Large Number Of Invertebrates Research Articles

New insights into the evolutionary dynamic and lineage divergence of gasdermin E in metazoa.

Gasdermin (GSDM) is a family of pore-forming proteins that induce pyroptosis. To date, the origin and evolution of GSDM in Metazoa remain elusive. Here, we found that GSDM emerged early in Placozoa but is absent in a large number of invertebrates. In the lower vertebrate, fish, three types of GSDME, i.e., GSDMEa, GSDMEb, and a previously unreported type (designated GSDMEc), were idenitied. Evolutionarily, the three GSDMEs are distinctly separated: GSDMEa is closely related to tetrapod GSDME; GSDMEb exists exclusively in fish; GSDMEc forms the lineage root of tetrapod GSDMA/B/C/D. GSDMEc shares conserved genomic features with and is probably the prototype of GSDMA, which we found existing in all tetrapod classes. GSDMEc displays fast evolutionary dynamics, likely as a result of genomic transposition. A cross-metazoan analysis of GSDME revealed that GSDMEa shares a conserved caspase recognition motif with the GSDME of tetrapods and cnidarians, whereas GSDMEb has a unique caspase recognition motif similar to that of mammalian GSDMD, and GSDMEc exhibits no apparent caspase recognition motif. Through functional test, four highly conserved residues in vertebrate GSDME proved to be essential to auto-inhibition. Together our results provide new insights into the origin, evolution, and function of metazoan GSDMs.

Diet of the little Athene noctua (Scopoli, 1769) on the territory of Berehovo district (Transcarpathian region)

Objectives. The Little Owl is the most common owl in the Western Palearctic and its population is declining significantly in Europe. Therefore, conservation and study of this owl is an important issue in most European countries. Analysis of trophic patterns at the local level provides interesting and valuable information about the predator’s eating habits. The owl’s diet investigation allows us to analyze their potential adaptations to habitats with different levels of environmental transformation. Materials and Methods. We studied nutrition of the Little Owl Athene noctua, in agricultural lands of Berehove district of Transcarpathian region in Ukraine. In total, 1446 pellets were collected at 15 pellet stations in 2002–2020 and 2506 prey items were identified. The prey items represented 18 vertebrate species (16 species of small mammals of three orders Rodentia, Soricomorpha, Carnivora, as well as reptiles of the family Lacertidae and birds of the order Passeriformes and arthropods. Results. Vertebrates play a major role in feeding the Little Owl (over 99 % of total prey biomass in all of the studied sites). The common vole is the most common prey in the owl’s diet (52.1 % of the total prey number and 67.5 % of the biomass of the prey caught), as well as a high proportion of mice of the genus Apodemus and Sylvaemus. The contribution of invertebrates to total prey biomass is insignificant (0.3 %). A large number of invertebrates were observed in the diet of the Owl in summer and were almost completely absent in winter. Conclusions. According to our data, the Little Owl is a typical predator generalist in Transcarpathia. The 28 taxa found in the pellets show a wide range of food objects in a relatively small area, and high level adaptations to habitats with different levels of environmental transformation (agrosystems and anthropogenic areas).

Agrilozodes Suarezi (Coleoptera: Buprestidae) as Secondary Colonizer of a Sclerolobium sp. Branch Girdled by Oncideres Saga (Coleoptera: Cerambycidae)

A large number of invertebrates use dead wood as shelter, food, and as a microclimate refuge. Ecological succession in this substrate depends on primary colonization, stimulating or inhibiting future successions. Twig girdler beetles girdle and lay eggs inside the bark of branches and trunks of different host plants. Branch girdling blocks the phloem flow, making it more nutritive for offspring and future colonizers. This study, in the State Park of Rio Doce (PERD), Minas Gerais, Brazil, is the first report of a secondary colonization by borers on a Sclerolobium sp. branch girdled by Oncideres saga (Coleoptera: Cerambycidae). A Sclerolobium sp. branch, girdled by O. saga was collected in Rio Doce State Park, cut into pieces, and brought to the laboratory, where it was stored in a cardboard box and moistened monthly. A total of 28 adult beetles of 4 species emerged from this branch. Agrilozodes suarezi was found for the first time developing inside a branch of its first host plant. The life history of insects of the genus Agrilozodes is poorly known, because this is the first report of aspects of its biology.

