Gyorgy Kriska

• DSc
• Professor (Associate) at Eötvös Loránd University

The anatomy, photoreceptive structure and optics of the two ocellar fields on the head of poduromorph springtails (Collembola) are here summarized. The water-surface-inhabiting Podura aquatica springtails have the ability to estimate both the degree and the angle of polarization. They are attracted to linearly polarized light, the polarization dire...

Mayflies are typically negatively phototactic during larval development, while their adults possess positive phototaxis. However, no extensive research was made about the wavelength dependence of phototaxis in any mayfly larvae. We measured the repellency rate of Ephoron virgo larvae to light as a function of wavelength in the 368 – 743 nm spectral...

Az áttekintő tanulmányban bemutatott kutatások egyrészt új adatokat eredményeztek különböző vízirovartaxonok polarizációérzékelésével és ennek biológiai szerepével kapcsolatban, másrészt bemutatták különböző mesterséges poláros fényforrások és polarizációs mintázatok vízirovarokra kifejtett hatásait. Az első részben ismertetett kutatások a kérészek...

Dark artificial surfaces reflecting highly and horizontally polarized light usually have negative effects on polarotactic aquatic insects detecting their habitats by the horizontal polarization of water-reflected light. This ecologically disadvantageous phenomenon is called polarized light pollution. We have observed that the water between the conc...

The brown marmorated stink bug (Halyomorpha halys) is an invasive pest insect species, which was recently introduced from Asia to America and then to Europe. Besides causing serious damage in agriculture, this species also represents a source of intense annoyance for humans in residential areas, because large amounts of individuals can aggregate on...

Aquatic insects detect water by the horizontal polarization of water-reflected light and thus are attracted to such light. Recently, in the Hungarian Lake Balaton we observed dark water patches forming between every autumn and spring because of the inflow of black suspended/dissolved organic matter into the bright lake water. Earlier, the polarizat...

Springtails (Collembola) are abundant in the soil and among decaying plant matter. Some species inhabit the water surface, where they can be observed throughout the year (Damborenea et al. 2019; Fitter and Manuel 1986; Hopkin 1997; Illies 1978; Kriska and Tittizer 2009; Quigley 1977; Schulz et al. 1997; Thorp and Rogers 2015). Their delicate, cylin...

Aquatic insect species that leave the water after larval development, such as mayflies, have to deal with extremely different visual environments in their different life stages. Measuring the spectral sensitivity of the compound eyes of the virgin mayfly ( Ephoron virgo ) resulted in differences between the sensitivity of adults and larvae. Larvae...

During the total solar eclipses on 11 August 1999 in Kecel (Hungary) and on 29 March 2006 in Side (Turkey), two Hungarian groups performed full-sky imaging polarimetric measurements of the eclipsed sky. They observed the spatiotemporal change of the celestial polarization pattern and detected three polarization neutral points as well as two points...

Gastropoda is the largest group in the phylum Mollusca, comprising over 25000 genus‐group names that encompass snails, conch, whelks, cowries, abalone, limpets, slugs, sea hares, and nudibranchs among others. The presence of a well‐defined head and foot, and asymmetric organs, a feature resulting from the unique torsion process that occurs during e...

An annelid, phylum name Annelida, also called segmented worm, is any member of a phylum of invertebrate animals characterized by the possession of a body cavity (or coelom), movable bristles (or setae), and a body divided into segments by transverse rings, or annulations, from which they take their name. The body wall consists of the epidermis, con...

1. Negative ecological effects of artificial night‐time illumination on wildlife are becoming more and more widely investigated. Flight‐to‐light behaviour of insects is a well‐known phenomenon, which becomes really conspicuous when numerous individuals are simultaneously attracted to light. Mass mortality of night‐swarming mayflies at lamp‐lit urba...

Many insect species rely on the polarization properties of object-reflected light for vital tasks like water or host detection. Unfortunately, typical glass-encapsulated photovoltaic modules, which are expected to cover increasingly large surfaces in the coming years, inadvertently attract various species of water-seeking aquatic insects by the hor...

