Welcome to Hydrobiologia's Cover Gallery


Volume 849 Issue 16

New Content ItemCover illustration Blackwater tributary of the Santiago river in the Kampankis mountains that lies between the Santiago and Morona rivers, stretching from the Perú–Ecuador border to the Marañón river in the Amazon rainforest of northern Peru. The photo was taken during a rapid biological and social inventory conducted primarily by The Field Museum (Chicago) and several Peruvian partners including the Natural History Museum of the Universidad Nacional Mayor de San Marcos (Lima). Photograph by Álvaro del Campo (Rapid Inventories’ Specialist, The Field Museum, Chicago, IL, USA) (Hydrobiologia 849(16): 3449–3462).

Volume 849 Issue 15

New Content ItemCover illustration Close-up view of the subumbrella of Cassiopea andromeda young medusa derived from indole-induced strobilation. Eight newly formed oral arms with digitata on the edge. Bluish body due to the absence of symbiotic zooxanthellae. Photograph by Liqiu Deng (Hydrobiologia 849(15): 3275–3285).

Volume 849 Issue 14

New Content ItemCover illustration This photo was taken in Darwin Island, Galápagos back in 2009. I entered the water and free dived down to 10 m to find myself completely surrounded by 100+ hammerhead sharks that were almost stationary in the current and unaware of my presence. I took this photo in the middle of the school when I got to position myself the closest I have ever been to dozens of hammerheads at the same time. Photograph by James T. Ketchum (Hydrobiologia 849(14): 3083–3099).

Volume 849 Issue 13

New Content ItemCover illustration The Upper Manso River is located in Patagonian Andes, in the Nahuel Huapi National Park in southwestern Argentina. This river is 23 km long with a drainage area reaching 250 km2 . The river begins in the proglacial Lake Ventisquero Negro at Mount Tronador (3481 m above sea level) and discharges into Lake Mascardi. Mount Tronador situated on the border between Chile and Argentina hosts one of the largest contiguous ice covers (52 km2 ) in the North Patagonian Andes. Photograph by Nicolas Martyniuk (Hydrobiologia 849(13): 2877–2894).

Volume 849 Issue 12

New Content ItemCover illustration An endangered Japanese endemic freshwater unionid, Pronodularia japanensis, living in an agricultural ditch in Ehime, Japan. This ditch will disappear within 5 years by land-consolidation, and the unionid population is trying to be conserved by nature-restoration and monitoring using an eDNA marker. Photograph by Koji Matsumoto (Ehime University Senior High School, Matsuyama, Ehime, Japan) (Hydrobiologia 849(12): 2635–2646).

Volume 849 Issue 10

New Content ItemCover illustration Two Cuvier’s beaked whales surface for a short period to breathe. This species dives to depths of over 2 kilometres, being the deepest recorded marine mammal. This characteristic means that they can be challenging to study as they are only available to observe for a short time at the surface. Citizen scientists can play a vital role to monitor these animals with extensive survey effort from platforms of opportunity (e.g., ferries and cruise ships). Photograph by Heather Bodie (ORCA, Portsmouth, UK) (Hydrobiologia 849(10): 2225–2239).

Volume 849 Issue 9

New Content ItemCover illustration Rock pool on sandstone during its wet phase in September. The rock pool is located in the Parco Nazionale dell’Appennino Tosco-Emiliano (Parma, Italy) and on the background the Lake Gemio Inferior is visible. The leaves fallen inside the rock pool provide food and shelter for a rich meiofauna community. Photograph by Claudio Ferrari (Hydrobiologia 849(9): 1995–2007)

Volume 849 Issue 8

New Content ItemCover illustration An agonistic encounter between two male red banded parrotfish Sparisoma aurofrenatum in Isla Aguja, Colombian Caribbean. Photograph by Santiago Estrada (Reef Shepherd Dive Center, Taganga – Santa Marta, Colombia) (Hydrobiologia 849(8): 1727–1741).

Volume 849 Issue 7

New Content ItemCover illustration Photograph taken in June 2017, of the distal portion of a colonial pyrosome, Pyrosoma atlanticum, using an Axiocam 705 mounted on a Zeiss Discovery V8 dissecting scope at the zooplankton lab in the Institute of Ocean Sciences, Pat Bay, Canada. Starting in late 2016 and continuing throughout 2017, this species was being found in large numbers from southern California to Hecate Strait off the northern British Columbia coast. The pyrosome was placed in a Petrie dish filled with seawater and the focus was zoomed to view the individual tunicates that make up the colony. Part of the study was to investigate the features of the inhalant siphon and details of feeding basket plus the encasing tunic exoskeleton. Fast growth, sexual and asexual reproduction modes, very efficient filter feeders make this species of high impact to the local zooplankton communities during marine heat wave and El Niño events. Photograph by Moira D. Galbraith (Hydrobiologia 849(7): 1543–1557).

Volume 849 Issue 6

New Content ItemCover illustration Ichthyology has an undisputed interest among Iberian researchers devoted to exploring all aspects of fish biology, fisheries and management from riverine to estuarine and marine biomes. Photographs taken during different fieldworks by members of the hydrobiology lab of the University of Santiago de Compostela, Spain (Rufino Vieira-Lanero, Sandra Barca, David José Nachón, María del Carmen Cobo, Javier Sánchez-Hernández and Fernando Cobo) (Hydrobiologia 849(6): 1313–1315).