Controlled excavations in the Pesciara and Monte Postale sites provide new insights about the palaeoecology and taphonomy of the fish assemblages of the Eocene Bolca Konservat-Lagerstätte, Italy

The Eocene Konservat-Lagerstätte of Bolca, Italy, is famous for the abundance and exquisite preservation of its fossils. Although the Bolca sites have provided one of the most studied ichthyofaunistic fossil assemblages of the world, several aspects about the community structure and the biostratinomic processes that led to the accumulation of its fish remains have been neglected or underestimated. In order to improve our knowledge concerning the palaeoecology and palaeoenvironment of Bolca, a quantitative palaeoecological and taphonomic analysis of the fish remains collected during controlled excavations at the Pesciara and Monte Postale sites is presented herein. The results of these analyses concur to suggest that these two sites have different speciose fish assemblages and different depositional contexts. The high-quality preservation of the fishes from the Pesciara site has allowed for the species level identification of most of its specimens, providing a good resolution of its palaeoecological spectrum. The Pesciara fish assemblage is defined by a sharp oligarchic structure clearly dominated by planktivorous taxa. The taphonomic features confirm that the sediments were deposited in an intraplatform basin in which anoxic conditions at the bottom and the development of the biofilm acted as promoters of high-quality fossil preservation. On the other hand, the moderate preservation quality of the fishes from Monte Postale does not allow for most of the specimens to be identified at the genus or species level, making it difficult to interpret the ecological and trophic relationships within this assemblage. Nevertheless, the abundance of marine and terrestrial plants, coupled with the large number of invertebrates (including abundant corals), concur to suggest that the sediments of Monte Postale were likely deposited close to an emerged coastal area characterized by mangroves, seagrass, and coral reefs. The prominent disgregation of fish skeletons, coupled with the unimodal dispersion of the elements and bioturbations, clearly indicate a high degree of disturbance in the Monte Postale palaeoenvironment, suggesting at least periodic aerobic conditions at the bottom.

Principais Acervos de Paleontologia do Brasil

Main Brazilian paleontological collections. This paper presents a summary of major paleontological collections in Brazil, without regard to institutions that are closed to reform or with predominantly didactic or academic collections. From thirty institutions listed, twelve of them are located in the southeast (Rio de Janeiro, Belo Horizonte, Peiropolis, Ouro Preto, Sao Paulo, Rio Claro, Taubate and Monte Alto), ten in the northeast (Ceara, Rio Grande do Norte, Pernambuco, Sergipe and Bahia), five in the southern (Mafra, Porto Alegre, Sao Leopoldo and Santa Maria), two in the northern region (Acre and Para), and one in central Brazilian region. The largest fossil collections in Brazil are in the Museu de Ciencias da Terra of the DNPM and the Museu Nacional, both in Rio de Janeiro, which gather around 260,000 specimens, even in Aracaju, Sergipe, is the third largest Brazilian paleontological collection, with approximately 38,000 fossils belonging to the Fundacao Paleontologica Phoenix. The most thematic collections are related to Cretaceous fossils, which is concordant with the abundance of Brazilian fossils of this age: in the northeast region, the collections are notables by the large number of invertebrates and fishes, and in Minas Gerais and Sao Paulo, by their reptiles. Other thematic collections are in Rio Grande do Sul (Triassic reptiles), Sao Paulo (Mesozoic trace fossils), Santa Catarina (Paleozoic invertebrates), Ceara and Pernambuco (Siluro-Devonian trace fossils), and Ceara, Bahia, Minas Gerais and Acre (Cenozoic megafauna). The oldest museums of Brazil with paleontological collections are all centenarians: the Museu Nacional, established in 1818 in Rio de Janeiro, Museu Paraense Emilio Goeldi, opened in 1866 in Belem, and the Museu de Ciencia e Tecnica in Ouro Preto, created in 1884.

