Behavior Of Aquatic Organisms Research Articles

Assessment of a new olfactometer for study of sensory ecology in small aquatic organisms

AbstractAll aquatic organisms rely on chemical stimuli at some point during their life cycles. These stimuli are typically associated with essential functions such as food‐, mate‐, or habitat‐finding, or predator avoidance. Historically, research on sensory ecology and behavior of aquatic organisms has been conducted using two‐channel choice flumes, which have many limitations when utilized on small organisms. Here, we describe functional features and results of pilot tests of an aquatic olfactometer, adapted from olfactometers used in studies on terrestrial arthropods, which eliminates these limitations. The initial implementation of this olfactometer is described. The structural integrity, hydrodynamics, and basic function of the olfactometer were tested and verified. The ability to clearly record the movements of a small organism within was also tested. Our experiments verify that the flow rate of water within the choice arena was accurate, water behaved as theorized in prior modeling, and chemical concentrations within each “zone” were distributed as expected based on computer simulations. We further show that video data could be obtained and analyzed using Ethovision XT to provide large amounts of raw data, including position, velocity, and acceleration, which can be used to investigate many potential questions associated with behavior. This olfactometer has the potential to become the new standard for research on chemotaxis and chemical ecology of small aquatic organisms.

The Effects of the Impact of the Spectral Composition of Light Radiation on Aquatic Organisms in the Cultivation of Aquaculture

The study of ecological groups of hydrobionts has scientific importance due to the tasks of industrial production of aquatic bio resources and environmental protection of a unique natural object under the protection of UNESCO — Lake Baikal. In the biota of Lake Baikal, gammarids and fish have a significant share of the biomass and play an extremely important role in the food chains. They utilize primary and partially secondary products and are themselves objects of fishing. Under the conditions of increasing industrial pollution of the Baikal water area, hydrobionts also act as indicators of the presence of pollutants. The dynamics of the abundance of hydrobionts of various ecological groups in relation to the impact of the illumination factor is an important indicator of the ecological state of a reservoir. We have reviewed research studies on the effect of illumination on the behavior of aquatic organisms. The results of the work can be used in choosing the conditions for growing production fish at different stages of its ontogenesis.

Altered acoustic community structure indicates delayed recovery following ecosystem perturbations

In the Anthropocene, there is an intensification of ecological disturbances that can be directly or indirectly attributed to human activities. Seagrass meadows are among the most imperiled ecosystems worldwide and are particularly sensitive to anthropogenic disturbance events. In Everglades National Park, Florida, USA, ecological disturbances including widespread seagrass die offs, can in part be attributed to anthropogenic alteration of historic freshwater flow. In this study, we assess the impacts of seagrass die offs on the composition and behavior of aquatic organisms in acoustic communities at two ecologically similar sites in Florida Bay: Buoy Key, which experienced massive seagrass die off in 2015, and Little Rabbit Key, which did not. We focused on three sonic indicator species for North American estuaries and coastal ecosystems, and specifically Florida Bay: spotted seatrout (Cynoscion nebulosus, family Sciaenidae), gulf toadfish (Opsanus beta, family Batrachoididae), and snapping shrimp (Alpheus spp. and Synalpheus spp., family Alpheidae). The sounds produced by these species are collectively indicative of a broader range of ecosystem function and services – including trophic transfer and recreational fishing – and are more indicative of ecosystem functioning at varying temporal scales than any one species alone. Using a combination of automated detection and visual spectrographic analysis on passive acoustic data, we found that the occurrence of seatrout and toadfish calls and/or chorusing were significantly lower at the disturbed site than the undisturbed site, with no seatrout or toadfish breeding choruses detected at the disturbed location. At both sites, toadfish call properties exhibited a direct relationship with water temperature. Snapping shrimp snap rates were significantly lower at the disturbed site, and snap rates were positively related to temperature at the undisturbed location. Further, examination of a short-duration, pre-disturbance acoustic dataset, showed minimal differences in the acoustic occurrence of the three species at the disturbed site between 2015 immediately after the die off and 2018. These results support the hypothesis that by 2018 the disturbed site had not fully recovered from the most recent seagrass die off and that restoration efforts may still needed. Acoustic community composition and behavior may be used as a reliable indicator of ecosystem health and restoration success or efficacy. This work lays the conceptual groundwork for using acoustic communities as indicators in human altered systems to inform managers that habitats either may be approaching disturbance or may require continued restoration efforts to meet achieve recovery goals.