Volume 849 Issue 5

New Content ItemCover illustration Tapacurá reservoir is an important water body in Northeast Brazil, providing several ecosystem services to people. Since the 90s this reservoir has been facing algal blooms due to cultural eutrophication. Therefore, the ecology of phytoplankton in this system and others in Northeast Brazil has helped to understand the eco-system functioning and propose strategies to control algal blooms. Photograph by Cihelio Amorim (Hydrobiologia 849(5): 1095–1113).

Volume 849 Issue 4

New Content ItemCover illustration Photo taken at the Sierra Nevada Aquatic Research Laboratory on 18 July 2014 in California, USA. These nine experimental channels are naturally fed by a nearby stream, Convict Creek, and are embedded within the eastern Sierra Nevada Mountains. The bends represent deeper pools, and straight sections represent riffle habitat. This photo was taken a day before a gradient of drought treatments were established in the channels. Photograph by Parsa Saffarinia (Hydrobiologia 849(4): 879–897).

Volume 849 Issue 3

New Content ItemCover illustration Individual of Palaemon macrodactylus Rathbun, 1902 on a seagrass leaf. The native distribution range of P. macrodactylus includes the Sea of China, a large part of the Sea of Japan and the Pacific coast of Japan. However, the species has rapidly spread worldwide, becoming invasive along Eastern Pacific coasts, Atlantic Ocean and Mediterranean Sea, often threatening native species. Indeed, its behavioural and life history traits indicate an aggressive and opportunistic attitude. Moreover, it was demonstrated to be more euryhaline and more eurythermal and to consistently consume less oxygen than the congeneric native species, hence having the potential to become the dominant estuarine shrimp in Europe and one of the most widespread introduced aquatic species. Photograph by Antonio Azzurro (DVS Digital Video Studio, Italy) (Hydrobiologia 849(3): 661–674).

Volume 849 Issue 2

New Content ItemCover illustration A small hydropower dam on the River Flåmselvi which runs through typical west coast scenery in Norway. With its spectacular waterfalls and high biodiversity, the area is a popular destination for both tourists and biologists. Part of the river system is protected, but the lower parts are regulated for hydropower production at the power stations Leinafoss and Kjosfossen. Photograph by Juliet Landrø, NINA (Norwegian Institute for Nature Research).

Volume 849 Issue 1

New Content ItemCover illustration The Australian eastern long-necked turtle, Chelodina longicollis, has a maximum carapace length of 28 cm. The retraction of the neck and limbs within the shell are a strategy that the species uses to resist potential predators when on land. Its natural range is from north Queensland to south-eastern South Australia, and it has been introduced to Tasmania. It is a carnivorous species that inhabits both still and running waters, but takes particular advantage of invertebrate prey found in temporary waters. Its adaptations include a low rate of evaporative water loss, a capacity for aestivation, and a proclivity for overland migration. Photograph taken by Bruce C. Chessman at Laura Station, Bundarra, New South Wales, Australia on 6 November 2021 (Hydrobiologia 849(1): 113–120)


Volume 848 Issue 21

New Content ItemCover illustration Micrasterias thomasiana W. Archer is a desmid of slightly mesotrophic waters and occurs particularly in samples taken after 1980 in the Dutch moorland pools studied by Van Dam & Meesters. Photograph by Marien van Westen (independent researcher of desmids in the Dutch province of Drenthe, http://desmids.science4all.nl/) (Hydrobiologia 848(21): 5011–5031).

Volume 848 Issue 20

New Content ItemCover illustration Channel of a Brazilian tropical river (Parnaíba River) and its riparian vegetation during dry season in the city of Teresina, Northeastern Brazil. Photograph by Givanilso Cândido Leal (Hydrobiologia 848(20): 4695– 4712).

Volume 848 Issue 19

New Content ItemCover illustration Odonata is the order of insects known as dragonflies and damselflies. Adults exhibit elegant flight, bright colors, and typical territorial defense behaviors for reproduction and predation. The Neotropical Savanna (Cerrado biome) has a great diversity of species, including this Erythrodiplax sp. (Libellulidae: Anisoptera) standing on a branch of riparian vegetation. Photograph by Diego M.P. Castro (Hydrobiologia 848(19): 4433– 4443).

Volume 848 Issue 18

New Content ItemCover illustration The bedrock of the lower Xingu River is unique in the lower Amazon Basin and provides a unique habitat for the plants and animals of the region. During the dry season, the rocks are exposed creating large rapids that in turn create a diversity of riverine habitats. This diversity of habitats has resulted in many endemic aquatic species in the region. Photograph by Carson Jeffres (UC Davis Center for Watershed Sciences, CA, USA) (Hydrobiologia 848(18): 4167– 4177).

Volume 848 Issue 17

New Content ItemCover illustration The sailfish (Istiophorus platypterus) is a circumtropical billfish species, considered an important fishery resource globally caught by different fishing fleets from large- to small-scale and artisanal fisheries. It is also a highly prized trophy for the sports fishery. Ferrette et al. (this issue) in order to improve the sailfish's management, evaluated the genetic population structure of the species and delimited three genetic stocks, a single population within the Atlantic Ocean, another in the Indo-Western Pacific, and a third in the Eastern Central Pacific. These results evidence the need for the regional fisheries management organizations (RFMOs) to update their management strategy for the species. The photograph was taken by research collaborator and the commander of the Tarpon boat, Marco Ribas (Rio de Janeiro's Yacht Club) in front of the city of Rio de Janeiro, Brazil (Hydrobiologia 848(17): 3883–3904).

