scholarly journals Cross-ecosystem bottlenecks alter reciprocal subsidies within meta-ecosystems

2020 ◽  
Vol 287 (1929) ◽  
pp. 20200550
Author(s):  
Amanda J. Klemmer ◽  
Mark L. Galatowitsch ◽  
Angus R. McIntosh
Keyword(s):  
Aquatic Insects ◽  
Energy Flow ◽  
Life Stage ◽  
Predatory Fish ◽  
Top Predator ◽  
Terrestrial Insect ◽  
Top Predators ◽  
Freshwater Pond ◽  
Terrestrial Life ◽  
Reciprocal Subsidies

Reciprocal subsidies link ecosystems into meta-ecosystems, but energy transfer to organisms that do not cross boundaries may create sinks, reducing reciprocal subsidy transfer. We investigated how the type of subsidy and top predator presence influenced reciprocal flows of energy, by manipulating the addition of terrestrial leaf and terrestrial insect subsidies to experimental freshwater pond mesocosms with and without predatory fish. Over 18 months, fortnightly addition of subsidies (terrestrial beetle larvae) to top-predators was crossed with monthly addition of subsidies (willow leaves) to primary consumers in mesocosms with and without top predators (upland bullies) in a 2 × 2 × 2 factorial design in four replicate blocks. Terrestrial insect subsidies increased reciprocal flows, measured as the emergence of aquatic insects out of mesocosms, but leaf subsidies dampened those effects. However, the presence of fish and snails, consumers with no terrestrial life stage, usurped and retained the energy within in the aquatic ecosystem, creating a cross-ecosystem bottleneck to energy flow. Thus, changes in species composition of donor or recipient food webs within a meta-ecosystems can alter reciprocal subsidies through cross-ecosystem bottlenecks.

scholarly journals Aquatic insects are dramatically underrepresented in genomic research

2020 ◽  
Author(s):  
Scott Hotaling ◽  
Joanna L. Kelley ◽  
Paul B. Frandsen
Keyword(s):  
Aquatic Insects ◽  
Small Body ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Future Research ◽  
Insect Genome ◽  
Terrestrial Insect ◽  
Body Sizes ◽  
Terrestrial Insects ◽  
Insight Into

AbstractAquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. Yet aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ∼9 terrestrial insect genomes. Instead, ∼24 terrestrial insect genomes have been sequenced for every aquatic insect genome. This discrepancy is even more dramatic if the quality of genomic resources is considered; for instance, while no aquatic insect genome has been assembled to the chromosome level, 29 terrestrial insect genomes spanning four orders have. We argue that a lack of aquatic insect genomes is not due to any underlying difficulty (e.g., small body sizes or unusually large genomes) yet it is severely hampering aquatic insect research at both fundamental and applied scales. By expanding the availability of aquatic insect genomes, we will gain key insight into insect diversification and empower future research for a globally important taxonomic group.Simple SummaryAquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. Yet aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ∼9 terrestrial insect genomes. Instead, ∼24 terrestrial insect genomes have been sequenced for every aquatic insect genome. We argue that the limited availability of aquatic insect genomes is not due to practical limitations—e.g., small body sizes or overly complex genomes—but instead reflects a lack of research interest. We call for targeted efforts to expand the availability of aquatic insect genomic resources to gain key molecular insight into insect diversification and empower future research.

scholarly journals Trophic cascades alter eco-evolutionary dynamics and body size evolution

2020 ◽  
Vol 287 (1938) ◽  
pp. 20200526
Author(s):  
Thomas M. Luhring ◽  
John P. DeLong
Keyword(s):  
Body Mass ◽  
Trophic Level ◽  
Evolutionary Dynamics ◽  
Trophic Cascades ◽  
Trophic Levels ◽  
Chain Model ◽  
Top Predator ◽  
Predator Prey ◽  
Top Predators ◽  
Time Changes

Trait evolution in predator–prey systems can feed back to the dynamics of interacting species as well as cascade to impact the dynamics of indirectly linked species (eco-evolutionary trophic cascades; EETCs). A key mediator of trophic cascades is body mass, as it both strongly influences and evolves in response to predator–prey interactions. Here, we use Gillespie eco-evolutionary models to explore EETCs resulting from top predator loss and mediated by body mass evolution. Our four-trophic-level food chain model uses allometric scaling to link body mass to different functions (ecological pleiotropy) and is realistically parameterized from the FORAGE database to mimic the parameter space of a typical freshwater system. To track real-time changes in selective pressures, we also calculated fitness gradients for each trophic level. As predicted, top predator loss generated alternating shifts in abundance across trophic levels, and, depending on the nature and strength in changes to fitness gradients, also altered trajectories of body mass evolution. Although more distantly linked, changes in the abundance of top predators still affected the eco-evolutionary dynamics of the basal producers, in part because of their relatively short generation times. Overall, our results suggest that impacts on top predators can set off transient EETCs with the potential for widespread indirect impacts on food webs.

