Gianluca PolgarTuscia University | Tuscia · Dipartimento per la Innovazione nei sistemi Biologici Agroalimentari e Forestali
Gianluca Polgar
Laurea degree in Natural Sciences, University of Rome "La Sapienza", Italy; PhD in Ecological Sciences, University of Rome "La Sapienza", Italy
About
72
Publications
51,994
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
694
Citations
Citations since 2017
Introduction
My main research interest is in water-to-land ecological and evolutionary transitions. In this field, I mainly worked with gobiid mudskippers, brachyuran crabs, gastropod snails and polychaetes, in the Indo-West Pacific region. Recently, I started to work in freshwater ecosystems, focusing on Italian salmonids. I typically adopt an interdisciplinary approach, focusing on specific animal groups.
Additional affiliations
April 2014 - May 2017
Position
- Lecturer
Description
- Teaching: Organisms and Environment; Diversity of Life; Conservation and Management of Living Resources; Animal Behaviour; Animal Form and Function Research: Evolutionary ecology of tropical wetlands
February 2013 - April 2014
Position
- Research Associate
Description
- ecophysiology of mudskippers and intertidal gastropods
July 2010 - January 2013
Position
- Visiting Senior Lecturer
Description
- TEACHING: Ichthyology, Animal Physiology, Limnology, Research Methodology - An Introduction to R RESEARCH: Trophic ecology; eco-physiology (Gobiidae: Oxudercinae); spatial and evolutionary ecology (Brachiura: Sesarmidae); community ecology (Polychaeta)
Education
May 2004 - February 2009
University of "La Sapienza", Rome Italy
Field of study
- Ecological Sciences
Publications
Publications (72)
Several intertidal and supratidal systems were investigated in the Brunei Bay to assess the diversity and assemblage structure of grapsoid crabs (Brachyura: Grapsoidea) in different salinity and substrate conditions, type of vegetation, and distance from water bodies. The structure of the assemblages differed remarkably across and within sites, and...
In the last century, Italian freshwater ecosystems have been invaded by several non-native fish species. In the subalpine Lake Mergozzo (northern Italy), several recently introduced non-native species dramatically expanded their populations. We used carbon and nitrogen stable isotopes to describe the isotopic niches and trophic positions of native...
SouthEast Asia is a biodiversity hot spot for several different animal and plant taxa, and grapsoid crabs are dominant components of its mangrove macrofauna. However, autecological traits of the species and assemblage structures are still largely undescribed. During the period 2012-14, we surveyed six mainland and insular mangrove sites along the w...
For centuries, mangrove forests and adjacent ecosystems have been cast in a negative light due to their (often perceived) ecosystem disservices. We give contemporary examples of how such viewpoints about mangroves continue to be communicated today, with potentially adverse consequences for mangrove conservation and public support. Since public perc...
The mudskipper Periophthalmus walailakae (Gobiidae) was first discovered in the Vellar Estuary in south-eastern India. In total, 5 specimens were collected from three stations between April and December 2017. Their total length (LT) ranged from 40 mm to 159 mm and their live weight from 8.3 g to 29.8 g. The diagnostic morphometric and meristic char...
Salmonid species are main actors in the Italian socio-ecological landscape of inland fisheries. We present novel data on the size-age structure of one of the remnant Italian populations of the critically endangered marble trout Salmo marmoratus , which co-occurs with other stocked non-native salmonids in a large glacial river of the Lake Maggiore b...
During the last 150 years, the trout-culture industry focused on enhancing trout populations by stocking, in response to the growing anglers’ demand and the habitat degradation associated to the rapid urbanization and hydropower development. The industrialized north of Italy, home to the Italian Alpine and subalpine trout populations, is the source...
During the last 150 years, the trout-culture industry focused on enhancing trout populations by stocking, in response to the growing anglers’ demand and the habitat degradation associated to the rapid urbanization and hydropower development. The industrialized north of Italy, home to the Italian Alpine and subalpine trout populations, is the source...
The peninsular trout, commonly referred to as the “Mediterranean brown trout” and here classified as Salmo ghigii, has an important role in the ongoing conflict on fish stocking. The Italian law defines as autochthonous species or differentiated populations that are part of the original flora or fauna of a certain area, or that arrived there withou...
Acoustic behaviour in Periophthalmus barbarus
The Universiti Brunei Darussalam Museum and Herbarium are two small zoological and botanical university collections that started in the 1980s, mainly as research facilities. They contain collections and type material from northern Borneo that are of historical and scientific interest, and have received the contributions of several internationally r...
A broad overview of the conservation status of mangrove, and peat, forests, as well as other associated wetland habitats is provided. The consequences of deforestation and habitat fragmentation to native organisms are discussed in the context of historical habitat management attempts.
