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At least 433 records · Page 24Linked to original sources
PubMed2000

First record of an actinosporean (Myxozoa) in a marine polychaete annelid.

The marine polychaete Nereis (Hediste) diversicolor (Annelida) from shallow water in the Oresund, Denmark, was found to be infected with an actinosporean stage of a myxozoan parasite. The body length of the pyriform actinospore is 12-16 microm and its maximum width is 10-12 microm. The spore is triangular in apical view, with the 3 spherical polar capsules distally. The spore is without caudal processes. Eight spores develop in each pansporocyst. Free spores and pansporocysts were found in the musculature and parapodia but not in the intestine. The myxosporean stage in fish is unknown. This is the first record of an actinosporean stage in a marine polychaete, but because marine oligochaetes are rare, compared with polychaetes, the latter are believed to play an important role as invertebrate (alternate) hosts in marine myxozoan life cycles.

Animals↗
PubMed2002

Morphological plasticity in metal-sequestering earthworm chloragocytes: morphometric electron microscopy provides a biomarker. of exposure in field populations.

Morphometric measurements of the volume fractions (Vv) of two prominent metal-sequestering compartments, chloragosome granules and debris vesicles, were made on transmission electron micrographs of chloragocytes in Dendrodrilus rubidus (Annelida: Oligochaeta: Lumbricidae) from one uncontaminated site and three qualitatively and quantitatively different metalliferous soils associated with disused Pb/Zn mines. We also examined the relative volume fractions of the alimentary wall and attached chloragogenous tissue by light microscopy. Several conclusions relevant to environmental diagnostics were reached: Metal identity and degree of soil pollution exert strong effects on chloragocyte ultrastructure; morphometry by light microscopy indicated that the metal-induced structural effects are characterized by intracellular alterations not accompanied by a significant expansion of the tissue volume; elevated metal burdens can reduce chloragosome Vv and, concomitantly, increase the Vv of their autophagic derivatives, the debris vesicles; the measured cellular alterations were more closely correlated with integrated tissue metal burdens than they were with integrated soil metal burdens; and estimates of tissue metal distribution, derived by combining morphometric data and published whole-worm and chloragosome metal concentrations, suggested that the alimentary wall of earthworms may sequester Pb, Zn, and Cd. Our study shows that cellular changes, directly or indirectly, may yield quantifiable expressions of metal loads bioaccumulated by earthworms. However, the practical use of cellular changes as biomarkers of soil quality probably will require automated light-microscopic morphometry in combination with organelle-specific molecular probes to be cost effective.

Animals↗
PubMed2005

Purification, characterization and sequence analyses of the extracellular giant hemoglobin from Oligobrachia mashikoi.

We purified an extracellular hemoglobin with the molecular mass of ca. 440 kDa from the whole homogenates of Oligobrachia mashikoi (phylum Pogonophora) by a one-step gel-filtration. The preparation was pure to be crystallized. The P50 values of the hemoglobin and the fresh blood prepared from O. mashikoi were about 0.82 Torr and 0.9 Torr, respectively, which were much lower than the P50 value of human hemoglobin. However, the n values of the hemoglobin and the blood were about 1.2 and 1.1, respectively. Using the improved tricine SDS-PAGE, we could separate O. mashikoi hemoglobin into four kinds of the globin chains, A1, A2, B1 and B2, and succeeded for the first time in cloning and sequencing of the complete cDNA encoding B1 globin gene, in addition to A1, A2 and B2 globin genes in full length. We found that all globin genes have the extracellular signal sequences in each molecule and the distal His of the B1 globin chain is replaced to Gln. Finally, we constructed phylogenetic trees of the hemoglobins from Pogonophora, Vestimentifera and Annelida.

Amino Acid Sequence↗
PubMed1981

Insulin in insects and annelids.

The fruitfly, Drosophila melanogaster, and the earthworm, Annelida oligocheta, were extracted with acid-ethanol by a classic method for recovering insulin from the pancreas. When each extract was filtered on a Sephadex G-50 column, a distinct peak of insulin immunoreactivity. The material in this peak had reactivity insulin (equivalent to 0.1 to 2 ng of insulin/g wet weight) was recovered in the region typical of insulin bioassay, measuring stimulation of glucose oxidation or lipogenesis by isolated rat adipocytes. The bioactivity was partially or largely neutralized by anti-insulin antibodies. In concordance with previous work showing the presence of material very similar to insulin in the blowfly and molluscs, we have confirmed the presence of insulin in insects and extended the observation to the earthworms. These findings suggest that insulin is more widespread in invertebrates than was previously thought. In a companion study (Proc. Natl. Acad. Sci. USA 77:6184-88, 1980), we have demonstrated material similar to insulin in unicellular organisms.