scholarly journals Aquatic Insects Diversity and Water Quality Assessment of a Tropical Freshwater Pond in Benin City, Nigeria

2020 ◽  
Vol 24 (7) ◽  
pp. 1129-1136
Author(s):  
B.O. Komolafe ◽  
T.O.T. Imoobe
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Aquatic Insects ◽  
Water Bodies ◽  
Total Alkalinity ◽  
Ex Situ ◽  
Insect Community ◽  
Insect Fauna ◽  
Benin City ◽  
Freshwater Pond

Aquatic insects are species of significant importance to water bodies because they serve various purposes including nutrient cycling, vectors of  pathogens and bioindicators of water quality. Analyzing their community structure is a veritable tool in studies of biodiversity and quality of limnetic  ecosystems. Therefore, we investigaTed the health status of a pond in Benin City, Nigeria using insect’s abundance, composition, distribution and physicochemical parameters of the waterbody. Insects were sampled using sweep nets and identified to the species level while water samples were collected and analyzed using in-situ and ex-situ methods to determine the physicochemical properties in three sampling stations. The results of the physicochemical assessment of the water indicated that conditions did not differ widely between sites (P > 0.05) except for total alkalinity, and the recorded values were well within the ambient FMEnv permissible limits for surface water except for dissolved oxygen,turbidity and phosphate. A total of 10 insect taxa, comprising of 103 individuals in 2 orders were recorded in the study and among the orders, Hemiptera comprised of 7 species and Coleoptera comprised of 3 species. Majority of the insect fauna found in this study are typically found in similar water bodies in the tropics. However, the obsereved insect community structure revealed a relatively low taxa richness with a dominance of pollution-resistant species which suggests a moderately polluted condition of the waterbody. Keywords: Aquatic insects, bioindicators, biodiversity, water quality, pond.

Early Life Stage Mortality Syndrome in Fishes of the Great Lakes and Baltic Sea

1998 ◽  
Keyword(s):  
Baltic Sea ◽  
Fish Species ◽  
Salmo Trutta ◽  
Anthropogenic Activities ◽  
Life Stage ◽  
Yolk Sac ◽  
Reproductive Disorders ◽  
Top Predators ◽  
Declining Populations ◽  
The Baltic

<em>Abstract.—</em>Populations of Baltic salmon <em>Salmo salar </em>and cod <em>Gadus morhua </em>are facing acute threats because of poor reproduction. The salmon is afflicted with high yolk sac fry mortality, and the incidence of cod larvae mortality is high. There are also indications that anadromous Baltic brown trout <em>Salmo trutta </em>populations are affected by reproductive disorders. These top predators have significant ecological, economic, and socioeconomic importance. Other species are also suffering from poor reproductive success and declining populations. Burbot <em>Lota lota </em>populations are locally affected by inadequate sexual maturation, resulting in a failure to spawn; gonad anomalies have also been described in roach <em>Rutilus rutilus</em>. High egg mortality has been recorded for whiting <em>Merlangius merlangus</em>, flounder <em>Platichtys flesus</em>, and herring <em>Clupea harengus</em>. Attempts have been made to discover the cause of reproductive disorders in Baltic fish species, but the available data suggest several possible causes, both abiotic and biotic. Species with pelagic eggs such as cod and flatfish are dependent on salinity and oxygen concentrations, factors that often limit the volume of reproduction in the Baltic Sea. A variety of biotic causes (i.e., infectious diseases, parasitism, and toxic algae) have been shown to affect species such as roach and herring. There are indications that nutritional factors (i.e., thiamine and astaxanthin) are involved in the cause of the yolk sac fry mortality syndrome affecting the Baltic salmon. Furthermore, anthropogenic activities causing both local point sources (i.e., metals and persistent organic pollutants) and long-range transport and deposition of acidic rain and pesticides must also be considered as potential threats to Baltic fish species.

scholarly journals Up and away: ontogenic transference as a pathway for aerial dispersal of microplastics

2018 ◽  
Vol 14 (9) ◽  
pp. 20180479 ◽  
Author(s):  
Rana Al-Jaibachi ◽  
Ross N. Cuthbert ◽  
Amanda Callaghan
Keyword(s):  
Life Stage ◽  
Malpighian Tubule ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Life Stages ◽  
Aerial Dispersal ◽  
Terrestrial Life ◽  
Reduced Rate ◽  
First Time ◽  
Feeding Larva