Acid–base status mediates the selection of organic habitats by upland stream invertebrates

Freshwater bryophytes support large numbers of invertebrates, but their importance compared to other organic habitats, e.g. submerged terrestrial leaf-litter, is seldom assessed. There is also little information about how water quality might affect bryophyte–invertebrate interactions. Here, we compare macroinvertebrate colonisation of bryophytes and leaf-litter in streams of contrasting acidity. Litterbags containing the liverwort Nardia compressa, a moss mixture dominated by Platyhypnidium riparioides, and oak leaves (Quercus spp.) were exposed in replicate streams at the Llyn Brianne Stream Observatory (Wales, UK), and collected after 42 and 75 days. The family richness and abundance of invertebrates were significantly higher in circumneutral than acid samples. In circumneutral streams, both were significantly higher in oak and N. compressa than in P. riparioides. Under acid conditions, invertebrate colonisation of bryophytes declined markedly relative to oak, due largely to reduced numbers of the otherwise-dominant Leuctridae. Invertebrate assemblage composition differed with both acid–base status and litter type, with acid-tolerant taxa positively associated with bryophytes. We conclude that oak litter and N. compressa are equally valuable habitat under circumneutral conditions, but in acid streams bryophyte quality declines even for acid-tolerant taxa. This effect is consistent with invertebrates using bryophytes as more than physical habitat alone.

The venus kinase receptor (VKR) family: structure and evolution

BackgroundReceptor tyrosine kinases (RTK) form a family of transmembrane proteins widely conserved in Metazoa, with key functions in cell-to-cell communication and control of multiple cellular processes. A new family of RTK named Venus Kinase Receptor (VKR) has been described in invertebrates. The VKR receptor possesses a Venus Fly Trap (VFT) extracellular module, a bilobate structure that binds small ligands to induce receptor kinase activity. VKR was shown to be highly expressed in the larval stages and gonads of several invertebrates, suggesting that it could have functions in development and/or reproduction.ResultsAnalysis of recent genomic data has allowed us to extend the presence of VKR to five bilaterian phyla (Platyhelminthes, Arthropoda, Annelida, Mollusca, Echinodermata) as well as to the Cnidaria phylum. The presence of NveVKR in the early-branching metazoan Nematostella vectensis suggested that VKR arose before the bilaterian radiation. Phylogenetic and gene structure analyses showed that the 40 receptors identified in 36 animal species grouped monophyletically, and likely evolved from a common ancestor. Multiple alignments of tyrosine kinase (TK) and VFT domains indicated their important level of conservation in all VKRs identified up to date. We showed that VKRs had inducible activity upon binding of extracellular amino-acids and molecular modeling of the VFT domain confirmed the structure of the conserved amino-acid binding site.ConclusionsThis study highlights the presence of VKR in a large number of invertebrates, including primitive metazoans like cnidarians, but also its absence from nematodes and chordates. This little-known RTK family deserves to be further explored in order to determine its evolutionary origin, its possible interest for the emergence and specialization of Metazoa, and to understand its function in invertebrate development and/or reproductive biology.

The structure of fish community in the river Mirna

Natural perturbations and human pressure increasingly affect the river ecosystems and their biological communities. Fish species are a good indicator of the river status and one of the factors for the assessment of ecological condition by the Water Framework Directive (Directive 2000/60/EC). River Mirna, one of the larger right tributaries of the river Sava, is a good example of anthropogenic pressure on the running water ecosystem. Fish community species structure was analyzed at selected eight sampling sites located over the 28 km length of the river. Abiotic conditions were determined by measuring the physical, chemical and hydro-morphological parameters and the influence of measured parameters on present fish community was analyzed. It has been determined, that the river Mirna is loaded with organic matter and physically changed by regulations, river beds canalizing and bank stabilization. Fish were sampled with standard electro-fishing method to determine species diversity, biomass of the specimens and their size. 29 fish species from seven families (26 native and 3 allochthonous species) were recorded along with one type of the Danubian brook lam- prey (Eudontomyzon vladykovi). Only two species, Telestes souffia and Cottus gobio, were present at all eight sampling sites. The largest number of specimens (890) and the largest biomass (5697 g) per 100 m2 was recorded at the sampling site located after the town as a result of the flow of purified water from the water treatment plant and a large number of invertebrates,which are an important food source. The minimum number of specimens per 100 m2 (86) and the minimum biomass of fish per 100 m2 (457 g) was measured at the relatively natural part of the channel. The most common causes for this are low temperatures, less food and a fast, turbulent flow. The study confirms that the changes in abiotic factors induced by anthropogenic activities significantly influence the structure of fish species community.