A sustainable and holistic management approach—Ecotonal Networks (ENTs)—is proposed to preserve the internal hydrologic connectivity of the entire catchment. Its application to wetland habitats is discussed within the theoretical framework of Resilience Theory.
Flagship species are key to conservation, and can act as umbrella taxa to represent entire ecosystems. The fourth chapter of the book presents a selection of potential flagship species that will help raise awareness to the imminent threats to Sundaland wetland ecosystems.
Sustainable ecotourism can be viable and profitable. The last chapter proposes suggestions to manage non-urban wetland areas of Sundaland. Future development of these areas must consider access to these imperiled systems by the general public, while protecting them.
The Sundaland biodiversity hotspot, defined by the biogeographic divides of the Kangar-Pattani line to the north and the Wallace’s line to the East, is a terrestrial unit of conservation priority within Southeast Asia. Within the Sundaland biodiversity hotspot—that includes the Nicobar Islands, part of the Malay Peninsula (southern Thailand and Pen...
This book informs readers on the ecology, ecosystem services, and management of Sundaland wetland ecosystems, discussing the concepts and tools necessary to conserve these imperiled habitats. Sundaland is a biogeographically defined area of South East Asia characterised by an exceptional concentration of endemic species. The unprecedented loss of w...
The conundrum of vertebrate ecological and evolutionary water-to-land transitions is the identification of the selective factors that facilitated them. In the intertidal zone, this transition is essentially a movement across the intertidal ecological gradient in a water-to-land direction, or a spatiotemporal change of the distribution of evolutiona...
We hypothesise that the body shapes of three mudskipper species (Boleophthalmus dussumieri, Periophthalmus waltoni, and Scartelaos tenuis) are ecomorphological adaptations to different epi- and infaunal habitats. We investigated: (i) the association between burrow density and selected ecological variables; (ii) the phylogenetic relationships among...
Acoustic communication in mudskippers and other gobies
French to English translation of:
Brillet C. (1980) Comportement sexuel du poisson amphibie Periophthalmus sobrinus Eggert. Ses rapports avec le comportement agonistique. Rev. Ecol. (Terre Vie), vol. 34: 427-468 [in French]
English translation from French to English of:
Brillet C. (1976) Structure du terrier, reproduction et comportement des jeunes chez le poisson amphibie Periophthalmus sobrinus Eggert. Revue d'Ecologie (La Terre et la Vie), 30: 465-483 [in French]
A study was conducted on the habitat distribution of four sympatric species of Periophthalmus (the silver-lined mudskipper Periophthalmus argentilineatus, the slender mudskipper Periophthalmus gracilis, the kalolo mudskipper Periophthalmus kalolo and the Malacca mudskipper Periophthalmus malaccensis) from northern Sulawesi. Molecular phylogenetic r...
The mudskipper Periophthalmus malaccensis is first reported from two mangrove areas of Brunei Darussalam, on the island of Borneo. This species has a relatively restricted geographic distribution and have been reported from Singapore, Philippines, Maluku Islands, western New Guinea, and northern Sulawesi. In Brunei, this species occurs at low popul...
We describe Periophthalmus pusing sp. nov., a mudskipper species from the Lesser Sunda Islands. This species closely resembles, and was previously identified as, its congener Periophthalmus gracilis Eggert, 1935. A black spot on the posterior portion of the first dorsal fin, a diagnostic character for P. gracilis, is also present in the new species...
The Asian arowana (Scleropages formosus), one of the world’s most expensive cultivated ornamental fishes, is an endangered species. It represents an ancient lineage of teleosts: the Osteoglossomorpha. Here, we provide a high-quality chromosome-level reference genome of a female golden-variety arowana using a combination of deep shotgun sequencing a...
For this study, 11 samples have been collected by scuba diving from 5 to 35 meters water depth off shore Brunei Darussalam. The locations sampled are known as: Pelong Rock (5 samples, shallow reef with soft and stony corals and larger foraminifera, 5 to 8 meters water depth), Abana Rock (1 sample, shallow reef with mainly soft corals and larger for...
Corresponding author at: Environmental and Life Sciences, Universiti Brunei Darussalam, Bandar Seri Begawan, Gadong, Negara Brunei Darussalam.
A new species of the genus Sabellaria Lamarck, 1818 (Annelida: Polychaeta: Sabellariidae) is described from the intertidal zone of Jeram, Selangor, Malaysia. Sabellaria jeramae n. sp. is a gregarious species that constructs large reefs several hundreds of meters long and 50–200 m wide. The new species is distinguished from other congeners by the ch...
The ecology of tropical sabellariid reefs is scarcely known, and only few records of such systems were reported from Southeast Asia. The present investigation describes the only documented polychaete reef of western Peninsular Malaysia, which has been previously reported on in two other studies. More recent surveys documented dramatic temporal chan...