Adipose Tissue↗
PubMed2004

Freshwater microcosms-based assessment of eco-toxicological effects of a chemical effluent from the Pilcam industry in Cameroon.

We studied the acute toxicity of a raw effluent from a battery manufacturing plant (Pilcam) in Douala, Cameroon, to a freshwater fish (Oreochromis niloticus), and subsequently evaluated its sub-acute effects on water quality and the biota in freshwater microscosms. The acute toxicity test was based on 96 hrs static renewal bioassays that resulted in 96-h LC50 and LC90 values of 16 and 20.7% (v/v), respectively. The sub-acute experiments were conducted by exposing several species of aquatic organisms (plankton, macroinvertebrates and mollusks) to lower effluent concentrations [1.6%, 8.0%, 16% (v/v)] for six weeks, and monitoring their survival rates, as well as the physical and chemical characteristics of water. These concentrations were based on 10%, 50%, and 100% of the 96 h - median lethal concentrations (LC50) of the effluent to the freshwater fish, Oreochromis niloticus. Significant effects on functional parameters, such as, chlorophyll-a and total protein could not be demonstrated. However, the activity of alkaline phosphatase was significantly inhibited at all concentrations tested. Phytoplankton, zooplankton, macro-invertebrate communities and snails were negatively affected by the effluent application at concentrations ? 8% (v/v), with chlorophyta, ciliates, ostracoda, annelida, planaria and snails being the most sensitive groups. The snails were eliminated after 24 h exposure from microcosms treated with effluent at concentration ? 8% (v/v). Effluent exposure also caused significant effects on water quality parameters (DO, pH, hardness, conductivity, color, turbidity, ammonia) in general at concentrations ? 8% (v/v). Temperature and alkalinity were not significantly affected. Overall, data from this research indicate that a dilution of the Pilcam effluent down to 1.6% does not provide protection against chronic toxicity to aquatic organisms. Further studies are needed to determine the no observable adverse effect level (NOAEL), as well as a chronic reference concentration for this effluent.

Animals↗
PubMedDate not supplied

Evolution of blood cells.

The most primitive blood cell may have been a protohemocyte which was first involved in phagocytosis and nutrition. When metazoans (sponges) appeared, their "blood" cells, the archeocytes, were phagocytic. In diploblastic cnidarians (e.g. Hydra) blood cells occur in the primitive mesenchyme or mesoglea and are still phagocytic. Although the flatworms and nemertean worms possess a pseudocoelom, a progressive differentiation of several leukocytic types occurred. In coelomate annelids or segmented worms, differentiated cells appeared that distributed food and oxygen, thus erythrocytes evolved in certain marine or polychaete annelids. The Annelida also show differentiation of leukocytes that resemble granulocytes, lymphocytes and monocytes, and cell-mediated immunity that persists throughout later evolution. The Mollusca, Arthropoda, Echinodermata and Tunicata possess essentially the same features as the annelids. The vertebrate blood cells may have evolved from the tunicates via the echinoderm line, the deuterostome invertebrates, although analogous blood cells are present in the annelids, molluscs, and arthropods, the protostomes. The vertebrate plan of blood cell differentiation occurs in two compartments: bone marrow (for both lymphoid and myeloid cells) and lymphoid organs (e.g. thymus, lymph nodes) for lymphocytes.

Animals↗
PubMed2002

[Abundance and diversity of littoral invertebrates in the Socorro Island, Revillagigedo Archipelago, Mexico].