Volume 848 Issue 16

New Content Item (1)Cover illustration Depicted is a male of Ctenochromis horei, a species of the endemic Lake Tanganyika cichlid tribe Tropheini. Unlike most other Tropheini, C. horei shows virtually no geographic color variation and is found in all types of shallow habitat throughout the lake, suggesting high dispersal capacity. Rahmouni et al. (this issue) studied the geographic structure of monogenean ectoparasites specific to C. horei in the north of Lake Tanganyika and compared it with monogeneans from a supposedly poorly dispersing cichlid species to test whether the hosts’ presumed differences in dispersal capacity are mirrored in the geographic population structure of their monogenean ectoparasites. Photograph by Wolfgang Gessl (www.pisces.at; Institute of Biology, University of Graz, Austria) (Hydrobiologia 848(16): 3833–3845).

Volume 848 Issue 15
New Content Item (1)Cover illustration Light micrographs of a specimen of Annelida; Clitellata collected from the Rodadero beach, Colombia. Photograph by Ana Milena Lagos and Maria Victoria Leon (Grupo de Investigación MIKU, Universidad del Magdalena, Colombia) (Hydrobiologia 848(15): 3407–3426).

Volume 848 Issue 14
New Content Item (1)Cover illustration The Wadden Sea is listed as UNESCO World heritage as the largest, undisturbed system of intertidal sand and mud flats in the World. It extends along the coasts of the Netherlands, Germany and Denmark. Its unique ecological values and ecosystem services are irreplaceable, due to its dynamic landscape, biodiversity and multitude of habitats. As tidal areas and salt marshes constitute most of the Wadden Sea’s landscapes, the area is invaluable for sedimental carbon capture and mitigation of sea level rise. The picture was taken at Mandøvejen, in the Danish Wadden Sea, by plant ecologist Franziska Eller (Department of Biology, Aarhus University, Denmark).

Volume 848 Issue 12-13

New Content Item (1)Cover illustration A Giant Freshwater Pearl Mussel Pseudunio auricularius, one of the most threatened invertebrate species on earth, is filtering the waters of the Vienne River in France. Usually found in large and deep rivers, this specimen had settled near the bank, in the shallow waters of summertime. Excessive water extraction together with climate change dramatically threaten freshwater invertebrates, long-lived and not very mobile freshwater bivalves being on the front line. Photograph by Vincent Prié (Hydrobiologia 848(12–13): 2931–2950).

Volume 848 Issue 11
New Content Item (1)Cover illustration Natural beauty comes from natural perfection. This feather star (Echinodermata: Crinoidea) holds itself in the perfect proportions of a fibonacci spiral. Crinoids are usually active during the night when they extend their sticky feathered arms to collect plankton suspended in the water. While in the day, they are closed and curled to form amazing patterns. However, if there is a high density of plankton during the day, they take advantage of the abundant food. This picture was taken in the Maldives, during a study on the effect of variation in coral cover on the population of the snail Drupella spp. (Mollusca: Gastropoda), 2 years after a coral mass bleaching event. Photograph by Luca Saponari (Hydrobiologia 848(11): 2653–2666).

Volume 848 Issue 10
New Content Item (1)Cover illustration Four freshwater eel species (Anguilla spp.) occur in southern African rivers that are increasingly anthropogenically modified. The African longfin eel (A. mossambica) is one of them and is endemic to Africa. This species is now regarded as near threatened due to its decline in range distribution in Kwazulu-Natal-Natal, South Africa. Photograph by Jeremy Shelton (Freshwater Research Center, South Africa) (Hydrobiologia 848(10): 2579–2593).

Volume 848 Issue 9
New Content Item (1)Cover illustration Electromicrography (SEM), of the harmful invasive worldwide spread dinoflagellate Ceratium furcoides (Dorsal view in 1.55kx of magnification, using ZEISS, AURIGA 45–38). The photographed specimens were sampled in Santa Branca Reservoir, an oligotrophic freshwater source in São Paulo, Brazil, taken during the Research & Development Program of Light Energy Company Project in July 2011. Photograph by Sara Teixeira de Macedo (Universidade Federal do Rio de Janeiro) and Rafael Lacerda Macêdo, funding by Christina W.C. Branco and image design by Karen Costa (NEL, Universidade Federal do Estado do Rio de Janeiro, Brazil) (Hydrobiologia 848(9): 2105–2117).

Volume 848 Issue 8
New Content Item (1)Cover illustration Four intermediate host snail species of the parasitic disease schistosomiasis (from left to right and top to bottom: Bulinus globosus, Biomphalaria pfeifferi, Bulinus truncatus, and Bulinus tropicus). Despite their importance as a disease vector, little ecological data is available on these snails. However, this data can assist in the design of effective snail control measures that are a vital part in the integrated strategy for schistosomiasis control, and in the assessment of schistosomiasis risk under changing climatic conditions. Photograph by Ruben Schols (Royal Museum for Central Africa, Tervuren, Belgium; https://www.africamuseum.be/nl/staff/1591) (Hydrobiologia 848(8): 1773–1793).

