Occurrence of 'Antrobathynella stammeri' (Jakobi, 1954) (Crustacea: Syncarida: Bathynellidae) in the hyporheic zones of two English karst rivers

This paper reports the first records of Antrobathynella stammeri in the British Isles since 1985. Numerous individuals were observed in hyporheic water extracted from the River Skirfare (Yorkshire, UK), whilst, in an independent study, a single confirmed specimen was recorded from hyporheic water pumped from the River Lathkill (Derbyshire, UK). The latter observation is the first record of the superorder Syncarida in the Peak District and provides an important geographical link between previously recorded individuals in Scotland and north-west England and records from the south of England. These records suggest that bathynellids may be more abundant in the UK than previously thought, highlighting the need for more effective sampling of subterranean habitats to determine the conservation status of such rarely seen species

Ontogeny and phylogenetic relationships of the species of the genus Niphargus Schiödte, 1947 (Crustacea: Amphipoda: Niphargus) from the territory of Srbija

Pored brojnih pokušaja i informacija dobijenih analizom morfoloških karakteristika i metodama molekularne taksonomije jedan od najbrojnijih rodova slatkovodnih rakova na svetu, rod Niphargus, i dalje ima problematičnu i nerazrešenu taksonomiju. Predložene grupe dobijene na osnovu morfoloških analiza koje se danas koriste u sistematici nisu u skladu sa rezultatima molekularno filogenetskih istraživanja. Nove vrste se često otkrivaju, mahom ih odlikuje stenoendemičnost, a detektovan je i veći broj kriptičkih vrsta. Svega par vrsta nije vezano isključivo za subterestičnu slatkovodnu sredinu. Odsustvo cirkadijalnog ritma, male godišnje temperaturne oscilacije sredine koju naseljavaju i nepravilni priliv hranljivih materija je uslovio drugačije životne strategije, uključujući i razviće, u odnosu na epigejske srodnike. Sve pripadnike roda karakteriše adaptacija na hipogejsku sredinu u vidu odsustva organa vida, izduženih ekstremiteta, većeg broja taktilnih dlačica, itd. Posebnu poteškoću u određivanju taksonomije ove grupe predstavlja to što se kod nekih vrsta određene morfološke strukture, koje se mogu koristiti ili se koriste kao taksonomski karakteri, menjaju tokom ontogenije, čineći tako da juvenilni primerci jedne vrste liče na odrasle jedinke druge vrste. U cilju rasvetljavanja filogenetskih odnosa i taksonomskog statusa u okviru roda Niphargus, korišćen je integrativno taksonomski pristup i kombinacija molekularnih markera. Vršeno je i praćenje alometrijskih promena u toku ontogenije ključnih morfoloških karaktera različitih preadultnih uzrasnih kategorija. Detektovani su glavni morfološki karakteri vrsta koje su do sada registrovane na teritoriji Srbije (151 morfometrijskih i 186 merističkih). Analiza karaktera je izvršena na sakupljenim uzorcima, kao na osnovu literaturnih podataka koji su do sada objavljeni za vrste koje naseljavaju područje Srbije. Od 22 navedene vrste koje žive u Srbiji, vrsta Niphargus euserbicus je odabrana kao organizam za dalju ontogenetsku studiju. Vrsta pripada morfološkoj grupi Niphargus remyi- ravanicanus, čija ontogenija do sada nije izučavana. Odabrani su određeni morfološki karakteri koji su se pratili tokom ontogenije. Utvrđeno je koji su od stabilnih karaktera na nivou vrste podložni alometrijskom rastu. Vremensko javljanje trnova i bodlji na gnatopodama, pereopodama, epimeralnim pločama i telzonu u postembrionalnom razviću je predstavljeno sekvencom koja se može koristiti za upoređivanje među vrstama. Dobijeni podaci idu u prilog hipotezi da heterohronija igra značajnu, ako ne i ključnu ulogu, u evoluciji ovog roda. Prilikom uzorkovanja i analiza u toku ove studije, detektovana je i nova vrsta za nauku, Niphargus mirocensis u speleološkom objektu Rakin ponor, planina Miroč, zapadna Srbija. Novootkrivena vrsta je ujedno i prva vrsta roda Niphargus na području Srbije koja je dokumentovana metodama molekularne genetike. Dobijeni molekularno-filogenetski rezulati sugerišu da vrsta pripada kladi jezerske ekomorfe rasprostranjene u Italiji i centralnoj oblasti Dinarida. Vrsta ima markantnu morfologiju sa velikim i robusnim telom, dužim ekstremitetima, glomaznim i predatorskim gnatopodama, što je tipično za jezerski ekomorfe. Novo otkriće predstavlja geografsko proširenje opsega pomenute klade, čije su vrste uglavnom poznate kao stenoendemične.Even after countless experiments and information obtained by morphology and molecular biology, one of the most numerous genera of freshwater crustaceans in the