ОБОСНОВАНИЕ МАСШТАБОВ ПОДОБИЯ АКУСТИЧЕСКИХ ВЕЛИЧИН В УСТАНОВКАХ ДЛЯ ВЫРАЩИВАНИЯ ГИДРОБИОНТОВ

The article is devoted to studying the problems of physical modeling of acoustic and hydroacoustic waves, which are reflected from hydrobionts in recirculation aquatic systems (RAS), as well as open aquaculture cages (OAC). The behavior of aquatic organisms in RAS and OAC is so complex that it is difficult to be described mathematically because it is necessary to determine the temporal and spatial parameters of hydrobionts and to provide favourable conditions for aquatic organisms in RAS and OAC close to the natural habitat, including the acoustic regime. The use of simulation and physical modeling for calculating the acoustic quantities will make it possible to use machine vision to and optimize technological processes, to increase the productivity of the ultrasonic and ultrasonic treatment pools, to raise productivity and to reduce costs. The aim of acoustic quantities similarity in RAS and OAC is to determine the parameters of sound sources, the reflecting ability of hydrobionts with different characteristics (length, volume, density and others). In the problems of acoustic quantities it is required to ensure the coincidence of mechanical and acoustic processes. It is necessary to reduce the quantities dependent on the dimensional attributes of the object (length of a sound wave, sound power, sound energy, sound intensity, speed of sound, frequency, etc.) to their independent dimensionless form. When studying the behavior of aquatic organisms in RAS and OAC it is important to take into account mechanical, hydrodynamic, electrodynamic, optical and light similarities. There have been proposed the additional similarity scales for acoustic values, the methods for their calculation and the graphs of their dependence on the geometric scale Cl. Knowing the scale of Cl, it is possible to determine the scale effect

Behavioural effects on marine amphipods exposed to silver ions and silver nanoparticles

Behavioural responses to contaminants are an important endpoint in ecotoxicology because they link effects at biochemical or cellular levels to impacts on individual fitness. Due to the increasing use of silver in nanomaterials, studies of its effects on the behaviour of aquatic organisms are important to assess the risks of silver nanoparticles (AgNP) released into the environment. The aim of this work was to evaluate the behavioural effects of silver on the marine amphipod Echinogammarus marinus after exposure to AgNO3 via water and AgCl or AgNP via food. Swimming activity of the amphipods was tracked during 6 min alternating dark and light conditions. Animals swam slower and responded less to light at higher concentrations of silver in the water. No differences were found in the behaviour of animals exposed via feeding up to 28 days, hence, longer exposure times may be required for the observation of effects. This is the first work to appraise behaviour effects of silver ions and AgNP on marine amphipods. Although the protocol has been successfully developed for this purpose, specimens appeared to habituate to test conditions during the experiments. Therefore, the need for further understanding of baseline behaviours in these model organisms is discussed.

Old model organisms and new behavioral end-points: Swimming alteration as an ecotoxicological response

Behavioral responses of aquatic organisms have received much less attention than developmental or reproductive ones due to the scarce presence of user-friendly tools for their acquisition. The technological development of data acquisition systems for quantifying behavior in the aquatic environment and the increase of studies on the understanding the relationship between the behavior of aquatic organisms and the physiological/ecological activities have generated renewed interest in using behavioral responses also in marine ecotoxicology. Recent reviews on freshwater environment show that behavioral end-points are comparatively fast and sensitive, and warrant further attention as tools for assessing the toxicological effects of environmental contaminants. In this mini-review, we perform a systematic analysis of the most recent works that have used marine invertebrate swimming alteration as behavioral end-point in ecotoxicological studies by assessing the differences between behavioral and acute responses in a wide range of species, in order to compare their sensitivity.

