Sublethal Injuries Research Articles

Sub-lethal predatory shell damage does not affect physiology under high CO2 in the intertidal gastropod Tritia reticulata

Ocean acidification (OA) poses a major threat to marine animals, especially marine shelled invertebrates such as molluscs. Although many organisms are capable of compensating for the effects of OA, this can impose physiological costs and impact performance (e.g. through increased metabolism and decreased growth). Sublethal injuries on shells may provoke changes in energy allocation. Under acidified conditions, organisms would spend less energy on reproduction and somatic growth to repair the damage. Therefore, we analysed the physiological responses of the intertidal gastropod Tritia reticulata during shell regeneration under OA conditions. We simulated a sub-lethal predation event (a notch in the outer lip of the shell) and individuals were exposed to control (pH 8.08) and low pH scenarios (pH 7.88 and 7.65). After two months exposure, all individuals showed shell repair, with a full repair rate observed in 75% of individuals. Contrary to expectations, shell repair following sub-lethal damage and OA had no apparent impact on physiological state in terms of energy reserves (as measured by whole-animal Carbon/Nitrogen) or growth potential (as measured by whole-animal RNA:Protein and RNA:DNA ratios). As an intertidal organism, T. reticulata could be resilient to future global environmental change because of compensatory mechanisms that are inherent in intertidal animals, and may represent a robust species with which to study future scenarios of OA in temperate coastal ecosystems. However, unrestricted food availability during experiment could have played a role in the results and therefore food limitation should be considered in future studies regarding shell repair and metabolism under the effects of OA.

A hermit crab preserved inside an ammonite shell from the Upper Jurassic of central Russia: Implications to ammonoid palaeoecology

The discovery of a hermit crab (superfamily Paguroidea) preserved in the likely immature shell of an ammonite, Craspedites nekrassovi is reported from the Upper Jurassic of Moscow, Russia. This is the oldest undoubtable symmetrical hermit crab to date which is known from non-reefal environments. This new occurrence combined with the documentation of numerous sublethal and lethal injuries on ammonite shells in the same beds (probably produced by such paguroids), all suggest that the hermit crabs not only lived in ammonite shells but also hunted these animals. The proportion of damaged shells (including healed ones) varies in different Upper Jurassic ammonite genera from 1.2% in Kachpurites up to 9.3% in Craspedites. Among damaged Kachpurites only 6.25% survived attacks whereas among Craspedites the percentage of survivors was 87.5%. These data imply that Craspedites likely lived near the sea bottom and often encountered hermit crabs, whereas Kachpurites likely lived in the water column.

Preliminary insights into the population characteristics and distribution of reef (Mobula alfredi) and oceanic (M. birostris) manta rays in French Polynesia

In French Polynesia, both currently recognized manta ray species, Mobula alfredi and M. birostris, are observed. Despite being an important cultural asset and generating significant economic benefits through manta ray watching tourism, published data on the ecology and threats to these species in the region are scarce. Based on an 18-year dataset of sighting records collected by citizen scientists and during two scientific expeditions, this study provides the first insights into the population characteristics and regional distribution of the two manta ray species in French Polynesia. A total of 1347 manta ray photographs (1337 for M. alfredi and 10 for M. birostris) were examined for the period January 2001–December 2017, with photo-identification techniques leading to the successful identification of 317 individual M. alfredi and 10 individual M. birostris throughout the Society, Tuamotu and Marquesas Islands. We provide the first confirmation of sympatric distribution of both species in the Society Islands. Our results highlight strong and long-term site fidelity of M. alfredi individuals to certain aggregation sites (> 9 years for 16 individuals) and reveal some degree of connectivity between populations, with 10 individuals recorded moving between islands located up to 50 km apart. Analysis of photographs of individuals bearing sub-lethal injuries (n = 68) suggests that M. alfredi are more likely to be injured at inhabited islands (Maupiti or Bora Bora; 75% of all injured individuals) than at uninhabited islands, with 75% of injuries related to boat propeller strikes and fishing gear entanglements. Our findings emphasize the need for further research to allow for a comprehensive evaluation of population structure, size and threats to manta rays in this region.

