Larvalentwicklung und Metamorphose vonPhoronis psammophila (Phoronida,Tentaculata)

The larval development ofPhoronis psammophila Cori is divided into 6 phases (on the basis of increasing pairs of larval tentacles); furthermore an initial and a ripe phase are distinguished. Specific aspects of the development are described: Formation and structure of larval tentacles; anlage of adult tentacles as a thickening in the larval tentacle base; late development of the metasome (larva with 4–6 tentacles); formation of the metasome pouch in the larva with 8 tentacles; enlargement of the apical plate; differentiation of the gut; differentiation of larval nephridia; formation of pigment particles in the larva with 6 tentacles (storage function of pigments and its significance for larval identification); different types of discoflagella in various regions of the body. The larval development shows the following tendencies: Improvement of locomotion; intensification of food filtration; anlage of adult organs in the larva leading to a shortening of metamorphosis duration. The larva ofP. psammophila is compared with those ofP. pallida, P. hippocrepia, andP. vancouverensis. Earlier larval determinations ofP. psammophila (e.g.Actinotrocha sabatieri, A. hatschekii) are shown to have been mistakes. Termination of the postembryonic phase (metamorphosis) can be induced experimentally by bacteria and also by cations. Pure or mixed bacteria cultures must be present at the beginning exponential growth phase. The bacteria density required is 20–94×10⁶ bact.ml^?1 for pure cultures and on the average 28×10⁶ bact. ml^?1 for mixed cultures. Metamorphosis initiation by cations can be induced with CsCl (0.06 M) and RbCl (0.035 M). Metamorphosis ofP. psammophila occurs in 6 phases: larva, ready for metamorphosis; larva, activated by bacteria or ions; evagination of the metasome diverticle, dislocation of gut; losing and swallowing of episphaere and larval tentacles; formation of the youngP. psammophila. All developmental phases are described and compared with those ofP. muelleri; imperfect metamorphosis is characterized and the youngP. psammophila compared with older stages and the adult Phoronis.     

The evolution of hemolytic saponin content in wild and cultivated Alfalfa (Medicago sativa,Fabaceae)

Hemolytic saponin content was determined of the leaves of 1213 plants of different variants ofMedicago sativa s.l. (including wild and cultivated alfalfa), and a close ally,M. papillosa. The latter species had a much higher content than any of the groups ofM. sativa. Medicago sativa ssp. caerulea, the most important ancestor of alfalfa, had a very low content of hemolytic saponins. The most primitive forms of cultivated alfalfa examined, from Turkey, and wildM. sativa ssp. sativa of Turkey, also both had very low contents of hemolytic saponins. This is consistent with, and likely explained by, a direct origin of the two Turkish groups from sympatricM. sativa ssp.caerulea. The second most important ancestor of alfalfa,M. sativa ssp.falcata, had the highest content of any of the examined groups ofM. sativa. Modern “Western” (European, NorthAmerican) cultivars and Western ruderal populations had intermediate levels of hemolytic saponins. This is consistent with, and likely explained by, their origin by hybridization and introgression between the low saponin groups noted above andM. sativa ssp.falcata.     

Enhanced intestinal epithelial barrier health status on European sea bass (Dicentrarchus labrax) fed mannan oligosaccharides

The study assesses the effects of dietary mannan oligosaccharides (MOS) in European sea bass (Dicentrarchus labrax) posterior intestinal lipid class composition and its possible relation to the potential prostaglandins production and Gut Associated Lymphoid Tissue (GALT) stimulation.Fish were fed 4 g kg^?1 MOS (Bio-Mos^® Aquagrade, Alltech, Inc., USA) for eight weeks. Fish fed MOS presented higher (P ≤ 0.05) weight gain, total length, and specific and relative growth rates than fish fed the control diet. Stimulated posterior gut of fish fed MOS showed higher (P ≤ 0.05) prostaglandins production than fish fed the control diet. Lipid class analyses of posterior gut revealed a reduction (P ≤ 0.05) in the neutral lipid fraction in fish fed MOS compared to fish fed the control diet, particularly due to a reduction (P ≤ 0.05) in triacylglycerols content. The polar lipid fraction increased (P ≤ 0.05) in fish fed MOS compared to fish fed the control diet, mainly due to an increase (P ≤ 0.05) in phosphatidylethanolamine and phosphatidylcoline contents.Light microscopy of posterior gut revealed increased number or goblet cells as well as higher level of infiltrated eosinophilic granulocytes for fish fed MOS. Transmission electron microscopy qualitative observations revealed a better preserved cytoarchitecture of the intestinal epithelial barrier in the posterior gut of fish fed MOS. Posterior gut of fish fed MOS presented more densely packed non-damaged enterocytes, better preserved tight junctions structure, healthier and more organized microvilli, and a higher presence of infiltrated lymphocytes and granulocytes compared fish fed the control diet.The present study indicates that dietary MOS enhances European sea bass posterior gut epithelial defense by increasing membrane polar lipids content in relation to a stimulation of the eicosanoid cascade and GALT, promoting posterior gut health status.     