Microplastics (MPs) are ubiquitous pollutants found in marine, freshwater and terrestrial ecosystems. With so many MPs in aquatic systems, it is inevitable that they will be ingested by aquatic organisms and be transferred up through the food chain. However, to date, no study has considered whether MPs can be transmitted by means of ontogenic transference, i.e. between life stages that use different habitats. Here, we determine whether fluorescent polystyrene beads could transfer between Culex mosquito life stages and, particularly, could move into the flying adult stage. We show for the first time that MPs can be transferred ontogenically from a feeding (larva) into a non-feeding (pupa) life stage and subsequently into the adult terrestrial life stage. However, transference is dependent on particle size, with smaller 2 µm MPs transferring readily into pupae and adult stages, while 15 µm MPs transferred at a significantly reduced rate. MPs appear to accumulate in the Malpighian tubule renal excretion system. The transfer of MPs to the adults represents a potential aerial pathway to contamination of new environments. Thus, any organism that feeds on terrestrial life phases of freshwater insects could be impacted by MPs found in aquatic ecosystems.

scholarly journals Aquatic Insects Are Dramatically Underrepresented in Genomic Research

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 601 ◽  
Author(s):  
Scott Hotaling ◽  
Joanna L. Kelley ◽  
Paul B. Frandsen
Keyword(s):  
Aquatic Insects ◽  
Small Body ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Genomic Research ◽  
Future Research ◽  
Insect Genome ◽  
Terrestrial Insect ◽  
Body Sizes ◽  
Terrestrial Insects

Aquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. However, aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ~9 terrestrial insect genomes. Instead, ~24 terrestrial insect genomes have been sequenced for every aquatic insect genome. This discrepancy is even more dramatic if the quality of genomic resources is considered; for instance, while no aquatic insect genome has been assembled to the chromosome level, 29 terrestrial insect genomes spanning four orders have. We argue that a lack of aquatic insect genomes is not due to any underlying difficulty (e.g., small body sizes or unusually large genomes), yet it is severely hampering aquatic insect research at both fundamental and applied scales. By expanding the availability of aquatic insect genomes, we will gain key insight into insect diversification and empower future research for a globally important taxonomic group.

scholarly journals Variation in reciprocal subsidies between lakes and land: perspectives from the mountains of California

2016 ◽  
Vol 73 (11) ◽  
pp. 1691-1701 ◽  
Author(s):  
Jonah Piovia-Scott ◽  
Steven Sadro ◽  
Roland A. Knapp ◽  
James Sickman ◽  
Karen L. Pope ◽  
...  
Keyword(s):  
Aquatic Insects ◽  
Inorganic Nitrogen ◽  
Elevational Gradient ◽  
Mountain Lake ◽  
Land Resource ◽  
Terrestrial Vegetation ◽  
Organic Input ◽  
Terrestrial Inputs ◽  
Terrestrial Habitats ◽  
Reciprocal Subsidies

Lakes are connected to surrounding terrestrial habitats by reciprocal flows of energy and nutrients. We synthesize data from California’s mountain lake catchments to investigate how these reciprocal subsidies change along an elevational gradient and with the introduction of a top aquatic predator. At lower elevations, well-developed terrestrial vegetation provides relatively large inputs of organic material to lakes, whereas at higher elevations, the paucity of terrestrial vegetation provides minimal organic input but allows for higher inputs of inorganic nitrogen. There are also pronounced elevational patterns in amphibians and aquatic insects, which represent important vectors for resource flows from lakes back to land. The introduction of trout can reduce this lake-to-land resource transfer, as trout consume amphibians and aquatic insects. We propose a conceptual model in which within-lake processes influence terrestrial consumers at higher elevations, while terrestrial inputs govern within-lake processes at lower elevations. This model contributes to a more general understanding of the connections between aquatic and terrestrial habitats in complex landscapes.

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes

2000 ◽  
Vol 78 (10) ◽  
pp. 1759-1766 ◽  
Author(s):  
Craig A Soupir ◽  
Michael L Brown ◽  
Larry W Kallemeyn
Keyword(s):  
Largemouth Bass ◽  
Aquatic Insects ◽  
Species Interactions ◽  
Yellow Perch ◽  
Trophic Ecology ◽  
Micropterus Salmoides ◽  
Northern Pike ◽  
Boreal Lakes ◽  
Limited Information ◽  
Top Predators