Overview of Hematopoietic Stem Cells in Systemic Cancer Treatment, Aging, Pregnancy, and Radiation Hormesis

Background: The unavoidable links between the benefits of conventional systemic treatment of cancer and the side effects such as lymphopenia. Objective: To analyze this phenomenon in view of the newly discovered trophic function of circulating hematopoietic stem cells (HSC) and their lymphocyte descendants. Method: We used population statistics and recent current research involving natural aging and preliminary aging with cancer, its cytotoxic therapy, eclampsia at pregnancy, and radiation hormesis. Results: In contrast to immune-defense interpretations of these health conditions, the trophic influence of HSC and morphogenic lymphocytes on natural tissue renewal and regeneration after sublethal injuries eliminates the majority of covered inconsistencies, which are inherent to the dominating idea of cellular immunity. Conclusion: Our examination led to the feeding influence of lymphopoiesis on tumor progression, an indirect mechanism of tumor growth control by systemic therapy via either destruction of trophic cells, or by competitive distraction from malignant tissue via reparation of sublethal injuries in normal tissues. Analyses also involved similarities of the mechanisms of systemic chemotherapy and total body/half body radiotherapy in low doses, as well as the futility of the theoretical opposition of the radiation hormesis phenomenon to the linear non-threshold model, dominant in radiobiology.

Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect.

Rapid cold hardening (RCH) is a type of beneficial phenotypic plasticity that occurs on extremely short time scales (minutes to hours) to enhance insects' ability to cope with cold snaps and diurnal temperature fluctuations. RCH has a well-established role in extending lower lethal limits, but its ability to prevent sublethal cold injury has received less attention. The Antarctic midge, Belgica antarctica, is Antarctica's only endemic insect and has a well-studied RCH response that extends freeze tolerance in laboratory conditions. However, the discriminating temperatures used in previous studies of RCH are far below those ever experienced in the field. Here, we tested the hypothesis that RCH protects against non-lethal freezing injury. Larvae of B. antarctica were exposed to control (2°C), direct freezing (-9°C for 24 h) or RCH (-5°C for 2 h followed by -9°C for 24 h). All larvae survived both freezing treatments, but RCH larvae recovered more quickly from freezing stress and had a significantly higher metabolic rate during recovery. RCH larvae also sustained less damage to fat body and midgut tissue and had lower expression of two heat shock protein transcripts (hsp60 and hsp90), which is consistent with RCH protecting against protein denaturation. The protection afforded by RCH resulted in energy savings; directly frozen larvae experienced a significant depletion in glycogen energy stores that was not observed in RCH larvae. Together, these results provide strong evidence that RCH protects against a variety of sublethal freezing injuries and allows insects to rapidly fine-tune their performance in thermally variable environments.

Long-Term Storage of Vegetable Juices Treated by High Hydrostatic Pressure: Assurance of the Microbial Safety.

Food business operators search for new, mild technologies, which extend the shelf life of product without changing the sensory and nutritional properties. High hydrostatic pressure (HHP) meets these requirements; however it also triggers sublethal injury of bacterial cells. Sublethal injuries could spoil the product during storage and potentially pose major public health concerns. This study aims to examine the changes of sublethally injured pathogens cells in two vegetable juices: carrot juice (pH 6.0-6.7) and beetroot juice (pH 4.0-4.2) that are induced by HHP (300-500 MPa). The possibilities of recovery of bacterial cells during 28 days of juices storage at two different temperatures (5°C and 25°C) were determined using plate count methods. During the entire period of storage of carrot juice at refrigerated temperature, the propagation and regeneration of L. innocua strains were observed. Storage at 25°C showed that the number of these bacteria drastically decreased between 14 and 21 days. The above phenomenon was not detected in E. coli case. There was no cells recovery during long-term refrigerated storage for all strains in beetroot juice. However, in some cases spoiling of this product intermittently occurred at 25°C storage temperature. This work demonstrates that carrot juice supports growth and regeneration of HHP-sublethally injured L. innocua, while beetroot juice can be classified as a safe product.