Isolation ofVibrio parahaemolyticus andVibrio cholerae (Non-O1 and O139) from moribund shrimp (Penaeus monodon) and experimental challenge study against post larvae and juveniles

Outbreak ofVibrio infection was reported from a shrimp farm near Chennai, south India. Both green and yellowVibrio were isolated from disease outbreak ofPenaeus monodon (Milne Edwards) culture farm and biochemically confirmed asVibrio parahaemolyticus andVibrio cholerae. Randomly selectedV. parahaemolyticus (VP1) andV. cholerae (VC1) were reconfirmed by partial 16S rRNA gene analysis. Both were tested against post larvae and juveniles ofP. monodon by bath challenge test and intramuscular injection respectively. The study revealed that VP1 is more virulent than VC1 isolated from same source againstP. monodon post larvae and juveniles. Phylogenetic tree based on comparison of partial 16S rRNA gene analysis revealed close relationship of VP1 with other shrimp pathogens likeVibrio harveyi andVibrio alginolyticus. There might be some close relationship for disease development among all these strains.     

A note on the feeding ofAmphichaeta leydigii (Oligochaeta,Naididae) in lacustrine sandy shores

The analysis of gut contents ofAmphichaeta leydigii, found for the first time in Italy in sandy shores of Lake Vico (Central Italy), proved grazing of the species on diatoms (Centrales and Pennales). Detritus and organic particles, abundant in the substratum, were observed only in small amounts.     

Antibacterial activity traceable to the marine blue green alga Trichodesmium erythraeum in the gastro-intestinal contents of two pelagic fishes

Summary The gastro-intestinal contents inHilsa kanagurta (Blkr.) andRastrelliger kanagurta (Cuv). were found to possess antibacterial activity. This could be traced to heavy accumulation ofTrichodesmium erythraeum in the gut. The bloom ofT. erythraeum started this year (1969) about the middle of February and attained a peak during the second week of March. During this period it was found that about 60 to 70 per cent of the fish catches in the inshore waters consistedH. kanagurta andR. kanagurta. Analysis of gut contents of six specimens of each of these two species showed thatT. erythraeum constituted 80 to 90 per cent of the contents. It has been reported previously by the author thatT. erythraeum maintained in cultures in the laboratory and also collected from the sea possesses antibacterial properties. In view of this finding, standard experimental procedures were adopted to determine whether extracts ofT. erythraeum occurring in the gut of the fishes examined also possessed antibacterial activity. It was found thatT. erythraeum collected from the gut ofHilsa andRastrelliger could inhibit both gram-positive and gram-negative bacteria. The gastro-intestinal extract ofHilsa kanagurta andRastrelliger kanagurta collected during nonbloom period ofTrichodesmium showed heavy bacterial and fungal growth. Evidently antibacterial or sterile conditions prevail in the guts of these fishes in a manner similar to what has been observed in polar marine animals by Sieburth (1959 and 1961).     