Composition, abundance, diversity and distribution of the littoral benthic invertebrates of Socorro Island with transects (parallel to the coast and with 1 m2 quadrats) were analyzed. During the spring of 1991 and 1992 samples were taken from the upper and middle levels of the intertidal zone in Vargas Lozano, Braithwaite, Blanca SW, Blanca NE, Binners, Grayson, Academia and Norte bays. The 161 species found belong to Porifera, Cnidaria, Platyhelmintha, Nemertina, Sipunculida, Annelida, Mollusca, Anthropoda and Echinodermata. Crustaceans and mollusks were the richest groups in both years, as in other rocky shores. Highest total density was found in Blanca NE bay in both samplings, with 281 orgs./m2 in the first and 172 orgs./m2 in the second. Most frequently found species were Isognomon janus (Mollusca, Pelecypoda), Littorina pullata (Mollusca, Gastropoda), Hipponix panamensis (Mollusca, Gastropoda), Pachygrapsus transversus (Crustacea, Grapsoidea) and Turbo funiculosus (Mollusca, Gastropoda). Because of the complexity of the habitat structure, Vargas Lozano was the bay with the highest specific richness (83 species), greatest diversity (4.7 bits/individual) and lowest dominance (0.065). Most species were classified as accidentals with the Dajoz's frequency classification, while the dominant species were accessories and only I. janus, in the spring 1991, was a constant species. Two kinds of bays were distinguished: those with some dominant species (density) and those in which there was no evident dominance by a particular species. Consequently, the diversity and evenness values were set apart: homogeneous communities (Vargas Lozano and Binners) and heterogeneous communities (Grayson bay and others), characterized by intermediate evenness values. The Jaccard similarity index identified two regions: one formed by bays found mainly in the southwest part of the island (Binners, Vargas Lozano, Braithwaite, Grayson and Blanca SW) and the other found in the northern region that included Blanca NE, Academia and Norte; however, Blanca NE had the most diverse species composition because of its physiographic particularities and because the sediment retained by the filamentous algae on the flat stones allow many species to settle down. Isognomon janus, Mitrella baccata (Mollusca, Gastropoda), P. transversus and Xanthodius cooksoni (Crustacea, Xanthoidea) were the most common species in all bays in both expeditions. The dominance-diversity relationship, the high specific richness and the low dominance of coastal invertebrates from the different bays, are indicative that the communities in Socorro Island are little disturbed; their specific richness are similar to those of coral reefs.

Animals↗
PubMed2002

Ecological effects of an anionic C12-15 AE-3S alkylethoxysulfate surfactant in outdoor stream mesocosms.

The ecological assessment of a C12-15 AE-3S linear alkylethoxysulfate (AES) anionic surfactant to invertebrates, fish, periphyton, and an aquatic macrophyte was conducted in a 30-d outdoor stream mesocosm study with five replicated concentrations and controls. Alkylethoxysulfate structural integrity and exposure concentrations were maintained during the 30-d treatment period, with average measured concentrations of 0.7, 1.27, 2.2, 4.31, and 10.18 mg/L. No effects were observed on the aquatic macrophyte Myriophyllum aquaticum at the highest concentration tested. A sevenfold increase in periphyton biomass at 10.18 mg/L was observed relative to controls primarily because of increases in density of the filamentous alga Mougeotia sp. Densities of the invertebrates Annelida (Stylaria), Amphipoda, Copepoda, Trichoptera (Hydropsychidae), Cladocera, and Diptera (Chironomidae) significantly decreased in streams treated with AES at 10.18 mg/L. Densities of drifting invertebrates were not observed to be affected at any concentration tested. Reproduction of Pimephales promelas significantly decreased at 1.27 mg/L and growth of juvenile Lepomis macrochirus was significantly affected at 4.31 mg/L. Multivariate cluster analysis and nonmetric multidimensional scaling ordination showed distinct structural effects on the invertebrate communities in the streams treated with AES at 10.18 mg/ L compared to the control and streams treated at < 10.18 mg/L through the 30-d treatment. Convergence of the communities treated at 10.18 mg/L toward control communities in the ordination suggests recovery in these communities after termination of surfactant treatment. The results from this study support an ecosystem value of > 2.0 mg/L, and indicate that the conservative Dutch risk assessment for AESs has at least a fivefold margin of safety.

Animals↗
PubMedDate not supplied

[Phylogeny of protostome moulting animals (Ecdysozoa) inferred from 18 and 28S rRNA gene sequences].

Reliability of reconstruction of phylogenetic relationships within a group of protostome moulting animals was evaluated by means of comparison of 18 and 28S rRNA gene sequences sets both taken separately and combined. Reliability of reconstructions was evaluated by values of the bootstrap support of major phylogenetic tree nodes and by degree of congruence of phylogenetic trees inferred by various methods. By both criteria, phylogenetic trees reconstructed from the combined 18 and 28S rRNA gene sequences were better than those inferred from 18 and 28S sequences taken separately. Results obtained are consistent with phylogenetic hypothesis separating protostome animals into two major clades, moulting Ecdysozoa (Priapulida + Kinorhyncha, Nematoda + Nematomorpha, Onychophora + Tardigrada, Myriapoda + Chelicerata, Crustacea + Hexapoda) and unmoulting Lophotrochozoa (Plathelminthes, Nemertini, Annelida, Mollusca, Echiura, Sipuncula). Clade Cephalorhyncha does not include nematomorphs (Nematomorpha). Conclusion was taken that it is necessary to use combined 18 and 28S data in phylogenetic studies.