Largemouth bass (Micropterus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited information exists on species interactions in the northern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assemblages of largemouth bass and northern pike in six interior lakes within Voyageurs National Park, Minnesota. Percentages of empty stomachs were variable for largemouth bass (38-54%) and northern pike (34.7-66.7%). Fishes (mainly yellow perch, Perca flavescens) comprised greater than 60% (mean percent mass, MPM) of the northern pike diet during all seasons in both allopatric and sympatric assemblages. Aquatic insects (primarily Odonata and Hemiptera) were important in the diets of largemouth bass in all communities (0.0-79.7 MPM). Although largemouth bass were observed in the diet of northern pike, largemouth bass apparently did not prey on northern pike. Seasonal differences were observed in the proportion of aquatic insects (P = 0.010) and fishes (P = 0.023) in the diets of northern pike and largemouth bass. Based on three food categories, jackknifed classifications correctly classified 77 and 92% of northern pike and largemouth bass values, respectively. Percent resource overlap values were biologically significant (greater than 60%) during at least one season in each sympatric assemblage, suggesting some diet overlap.

scholarly journals Comparative genomics of the coconut crab and other decapod crustaceans: exploring the molecular basis of terrestrial adaptation

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Werner Pieter Veldsman ◽  
Ka Yan Ma ◽  
Jerome Ho Lam Hui ◽  
Ting Fung Chan ◽  
J. Antonio Baeza ◽  
...  
Keyword(s):  
Life Stage ◽  
Spiny Lobster ◽  
Parallel Evolution ◽  
Complex Life Cycle ◽  
Subtidal Zone ◽  
Adaptation Mechanism ◽  
Protein Coding ◽  
Cuticle Sclerotization ◽  
Terrestrial Life ◽  
Terrestrial Environments

Abstract Background The complex life cycle of the coconut crab, Birgus latro, begins when an obligate terrestrial adult female visits the intertidal to hatch zoea larvae into the surf. After drifting for several weeks in the ocean, the post-larval glaucothoes settle in the shallow subtidal zone, undergo metamorphosis, and the early juveniles then subsequently make their way to land where they undergo further physiological changes that prevent them from ever entering the sea again. Here, we sequenced, assembled and analyzed the coconut crab genome to shed light on its adaptation to terrestrial life. For comparison, we also assembled the genomes of the long-tailed marine-living ornate spiny lobster, Panulirus ornatus, and the short-tailed marine-living red king crab, Paralithodes camtschaticus. Our selection of the latter two organisms furthermore allowed us to explore parallel evolution of the crab-like form in anomurans. Results All three assembled genomes are large, repeat-rich and AT-rich. Functional analysis reveals that the coconut crab has undergone proliferation of genes involved in the visual, respiratory, olfactory and cytoskeletal systems. Given that the coconut crab has atypical mitochondrial DNA compared to other anomurans, we argue that an abundance of kif22 and other significantly proliferated genes annotated with mitochondrial and microtubule functions, point to unique mechanisms involved in providing cellular energy via nuclear protein-coding genes supplementing mitochondrial and microtubule function. We furthermore detected in the coconut crab a significantly proliferated HOX gene, caudal, that has been associated with posterior development in Drosophila, but we could not definitively associate this gene with carcinization in the Anomura since it is also significantly proliferated in the ornate spiny lobster. However, a cuticle-associated coatomer gene, gammacop, that is significantly proliferated in the coconut crab, may play a role in hardening of the adult coconut crab abdomen in order to mitigate desiccation in terrestrial environments. Conclusion The abundance of genomic features in the three assembled genomes serve as a source of hypotheses for future studies of anomuran environmental adaptations such as shell-utilization, perception of visual and olfactory cues in terrestrial environments, and cuticle sclerotization. We hypothesize that the coconut crab exhibits gene proliferation in lieu of alternative splicing as a terrestrial adaptation mechanism and propose life-stage transcriptomic assays to test this hypothesis.

scholarly journals Population modelling insights of extinct environments: the case of the Kem Kem palaeocommunity

2021 ◽  
Author(s):  
Lucas dos Anjos
Keyword(s):  
Functional Group ◽  
Food Sources ◽  
Small Community ◽  
Population Modelling ◽  
Top Predator ◽  
Top Predators ◽  
Large Predators

AbstractThe Kem Kem beds are well-known palaeontological deposits. Among the species that lived there, there are some large theropods, such as Deltadromeus agilis, Carcharodontosaurus saharicus, and Spinosaurus aegyptiacus. It is possible that these large predators were facultative scavengers, and they could compete for carrion. In the present paper, I simulate a small community module of this environment, consisting of Carrion, Fishes, Spinosaurus, and a functional group composed of large terrestrial Theropods. I assume that these top predators feed on carrion, but they also have exclusive food sources. I show that these exclusive food sources could have assured the possibility of coexistence, and in their absence, one top predator could be locally extinct.

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