Morphological,chemical, and cytogenetic characters of F1 hybrids betweenParthenium argentatum (Guayule) andP. fruticosum var.fruticosum (Asteraceae) and their potential in rubber improvement

Interspecific hybrids betweenParthenium argentatum, the guayule rubber plant, andP. fruticosum var. fruticosum were evaluated for their potential rubber content and quality. Fifteen-mo-old field-grown plants ofP. fruticosum var.fruticosum measured four times more in height and spread than those ofP. argentatum, but contained less than 0.05% rubber of low mol wt.Parthenium argentatum showed 2% rubber content, with a mol wt of about one million. Resin contents varied little among parents or hybrids. The same age F₁ hybrids were intermediate in height and spread and had low rubber content, but showed presence of high mol wt rubber like the guayule parent. This indicates that high mol wt rubber is expressed over the low mol wt rubber in F₁ hybrids. Despite low rubber content but favorable biomass production, F₁ hybrids revealed irregular meiotic chromosome behavior and low pollen and seed germination. These results suggest that interspecific F₁ hybrids may be used in backcross programs to increase biomass and rubber content in guayule.     

A new species ofMesopropithecus (Primates,Palaeopropithecidae) from Northern Madagascar

We diagnose new subfossil specimens belonging to the extinct palaeopropithecid, Mesopropithecus,from several caves at the Ankarana massif in northern Madagascar. They include three partial crania with mandibles, and the first vertebrae, ribs, clavicle, pelvis, ulna, and hand and foot bones of Mesopropithecusever found. Several other postcranial elements are known for this northern variant of Mesopropithecusand for previously described species from central and southern Madagascar. The new materials cannot be accommodated in either currently recognized species of this genus and are,hereby, given the name Mesopropithecus dolichobrachion. M. dolichobrachionis the second new species of extinct subfossil lemur to be found in the caves of Ankarana. It is unlike the two previously described species of this genus primarily in its larger size, different limb proportions, and aspects of its long bone morphology. Most notable is the fact that this is the only species of Mesopropithecuswith the forelimb longer than the hind limb— hence the name, the “long-armed” Mesopropithecus.Various characteristics place M. dolichobrachionphenetically closest (of species belonging to Mesopropithecus)to Babakotia radofilai, Archaeoindris,and Palaeopropithecus.If these similarities are derived specializations rather than primitive for palaeopropithecids, a new generic name will be required.     

Reduced gut bacterial translocation in European sea bass (Dicentrarchus labrax) fed mannan oligosaccharides (MOS)

The objective of this study was to determine the effect of mannan oligosaccharides derived from the outer cell wall of a select strain of Saccharomyces cerevisiae (Bio-Mos, Alltech Inc, USA) on mucus production, selected mucus immune parameters activity, gut morphology and in vivo and ex vivo gut bacterial translocation for European sea bass (Dicentrarchus labrax). Specimens were fed 4 g kg^?1 dietary MOS level of inclusion in a commercial sea bass diet for eight weeks. At the end of this period, anterior gut mucosal folds height, width and folds surface area were increased by MOS supplementation (P < 0.05, n = 240). Posterior gut presented shorter folds (P < 0.05, n = 240) but wider that those fed control diet (P < 0.05, n = 240) resulting in increased total surface area (P < 0.05, n = 240). For rectum, feeding MOS reduced fold length (P < 0.05, n = 240). Gut morphological analyses showed an enhancement in the number of cells secreting acid mucins by area unit, higher density of eosinophilic granulocytes (ECGs) in the mucosa for fish fed MOS together with an improvement in gut mucus lysozyme activity which could be related to the reduced in vivo and ex vivo gut bacterial translocation found. No differences were found for the skin mucus immune parameters evaluated.     

A skull ofCyamodus kuhnschnyderi Nosotti &Pinna 1993, from the Muschelkalk of wasselonne (Alsace, France)

A partial skull from the upper Muschelkalk (mo3,praenodosus to lowernodosus Zone) of Wasselonne (Alsace, France) is described and identified as third specimen ofCyamodus kuhnschnyderi. The dentition of all species currently included in the genusCyamodus is discussed, and instances of individual variation are identified. In contrast to the type material, the new specimen ofCyamodus kuhnschnyderi has two pairs of premaxillary teeth, and thus adds incongruence to the stratophenetic trend of dental reduction previously identified within the genusCyamodus.     