Animals↗
PubMed2005

Allergy to sea fishing baits.

We report a new case of rhinitis and asthma caused by sea fishing baits. The results showed exposure to Sipunculus nudus (Phylum Sipuncula; order Sipunculida: Sipunculidae) to be the main cause of the allergic symptoms. The intervention of IgE was demonstrated, with the presence of cross-reactions with allergenic extracts from other worm species used as baits, belonging to different orders of Annelida.

Allergens↗
PubMed1991

[Homologies between hemerythrins of sipunculids and cadmium-binding metalloprotein (MP II) from a polychaete annelid, Nereis diversicolor].

The determination of the first 33 amino acids of the Cd-binding-protein (MP II) of Nereis diversicolor (Annelida, Polychaeta) shows a homology of 79 and 61% with 2 respiratory proteins of sipunculids, respectively the myohemerythrin and the hemerythrin. The positive reaction obtained by immunocytochemistry over the hemerythrocytes of Sipunculus nudus using antibodies raised against MP II and the presence of iron on the MP II reinforce this similarity.

Animals↗
PubMed1988

Spatial organization of collagen in annelid cuticle: order and defects.

The epidermis of Paralvinella grasslei (Polychaete, Annelida) is covered by an extracellular matrix, the cuticle, mainly composed as in other annelids of superimposed layers of non-striated collagen fibrils. The collagen fibrils of annelid cuticle are shown to be composed of parallel and sinuous microfibrils (thin sections and freeze-fracture replicas). The 3-dimensional organization of collagen is characterized by 2 different types of geometrical order: (a) Fibrils form a quasiorthogonal network, whose structure is comparable to that of a "plywood"; (b) Fibrils are helical, and goniometric studies show that microfibrils present a definite order within each fibril, which is termed "cylindrical twist". These 2 characteristics are those which have recently been evidenced in "blue phases", i.e., liquid crystals which are closely related to cholesteric liquid crystalline phases. Non-fluid analogues of cholesteric liquids are widespread among invertebrate cuticles and the presence of blue phase analogues suggests that a self-assembly mechanisms is involved in cuticle morpho-genesis, which is derived from that governing blue phase growth. The cuticular network presents local rearrangements of fibrils called "defects", despite the fact that they are elaborate structures which trigonal and pentagonal singularities. Branched fibrils are regularly observed. We discuss the involvement of these pattern disruptions in the cuticle growth process.

Animals↗
PubMed1982

The vascular biological stereotype and the achievement problem of the neurohumoral integration during phylogenesis.

There is developed Bertalanffy's theory of systems on the evolution process of biological stereotypes (theory of Mârza, Repciuc, Eskenasy 1962) and the systemic theory nomenclature used in biology is critically discussed. A more complete definition of the reactivity is attempted. Biological stereotypes are analogous to the Pavlovian absolute reflexes and represent specialized and integrated parts of the reactivity, which forms a unity of contraries with the metabolism. There is considered that a biological stereotypes achieves to form a system when the specific organ is differentiated. On this basis is pursued the achievement of the systemic stage of nervous, emunctory (excretory), alimentary, vascular, respiratory subsystems. The nervous subsystem--and implicitly the nervous integration--is the first subsystem to be differentiated in phylogeny. The humoral integration is tardier appeared. The formation of the vascular subsystem represents a qualitative leap which allowed the evolution of all the other subsystems, inclusively of the nervous and endocrine ones, as well as of the homeostasis system. The last chapter present 6 phases of the vascular subsystem evolution starting from the structural plan of circulation in Annelida, and passing through those of Stomochordata, of fishes, of Dipnoi fishes, of Anura and Mammalia. The highly stable characters of the structural plan of the vascular subsystem evolution (the morphofunctional stereotypes of Mârza, Repciuc and Eskenasy 1962) are pointed out. This stability is interpreted in the light of the stabilizing selection. The cardiac pump and the lymphatics are differentiated from venous vessels. The integration of the arterial circulation with the heart starts in Dipnoi fishes and reached the highest form only in mammalians.