Tabanid flies (Diptera: Tabanidae) are attracted to shiny black targets, prefer warmer hosts against colder ones and generally attack them in sunshine. Horizontally polarised light reflected from surfaces means water for water-seeking male and female tabanids. A shiny black target above the ground, reflecting light with high degrees and various dir...

Amber contains numerous well-preserved adult aquatic insects (e.g., aquatic beetles – Coleoptera, water bugs – Heteroptera, dragonflies – Odonata, caddisflies – Trichoptera, mayflies – Ephemeroptera, stone flies – Plecoptera). Since amber is fossilised resin of terrestrial conifer trees, it is an enigma how aquatic insects have ended up in the resi...

A unique form of optical ecological traps is polarised light pollution. Typical sources of this phenomenon is asphalt roads that attract a variety of polarotactic aquatic adult insects seeking horizontally polarised sources recognized as water surfaces. Several harmful effects of polarised light pollution have been previously demonstrated but no qu...

Optical detection of horizontally polarized light is widespread among aquatic insects. This process usually occurs in the UV or blue spectral ranges. Recently, it was demonstrated that at least one collembolan species, the water springtail (Podura aquatica) also possesses positive polarotaxis to horizontally polarized light. These hexapods are posi...

Bodypainting is widespread in African, Australian and Papua New Guinean indigenous communities. Many bodypaintings use white or bright yellow/grey/beige stripes on brown skin. Where the majority of people using bodypainting presently live, blood-sucking horseflies are abundant, and they frequently attack the naked brown regions of the human body su...

Researchers studying the polarization characteristics of the optical environment prefer to use sequential imaging polarimetry, because it is inexpensive and simple. This technique takes polarization pictures through polarizers in succession. Its main drawback is, however, that during sequential exposure of the polarization pictures, the target must...

Artificial shiny dark objects reflecting horizontally polarized light (e.g. asphalt roads, black cars, solar panels) can attract polarotactic aquatic insects in mass. Glass buildings on the riverside also lure swarming caddisflies emerging from the river. These caddisfly swarms are a temporary rich food source for certain bird species, such as whit...

Numerous negative ecological effects of urban lighting have been identified during the last decades. In spite of the development of lighting technologies, the detrimental effect of this form of light pollution has not declined. Several insect species are affected including the night-swarming mayfly Ephoron virgo: when encountering bridges during th...

When an artificial surface (e.g. an asphalt road) reflects strongly and horizontally polarized light as water bodies do in the nature, polarotactic aquatic insects, like the creek-dwelling Ephemera danica mayflies easily become deceived. After swarming above the creek surface, E. danica females begin their upstream compensatory flight and can be de...

Photovoltaic solar panels represent one of the most promising renewable energy sources, but are strong reflectors of horizontally polarized light. Polarized light pollution (PLP) associated with solar panels causes aquatic insects to prefer to oviposit on panels over natural water bodies, with potential to negatively impact their global populations...

The 6-ommatidium ventral eye of the water-surface-inhabiting springtail Poduara aquatica has horizontal and vertical microvilli and perceives light from the ventral, frontal and frontodorsal regions, while the 2-ommatidium dorsal eye possesses two upward-looking ommatidia with vertical microvilli. The ventral eye may serve water detection by its po...

Availability: Class of bony fishes (Osteichthyes) represents the largest group of vertebrates both in number of species (more than 20,000) and in number of individuals. The crucian is a common freshwater fish widely distributed through Europe from England to Russia and it is a heavily farmed fish worldwide. Fresh specimens can be purchased from loc...

The cnidarian body consists of a central blind sac, the coelenteron (gastrovascular cavity), enclosed by a body wall comprising two epithelia, the outer epidermis and the inner gastrodermis (Fig. 1.1). A gelatinous connective tissue layer, the mesolamella (mesogloea), lies between the two epithelia. The mouth opens at one end of the coelenteron and...