Volume 848 Issue 7
New Content Item (1)Cover illustration Male of the banded killifish, Aplocheilichthys spilauchen, imported from the mangroves and brackish waters of Nigeria. The bright red dorsal region of eye, the bars along the flank and the banded anal, dorsal and caudal fins are key traits for the identification of males and in distinguishing A. spilauchen from other procatopodids. Photograph by Peter Venstermans (a Belgium-based aquarist) (Hydrobiologia 848(7): 1433–1453).

Volume 848, Issue 6
New Content Item (1)Cover illustration American Toad, Anaxyrus americanus, male calling at a spring chorus in a wetland on Otterbein University campus in Westerville Ohio, USA. Photograph by Sarah S. Bouchard (Hydrobiologia 848(6): 1219–1230).

Volume 848, Issue 5
New Content Item (1)Cover illustration Illustrated is a section of ‘Sea Soup’ – an award-winning science-art quadtych made by Scott Luís Masson in collaboration with Russell Arnott as part of the University of Bath’s Visions of Science art prize. The illustration depicts the mesocosm facilities at Umeå Marine Science Centre together with a community of phytoplankton species found in the Gulf of Bothnia. The different sized waves represent various levels of turbulence intensities. Scott Luís Masson is a UK-based illustrator who frequently explores the marine environment throughout his work (www.slmillustration.com). (Hydrobiologia 848(5): 961–991).

Volume 848, Issue 4
New Content Item (1)Cover illustration Specific wetland ecosystem at the secondary channel to the Roşu-Puiu lake complex, Danube Delta Biosphere Reserve, Romania. Photograph taken during the CyanoArchive Project sampling trip in July 2013, by Maria Iasmina Moza (Hydrobiologia 848(4): 753–771).

Volume 848, Issue 3
New Content Item (1)Cover illustration Dorsal fin of a European grayling (Thymallus thymallus), where the monogenean parasite Gyrodactylus thymalli likes to attach itself. Photograph taken during field work at Lake Mjøsa, Norway, by Ruben Alexander Pettersen (Hydrobiologia 848(3): 547–561).

Volume 848, Issue 2
New Content Item (1)Cover illustration The marbled crayfish Procambarus virginalis is the only known parthenogenetic freshwater crayfish. It was detected in 1995 in the German aquarium trade and is now widespread among aquarists. It is also used as a research model in many laboratories. Releases have led to the establishment of wild populations in 18 countries in Europe, Africa and Asia. Due to parthenogenetic reproduction, it was suggested to establish this species in aquaculture. However, because of relatively small body size, conservation concerns resulting from high invasiveness, and economic reasons the marbled crayfish is considered unsuitable for aquaculture. Photograph by Chris Lukhaup (Hydrobiologia 848(2): 285–298).

Volume 848, Issue 1

New Content Item (1)Cover illustration Artwork by Magalí Izaguirre. Algal pictures taken by Rossella Barone (Staurastrum); Gábor Borics (Cosmarium); Martin Dokulil (Surirella peisonis Pantocsek); and Nico Salmaso (Tabellaria, Fragilaria, Mougeotia). Colin Reynolds’ photograph was made available by Jean Reynolds and scanned by Stephen Maberly from the analogue picture.


New Content Item (1)Volume 847, Issue 21

Cover illustration Fisherman Ilkka Tonteri unloads cyprinid fish caught with a seine from Lake Vesijärvi, Finland, close to the site of the Lahti Lakes 2018 symposium. Management fishing is employed in Lake Vesijärvi to control cyprinid populations, remove nutrients and suppress internal phosphorus loading, thereby supporting the productivity of valuable fish stocks. The average catch target is 20 kg/ha/year. Since 1987, more than 4.5 million kilograms of cyprinid biomass have been removed from Lake Vesijärvi, corresponding to more than 34 tonnes of phosphorus. The food industry uses the catch to produce fish mass as a raw material for fish steaks and canned roach. Smaller fish are used to produce biogas and compost in the Lahti area. Photograph by Juha-Pekka Huotari (City of Lahti, Finland).

Volume 847, Issue 20
New Content Item (1)Cover illustration Shallow tropical floodplain lake with a direct and short connection with the Paraná River (Brazil). Photograph by Sidinei M. Thomaz (UEM/PEA/Nupélia, Maringá, PR, Brazil).

Volume 847, Issue 19
New Content Item (1)Cover illustration Macrophyte and Black Lechwe antelope (Kobus leche) interaction at the Lukulu River within the Bangweulu Swamps of Northern Zambia. Photograph by M. Celeste Franceschini (Hydrobiologia 847(19): 3931–3950).

Volume 847, Issue 18
New Content Item (1)Cover illustration Lemna minor and Spirodela polyrhiza are growing on the surface of one of the study lakes included in temporal lake data of aquatic macrophytes from the 1940s to the 2010s from southern Finland. This data was used in a study that focused on the issue of functional homogenisation and differentiation by examining functional features of vascular aquatic macrophytes. Findings revealed that functional homogenisation has not occurred across these boreal lakes, ranging from small oligotrophic forest lakes to larger lakes affected by human impacts. Even though there were no signs of functional homogenisation or differentiation, changes in the environment have affected functional community composition and changes in functional richness to some extent. Photograph by Marja Lindholm (Hydrobiologia 847(18): 3811–3827).