Mudskippers are amphibious fishes that have developed morphological and physiological adaptations to match their unique lifestyles. Here we perform whole-genome sequencing of four representative mudskippers to elucidate the molecular mechanisms underlying these adaptations. We discover an expansion of innate immune system genes in the mudskippers t...
We use dated phylogenetic trees for tetrapod vertebrates to identify lineages that shifted between terrestrial and aquatic ecosystems in terms of feeding or development, and to assess the timing of such events. Both stem and crown lineage ages indicate a peak in transition events in correspondence with the K-Pg mass extinction. This meets the predi...
The body shape variation among 244 specimens of Periophthalmus waltoni Koumans, 1941, collected from seven stations in the Persian Gulf and Gulf of Oman, was analysed by utilising geometric morphometrics (GM) and truss-based morphometrics methods (TBM). Discriminant function analysis did not show significant differences between the shape of females...
English translation of Dotu (Dotsu) (1961) タ ビ ラ ク チ の 生 態・ 生 活 史 道 津 喜 衛
. The Bulletin of the Faculty of Fisheries. Nagasaki University, 10: 133-139, 1 plate [in Japanese]; original paper: http://naosite.lb.nagasaki-u.ac.jp/dspace/bitstream/10069/31715/1/suisan10_133.pdf
English translation of: Chen Hui, Polgar Gianluca, Yin Wei and Fu Cui-Zhang (2014) 西北太平洋海岸带大弹涂鱼复合体的隐存种与进化历史. Acta Hydrobiolica Sinica, 38(1): 75-86; original paper: http://ssswxb.ihb.ac.cn/EN/10.7541/2014.10 or http://ssswxb.ihb.ac.cn/EN/Y2014/V38/I1/75
This study provides a first description of the phylogeographic patterns and evolutionary history of two species of the mudskipper genus Periophthalmus. These amphibious gobies are distributed throughout the whole Indo-Pacific region and Atlantic coast of Africa, in peritidal habitats of soft-bottom coastal ecosystems. Three sequence datasets of two...
English translation of: Tomokichi Kobayashi, Yoshie Dotsu and Nobuo Miura (1972) トビハゼ の 卵 発生 お よび 稚仔 の 飼育, 小 林 知 吉*・ 道 津 喜 衛 ・三 浦 信 男. Bulletin of the Faculty of Fisheries, Nagasaki University, 33: 49–62 [in Japanese]; original paper: http://naosite.lb.nagasaki-u.ac.jp/dspace/bitstream/10069/31073/1/suisan33_049.pdf
The species range of Boleophthalmus pectinirostris sensu lato includes two disjunctive areas, i.e., East Asia and Strait of Malacca in Malaysia along the northwestern Pacific coast. However, the species status of Malaysian populations remains disputed. Mitochondrial ND5 gene (718 bp) and nuclear Rag1 gene (1395 bp) were used to reconstruct phylogen...
The Andaman Sea is a reef- and coastal seagrass-rich basin that connects the South China Sea with the Indian Ocean via the Straits of Malacca
Rivers are defined as lotic biomes (from the Latin lotus, meaning “washed”); that is, inland watercourses that unidirectionally flow through topographic gradients in the landscape. The English word comes from the Vulgar Latin riparia (“riverbank, seashore, or river”). This term is frequently utilized to indicate relatively large water streams. The...
The richly diverse habitats of the vast Mekong Delta, heavily affected by past exploitation and destructive events, are newly threatened by rapid and uncontrolled development.
Boleophthalmus poti, new species, is described from the Gulf of Papua, Papua New Guinea. It is distinguished from its congeners by a combination of characters, including: un-notched, fl attened and horizontally disposed dentary teeth; pelvic-disc length ~10% of SL; D1 base length ~15% of SL; D2 base length ~40% of SL; ~5 interdorsal scale rows; ~11...
For the first time in the history of our species, the opportunity of halting the expansion of our global population discloses future scenarios of stably coexisting urbanised and non-urbanised ecosystems. The need for the establishment of such scenarios is particularly urgent in tropical regions, whose higher biodiversity is being rapidly eroded by...
A preliminary description of the polychaete reef of Jeram, Selangor, Malaysia.
Coupled behavioural observations and acoustical recordings of aggressive dyadic contests showed that the mudskipper Periophthalmodon septemradiatus communicates acoustically while out of water. An analysis of intraspecific variability showed that specific acoustic components may act as tags for individual recognition, further supporting the sounds'...
Mudskippers (Gobiidae: Oxudercinae) are air-breathing gobies, which are widely distributed throughout the West African coast and the Indo-Pacific region. They are closely linked to mangrove and adjacent soft bottom peri-tidal ecosystems. Some species are amongst the best adapted fishes to an amphibious lifestyle. All mudskippers are benthic burrowe...