Availability: Earthworms are found all over the earth. They prefer moist rich soil that is not too dry and sandy. Among earthworms there are many species which grow large enough to be used for dissection. There are a number of differences in the number and position of the internal organs which may affect the dissection. It is therefore important to...

Availability: Roman snails (Helix pomatia) like places which are dark and damp. In spring and autumn, they are most active and easy to collect. When it’s dry or cold, they seal themselves up; they hibernate in winter and aestivate in summer. During these periods giant Ghana snail (Achatina sp.) can be purchased from zoos instead. Different species...

Availability: Rats are most frequently used as type specimen for mammalian dissection because they are readily available and they possess the typical mammalian body plan. Most of what you learn on the rat is applicable to the anatomy of other mammals, such as humans. Rats can be obtained from pet shops, biological supply companies or pharmaceutical...

The simplest animals that are bilaterally symmetrical and triploblastic (having three germ layers) are the flatworms (Platyhelminthes). Flatworms have no body cavity (acoelomate) and lack an anus. One of their groups is the freshwater triclads (Tricladida), or planarians. They are large free-living flatworms which are commonly found on the undersid...

Availability: The crayfish is found in freshwater streams and ponds all over the world. There are about 300 species worldwide (Cambarus, Procambarus, Astacus and Orconectes). They are omnivorous, feeding on fish, tadpoles, worms, insects and plants. We can purchase fresh crayfishes from fishing companies supplying restaurants. Alternatively the dis...

Availability: Insects are the most extensive group of animals in the world. Approximately 800,000 species of insects have been recorded, and probably as many more remain to be discovered. Cockroaches are insects of the order Blattodea, of which about 30 species out of 4600 are associated with human habitats. They are terrestrial, cosmopolitan, noct...

Availability: Amphibians are a transition group between the aquatic and the strictly terrestrial animals. Ranid frogs (Ranidae) are almost worldwide in distribution. Their favourite habitats are swamps, low meadows, brooks and ponds, where they feed on insects. In their larval form, the tadpoles develop in water and herbivorous. All amphibian speci...

Availability: Birds differ from other vertebrates by their adaptations to flight. These adaptations have limited further structural variation so that although over 8,600 species of birds are known, structural differences between the groups are small. The domestic fowl belongs to the genus Gallus which includes four species. It is very probable that...

Availability: Specimens preserved in alcohol are available at biological supply companies. Cross section slides are also offered commercially. Ascaris eggs are extremely resistant to chemical treatment. Although it is unlikely, some eggs may survive immersion in preservatives for short periods. To avoid ascariasis (a disease caused by the parasitic...

Availability: Mussels live in a variety of freshwater habitats but are most prevalent in lakes, ponds, rivers, streams and canals. They are common in areas with muddy, silty or sandy bottoms and slowly flowing permanent water where they can be collected. Alternatively we can purchase mussels from companies supplying restaurants.

Like other aquatic insects, mayflies are positively polarotactic and locate water surfaces by means of the horizontal polarization of water-reflected light. However, may vertically polarized light also have implications for the swarming behaviour of mayflies? To answer this question, we studied in four field experiments the behavioural responses of...

The purpose of this book is to provide an introduction to comparative anatomy and histology for biology undergraduates and for all those who are interested in the internal structure of animals. The information is presented in the form of colour photographs of step-by-step dissection stages integrated with histological sections of actual organs. A s...

Ecological photopollution created by artificial night lighting can alter animal behavior and lead to population declines and biodiversity loss. Polarized light pollution is a second type of photopollution that triggers water-seeking insects to ovisposit on smooth and dark man-made objects, because they simulate the polarization signatures of natura...

Blood-sucking female tabanid flies cause serious problems for animals and humans. For the control of tabanids, the knowledge about their seasonality and daily activity is of great importance. Earlier, only traditional traps capturing exclusively female tabanids have been used to survey tabanid activity. The data of such temporal trapping do not ref...