The Effects of Biodiesel and Crude Oil on the Foraging Behavior of Rusty Crayfish, Orconectes rusticus.

Environmental pollutants, such as crude oil and other petroleum-based fuels, inhibit and limit an organism's ability to perceive a chemical stimulus. Despite the increased use of alternative fuels, such as biodiesel, there have been few studies investigating the impact of these chemicals on the behavior of aquatic organisms. The purpose of this study was to compare the sublethal effects of biodiesel and crude oil exposure on chemically mediated behaviors in a freshwater keystone species. Crayfish (Orconectes rusticus) were tested on their ability to respond appropriately to a positive chemical stimulus within a Y-maze choice paradigm. Behavior was quantified by measuring time spent finding an odor source, duration of time spent at the odor source, percentage of crayfish that found the odor source, and percentage of crayfish that chose the correct arm of the arena. Results indicated negative impacts of both biodiesel and crude oil on the ability of crayfish to locate the food source. However, there were no significant differences between behavioral performances when crayfish were exposed to crude oil compared with biodiesel. Thus, biodiesel and crude oil have equally negative effects on the chemosensory behavior of crayfish. These findings indicate that biodiesel has the potential to have similar negative ecological impacts as other fuel source toxins.

Influence of relative submergence on spatial variance and form-induced stress of gravel-bed flows

[1] Spatial flow variance has a strong control on sediment transport, sediment-water interface exchange mechanisms, and the distribution and behavior of aquatic organisms in rivers. Thus, being able to quantify spatial flow variance, and how it varies with different water levels, is important for understanding how fluvial processes change during periods of time varying flow. In this paper, laboratory flume measurements of near-bed flow velocity were used to quantify spatial flow variance and form-induced stress, and their variation with flow submergence, within and above the surface of porous, gravel beds with differing grain roughness. The analysis revealed spatial flow variance was usually four or five times higher within the roughness layer than above. A rise in relative submergence resulted typically in a decrease in spatial variance—relative to bed shear velocity—in streamwise form-induced intensity, streamwise turbulence intensity, and form-induced momentum flux, both within and above the roughness layer. Flow submergence had no consistent influence on spatial variance in the vertical flow direction and in Reynolds stress. Form-induced stress was significant within the roughness layer, more so at shallow depths. The greater significance was driven primarily by higher spatial flow variance in time-averaged streamwise velocity at these depths. The implication is the relative role of momentum transfer mechanisms within the roughness layer, and thus, sediment-water interface exchange processes in rivers will change during periods of time varying flows.

Eutrophication alters social preferences in three-spined sticklebacks (Gasterosteus aculeatus)

Algae blooms, which can be caused by eutrophi- cation, drastically influence the ecology and behaviour of aquatic organisms. Such impact is often demonstrated in the context of mate choice and predator-prey interactions. In con- trast, the influence of increased turbidity on social behaviour is less well understood, although it may have strong influence, at both the level of the individual and the population. We aimed to address this gap in our knowledge by using the well-described preference of three-spined sticklebacks (Gasterosteus aculeatus) to shoal with the larger of two shoals as model behaviour. In our experiments focal fish had the choice between two shoals of different sizes, either in clear or in turbid water containing green algae. Fish in clear water spent significantly more time near the larger shoal, while fish in algae water showed no significant preferences. Furthermore, fish tested in clear water changed more often between the shoals than fish tested in algae water. These results indicate that eutrophication-induced algae blooms have the potential to alter social decisions of sticklebacks. Such changes of social decisions do not only influence the behaviour of individuals, furthermore it might influence entire populations. This might eventuallyleadtochangesofthestructureofthesocialsystem.