Fragility of Red Blood Cells Collected Under Different Conditions With a Cell Saver Device

To quantify the degree of lethal and sublethal damage to red blood cells (RBCs) by cell saver (CS) processing among different conditions of shed blood in cardiac surgery. Prospective randomized, double-blinded, controlled study. Single university hospital. Twenty rabbits were divided randomly into non-heparinized and heparinized groups. Thereafter, each group was subdivided into non-gauze and gauze groups based on whether the blood was collected with gauze and squeezed out. Blood from each group was aspirated directly from the heart and underwent CS processing. Mechanical fragility index (MFI) and percent hemolysis were measured pre- and post-CS processing. In RBCs after CS processing, the MFI and percent hemolysis were increased significantly in both the non-heparinized and heparinized groups compared to pre-CS processing. The MFI was significantly higher in the heparinized group than in the non-heparinized group (p = 0.002). However, no differences in percent hemolysis were detected between groups (p = 0.696). The MFI and percent hemolysis of the non-gauze and gauze groups did not differ. This study reports the increase in sublethal and lethal injuries to RBCs from heparinized and non-heparinized blood after CS processing. CS-processed heparinized blood contained more sublethally injured RBCs compared to CS-processed non-heparinized blood. RBCs collected by squeezing blood-saturated gauze did not exhibit additional trauma. Further investigation is required to determine the clinical implications of transfusing rescued but injured RBCs using a CS.

Metabolite profiling of Listeria innocua for unravelling the inactivation mechanism of electrolysed water by nuclear magnetic resonance spectroscopy

Bactericidal effects of low concentration electrolysed water (LcEW) on microorganisms are previously well reported; however, the inactivation mechanism of EW is not understood. The lethal and sublethal injuries of L. monocytogenes and L. innocua by EW treatments were determined and the metabolic profile changes for L. innocua were characterised using nuclear magnetic resonance (NMR). Microbial metabolomics approach combined with multivariate data analyses was used to interpret the cellular chemical fingerprints of L. innocua. The relative amount of intracellular reactive oxygen species (ROS) was assayed using 2′,7-dichlorodihydrofluorescein diacetate (H2DCFDA). The results showed that the proportion of the sublethally injured microbial cells L. monocytogenes and L. innocua increased from 40% to 70% and from 35% to 65%, respectively, when the free available chlorine (FAC) of LcEW increased from 2 to 8 mg/L. Overall, 36 low-molecular-weight metabolic compounds in L. innocua extracts were characterised by NMR spectroscopy. EW perturbation resulted in a drastic and multitude disruption across a wide range of biochemical process including peptidoglycan synthesis, nucleotides biosynthesis and amino acid metabolism. Elevated levels of α-ketoglutarate and succinate implicated the enhanced glutamate decarboxylase (GAD) system and γ-aminobutyric acid (GABA) shunt for the protection against oxidative stress. These findings provided the comprehensive insights into the metabolic response of Listeria to EW oxidative stress and can serve as a basis for better utilisation for sanitisation.

Biological consequences of weak acidification caused by elevated carbon dioxide in freshwater ecosystems

Weak acidification can occur in freshwater ecosystems when free carbon dioxide (CO2) levels increase, which can happen for a variety of reasons. To define the state of knowledge for how weak acidification influences freshwater biota and ecosystems, a review of the primary literature was conducted. Despite few empirical studies focused on weak acidification in the primary literature (~100 studies), some themes have emerged from our literature review. Most studies focused on physiological responses at the organismal level, and fish were the most studied taxa. Animals exhibited reduced individual growth rates, and, in contrast, primary producers demonstrated increased individual and population growth rates. In animals, mortality, sub-lethal injuries, and changes to behaviours were also observed. Negative consequences to reproduction in macrophytes were found. Few studies have focused on population, community, or ecosystem levels, though broad scale studies suggest that weak acidification can limit species community diversity, specifically in invertebrates and fish. Moving forward, researchers need to continue to advance our understanding of the consequences of weak acidification for freshwater biota. Furthermore, priority should be placed on research that can evaluate the potential for weak acidification in freshwater to lead to changes in ecological regimes or economical outcomes, such as fisheries collapses.

First record of true conulariids from the Upper Devonian of Poland

Phosphatized remains indisputably belonging to conulariids have been found in the lower Famennian (Upper Devonian) deposits at the Kowala quarry in the Holy Cross Mountains, Poland for the first time. The ornamentation patterns and characteristics of the exoskeleton indicate that the conulariids, represented by at least two incomplete specimens, belong to a single species within the genus? Paraconularia. Some Polish Ordovician fossils previously described as conulariids either do not possess morphological characters seen in conulariids, or are too fragmentary to be confidently assigned to conulariids. Therefore, the fossils reported here not only represent the first documented record of conulariids in the Devonian of Poland, but the first true conulariids ever reported and illustrated from Poland. The exoskeleton of one specimen possesses at least three sublethal injuries. As the host deposit of marly shale originated in deep water, it is possible that the injuries did not result from purely physical factors, but rather from attempted predation. This interpretation is consistent with the fact that the lower Famennian deposits at Kowala preserve other predation-related structures such as fish coprolites, fragmented arthropod cuticle and regurgitated remains.