Volume 847, Issue 17
New Content Item (1)Cover illustration Charophytes (submerged macrophytes) can form dense meadows in freshwater ecosystems that structure the whole community through trophic and non-trophic interactions (e.g. allelopathy against primary producers, refuge for zooplankton or vital support for periphyton). Furthermore, these organisms are very vulnerable to environmental changes. These facts place them in a central position regarding the structure and function of freshwater ecosystems facing current global change. The underwater photograph shows a dense charophytes meadow of the species Chara hispida L. from an interdunal pond on the Mediterranean coast near Valencia (Spain) in spring, when these organisms are at their growth peak. Photograph by Eric Puche (Hydrobiologia 847(17): 3549–3569).

Volume 847, Issue 16
New Content Item (1)Cover illustration A landscape of Damavand Volcano and Lar River main stream in Gozal Valley, Lar National Park, Iran. Mount Damavand (5610 m above sea level, an Iranian National heritage site), a majestic stratovolcano is the highest peak in the Middle East and the second-highest volcano in Asia. The Lar River (55 km length) and its tributaries are the best habitat for Salmo caspius, in the southern Caspian Sea basin. The river drains into Lar reservoir from where the tail water flows toward the Caspian Sea. The national park (30,000 ha) is a stunning combination of unique natural sights and an incredibly rich ecosystem that hosts other important flora and fauna. Photograph by Seyedeh Narjes Tabatabaei (Hydrobiologia 847(16): 3339–3353).

Volume 847, Issue 15
New Content Item (1)

Cover illustration The rare Blind Cave Eel Ophisternon candidum is restricted to only a few sites in northern Western Australia’s arid zone and lives entirely in aquatic subterranean habitats. Its bizarre appearance with no eyes or skin pigment reflect a life in total darkness. This cryptic species is very difficult to sample using traditional sampling methods but environmental DNA (eDNA) approaches offer a promising method to indirectly detect where it occurs and allows for conservation planning. Photograph by Mark Allen & Glenn Moore (Western Australian Museum) (Hydrobiologia 847(15): 3201–3211).

New Content Item (1)Volume 847, Issue 14
Cover illustration Burbot (Lota lota) exhibit a circumpolar distribution and is a high trophic level predator in all aquatic systems where found. A gadiform peripheral freshwater species, these fish hatch at around 3mm and then passively drift and feed on small zooplankton for much of their early life. The ten week old larvae pictured was propagated from wild Lake Superior (Michigan) spawners to compare morphology to similarly propagated larvae from the Kootenai River, Idaho, USA. Differences in growth patterns and developmental morphology were present between the populations. These differences are likely driven by spatial separation and source environments, and warrant further consideration for the conservation of this species. Photograph by Thornton A. Ritz (Hydrobiologia 847(14): 2981–2998).

New Content Item (1)Volume 847, Issue 13
Cover illustration Lake Markakol is located in Eastern Kazakhstan in the southern Altai mountains at an altitude of 1449 m above sea level. It is the largest lake of the entire Altai mountain system having an area of 455 km2. The lake is fed by 50 tributaries, and has one outflow, the Kaldzhir River. This golden autumn image is from the North-Eastern end of the lake with the Samovar mountain in the background. October brings a thin edge of ice and snow along the lake’s shores. The lake lies almost entirely in a 100,000-hectare nature preserve known for its picturesque scenery and highly diverse fauna and flora. Photograph by Mirgaliy Baimukanov (Hydrobiologia 847(13): 2823–2844).

New Content Item (1)Volume 847, Issue 12
Cover illustration The following fifteen taxa are displayed from top to bottom, left to right: Ostracoda (Afon Gam, Wales, UK); Copepoda (Acanthocyclops sp.) Huicha River, Chiloé, Chile; Chironomidae (Glyptotendipes pallens Meigen) City Mills River and Lea Navigation, London, UK; Hydrachnidia (Sperchon violaceus Walter) Adur River, UK; Cladocera (Alona sp.) Regents Canal, London, UK; Harpacticoida [A. (Delachauxiella) wiesseri Löffler] and Bdelloidea [Dissotrocha macrostyla (Ehrenberg)] both Huicha River, Chiloé, Chile; Nematoda (Mononchus niddensis Skwarra) Lake Schöhsee, Plön, North Germany (Photograph courtesy of W. Traunspurger); Tardigrada (Macrobiotus sp.) Afon Mynach, Wales, UK; Aelosomatidae [Aelosoma hemprichi (Ehrenberg)] Lone Oak stream, UK; Microturbellaria (Stenostomum grabbskogense Luther), Huicha River, Chiloé, Chile; Rotifera (Cephalodella intuta Myers) Huicha River, Chiloé, Chile; Gastrotricha (Chaetonotus similis Zelinka) Lake Pratignano, Italy (Photograph courtesy of M. Balsamo); Heliozoa (Actinosphaerium nucleofilum Barrett) Calle-Calle River, Chile; Ciliophora (Amphileptus pleurosigma (Stokes) Foissner) Calle Calle River, Chile; Testacea (Lesquereusia spiralis (Ehrenberg)) Huicha River, Chiloé. Photographs courtesy of P.E. Schmid and J.M. Schmid-Araya (except where indicated otherwise).