Diet of the Invasive Lizard Chamaeleo jacksonii (Squamata: Chamaeleonidae) at a Wet-Forest Site in Hawai‘i

We assessed diet from a sample of Jackson's chameleons inhabiting wet forest in Volcano Village, Hawai‘i Island, Hawai‘i. Most lizards contained food in their gastrointestinal tract, diet was broad, and large numbers of invertebrates, mostly insects, were consumed. Native insects composed the largest component of dietary items, and these spanned most of the body-size range found in the native invertebrate community. Taxonomic composition of diets does not conform to expectations for iguanian lizards inasmuch as hymenopterans form only a small portion of consumed items. Insect chemical or stinging defenses did not preclude consumption by lizards. The study site is a mixture of native and alien vegetation. Chameleons collected from alien plants contained larger numbers of native prey items than did those lizards removed from native plants, suggesting that lizard residency on non-native plants will not reduce their predation impact on native invertebrates in mixed forest. Our results confirm the finding of a similar study in dry-forest habitat on Maui that Jackson's chameleons are likely to pose a substantial threat to a broad range of native invertebrate biodiversity in Hawai‘i.

Behavioural and physiological mechanisms of polarized light sensitivity in birds

Polarized light (PL) sensitivity is relatively well studied in a large number of invertebrates and some fish species, but in most other vertebrate classes, including birds, the behavioural and physiological mechanism of PL sensitivity remains one of the big mysteries in sensory biology. Many organisms use the skylight polarization pattern as part of a sun compass for orientation, navigation and in spatial orientation tasks. In birds, the available evidence for an involvement of the skylight polarization pattern in sun-compass orientation is very weak. Instead, cue-conflict and cue-calibration experiments have shown that the skylight polarization pattern near the horizon at sunrise and sunset provides birds with a seasonally and latitudinally independent compass calibration reference. Despite convincing evidence that birds use PL cues for orientation, direct experimental evidence for PL sensitivity is still lacking. Avian double cones have been proposed as putative PL receptors, but detailed anatomical and physiological evidence will be needed to conclusively describe the avian PL receptor. Intriguing parallels between the functional and physiological properties of PL reception and light-dependent magnetoreception could point to a common receptor system.

A laboratory technique to speed processing of samples with large numbers of invertebrates

AbstractThe amount of time needed to process samples with large numbers of terrestrial invertebrates in the laboratory has been a long‐standing obstacle impeding progress in invertebrate conservation biology and applied ecology. Laboratory subsampling of samples with large numbers of invertebrates is one method that saves time and reduces processing cost. In this study, a laboratory vacuum processing technique, consisting of a vacuum pump, aspirator and voice recognition software, was compared with a subsampling technique, and a conventional whole sample counting method. Vacuum processing was the most efficient technique; on average, more than five times more insects were processed per minute compared with whole sample counting and subsampling techniques. Differences in efficiencies among techniques were affected by trap type and invertebrate abundance. The vacuum technique was most efficient when processing high abundance pitfall trap samples, and was less efficient in processing pan trap samples that had invertebrates entangled by algae and other materials. Caution should be exercised when using the technique on soft‐bodied or poorly preserved specimens; a subsampling technique may be more appropriate in these cases, especially if specimens must be identified to genus or species level at a later time. The efficiency of the vacuum technique is reduced relative to the amount of time it takes to locate invertebrates in a sample; therefore, the technique does not save substantial time when processing samples with large amounts of substrate or debris, such as is the case with some aquatic invertebrate samples. However, if flotation or another method that separates invertebrates from other materials is used first, then the vacuum method would be useful for these types of samples as well.

Effects of Sampling Area and Subsampling Procedure on Comparisons of Taxa Richness among Streams

the biotic integrity of communities. In all cases, we make the implicit and sometimes brash assumption that we can really measure the number of taxa in a community. Although measuring taxa richness might appear straightforward, accurate measurement has been extraordinarily difficult; and despite years of effort, no universally accepted methods for its measurement have emerged. The essential problem is that we can never completely census a taxonomic assemblage or entire community; we rely instead on estimates that describe some portion of the real taxa richness of an assemblage. The problem of knowing what percent of the taxa present have been collected is exacerbated when investigators fail to explicitly define their universe of interest (i.e., the spatial bounds of the community or communities in question). Comparisons of taxa richness among studies that used different sampling and subsampling methods are especially difficult and should be viewed skeptically. The difficulty of obtaining accurate measurements of richness is due to the collector's curve