Diel patterns of hooking depth for active and passive angling methods for two freshwater teleost fishes

The increasing popularity of catch-and-release angling indicates a need to identify best practices that minimize sublethal injuries, impairments, and mortality. One factor impacting the viability of catch and release is the risk of hooking injury, which can impact survival in released fishes. In particular, deep hooking is known to increase post-release mortality in numerous species. As such, best practices include the use of equipment and promotion of angler behaviors that reduce incidences of deep hooking. In some areas, angling at night is restricted because of concerns that deep hooking is elevated relative to angling during the day. However, there has been little empirical research investigating whether deep hooking is influenced by the time of day (light levels). In the present study, we captured bluegill (Lepomis macrochirus Rafinesque, 1810) and pumpkinseed (Lepomis gibbosus Linnaeus, 1758) using active angling (cast and retrieve) and passive angling (with a bobber) throughout the 24-hr period, and recorded hook depth and hook location for each fish. We found that passive angling methods resulted in deeper hooking than active angling methods for both bluegill and pumpkinseed across all time periods. Although few pumpkinseed were caught at night, we found that the pumpkinseed caught were hooked more deeply and in more damaging hooking locations at night relative to the day. Hooking injury was independent of diel period for the more frequently landed species, bluegill. These findings emphasize the species-specific nature of catch-and-release outcomes, and suggest that further research is warranted to adequately quantify the impacts of recreational fishing at night.

Sublethal injuries in non-marine microconchid tubeworms from the Lower Carboniferous of West Virginia, USA

More than 10,000 non-marine microconchid tubeworms (order Tentaculita) from the Lower Carboniferous (Mauch Chunk Group) of West Virginian, USA, have been inspected with respect to the occurrence of specimens having repaired injuries. The inspection showed that only nine specimens bear distinct regenerations of their tubes which constitute only 0.08% of the total specimens. This value, although much lower than that obtained from other encrusting tentaculitoid tubeworms, is very similar to that calculated before for the thousands of Early Devonian planktonic tentaculitids. This clearly indicates that sample size (specimen number) is critical for obtaining the reliable data about the proportion of regenerated vs. unaffected specimens. The sublethal injuries present in these few individuals probably resulted from failed predation, most probably by grazing fishes. However, the repaired injuries only indicate that some individuals survived but do not provide any information about the predation intensity on the group in the given paleoenvironment. Microconchids encrusted a given substrate in large quantities, so grazing fishes may have easily removed the majority of individuals, leaving no trace of predation activity in the Early Carboniferous, non-marine paleoenvironments of what is now West Virginia.

Growth of Stressed Strains of Four Non-O157 Shiga Toxin-Producing Escherichia coli Serogroups in Five Enrichment Broths

The purpose of this study was to evaluate (i) the behavior of several strains of non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O103, O111, and O145) exposed to different stress conditions and (ii) the growth dynamics of stressed and nonstressed non-O157 STEC cells in five enrichment media. STEC strains were exposed to acid, cold, and freeze stresses. Lethal and sublethal injuries were determined by plating in parallel on selective and nonselective agar media. Freeze stress (8 days, -20°C) caused the most lethal (95.3% ± 2.5%) injury, as well as the most sublethal (89.1% ± 8.8%) injury in the surviving population. Growth of stressed and nonstressed pure cultures of non-O157 STEC on modified tryptic soy broth, buffered peptone water (BPW), BPW with sodium pyruvate, Brila, and STEC enrichment broth (SEB) was determined using total viable counts. To compare growth capacities, growth after 7 and 24 h of enrichment was measured; lag phases and maximum growth rates were also calculated. In general, growth on BPW resulted in a short lag phase followed by a high maximum growth rate during the enrichment of all tested strains when using all three stress types. Furthermore, BPW ensured the highest STEC count after 7 h of growth. Supplementing the medium with sodium pyruvate did not improve the growth dynamics. The two selective media, Brila and SEB, were less efficient than BPW, but Brila’s enrichment performance was remarkably better than that of SEB. This study shows that irrespective of the effect of background flora, BPW is still recommended for resuscitation of non-O157 STEC.