New Content Item (1)Volume 847, Issue 11
Cover illustration Paratya australiensis Kemp 1917 is the most common freshwater shrimp found in streams of eastern Australia. This female has a brood of eggs held under her abdomen. Stable isotope analyses indicates that they predominately derive their energy (carbon) from instream sources, regardless of variations in adjacent land use. Photograph by Simon Hartley (School of Environment, Science and Engineering, Southern Cross University, Lismore, Australia) (Hydrobiologia 847(11): 2377–2392).

New Content Item (1)Volume 847, Issue 10
Cover illustration Straight-hinged veliger of the golden mussel (Limnoperna fortunei) on a carbon substrate under Scanning Electron Microscopy (SEM), digitally coloured. SEM Magnification: 3.10kx, HV: 10kV, WD: 17.02mm. Equipment: Vega 3 Tescan. Image courtesy of Arthur Corrêa de Almeida*, Anna Carolina Paganini Guañabens* & Gabriela Rabelo Andrade* (*2014, Bioengineering Centre of Invasive Species (CBEIH), Brazil – www.cbeih.org) (Hydrobiologia 847(10): 2193–2202).

New Content Item (1)Volume 847, Issue 9
Cover illustration Skull ontogenetic variation of the coastal developmental stage of the loggerhead turtle (Caretta caretta) in the South Western Atlantic ocean. Photograph by Pedro Luz (Bird and Mammal Evolution, Systematics and Ecology Lab, Universidade Federal do Rio Grande do Sul, Brazil) (Hydrobiologia 847(9): 1999–2019).

New Content Item (1)Volume 847, Issue 8
Cover illustration Juvenile Eurasian otter (Lutra lutra) with a goldfish prey at Cecebre reservoir (NW Spain). Otters showed marked diet seasonality. They hunted mainly for fish in autumn-winter, when the amount of water stored in the reservoir reached its annual minimum, but fish abundance was highest. They shifted to hunt mainly for crayfish in spring-summer when water level was highest, fish abundance was lowest and crayfish were not hibernating. Otters also shifted from eating mainly goldfish in autumn to eating mainly nases in winter, due to the cumulative predation of large rafts of great cormorants on goldfish during autumn, and also because goldfish reduced their biological activity with the lower water temperatures of the winter. Photograph by Alejandro Martínez-Abraín (Hydrobiologia 847(8): 1803–1816).

New Content Item (1)Volume 847, Issue 7
Cover illustration Antarctica is considered to be a sentinel of climate change. This image depicts the coastal site of Tethys Bay, where the study by Piazza et al. (this issue) was performed. The site was photographed in mid-January, when open water conditions occur at sea and just a few scattered fragments of pack ice are still present. The annual duration of open water condition in Antarctic coastal areas might increase in the near future and there is an urgent need for long term monitoring programs that may help in documenting changes. Photograph by Stefano Schiaparelli (© PNRA) (Hydrobiologia 847(7): 1753–1771).

New Content Item (1)Volume 847, Issue 6

Cover illustration The roach (Rutilus rutilus L.) is a common European cyprinid which responds to predation threat by size-dependent presence in particular habitats. Because females are usually larger than males they can occupy risky open water habitat at a higher frequency than smaller males. This size-specific response to predation risk coupled with sexual size dimorphism leads to the sexual segregation of roach with dominance of females over males in open water habitat. Photograph by Rostislav Štefánek (Uherské Hradiště, Czechia, www.zezivotaryb.cz) (Hydrobiologia 847(6): 1439–1451).

New Content Item (1)Volume 847, Issue 5
Cover illustration Parthenogenetic female of Daphnia magna with asexual eggs, a zooplankton species that inhabit the Doñana temporary ponds (SW Spain). These temporary ponds are characterized by wide interannual variation in the filling season, which in turn, conditions the environmental characteristics that trigger egg hatching after pond filling, and the composition of the zooplankton communities. Photograph by Alexandre Portheault (Solignac, France; e-mail: aportheault@hotmail.com) (Hydrobiologia 847(5): 1195–1205).

New Content Item (1)Volume 847, Issue 4
Cover illustration The giant water bug Abedus herberti Hidalgo 1935 is an agile, sit and wait predator in perennial montane streams of the southwestern USA and northern Mexico. A. herberti adults are top predators in fishless streams preying on a variety of organisms. Stable isotopes suggest their prey are derived mainly from terrestrial sources of carbon. Photograph by Emily Hartfield Kirk (Hydrobiologia 847(4): 983–997).

New Content Item (1)Volume 847, Issue 3
Cover illustration Serranus scriba (the painted comber) at Cabo de Palos-Islas Hormigas Marine Reserve, Spain. This species is a typical mesopredator found until 150m deep in subtropical rocky reefs habitats and Posidonia meadows at the Mediterranean, Black Sea and Eastern Atlantic Ocean. They primarily feed on crustacean and small fish as well as on other combers such as S. cabrilla, but they avoid competition by partitioning their habitat by occupying different depth strata. On the other hand, an overlapping habitat distribution with a common top predator species, Epinephelus marginatus, cause a mediated top-down control of S. scriba populations when top predators are at high densities, such as inside marine protected areas. Photograph by Carlos Werner Hackradt (Hydrobiologia 847(3): 757–770).