A Simple and Inexpensive Method to Separate Live and Preserved Benthos from Sediments

ABSTRACT We used a simple and inexpensive water-based method to separate live and preserved invertebrates from lake and stream sediments. Sediment samples were emptied onto a large screen and slowly immersed in water which caused the invertebrates to become trapped in the surface film from which they were easily removed. Invertebrates with setae or numerous appendages were separated most successfully, whereas dense organisms had to be removed by hand. On average 74% of all invertebrates per sample were removed by sieving in 23 minutes. We suggest that the time and effort spent sorting samples can be reduced by combining sieving with hand-sorting, especially when samples contain large numbers of invertebrates.

Stream flow and predation effects on the spatial dynamics of benthic invertebrates

Field experiments were carried out to determine the influence of predation and prey movements on the accumulation of prey in enclosures. Experimental enclosures permitted exchange of prey with the benthos, but not of the large, predatory larvae of the caddisfly, Plectrocnemia conspersa (Curtis). Unseasonally heavy rainfalls during the experiment resulted in high flows and enabled us to examine the effects of a major, abiotic disturbance on invertebrate spatial dynamics. Prey colonization rates of cages without predators were determined in nine 24 h periods. Colonization rates increased exponentially with flow and were species-specific, depending on dispersal behaviour. Prey accumulation and predator impacts were measured in cages, with and without P. conspersa larvae, placed in the stream for 1, 2 or 3 weeks. Prey densities in cages increased with exposure time, but increases were not gradual and depended on flow regime. Flow was reduced within cages and they accumulated large numbers of invertebrates during high discharge. Analogous, naturally occurring refugia in the stream channel could be important for the recovery of lotic communities after major disturbances. Overall, prey densities were lowest in cages with predators. For fast colonizers, predation effects were detectable early in the experiment, but quickly obscured thereafter by continuous exchange of prey. For slow colonists, predation effects were detectable later, but persisted longer. Consumption rates for P. conspersa varied with prey density and flow regime. We suggest that the spatial dynamics of benthic invertebrates, especially as they are influenced by stochastic events, are important in understanding and detecting predation effects in stream communities.

The structure of the sand dune ecosystem of Wadi El Raiyan, Egypt

Physical and biotic elements of a sand dune ecosystem in the Wadi El Raiyan area of the Egyptian Western Desert are identified and described. The study area is the site of extensive eolian sand deposition and active dune formation. It has a typical hyperarid warm Saharan climate. A superfacial groundwater table is the main source of water. Vegetation is limited to low-lying interdune areas and the bases of larger dunes, and is represented by 13 species of perennial plants. Vegetation density, distribution and composition vary with local topographic and edaphic variations. Animal life is concentrated in the vegetated areas and is represented by a large number of invertebrates, mostly insects and arachnids. Eleven reptiles, 13 resident birds and nine mammals, are also present, many with adaptations for either sandy or other desert habitats. The special characteristics of this ecosystem and its elements are discussed.

The Faunal Assemblage Inhabiting Seasonal Sea Ice in the Nearshore Arctic Ocean with Emphasis on Copepods

Large numbers of invertebrates were collected from the lower layer of seasonal ice in the nearshore Beaufort Sea, off the northern coast of Alaska in spring 1980. Over 90 % of the individuals found belonged to meiofaunal taxa. Although density within the ice was low compared to that typically found in sediments, it was comparable to the highest previous estimate from sea ice. Densities were lowest in samples taken in April and reached a maximum of around 50 000 individuals m-2 in June. Nematodes were numerically dominant, but copepods and turbellanans were also abundant. Population structures of the 2 most numerous copepod species were examined and found to differ greatly. Cyclopina gracilis appeared to reproduce continuously during the study; both adults and young copepodites were always present. The population of Harpacticus sp. initially consisted only of juveniles; the growth of a single cohort was observed. Harpacticus sp. mated in the ice, but gravid females did not appear during the sampling period. Although the ephemeral seasonal sea ice habitat would seem to be very different from typical habitats of benthic copepods, these 2 species did not appear to possess any special strategies for living there.