In the last decade it has been recognized that the artificial polarization of light can have uniquely disruptive effects on animals capable of seeing it and has led to the identification of polarized light pollution (PLP) as a new kind of ecological photopollution. In this chapter we review some typical examples for PLP and the resulting polarized...

The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces) attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies mat...

Based on an earlier observation in the field, we hypothesized that light intensity and horizontally polarized reflected light may strongly influence the flight behaviour of night-active aquatic insects. We assumed that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of these insects than they would have separa...

It is widely accepted that Vikings used sun-compasses to derive true directions from the cast shadow of a gnomon. It has been hypothesized that when a cast shadow was not formed, Viking navigators relied on crude skylight polarimetry with the aid of dichroic or birefringent crystals, called “sunstones.” We demonstrate here that a simple tool, that...

The order of mayflies (Ephemeroptera) is relatively small, containing app. 3000 known species, classified into 42 families. This group of insects was already present in the Carboniferous, yet previously the order was much more diverse. These animals of fragile body and transparent wings do not feed after reaching maturity and mostly live only for f...

Aquatic beetles belong to the suborders Adephaga and Polyphaga. The suborder Adephaga contains 5 families of water-related species. A characteristic behaviour of their representatives is taking air reserves under the water surface. In well-oxygenated streaming waters this air bubble also functions as a physical gill being capable of absorbing disso...

Dragonflies and damselflies comprise one of the eldest orders of insects; moreover, their appearance remained almost unaltered for as many as 150 million years. They have about 5,000 species inhabiting the terrestrial habitats all over the world except for the arctic regions. These insects play a significant role in the cycle of materials both in a...

Caddis– (or sedge) flies being in close relation to the butterflies comprise the largest order of aquatic insects. Known number of species on Earth approximately 13,574. Imagos are greyish-brown, fragile terrestrial insects resembling the moths (Fig. 301/1). Their body length ranges from 3 mm (microcaddisflies – Hydroptilidae) to 60 mm (large casem...

Alderflies (family Sialidae) are blackish or brownish, soft-bodied insects of 10–16 mm length (Figs. 295/1 and 299/6). The broad head bears long filiform antennae. At rest, the smoke coloured wings are held roof-like above the body. A conspicuous peculiarity of the wings is the dark nervation. Adult alderflies are common waterside insects of the ea...

Several members of the order Heteroptera (‘bugs’) live either on or below the water surface. In contrast with terrestrial heteropterans, among which a considerable proportion of the species is herbivorous, water bugs are the predators of the water world (but for the water boatmen). The postembryonic development (i.e. that of the larvae after their...

By the superficial observer moss animals or bryozoans (Bryozoa) are easily confused with the sponges, although bryozoans differ remarkably from the latter creatures of a far more complex organisation. Colonies of the sessile moss animals are mostly composed of narrow, branching tubules, and they live attached to the substratum. Colonies may form an...

The computer program was created to facilitate the freshwater macroinvertebrate studies carried out by researchers, students as well as interested lay people. Different items of the software can be started using the buttons of the opening screen. Within each item, certain functions can be activated by the buttons set on the upper and the lower regi...

Springtails (Collembola) are abundant in the soil and among decaying plant matter. Some species inhabit the water surface, where they can be observed throughout the year. Their delicate, cylindrical bodies are covered by a fur of velvety hairs. Two compound eyes and well-discernible antennae are situated on the head. Their thorax bears three pairs...

The phylum of sponges (Porifera) contains sessile organisms, most of which live in marine habitats. The few species of freshwaters all belong to the class of demosponges (Demospongiae). Sponges live in colonies and represent a differentiation level not reaching that of the real tissues. Their most common growth form is an encrustation of some milli...

Besides several small, marine groups, the phylum of molluscs (Mollusca) contains three large, well-known classes, that of the gastropods (snails and slugs, Gastropoda), bivalves (mussels and clams, Bivalvia) and cephalopods (Cephalopoda). Among them, gastropods and bivalves occur in freshwater habitats. Gastropods are unsegmented animals with a bod...