Feeding ecology ofBranchinecta gaini (crustacea: Anostraca) in ponds of south Shetland Islands,Antarctica

The feeding habits and food selectivity ofBranchinecta gaini were studied in six ponds on an Antarctic island.B. gaini behaves as a detritovorous, herbivorous filter-feeder, feeding largely on organic sediments and bottom communities. The bulk of the gut contents were formed from amorphous organic material presumably of vegetal origin, and a great variety of organisms from algae to remains of larval stages of Diptera. Filamentous algae were negatively selected but hyphae and spores, as well as remains ofB. gaini, were positively selected.     

Endosymbiotic and Host Proteases in the Digestive Tract of the Invasive Snail Pomacea canaliculata: Diversity,Origin and Characterization

Digestive proteases of the digestive tract of the apple snail Pomacea canaliculata were studied. Luminal protease activity was found in the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Several protease bands and their apparent molecular weights were identified in both tissue extracts and luminal contents by gel zymography: (1) a 125 kDa protease in salivary gland extracts and in the crop content; (2) a 30 kDa protease throughout all studied luminal contents and in extracts of the midgut gland and of the endosymbionts isolated from this gland; (3) two proteases of 145 and 198 kDa in the coiled gut content. All these proteases were inhibited by aprotinin, a serine-protease inhibitor, and showed maximum activity between 30°C and 35°C and pH between 8.5 and 9.5. Tissue L-alanine-N-aminopeptidase activity was determined in the wall of the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Our findings show that protein digestion in P. canaliculata is carried out through a battery of diverse proteases originated from the salivary glands and the endosymbionts lodged in the midgut gland and by proteases of uncertain origin that occur in the coiled gut lumen.     

Determination of the ploidy level in the genusHieracium subgenusPilosella (Hill) S.F. Gray by flow cytometric DNA analysis

Ploidy levels of 8 taxa of the genusHieracium subgenusPilosella collected from the same locality were determined by means of flow cytometric estimation of relative nuclear DNA content. The DNA anaysis of isolated nuclei stained with propidium iodide was performed with a flow cytometer equipped with an argon-ion laser. The diploid speciesH. lactucella (2n=18) was used as internal standard. As a rule 20 individuals per taxon were analysed. The flow cytometric analysis proved to be a rapid, accurate and sensitive method for screening of ploidy levels. Considering the known cytological data, the following ploidy levels were determined:H. aurantiacum 4x,H. pilosella 4x,H. piloselloides 4x,H. bauhini 5x,H. caespitosum 5x,H. stoloniflorum 4x,H. brachiatum 4x and 6x,H. leptophyton 7x.H. piloselloides, H. bauhini andH. caespitosum yield relative DNA contents which are the exact multiples of the haploid DNA content ofH. lactucella. In the case ofH. pilosella the haploid DNA content is lower than that predicted from the diploid, namely 0.43 instead of the expected 0.5. The haploid 1x DNA contents of bothH. brachiatum andH. leptophyton range between the value found forH. pilosella and those for the other investigated species, confirming their hybrid origin.     

Changes in the West Indian operculina (Convolvulaceae)

Two West Indian names inOperculina are briefly discussed and compared with the Old WorldO. turpethum (L.) S. Manso. The conclusions are made thatO. triquetra (Vahl) H. Hallier is a taxonomic synonym ofO. turpethum and thatO. ventricosa (Bertero) Peter may best be considered a variety ofO. turpethum. Typification ofOperculina is discussed, and it is found that, although S. Manso had a mixed concept ofO. turpethum, this species must be the type of the genus.     

The Gastrointestinal Tract of the White-Throated Woodrat (Neotoma albigula) Harbors Distinct Consortia of Oxalate-Degrading Bacteria

The microbiota inhabiting the mammalian gut is a functional organ that provides a number of services for the host. One factor that may regulate the composition and function of gut microbial communities is dietary toxins. Oxalate is a toxic plant secondary compound (PSC) produced in all major taxa of vascular plants and is consumed by a variety of animals. The mammalian herbivore Neotoma albigula is capable of consuming and degrading large quantities of dietary oxalate. We isolated and characterized oxalate-degrading bacteria from the gut contents of wild-caught animals and used high-throughput sequencing to determine the distribution of potential oxalate-degrading taxa along the gastrointestinal tract. Isolates spanned three genera: Lactobacillus, Clostridium, and Enterococcus. Over half of the isolates exhibited significant oxalate degradation in vitro, and all Lactobacillus isolates contained the oxc gene, one of the genes responsible for oxalate degradation. Although diverse potential oxalate-degrading genera were distributed throughout the gastrointestinal tract, they were most concentrated in the foregut, where dietary oxalate first enters the gastrointestinal tract. We hypothesize that unique environmental conditions present in each gut region provide diverse niches that select for particular functional taxa and communities.     