world, Niphargus, still has a problematic and unresolved taxonomy. The proposed morphological groups, which are used today, are inconsistent with the molecular phylogeny. New species are frequently discovered and are mostly characterized by stenoendemicity, and a larger number of cryptic species have been detected. Only a few species are not related exclusively to the subterrestrial freshwater environment. The absence of circadian rhythm, smaller environmental annual temperature oscillations, and irregular inflows of nutrients have conditioned different life strategies, including their development, with regard to their epigeic relatives. The members of order are characterized by adaptation to the underground environment in the form of the absence of organs of sight, elongated extremities, a larger number of tactile hairs, etc. In some species, certain morphological structures, which can be used or are used as taxonomic characters, are changing during ontogeny, which makes juvenile specimens of these species resemble adult individuals of some other species. In order to resolve the phylogenetic relationships and taxonomical status of genus Niphargus, the combination of molecular methods and morphological analysis was used. Allometric changes during the ontogeny of key morphological characters were also observed in specimens of pre-adult age categories. Key morphological characters of the genus were detected (151 morphometric and 186 meristic). Character analysis was performed on collected samples and from literature data, for species inhabiting the territory of Serbia. During sampling a species new to science was described, Niphargus mirocensis. Of the 22 listed species, Niphargus euserbicus was chosen to be a study animal for ontogenic analysis. The species belongs to the artificial morphological group Niphargus remyi-ravanicanus, whose ontogenetic development has not been studied so far. Characters to follow during ontogenetic development were selected. They have been tested to be stable at the species level, susceptible to allometric growth and being polymorphic. The temporal occurrence of thorns and spines in postembryonic development is presented by a sequence that can be used for comparison between species. The obtained data further support the hypothesis that heterochrony plays a significant, if not a key role in the evolution of the genus. The newly discovered species Niphargus mirocensis, is the first species on the territory of Serbia that is molecularly discriminated. The obtained phylogenetic results suggest that it belongs to the clade of the lake ecomorph, also distributed in Italy and the central Dinaric region. The species has a recognizable morphology with a large and robust body, the longer body extremities, bulky and predatory gnathopods, that is typical for a lake ecomorph. The new discovery represents a geographical expansion of the range of the mentioned clade, whose species are mostly known as stenoendemic

Diversity and distribution of freshwater amphipod species in Switzerland (Crustacea: Amphipoda).

Amphipods are key organisms in many freshwater systems and contribute substantially to the diversity and functioning of macroinvertebrate communities. Furthermore, they are commonly used as bioindicators and for ecotoxicological tests. For many areas, however, diversity and distribution of amphipods is inadequately known, which limits their use in ecological and ecotoxicological studies and handicaps conservation initiatives. We studied the diversity and distribution of amphipods in Switzerland (Central Europe), covering four major drainage basins, an altitudinal gradient of>2,500 m, and various habitats (rivers, streams, lakes and groundwater). We provide the first provisional checklist and detailed information on the distribution and diversity of all amphipod species from Switzerland. In total, we found 29 amphipod species. This includes 16 native and 13 non-native species, one of the latter (Orchestia cavimana) reported here for the first time for Switzerland. The diversity is compared to neighboring countries. We specifically discuss species of the genus Niphargus, which are often receiving less attention. We also found evidence of an even higher level of hidden diversity, and the potential occurrence of further cryptic species. This diversity reflects the biogeographic past of Switzerland, and suggests that amphipods are ideally suited to address questions on endemism and adaptive radiations, post-glaciation re-colonization and invasion dynamics as well as biodiversity-ecosystem functioning relationships in aquatic systems