Animals↗
PubMedDate not supplied

Gut-islet endocrinology-some evolutionary aspects.

Immunological and biological studies have shown that many of the mammalian gastroenteropancreatic (GEP) hormones have counterparts in lower vertebrates. Hormonal localization in cyclostomes and fishes suggests that insulin was phylogenetically the first islet hormone, followed by somatostatin, glucagon and, last, pancreatic polypeptide (PP). Some of the GEP peptides are present in the central and peripheral nervous system of lower vertebrates as well as mammals. GEP hormone-like substances resembling insulin, somatostatin, glucagon, PP, gastrin, secretin, VIP, substance P and enkephalin also occur in protostomian invertebrates (Annelida, Arthropoda, Mollusca), particularly in their nervous system. These findings indicate that the vertebrate hormones may have originated in neural tissue before the development of the vertebrate line of evolution.

Animals↗
PubMed1984

Regeneration and pattern formation in planarians. I. The pattern of mitosis in anterior and posterior regeneration in Dugesia (G) tigrina, and a new proposal for blastema formation.

Mitotic activity during regeneration in the planarian Dugesia (G) tigrina shows a biphasic pattern, with a first maximum at 4-12 h, a second and higher maximum at 2-4 days, and a relative minimum in between. The first peak is mainly due to pre-existing G2 cells entering mitosis shortly after cutting, whereas the second maximum is due to cells that divide after going through the S period from the onset of regeneration. From a spatial point of view, the highest mitotic values are found in stump (postblastema) regions near the wound (0-300 micron), though regions far from it also show increased mitotic values but always lower overall values. As regeneration continues the postblastema maximum shifts slightly to more proximal regions. In contrast, no mitosis has been found within the blastema, even though the number of blastema cells increases steadily during regeneration. The results suggest that blastema in planarians forms through an early accumulation of undifferentiated cells from the stump to the base of blastema. The results obtained demonstrate that blastema formation in planarians occurs through mechanisms somewhat different to those shown to occur in the classical epimorphic models of regeneration (Annelida, Insecta, Amphibia), and suggest that planarian regeneration could represent an intermediate stage between morphallactic and epimorphic modalities of regeneration.

Animals↗
PubMed1978

[Structure of the neuropile of the abdominal brain of polychaetes].

By means of vital staining of neuronal elements with methylene blue, new data were obtained on the structure of neuropil in the abdominal brain of Polychaete (Nereis diversicolar). Neuronal composition and interrelationship between sensory, motor and associative areas are clarified. Dorsoventral differentiation of the neuropil is analyzed; common level of intraneural relations of Polychaetes in the line of Annelida is determined.

Animals↗
PubMed1994

DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.

We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, Mollusca, Annelida, Pogonophora, Arthropoda, Nemertinea, Echiura, Sipuncula, Platyhelminthes, Tardigrada, and Coelenterata, as well as the putative phylum Vestimentifera. Preliminary comparisons revealed that these COI primers generate informative sequences for phylogenetic analyses at the species and higher taxonomic levels.

Amino Acid Sequence↗
PubMedDate not supplied

[Gastrointestinal bacteriology of the earthworm Eisenia foetida grown in composted broiler litter].

The high animal concentration in intensive production brings about problems due to the volume of excreta and environmental pollution with the consequent risk for animal and human health. Therefore, previous to the application of any strategy of organic wastes recycling it is necessary to know possible sanitary risks. Farm organic wastes can be recycled through the intensive breeding of earthworms from species Eisenia foetida (Annelida, Oligochaeta) which can break down the consumed organic substance into humus. E. foetida is able to accelerate biodegrading wastes decomposition. It has been selected for recycling because its self productivity, its capacity to live in high concentrations, its feeding habits as well as its resistance to stress. The aim of this work is to study the microbial flora potentially pathogenic and their survival in the intestinal tract in sexually mature earthworms cultivated in composted broiler litter. Total coliforms, faecal coliforms, Salmonella, Pseudomonas and other enteric bacteria were sought in accordance with the recommended methodology. In E. foetida no positive results were obtained in the MPN/g (most probable number) of total coliforms, faecal coliforms, Salmonella, Pseudomonas and other Enterobacteriaceae family bacteria. These results suggest an antimicrobial response upon Gram negative bacteria from the gizzard and through the intestinal tract.

Animal Husbandry↗