Biology of mistletoes and their status in Nepal Himalaya

The mistletoes constitute a polyphyletic group of flowering parasitic plants and are commonly known as “Ainjeru” or “Lisso” in Nepali. Of the over 1300 mistletoe species occurring worldwide, Nepal is home to 19. Mistletoes are entirely dependent on their hosts for water and nutrients and affect their hosts mainly by competing for limited resources. Mistletoes play a vital role in natural plant communities by interacting with hosts, herbivores and dispersers. A large number of invertebrates and vertebrates use mistletoes as a shelter, as nesting and roosting place and as an important source of food. Oddly, botanists have accorded little attention to Nepal’s mistletoes, and our knowledge of this remarkable group of plants is quite deficient.
 
 Himalayan Journal of Sciences 3(5) 2005 p.84-86

Soil Animals as Vectors of Organochlorine Insecticides for Ground-Feeding Birds

The uptake of small sublethal doses of organochlorine pesticides by birds appears now to be quite a common phenomenon, but the pathways have been, for the most part, little examined. This paper discusses some of the ecological factors affecting the uptake and passage of organochlorine compounds in terrestrial ecosystems with particular reference to soil animals and ground-feeding birds such as the Robin (Erithacus rubecula), Skylark (Alauda arvensis), Lapwing (Vanellus vanellus), Starling (Sturnus vulgaris), thrushes (Turdus spp.) and corvids (Corvus spp.) for which animals form a large fraction of the diet. Blackbird (Turdus merula) and the Kestrel (Falco tinnunculus), both of which take large numbers of invertebrates, though the Blackbird is an omnivore with a partiality for fruit and the Kestrel a raptor feeding largely on small mammals. The ppm intervals chosen follow approximately a log scale which is rounded to the nearest convenient figures. The two species cannot be compared in detail since liver alone was used for analysis of the Kestrels and mixed viscera, which consisted of liver, heart and spleen (and possibly gut in some instances), in the Blackbirds. Both species came from a large number of counties but as the birds were generally found dead and the cause of death unknown neither set can be assumed to be a fair sample of the population. However, several features can be deduced. First, that both species had picked up residues of all the common organochlor- ine pesticides used in this country and secondly, apparently in contrast to the American situation, dieldrin and heptachlor epoxide residues are commonly present. DDT itself features very insignificantly but the preponderance of DDE indicates a large original DDT source. The relatively high amounts of heptachlor epoxide and low amounts of BHC contrast with the annual depositions of these compounds (see Strickland 1965) and reflect probably the biased nature of the samples as well as the known properties of relative persistence of these compounds in biological tissues.

Control of Swimming Position By Mechanical Factors and Proprioception

IT IS a well-known fact that most types of free-swimming Metazoa swim in characteristic positions. The bodyhas usually a dorsal and a ventral surface, and the more typical animals swim with the back directed upwards. Some forms adopt the opposite position, with the back directed downwards, and there are various other orientations characteristic for certain species. In many cases the normal position is maintained by an active reflex mechanism, which may be associated either with statocysts or with a response to light. Light, however, is often absent, and there are a large number of invertebrates in which statocysts have not been found. Proprioceptive orientation might occur, or orientation based on some special sensitivity to currents, but as yet we have no adequate evidence to support these possibilities. It is particularly in the absence of any reflex orientation to stimuli that purely mechanical forces may be important for controlling the swimming position of an aquatic animal. In the present paper the discussion will center mainly on the various types of such mechanical orientation which theoretically might occur. The possible role of proprioception will be discussed briefly towards the end. Although a large number of authors have appreciated that mechanical forces may be concerned in the swimming position of an aquatic animal, attempts to analyse these forces have not been satisfactory. There has been some valuable work on such topics as propulsive mechanisms and directional stability (see, for example, papers on fish by Magnan, 1929, 1930; and by Harris, 1936, 1937, 1938). But very little has been done on the mechanical factors which would favor return to a stable position. Perhaps the best papers in this field are those of Bethe (1894, 1910) and Woltereck (1913). These, however, do not give a complete picture, and most later authors have underestimated the complexity of the problem, frequently reaching conclusions which were not justified by the experimental evidence available. There appears to be a real need for a simple statement of the nature of the problem, if for no other reason than to serve as a gentle caution. To supply this need it seems best to make the treatment as elementary as possible, perhaps to the disappointment of those who have any real appreciation of aeroor hydrodynamics.