Biogeography and ecology of blind shrimp Niphargus (Crustacea, Amphipoda) in Croatia

Porodica Niphargidae unutar reda rakušaca (Amphipoda), broji 319 vrsta i svrstavamo je unutar podreda Senticaudata. Zastupljena je s najvećim brojem podzemnih slatkovodnih svojti (vrsta i podvrsta) rakušaca u Hrvatskoj. Najraznovrsniji rod slatkovodnih rakušaca je rod Niphargus s preko 300 poznatih vrsta u svijetu. Rod Niphargus je unatoč velikoj raznolikosti u podzemnim vodama, slabije prisutan u površinskim staništima. Rasprostranjen je u Europi, a zabilježen je i u Maloj Aziji, Iranu i na Arapskom poluotoku. Prva istraživanja Amphipoda u Hrvatskoj su provedena sredinom 19. st. Od prvog popisa G. Karamana iz 1974. god. do danas, zabilježeno je ukupno 59 vrsta i podvrsta roda Niphargus u Hrvatskoj. Ovaj rad daje na uvid popis vrsta i podvrsta prema najnovijoj taksonomiji, pregled biogeografskih regija te tipova staništa u kojima su pronađene. Zbog osjetljivosti na onečišćenje, malog areala rasprostranjenosti, fragmentacije i uništavanja staništa, pojedine vrste su uvrštene na Crveni popis rakova slatkih i bočatih voda te Crveni popis špiljske faune u Hrvatskoj.Niphargidae, suborder of Senticaudata, is a family of amphipod crustaceans with 319 species and subspecies. It is represented with the largest number of subterranean freshwater species and subspecies of Croatian amphipods. Niphargus is the most diverse genus in the world with more than 300 species. Despite its high diversity in subterranean waters, the genus is less diverse in surface waters. The genus Niphargus is wildly distributed throughout Europe and Middle East. The first important research on amphipods in Croatia were conducted in the mid 19th century. Total of 59 species and subspecies of Niphargus have been described in Croatia since the first list made by G. Karaman in 1974. till now. This paper provides a list of species and subspecies sorted using the most recent taxonomy, their biogeographical regions, and types of habitats the species were found in. Due to being highly sensitive to pollution, having a small areal of distribution and fragmentation of their habitats, some species have been included in The IUCN Red List of Threatened Species of Croatia

Think of what lies below, not only of what is visible above, or: a comprehensive zoological study of invertebrate communities of spring habitats

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. balcanicus and 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

Do Salamanders Limit the Abundance of Groundwater Invertebrates in Subterranean Habitats?

Several species of surface salamanders exploit underground environments; in Europe, one of the most common is the fire salamander (Salamandra salamandra). In this study, we investigated if fire salamander larvae occurring in groundwater habitats can affect the abundance of some cave-adapted species. We analyzed the data of abundance of three target taxa (genera Niphargus (Amphipoda; Niphargidae), Monolistra (Isopoda; Sphaeromatidae) and Dendrocoelum (Tricladida; Dedrocoelidae)) collected in 386 surveys performed on 117 sites (pools and distinct subterranean stream sectors), within 17 natural and 24 artificial subterranean habitats, between 2012 and 2019. Generalized linear mixed models were used to assess the relationship between target taxa abundance, fire salamander larvae occurrence, and environmental features. The presence of salamander larvae negatively affected the abundance of all the target taxa. Monolistra abundance was positively related with the distance from the cave entrance of the sites and by their surface. Our study revealed that surface salamanders may have a negative effect on the abundance of cave-adapted animals, and highlited the importance of further investigations on the diet and on the top-down effects of salamanders on the subterranean communities