Geographically conserved rates of background mortality among common reef-building corals in Lhaviyani Atoll, Maldives, versus northern Great Barrier Reef, Australia

Even in the absence of major disturbances (e.g., cyclones and bleaching), corals are consistently subject to high levels of background mortality, which undermines individual fitness and resilience of coral colonies. Most studies of coral mortality however only focus on catastrophic mortality associated with major acute disturbance events, neglecting to consider background levels of chronic mortality that have a significant influence on population structure and turnover. If, for example, there are geographic differences in the prevalence of injuries and rates of background mortality, coral communities may vary in their susceptibility to acute large-scale disturbances and environmental change. This study quantified the prevalence and severity of partial mortality for four dominant and widespread coral taxa (massive Porites, encrusting Montipora, Acropora hyacinthus, and branching Pocillopora) at Lhaviyani Atoll, Maldives, and on the northern Great Barrier Reef, Australia. The prevalence and severity of sublethal injuries varied greatly among taxa, but was generally similar between locations; on the Great Barrier Reef, 99.4 % Porites colonies, 66 % of A. hyacinthus, and 64 % of Pocillopora had conspicuous injuries, compared to 92.4 % of Porites, 47.5 % of A. hyacinthus, and 44 % of Pocillopora colonies in Lhaviyani Atoll. These results suggest that background rates of mortality and injury, and associated resilience of coral populations and communities to large-scale disturbances, are conserved at large geographic scales, though adjacent colonies can have markedly different injury regimes, likely to lead to strong intraspecific variation in colony fitness and resilience.

Влияние криоконсервирования в присутствии криопротектора ПЭГ-1500 на поверхностные характеристики эритроцитов

The studies of changes in surface characteristics of erythrocyte membranes caused by freeze-thawing can be important for assessment of structural and functional integrity of cells and understanding the mechanisms responsible for their damage under extreme conditions. In the research we studied the effect of cryopreservation in presence of exocellular cryoprotectant PEG-1500 on asymmetric distribution of phosphatidylserine in membrane and characteristics of the surface marker CD44 in erythrocyte suspension (the amount of CD44-positive cells and the expression level). It was found that cell amount with the impairments of transmembrane asymmetry of phosphatidylserine increased up to 30% after a short-term exposure of frozen-thawed erythrocytes at 37°C. The decrease in CD44-positive cell amount and lowering of the marker expression were also observed in cryopreserved erythrocyte suspension. Washing of erythrocytes from the cryoprotectant and hemolysis accompanying this process led to restoration of CD44 parameters in suspension of erythrocytes which preserved their integrity. The revealed impairments of surface characteristics of erythrocytes indicate a presence of sublethal membrane injuries in the cells cryopreserved under the protection of PEG-1500. This was true, at least in terms of the changes in the surface marker CD44 indices, since after lysis of cells compromised with sublethal injuries occured during removal of cryoprotectant, the marker indices in erythrocyte suspension did not differ from the control values. Probl Cryobiol Cryomed 2015; 25(2): 104-113

Pelagic palaeoecology: the importance of recent constraints on ammonoid palaeobiology and life history

AbstractA review of fossil evidence supports a pelagic mode of life (in the water column) of ammonoids, but they may have spent their life close to the seabottom (demersal), planktonically, or nektonically depending upon the ontogenetic stage and taxon. There are good indications for a planktonic mode of life of ammonoid hatchlings, but a broad range of reproductive strategies might have existed (egg‐laying, fecundity). Isotope and biogeographical studies indicate that some forms migrated or swam for considerable distances, whereas others may have been primarily transported by oceanic currents during early and/or late ontogeny. Diverse ammonoid habitats are also supported by evidence from predator–prey relationships derived from characteristic injuries and exceptional fossil finds, which indicate chiefly predatory or scavenging lifestyles. Sublethal injuries preserved in some ammonoid shells, as well as rare stomach and coprolite contents, provide evidence of predation by other cephalopods, arthropods and various jawed vertebrates. Various lines of evidence suggest that different groups of ammonoids had quite different ecologies, but shell shape alone can only give upper constraints on ammonoid capabilities, a matter that needs to be considered when interpreting their diversity and evolutionary history.