New Content Item (1)Volume 847, Issue 2
Cover illustration This anuran is a 117 mm male of Boana boans, a species that belong to the group of gladiator tree frogs. The specimen is perched on the branch of a Pouteria sp. tree at the end of the rainy season. Males of this species have the habit of vocalizing at night on branches along rivers and streams, and after the amplexus, females descend to the ground and spawn in sand basins previously built by males. Photograph by Rainiellen Carpanedo (undergraduate student in Forestry Engineering, Universidade Federal de Mato Grosso, Sinop, Mato Grosso, Brazil) (Hydrobiologia 847(2): 321–330).

New Content Item (1)Volume 847, Issue 1
Cover illustration Peruvian scallop (Argopecten purpuratus) or Concha de abanico (in Spanish) from natural banks of Lobos de Tierra island, Peru. Photograph by Jaime Mendo (Hydrobiologia 847(1): 11–26).


New Content Item (1)Volume 846
Cover illustration Many species of the genus Daphnia display inducible morphological defences. In the presence of predators, one genotype can express adaptive phenotypes reducing the predation risk. D. cucullata develops helmets and D. pulex neck teeth in the presence of the phantom midge larvae Chaoborus spec. D. Lumholtzi develop elongated head and tail spines in the presence of the three-spined stickleback Gasterosteus aculeates. D. Longicephala defends the heteropteran backswimmer Notonecta glauca by developing enlarged crests. D. barbata can even display two different adaptive phenotypes in form of alternative head morphologies defending either N. glauca or the tadpole shrimp Triops spec. Photograph by Linda C. Weiss.

New Content Item (1)Volume 845
Cover illustration Edible crab (Cancer pagurus) on European flat oyster (Ostrea edulis) with below common brittle stars (Ophiothrix fragilis) at approximately 15 m deep near Wemeldinge, Eastern Scheldt, The Netherlands. Photograph by Jos Meulendijks (Graphics Designer & Underwater Photographer, Best, The Netherlands https://nl.linkedin.com/in/jos-meulendijks-850542b3).

New Content Item (1)Volume 844
Cover illustration Platyias quadricornis (Ehrenberg, 1832) is a common ploimid rotifer found in limnetic habitats across the globe. This female was photographed by Adán Jiménez Nigó using a Nikon Eclipse E600 at the Laboratorio de Zoología Acuática, Edificio UMF Universidad Nacional Autónoma de México, Campus Iztacala/FES Iztacala, Los Reyes Tlalnepantla, México.

New Content Item (1)

Volume 843
Cover illustration Massive Corbicula beds found on muddy substrate at the eastern shore of ancient Lake Lanao (Mindanao, Philippines) at ca. 2 m water depth. Photograph by Björn Stelbrink (Hydrobiologia, 843, pp. 31–49).839

New Content Item (1)Volume 842
Cover illustration Two bottlenose dolphins (Tursiops truncatus) swimming at the bow of the research ship, Andratx, SW of Mallorca, Balearic Islands. Photograph by José M. Brotons (Hydrobiologia 842, pp. 233–247).

New Content Item (1)Volume 841
Cover illustration      Anadromous brown trout (Salmo trutta) in the river Uskedalselva in Western Norway. The species depends on gravel substrate to reproduce. The article by Pulg et al. in this issue focusses on the influence of spawning gravel availability on the abundance of juvenile trout in rivers. Photograph by Ulrich Pulg (Hydrobiologia, 841, pp. 13–29).

New Content Item (1)Volume 840
Cover illustration A Lake Charr pictured in a clear lake in the Northwest Territories of Canada. Photograph by Paul Vecsei. Paul is a fisheries biologist with the Department of Fisheries and Oceans Canada. He also specialises in freshwater underwater photography of northern fishes.

Volume 839

New Content Item (1)Cover illustration Assessing the ecological status of rivers: usefulness of combined biomarker and macroinvertebrate community-based approaches. Image design by Pedro Teixeira (freelance designer) and Carolina Rodrigues (Hydrobiologia, 839, pp. 1–24).

Volume 838

New Content Item (1)Cover illustration Representative mayflies (Andesiops peruvianus, Mayobaetis sp. Andesiops sp.1, Baetodes sp.1. Baetodes sp. 2) from Andean-Amazon streams of the Napo River Basin, Ecuador. Photographs by José Vieira (Laboratory Aquatic Ecology, Universidad San Francisco de Quito, USFQ, Ecuador) (Hydrobiologia 838, pp. 13–28).

Volume 837

New Content Item (1)Cover illustration Elephants enjoying a mud shower in Mandavu Pound, Hwange National Park, Zimbabwe. While walking in the water, they stir together sediment and water with their trunk to suck runny mud and spray themselves. Doing so, they resuspend sediments and, possibly, foul water with their urine and faeces. Phototograph by Florence D. Hulot (Hydrobiologia, 837, pp.161–175).

Volume 836

New Content Item (1)Cover illustration Salminus brasiliensis at the bottom of the Olho d’Água karst river in the Bodoquena Plateau, Brazil. Photograph by José Sabino (Projeto Peixes de Bonito, Universidade Anhanguera – Uniderp, Campo Grande, MS, Brazil) (Hydrobiologia, 836, pp. 21–34).