Species of the order Bathynellacea are small crustaceans of an extraordinary outlook, up to some millimetres. The head of the animal with cylindrical body is clearly distinct from the eight segmented thorax. Abdominal segments are of similar size to those of the thorax. The body ends in a telson bearing a caudal furca.

Stoneflies (Plecoptera) comprise a world-wide distributed order of insects. They mostly live in cold regions, e.g. in the mountains of the temperate region, while they occur rather rarely in the warmer regions of the continents. Since nymphs prefer certain types of water and imagos fly within a restricted area, the distribution of most species are...

Hairybacks (Gastrotricha) (Figs. 45/1–2) are microscopic organisms up to 600 µm. These bilateral animals have elongated, wormlike body. Their body surface is covered with cilia arranged in longitudinal and transverse stripes. Despite their common name cilia are more frequent on the ventral surface than on the back. With these organelles the flexibl...

The flies and midges within the order Diptera (true flies) bears membranous forewings, whilst their hindwings are vestigial, modified into balancing organs called halteres. These insects develop via holometabolous metamorphosis including all the following developmental stages: egg, larva, pupa and imago. The larva hatching from the egg differs rema...

The phylum of segmented worms (Annelida) contains truly metameric animals. Their body consists of similar ‘rings’ that are alike not only concerning their appearance but also their inner structure. The epithelium of annelids composes a functional unit together with the muscle fibres beneath. The characteristic type of locomotion of segmented worms...

Rotifers (wheel animals) are widespread throughout the world. They comprise a remarkably diverse group concerning their form, shape and species number, as well. More than 1,000 species are known from Europe. Only some genera are present in the sea; the majority occurs in freshwaters. These latter species are abundant animals of all kinds of wet or...

The phylum of cnidarians (Cnidaria) contains species of simple structure having two main forms: the sessile polyp and the freeswimming medusa (jellyfish). Polyps are soft, contractile animals with tube-like body that binds to the substratum with an attachment disc. On the other pole of the body, around the mouth are the contractile tentacles that p...

All lepidopterans with a life cycle related to aquatic habitats belong to the family of crambid snout moths (Crambidae). Brown China-mark (Elophila nymphaeata) (Fig. 333/5) is a white moth with brown markings and of 11–14 mm wingspan. Adults live for a few days. They fly from June to September. During the day they lurk amongst the waterside vegetat...

Freshwater mites (Hydrachnidae) (Fig. 117/1) are chelicerates, often of vivid red, yellow or green colour and with an unsegmented body up to 8 mm. Species inhabiting stagnant or slow-streaming waters are round or oval, while those living in fast-flowing waters are more or less flattened. Due to the mucus of unpleasant flavour, secreted by the gland...

Horsehair (Gordian) worms (phylum Nematomorpha) are extremely elongated cylindrical worms often exceeding 20 cm in length. The diameter of their unsegmented body is chiefly less than 1 mm. Their colour is light brown or reddish. Body surface is covered with thick, more-or-less hardened cuticle. Muscular system consists only of longitudinal muscle e...

Although the majority of the species in the phylum of flatworms is parasitic, the subphylum Turbellaria contains free-living animals. One group of freshwater turbellarians consists of microscopic animals up to 3 mm in length. With the aid of the cilia covering their body and their muscle system, these species principally slide on the substratum, ye...

Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe p...

Trapping flies with sticky paper sheets is an ancient method. The classic flypaper has four typical characteristics: (i) its sticky paper is bright (chamois, light yellow or white), (ii) it is strip-shaped, (iii) it hangs vertically, and (iv) it is positioned high (several meters) above ground level. Such flypapers, however, do not trap horseflies...

This up-to-date guidebook on freshwater invertebrates of the central European region is a richly illustrated work, providing an excellent source of systematic information on freshwater macroinvertebrates. Numerous colour photos and additional vector graphic figures allow readers to identify specific species at a higher taxonomic level (family). The...

