0263 (Online) Journal homepage: https://www.tandfonline.com/loi/tizo21 Think of what lies below, not only of what is visible above, or: a comprehensive zoological study of invertebrate communities of spring habitats R. Manenti & E. Pezzoli To cite this article: R. Manenti & E. Pezzoli (2019) Think of what lies below, not only of what is visible above, or: a comprehensive zoological study of invertebrate communities of spring habitats, The European Zoological Journal, 86:1, 272-279 To link to this article: https://doi.org/10.1080/24750263.2019.1634769 © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Published online: 18 Jul 2019. Submit your article to this journal View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tizo21 The European Zoological Journal, 2019, 272–279 Vol. 86, No. 1, https://doi.org/10.1080/24750263.2019.1634769 Think of what lies below, not only of what is visible above, or: a comprehensive zoological study of invertebrate communities of spring habitats R. MANENTI 1* & E. PEZZOLI2 1Department of Environmental Science and Policy, Università degli Studi di Milano, Milano, Italy, and 2Bedulita, Bergamo, Italy (Received 31 March 2019; accepted 14 June 2019) Abstract Springs are interface habitats between the surface and subterranean environments, often neglected by zoological studies and generally regarded only from a surface perspective. Springs are also often collected and managed by humans: catching buildings that collect spring water may provide an accessible window over groundwaters. With this paper, we aim to assess the determinants of invertebrates’ occurrence in springs using a comprehensive approach and considering the role of catching buildings and of predator occurrence. During 2017 and 2018, we performed six repeated surveys in 44 springs of N-Italy. We distinguished between collected and natural springs, assessed the springs morphological features and recorded the occurrence of predator Salamandra salamandra (Linnaeus, 1758) larvae and of four invertebrate taxa corresponding to strictly spring-dwelling, groundwater-dwelling and stream-dwelling groups, such as the gastropod Graziana alpestris (Frauenfeld, 1863), the amphipods Niphargus thuringius Schellenberg, 1934 and Gammarus balcanicus Schäferna, 1922 and dipterans larvae of the family Tipulidae. We used a constrained redundancy analysis to evaluate the relative role of fire salamander occurrence and of springs features on the occurrence of the invertebrate taxa surveyed. Spring typology and fire salamander larvae were the major determinants of spring invertebrates’ occurrence. G. alpestris was positively related to artificial catching structures. Fire salamander was related to the occurrence of N.thuringius,G.balcanicusand Tipulidae larvae. Our results provide evidence that catching spring structures can significantly favour the detection of strictly spring-dwelling species; moreover, we reveal that the breeding of semi-aquatic predators like salamanders may play important roles on the community of invertebrates occurring in the spring habitats. Keywords: Gastropod, seepage, headwater, stream, amphibians Introduction often approached only under a surface perspective, Among freshwater habitats, one of the most interest- neglecting the role played by groundwaters (Galassi ing from both a zoological and management perspec- 2001;Fiascaetal.2014). From an ecological point of tive is the spring habitat. Springs have since a while view, springs have been distinguished in three main played a fundamental role for humans, being impor- categories such as (a) flowing springs (also named tant for the intake of potable water. Currently, spring rheocrenic), in which water flow feeds small streams; habitats are defined as groundwater-dependent eco- (b) pool springs (also named limnocrenic), where the systems (Eamus & Froend 2006) and are broadly flow is low and creates lentic habitats; and (c) seepage spread worldwide. Generally, springs can be defined springs (also named helocrenic) that create a shallow as the interface between groundwaters and surface damp zone (Thienemann 1922; Martin & Brunke freshwater habitats (Alfaro & Wallace 1994), with 2012). both the subterranean and the epigean habitat fea- Moreover, due to the human action, together with tures that interplay in characterising each spring. natural springs, there are also different typologies of However, zoological studies focusing on springs are artificial catchment buildings used, especially in the *Correspondence: R. Manenti, Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milano, Italy. Tel: 3490733107. Fax: 02 50314755. Email: [email protected] © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Determinants of invertebrates in springs 273 past, to collect and laminate groundwater for agri- organisms, like salamanders and some dragonfly cultural and civil purposes. There are two main species, may often exploit spring habitats for their typologies of artificial springs: draining galleries larval cycles, becoming often the top predator of the and catchment houses (also often called “bottini di source trophic webs (Lowe & Bolger 2002; Gillespie presa”). These artificial springs are characterised by 2013) and contributing substantially to the whole a more or less developed accessible part that pene- aquatic biomass of springs living organisms trates the side of a slope, to catch and bring outward (Barzaghi et al. 2017). water; these buildings collect water directly in the In Europe, among the amphibian species that are groundwater table. Old artificial springs base their more strictly connected with spring habitats, there is catching activity essentially on gravity and are asso- the fire salamander (Salamandra salamandra ciated with the urban and agricultural landscape of Linnaeus, 1758) (Manenti et al. 2009a). This spe- all the world, with particular importance for Europe, cies is ovoviviparous and typically breeds in small Japan, Asia and Northern Africa (Balland 1992). shallow streams with highly diversified substrate, The importance of old catching buildings other rich macrobenthos and absence of fish (Manenti than historical factors may also be significant for et al. 2009b, 2017; Manenti & Ficetola 2013). zoological studies. Catching buildings often occur Several observations have also been reported for in non-karst areas where natural caves or spaces different typologies of natural and artificial spring allowing the observation of groundwaters are not where the larvae of this species may reach strong available. Catching buildings may thus represent densities (Limongi et al. 2015). Fire salamander a window over freshwater subterranean environ- larvae are predators, and their occurrence is likely ments that could be otherwise accessible only using to affect the composition of the invertebrate fauna. expensive samplings. As studying distribution and From a zoological perspective, spring surface habitats of underground animals is quite complex organisms are often studied, and communities’ and is receiving growing interest (Mammola & assemblages of the invertebrate fauna of natural Leroy 2018; Ficetola et al. 2019), accessible win- springs are available, even if temporarily and spa- dows to subterranean aquifers may have strong zool- tially fragmented. At the same time, few information ogical importance. Moreover, from a zoological is available on the use of springs by typical ground- point of view, old catching buildings may expand water fauna, on the use and role of semi-aquatic the area of the border between the surface and sub- organisms as amphibians and on the importance terranean waters favouring both surface and subter- that old catching buildings may play for spring- ranean populations of organisms related to the fauna occurrence and observation. spring habitat. When springs are stable and isolated, Considering all these aspects, with this paper, we the environmental conditions may favour the devel- aim to (a) determine if spring catching buildings opment of a highly specialised fauna; spring- may affect communities of invertebrates and (b) dwelling specialised organisms are often called cre- understand if the occurrence of semi-aquatic preda- nobionts and are organisms that are necessarily asso- tors may affect the distribution of groundwater, cre- ciated with spring source habitats to survive and nobiont and surface invertebrates living in springs. accomplish their life cycles (Di Sabatino et al. We hypothesise that (a) both crenobiont and 2000; Hoffsten & Malmqvist 2000). Generally, groundwater organisms may be positively related to strict crenobiont species are quite rare and are catching spring buildings and that (b) all inverte- mainly represented by some species of snails of the brates’ categories are related to the fire salamander superfamily Hydrobioidea and by different species larvae occurrence in springs. of water mites (Roca & Gill 1992; Pezzoli 1996, 2010; Di Sabatino et al. 2000). However, much more organisms are often associated with spring Materials and