During several surveys made in the region of the lower Fly River and delta, Papua New Guinea, nine species of oxudercine gobies (Gobiidae: Oxudercinae) were recorded: Boleophthalmus caeruleomaculatus, Oxuderces wirzi, Periophthalmodon freycineti, Periophthalmus darwini, Periophthalmus novaeguineaensis, Periophthalmus takita, Periophthalmus weberi,...
![Fig. 3. Fish size (total length [TL]) per stratum (A to E) and per...](profile/Gianluca-Polgar/publication/235734978/figure/fig2/AS:299756929732612@1448479029670/Fish-size-total-length-TL-per-stratum-A-to-E-and-per-species-a-Fish-size-per_Q320.jpg)
Reduction in size from sea to land is a common trend of many fish species and communities, at both the intraspecific and interspecific level. Within the intertidal zone, similar trends have been described at the intraspecific level in several transient and resident fish species. Oxudercines are a group of intertidal gobies (Gobiidae: Oxudercinae) i...
Tidal mudflats and coastal swamps are distributed along the sea-land ecological transition in humid tropical and subtropical regions. They are among the most endangered ecosystems on Earth, and have been intensively impacted both from water and land during the last 50 years. These transitional systems play a key-role in the homeostasis of inshore w...
Mudskippers (Gobiidae: Oxudercinae) are amphibious gobies. The occurrence and habitats of seven sympatric species of Malayan mudskippers were recorded: Boleophthalmus boddarti, Boleophthalmus pectinirostris, Periophthalmodon schlosseri, Periophthalmus chrysospilos, Periophthalmus gracilis, Periophthalmus variabilis and Scartelaos histophorus. A tot...
The rapid and extensive destruction of mangrove forests and adjacent peritidal ecosystems in the Indo-Pacific region requires the development of efficient management and conservation actions. Mudskippers (Gobiidae: Oxudercinae) are amphibious gobies that are strictly linked to mangrove forests and tropical mudflats. I recorded the presence and habi...
A host-parasite relationship was observed, for the first time, between a piscicolid leech and a species of amphibious goby (Scartelaos tenuis) from an intertidal mud flat in southern Iran. Morphological and molecular investigations assign the leech to Zeylanicobdella arugamensis. Of the 3 endemic and sympatric mudskipper species living in the Persi...
Mudskippers (Gobiidae: Oxudercinae; Murdy, 1989) are a conspicuous component of tropical intertidal ecosystems. These fishes are abundant on tropical mudflats and mangrove forests from Western Africa in the Atlantic, to the entire Indo-Pacific region. Periophthalmus Bloch & Schneider, 1801, with 17 species, is the richest genus (Murdy, 1989; Lee et...
Questions
Questions (12)
It appears that about 50 million scientific papers have been published, and likely hundreds of papers are being published each minute.
The number of "scientific journals" has been estimated to be 20k-40k
However, there still appears to be a considerable degree of confusion about what defines a "scientific journal". For example, many national journals not published in English, such as "bulletins" and "notes" of museums and research/academic institutions, appear to match the criteria of peer-reviewed scientific published information.
Is it possible to find a set of criteria to discriminate a scientific periodical publication (journal) from other types of literature?
Are scientists, lost in the unmanageable ocean of "scientific" literature, increasingly limited both in their literature sources and publication options by the standards set by largely used databases (ISI WoS, Scopus, Google Scholar)?
When applying their principal coordinates of neighbor matrices (PCNM; Borcard et al. 2002, Ecological Modelling) method to real ecological data, Borcard et al. (2004, Ecology) recommended to check for linear spatial trends in the response data (linear gradients), prior to the analysis. They advocated that linear trends in the response data could obscure other recoverable structures in the data at finer scales.
When Dray et al. (2006, Ecological Modelling) introduced their Moran's Eigenvector Maps (MEMs), they showed that PCNMs are a particular case of MEMs. When they analysed one of the datasets of Borcard et al. (2004; the "famous" oribatid mites dataset), they also detrended the response variables (species abundances) by multiple linear regression on geographic coordinates. Using this same dataset, Jombart et al. (2009, Ecography) also detrended the environmental variables.
However, in my dataset (irregular 2D sampling grid), regression on geographic coordinates both: 1) prevents from selecting the best method for constructing the spatial weighting matrix, and 2) when the regression line (e.g. abundance vs. coordinate x) has a negative intercept, the regression can have positive residuals at abundance values = 0, for small-enough values of the geographic coordinates. This hampers the interpretation of the analysis.
Is it mandatory to detrend both the response variables and the environmental variables, if a linear gradient is found? In this case, how to solve the mentioned issues?
We're working in R, adespatial package (https://cran.r-project.org/web/packages/adespatial/vignettes/tutorial.html#swm)