The experts of animal locomotion well know the characteristics of quadruped walking since the pioneering work of Eadweard Muybridge in the 1880s. Most of the quadrupeds advance their legs in the same lateral sequence when walking, and only the timing of their supporting feet differ more or less. How did this scientific knowledge influence the corre...

During blood-sucking, female members of the family Tabanidae transmit pathogens of serious diseases and annoy their host animals so strongly that they cannot graze, thus the health of the hosts is drastically reduced. Consequently, a tabanid-resistant coat with appropriate brightness, colour and pattern is advantageous for the host. Spotty coats ar...

Aquatic insects find their habitat from a remote distance by means of horizontal polarization of light reflected from the water surface. This kind of positive polarotaxis is governed by the horizontal direction of polarization (E-vector). Tabanid flies also detect water by this kind of polarotaxis. The host choice of blood-sucking female tabanids i...

Horseflies (Diptera: Tabanidae) can cause severe problems for humans and livestock because of the continuous annoyance performed and the diseases vectored by the haematophagous females. Therefore, effective horsefly traps are in large demand, especially for stock-breeders. To catch horseflies, several kinds of traps have been developed, many of the...

The characteristic striped appearance of zebras has provoked much speculation about its function and why the pattern has evolved, but experimental evidence is scarce. Here, we demonstrate that a zebra-striped horse model attracts far fewer horseflies (tabanids) than either homogeneous black, brown, grey or white equivalents. Such biting flies are p...

Freshwater biodiversity is declining faster than marine or terrestrial diversity, yet its drivers are much less known. Although dams were shown to negatively affect river habitats, fragmentation by bridges has received less attention and is not as well understood. We tested whether and how bridges present barriers to aquatic insects by studying mas...

The strongest known circular polarization of biotic origin is the left-circularly polarized (LCP) light reflected from the metallic shiny exocuticle of certain beetles of the family Scarabaeidae. This phenomenon has been discovered by Michelson in 1911. Although since 1955 it has been known that the human eye perceives a visual illusion when stimul...

Some studies found no, or weak evidence that dense monotypic cattail (Typha spp.) stands exclude water beetle species from aquatic habitats, or modify aquatic beetle assemblages. Other studies suggest that cattail may reduce the chance of aerial water beetle colonization, and decreases water temperature; negatively affecting these insects. We exami...

Human-made objects (e.g., buildings with glass surfaces) can reflect horizontally polarized light so strongly that they appear to aquatic insects to be bodies of water. Insects that lay eggs in water are especially attracted to such structures because these insects use horizontal polarization of light off bodies of water to find egg-laying sites. T...

It is a widespread belief that plants must not be watered in the midday sunshine, because water drops adhering to leaves can cause leaf burn as a result of the intense focused sunlight. The problem of light focusing by water drops on plants has never been thoroughly investigated. Here, we conducted both computational and experimental studies of thi...

White horses frequently suffer from malign skin cancer and visual deficiencies owing to their high sensitivity to the ultraviolet solar radiation. Furthermore, in the wild, white horses suffer a larger predation risk than dark individuals because they can more easily be detected. In spite of their greater vulnerability, white horses have been highl...

The surface of dry or wet asphalt roads reflect partially linearly polarized light, the degree of linear polarization p of which depends on the darkness and roughness of asphalt: the darker and/or the smoother the asphalt, the higher the p of light reflected from it. If the asphalt is sunlit and the direction of view is parallel to the solar-antiso...

This atlas contains 189 coloured images taken from transversal, horizontal and sagittal sections of eleven organisms widely used in university teaching. Six invertebrate and five vertebrate species – from the nematode worm (Ascaris suum) to mammals (Rattus norvegicus) – are shown in detailed images. Studying the macrosections with unaided eyes, wit...

Studying 0.5–1 cm thick, unstained slices of different fixed animal carcasses by the unaided eye, with a magnifying glass or a dissecting stereo microscope (sectional anatomy) might be of great help in supporting traditional anatomical studies, in gaining true and detailed spatial perception. The sectional anatomic approach is useful also, because...