Do Larvae and Ovipositing Chironomus riparius (Diptera: Chironomidae) Females Avoid Copper-Contaminated Environments?

ABSTRACT Studies on the avoidance behavior of aquatic organisms to contaminants have confirmed that such behavior can be relevant in field situations. However, almost all toxicity tests involve the forced exposure of organisms to toxicants. In particular, despite the importance of Chironomus riparius Meigen larvae in sediment toxicity testing, only a few studies on avoidance behavior have been performed. This study investigated the ability of different life stages of C. riparius, including ovipositing females, first-, second-, and fourth-instar larvae, to avoid copper-contaminated environments. Ovipositing females were given a choice between a control and copper solution (1.3 mg Cu l− 1). First-instar larvae were provided with a choice between a control and a copper (2.0 mg Cu l− 1)-spiked sediment. Both second- and fourth-instars were exposed to a copper gradient (0.38–3.4 mg Cu l− 1) in a flow-through system. None of the life stages avoided copper, even though the highest concentrations caused lethal effects on midges. The avoidance behavior of C. riparius is not a sensitive endpoint to assess copper sublethal toxicity.

Effects of lunar cycles on Artemia density in hypersaline environments

The effects of lunar cycles are known to have an influence, although not yet clear, on the behavior of aquatic organisms. A study was conducted in two different locations (Manaure, Guajira and Chengue, Magdalena, Caribbean coast, Colombia) during July and August, 1997 and November, 1998 to determine the effects of medium term cycles (lunar cycles) on the presence of Artemia franciscana (Crustacea: Anostraca) density. Samples were collected every 4 h from each of 20 fixed stations in a salt production pond during a 24-h sampling period at the peak of the four lunar phases. The data were analyzed using a mixed ANOVA model, setting lunar phases and sampling time intervals as fixed effects, station as the random effect and density as the dependent variable. No significant difference was determined between increasing and decreasing moon. Artemia density was not significantly (P>0.05) higher during new moon compared to full moon. The influence of temperature over Artemia sampling density was clearly noticed, and was a shading factor over the possible effects of any particular lunar phase over Artemia density at any particular sampling time.

Impedance conversion as a method of research for assessing behavioural responses of aquatic invertebrates

The concept of non-invasive, remote monitoring of the behaviour of aquatic organisms has been a long-sought research goal. In an effort to overcome the induction of artefacts and the generation of unnatural behaviour, a system of quantification of organism activity was developed based upon the theory of impedance conversion. The system is described in detail, and application was made to assess the respiratory behaviour of three aquatic invertebrates,Daphnia magna, Chironomus sp., andTanytarsus sp. in response to declining oxygen tensions. The system shows broad applicability for quantifying organism behaviour over four orders of magnitude in size range.

Behavior of Aedes aegypti (L.) larvae and pupae in direct-current electric fields.

Larval instars and pupae of Aedes aegypti (L.) were subjected to direct-current electrical fields of 0.1–13.44 V per centimeter and 0.0106–1.06 mA per square centimeter. In general, when field strengths reached a certain level more larvae were attracted to the cathode than to the anode. As field strengths were increased, this reaction was reversed and then as they were further increased the cathode again exerted the greater attraction. Maximum numbers attracted to either anode in 20 min were first instar 80%, second instar 62%, third instar 86%, fourth instar 72%, and pupae 82%. No explanation can be given for the changes in polarity of attraction and it has no counterpart in other work recording the behavior of aquatic organisms (mainly fish) in electrical fields, in which attraction was always to the anode. Change of effect caused by increasing the current while holding voltage constant was found to be due to the larvae absorbing NaCl via the anal gills and thus changing their resistance. At the higher field strengths some paralysis was caused, varying from temporary to lethal.