Volume 835

New Content Item (1)Cover illustration Amazonian manatees (Trichechus inunguis) in the rehabilitation tanks of the National Research Institute of the Amazon, after an ornamentation, simulating the natural environment, for a documentary made by NHK (Japan’s national public broadcasting organization). Photograph by José Anselmo d’Affonseca Neto (Veterinarian at the Aquatic Mammals Laboratory [MLA] of the National Institute of Amazonian Research [INPA]) (Hydrobiologia, 835, pp. 1–19).

Volume 834

New Content Item (1)Cover illustration Male Anax speratus (Odonata: Aeshnidae) mate-guarding during oviposition, Rondegat River, Western Cape Province, South Africa. One of the many dragonfly taxa encountered during our five-year study published in this issue, monitoring for non-target effects of rotenone on aquatic invertebrates coupled with the removal of non-native fish from the Rondegat River. Photograph by Terence A. Bellingan (South African Institute for Aquatic Biodiversity, Grahamstown, South Africa) (Hydrobiologia, 834, pp. 1–11).

Volume 833

New Content Item (1)Cover illustration Victoria cruziana in a shallow lake of the lower Paraná River Floodplain in Argentina. It is called ‘Irupé’ that means dish that carries the water. Victoria cruziana is a floating, fixed, aquatic plant with giant leaves and spectacular flowers. This plant is typical of shallow lakes in our study area. Photograph by Maira P. Gayol (Hydrobiologia, 833, pp. 9–24).

Volume 832

Cover illustration Depicted is a male of Tropheops tropheops from Makokola Reef at the southern tip of Lake Malawi in Malawi in nuptial colors. Tropheops is a species-rich and ecologically diverse cichlid genus endemic to Lake Malawi. Tropheops are characterized by their blunt, usually steeply descending snout and a slightly subterminal narrow mouth, which they use to feed on algae attached to rocks. The males are quite colorful and a considerable degree of geographic color variation is present. By comparing levels of morphological disparity between Tropheops and the highly specialized and species poor genus Labeotropheus, Albertson & Pauers (on pages 153–174 of this issue) provide insights into the relationship between ecology, morphological variability and evolvability. Photograph by Wolfgang Gessl (www.pisces.at; Institute of Biology, University of Graz, Austria).

Volume 831

Cover illustration Prymnesium parvum Carter in Lake Biviere di Gela (Sicily, Italy). The cells are swimming across leaf debris. Photograph by Rossella Barone (University of Palermo, STEBICEF, Italy) (Hydrobiologia 831, pp. 33–41).

Volume 830

Cover illustration Common pochard Aythya ferina are rapidly declining globally, partly due to human induced water quality change at breeding habitats. Lake restoration at two southern Danish lakes improved water clarity and submerged macrophyte cover, increasing nesting pochard by 4 to 6 fold. Breeding pochard numbers were related to submerged macrophyte cover and water turbidity, confirming eutrophication contributes to their decline, but confirms the benefits of lake restoration as a means of re-establishing nesting pochard and other biodiversity features locally. The cover photograph shows a female common pochard at Siemień ponds, Poland, 28 May 2016 taken by Damian Kwasek (Hydrobiologia 830, pp. 33–44).

Volume 829

Cover illustration Pink Flamingo (Phoenicopterus ruber ruber L.) in the Celestun Biosphere Reserve, Yucatan, Mexico. These birds feed on Artemia salina (L.) and breed in this hypersaline estuary. The photograph was taken by S. Nandini during the mid-conference excursion of the IX International Symposium on Shallow Lakes held in Merida, Mexico, 19–24 February 2017. (Hydrobiologia 829, pp. 1–4).

Volume 828

Cover illustration Didymosphenia geminata mats in the South Fork Holston River, Tennessee USA. Mats are up to 5 cm thick and cover approximately 80–90% of the stream bottom. The mats are mainly composed of non-living filaments (white areas) used to attach cells to the substrate, with living D. geminata cells on the perimeter (brown areas). Photograph by Justin Murdock (Tennessee Technological University). (Hydrobiologia 828, pp. 147–164).

Volume 827

Cover illustration Red-crowned crane (Grus japonensis) is the most famous species living in the coastal reclamation habitat. It is the second rarest of the 15 crane species in the world and the IUCN Red List designated it as ‘endangered’ in 2013. Photograph taken in Yancheng City, Jiangsu Province, China, by Yongxiang Han (Hydrobiologia 827, pp. 21–29).

Volume 826

Cover illustration Ringed Kingfisher–Megaceryle torquata (Linnaeus, 1766)–is one of the six species of Kingfisher from the New World and is the largest Kingfisher of South America (40–42 cm / 300–340 g). The main realm of this monogamous and abundant bird is the mighty wetlands of the Amazon. They are territorial and mainly piscivorous, and with their stout and compact body they plunge from an overhanging bough to catch fishes of 2–20 cm in length. They excavate their nest in a burrow in the earth making a tunnel near 1.5 cm length with a chamber at the end. The clutch size can be 4–8 nestlings and only once a year. Water pollution of various sources has been the main threat causing local extinction of this wonderful bird in the Amazon region. Photograph by Renato Cintra (Hydrobiologia 826, pp. 43–65).