Size-related variation in arm damage frequency in the crown-of-thorns sea star, Acanthaster planci

Objective: To examine variation in the frequency of arm damage in different sizes of Acanthaster planci (A. planci), assess how this damage is inflicted by fish predators, and infer the potential role of predation in population regulation. Methods: Diameters of A. planci collected from three sites in the Philippines were measured and arm damage frequency and severity was assessed. Frequency of arm damage was compared between sizes. Feeding behavior of fish predators was also observed in the laboratory. Results: This study demonstrates that sublethal predation by triggerfishes on A. planci result in extensive arm damage. Overall, 60% of A. planci sampled across all sites had sublethal injuries. The frequency of individuals with missing or regenerating arms was highest in medium-sized young adults (11-20 cm), which coincides with the phase where A. planci shift from cryptic to exposed daytime feeding. Conclusions: The high incidence of arm damage within intermediate-sized sea stars indicates that predators exercise some level of regulation on A. planci populations at a local scale. Identification and protection of putative predators that target the most vulnerable life history stages of A. planci are essential in developing population control strategies and reverse sustained declines in coral cover.

Ephemeral injuries, regeneration frequencies, and intensity of the injury-producing process

Organisms may suffer sublethal injuries that lead to the loss of body parts and that leave either permanent or ephemeral scars, and these can be used to understand some aspects of the injury-producing processes, such as predation. It has been shown theoretically that for injuries that leave detectable scars throughout life, proportion of injured individuals in a population reflects the probability of fatal incidents rather than the intensity of the injury-producing process itself (Schoener in Ecology 60:1110–1115, 1979). When injuries are ephemeral and leave no detectable signature, it is shown here that frequencies of injury are a function of the intensity of the injury-producing process. Moreover, if the probability of fatality from the injury-producing process is low, as would be the case for partial or cropping predation, regeneration frequencies can be used to infer the intensity of the injury-producing process if the rate of regeneration is known.

Real-time monitoring of cell viability and cell density on the basis of a three dimensional optical reflectance method (3D-ORM): investigation of the effect of sub-lethal and lethal injuries

Cell density and cell viability have been followed on-line by using a three-dimensional optical reflectance method (3D-ORM) probe. This method has allowed to highlight the differences between a well-mixed and a scale-down bioreactor configured in order to reproduce mixing deficiencies during a fed-batch culture of Escherichia coli. These differences have been observed both for the obscuration factor (OBF) and the coincidence probability delivered by the probe. These parameters are correlated to flow cytometry measurement based on the PI-uptake test and cell density based on optical density measurement. This first set of results has pointed out the fact that the 3D-ORM probe is sensitive to sub-lethal injuries encountered by microbial cells in process-related conditions. The effect of lethal injuries has been further investigated on the basis of additional experiments involving heat stress and a sharp increase of the OBF has been observed indicating that cells are effectively injured by the increase of temperature. However, further improvement of the probe are needed in order to give access to single-cell measurements.

Western mosquitofish (Gambusia affinis) bolster the prevalence and severity of tadpole tail injuries in experimental wetlands

Species introduced outside their native range to serve anthropogenic purposes may have unintended consequences on native organisms. Mosquitofish (Gambusia affinis and Gambusia holbrooki) have been introduced throughout the world to control larval mosquito populations in aquatic environments, but they have also been implicated in the decline of native fish, amphibian, and aquatic invertebrate populations. We investigated the roles of introduced western mosquitofish (G. affinis), and two naturally colonizing predators (crayfish and dragonfly naiads) in inflicting tail injuries observed on ranid frog tadpoles in experimental constructed wetlands. We also examined the influence of vegetation in reducing tail injury severity. We found that mosquitofish significantly increased the prevalence and severity of tail injuries, but crayfish and dragonfly naiads contributed much less to increased injury levels. Furthermore, increased vegetation cover did not significantly attenuate tail injuries. However, after chemical removal of Gambusia, injury prevalence and severity was significantly reduced. Although previous investigations have concluded that mosquitofish prey upon the eggs and larvae of some amphibians, our results illustrate that these fish can cause substantial but apparently sub-lethal injuries to large numbers of larval amphibians in a wetland. Further investigations are needed to determine if these injuries impede the fitness of victims and lead to population reductions.