The selection and ingestion of epilithic algae byNais elinguis (Oligochaeta: Naididae)

The gut contents ofNais elinguis in an organically polluted river were dominated by epilithic chlorophycean unicells and pennate diatoms with an average cell volume of 1.3 × 10³ µm³. The worm unselectively and opportunistically ingested unicellular algae up to a maximum length of 196 µm and a maximum volume of 24 × 10³ µm³, but colonial and filamentous algae were discriminated against. The morphometry of the pharynx ofN. elinguis probably determined the maximum size of algal cells which could be ingested.     

Functional and translational analyses of a beta-glucosidase gene (glycosyl hydrolase family 1) isolated from the gut of the lower termite Reticulitermes flavipes

This research focused on digestive beta-glucosidases from glycosyl hydrolase family (GHF) 1 from the gut of the lower termite Reticulitermes flavipes. In preceding studies on R. flavipes, we characterized beta-glucosidase activity across the gut and its inhibition by carbohydrate-based inhibitors, and subsequently we identified two partial beta-glucosidase cDNA sequences from a host gut cDNA library. Here, we report on the full-length cDNA sequence for one of the R. flavipes beta-glucosidases (RfBGluc-1), the expression of its mRNA in the salivary gland and foregut, the production of recombinant protein using a baculovirus–insect expression system, optimal recombinant substrate specificity profiles and parameters, and significant inhibition by the established beta-glucosidase inhibitor cellobioimidazole. We also report the partial cDNA sequence for a second gut beta-glucosidase (RfBGluc-2), and show that like RfBGluc-1 its mRNA is localized mainly in the salivary gland. Other results for RfBGluc-1 showing activity against laminaribose, a component of microbial cell walls, suggest that RfBGluc-1 may serve dual functions in cellulose digestion and immunity. These findings provide important information that will enable the testing of hypotheses related to collaborative host–symbiont lignocellulose digestion, and that contributes to the development of next-generation termiticides and novel biocatalyst cocktails for use in biomass-to-bioethanol applications.     

Gut contents in field sampled adults ofCoccinella septempunctata (Col.: Coccinellidae)

During two years adultCoccinella septempunctata L. were sampled at two localities in cereals and at another location throughout the whole year in different habitats. Frequency of different food types was recorded using gut dissection. Food remains were classified into aphids, other arthropods, fungal spores, pollen, soil particles. Soil particles were relatively frequent only in early spring and pollen in late summer, whereas fungal spores were most frequent in both these periods. During ladybird reproduction in winter wheat, aphid remains were present in 76.9–91.7% of all individuals and surprisingly spores were again more frequent than remains of other arthropods. Cannibalism was rare. Food ofC. septempunctata was very uniform, because nearly always the same spores (Alternaria sp.) and other arthropods (Thysanoptera) were found. Additionally a semiquantitative analysis was performed with a simple scale of gut fullness. Only in certain cases significant positive correlation were determined between aphid density in the field and the calculated “feeding state” as well as frequency of aphid remains.     

A pre-leptocephalus larva ofConger myriaster (family Congridae) collected from Suruga Bay,Central Japan

One specimen of leptocephalus larva, measuring 16.0 mm in total length, was collected from the northern part of Suruga Bay (34°56′N, 138°39′E) by the T/V Bosei Maru II of Tokai University on November 7, 1982. This larva is identified asConger myriaster because of having melanophores under the eye, simple gut with melanophores, 142 total number of myomeres and the position of the last vertical blood vessel at the 52nd myomere. Judging from the body length, appearances of teeth and fins, and disposition of the anus, the present larva belongs to the preleptocephalus stage. The presence of this early larva in this area suggests that one of the spawning grounds ofC. myriaster exists in or near Suruga Bay in autumn.     

Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria

The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV). Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135) and 113(103) genera were found in the gut content of the healthy control female (male) larvae and BmCPV-infected female (male) larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.