Tube-dwelling in early animals exemplified by Cambrian scalidophoran worms

Background The radiation of ecdysozoans (moulting animals) during the Cambrian gave rise to panarthropods and various groups of worms including scalidophorans, which played an important role in the elaboration of early marine ecosystems. Although most scalidophorans were infaunal burrowers travelling through soft sediment at the bottom of the sea, Selkirkia lived inside a tube. Results We explore the palaeobiology of these tubicolous worms, and more generally the origin and evolutionary significance of tube-dwelling in early animals, based on exceptionally preserved fossils from the early Cambrian Chengjiang Lagerstätte (Stage 3, China) including a new species, Selkirkia transita sp. nov. We find that the best phylogenetic model resolves Selkirkia as a stem-group priapulid. Selkirkia secreted a protective cuticular thickening, the tube, inside which it was able to move during at least part of its life. Partly based on measured growth patterns, we construe that this tube was separated from the trunk during a moulting process that has no direct equivalent in other scalidophorans. Although the ontogeny of Selkirkia is currently unknown, we hypothesize that its conical tube might have had the same ecological function and possibly even deep development origin as the lorica, a protective cuticular thickening found in larval priapulids and adult loriciferans. Selkirkia is seen as a semi-sedentary animal capable of very shallow incursions below the water/sediment interface, possibly for feeding or during the tube-secreting phase. Brachiopod epibionts previously reported from the Xiaoshiba Lagerstätte (ca. 514 Ma) also presumably occur in Selkirkia sinica from Chengjiang (ca. 518 Ma). Conclusions Our critical and model-based approach provides a new phylogenetic framework for Scalidophora, upon which to improve in order to study the evolution of morphological characters in this group. Tube-dwelling is likely to have offered Selkirkia better protection and anchoring to sediment and has developed simultaneously in other Cambrian animals such as hemichordates, annelids or panarthropods. Often lost in modern representatives in favour of active infaunal lifestyles, tube-dwelling can be regarded as an early evolutionary response of various metazoans to increasing environmental and biological pressure in Cambrian marine ecosystems.

Shanshar-Asarshyq arheologııalyq kesheninde júrgіzіlgen barlaý jumystarynyń nátıjelerі [The Results of Research Work in the Archaeological Complex Shanshar-Asarshyk]

The article discusses a new scientific concept made in the course of the excavation and the results of exploration at the archaeological complex of Shanshar-Asarshyk. It provides data on the existence of people during the Paleolithic and iron age and their occupation of sedentary animal husbandry and nomadic cattle breeding. The collected ceramics were analyzed from a macroscopic point of view and described. The found ceramic objects were compared with ceramic objects from other places and the corresponding conclusions were made. In addition, The Shanshar-Asarshyk settlement was compared with other cities in Central Asia and its architectural features and structure were revealed. With the help of the discovered material data, a predictive Dating of the monument was made. The article substantiates the necessity of conducting archeological excavations in the archaeological complex of Shanshar-Asarshyk. Мақалада Шаншар-Асаршық археологиялық кешенінде жүргізілген барлау нәтижелері мен қазба жұмыстары барысында жасалған жаңа ғылыми тұжырымдамалар сөз болады. Бұл жерде адамдардың палеолит және темір дәуірі кезінде өмір сүргені және отырықшы мал шаруашылығы мен көшпенді мал шаруашылығы кәсібімен айналысқандығы туралы деректер айтылады. Жиналған керамикалар макраскопиялық тұрғыдан сарапталып, талдау жүргізіліп, сипаттамасы жасалынды. Табылған керамикалық заттар басқа жердегі керамикалық заттармен салыстырылып, тұжырымдамалар жасалынды. Сонымен қатар Шаншар-Асаршық қалажұрты Орта Азиядағы басқа қалалармен салыстырылып, архитектуралық ерекшелігі мен құрылымы айқындалды. Табылған заттай деректер арқылы ескерткіштің болжамды мерзімдемесі жасалынды. Мақалада Шаншар-Асаршық археологиялық кешенінде археологиялық қазба жұмыстарының жүргізілу қажеттіліктері айтылды.

The Concentration of Lead in Windowpane Oyster (Placuna placenta) and Potential of Condition Index as a Morphological Biomarker to Detect Metal Pollution

As a filter feeder, windowpane oyster, Placuna placenta, which lives as a sedentary animal is very appropriate to be used as an eco-sentinel organism in marine bio-monitoring campaign. The study of lead (Pb) content in the tissue and shell of P. placenta was conducted in coastal waters of Mandalle, Pangkajene Kepulauan District, South Sulawesi. A hundred of oysters were collected from coastal waters of Mandalle. Morphometry parameters which were length, high, width, and dry weight of tissue were measured in the laboratory. Those parameters were used for determination of Condition Index (CI). Metal was analyzed by Atomic Absorption Spectrometry. The results showed that the contents of Pb in tissue and shell were 0.021 and 0.014 mg/kg DW (dry weight) respectively. The concentration of Pb in tissue was not overreach by BPOM 2009 Number Hk.00.06.1.52.4011 of 1.5 mg / kg DW (dry weight). After calculating Maximum Tolerable Intake (MTI), we found that MTI was 7.79 kg/day. In terms of marine monitoring campaign, we can theoretically use the CI as a morphological biomarker. After calculating the relationship between Pb in tissue and shell, we found that the value of CI was not correlated significantly with Pb content in tissue and shell. However, the correlation coefficient between Pb in tissue and CI was stronger than that in the shell. The potential of CI of windowpane oyster as a morphological biomarker was discussed.Keywords: Placuna placenta, lead, MTI, morphological biomarker

Physical Activity Increases the Total Number of Bone-Marrow-Derived Mesenchymal Stem Cells, Enhances Their Osteogenic Potential, and Inhibits Their Adipogenic Properties

Aging and sedentary lifestyle are common nowadays and are associated with the increasing number of chronic diseases. Thus, physical activity is recommended as one of three healthy behavior factors that play a crucial role in health prophylaxis. In the present study, we were interested whether physical activity influences the number and potential of bone-marrow-derived mesenchymal stem cells BMMSCs. In this study, four-week-old male C57Bl/6 mice were trained on a treadmill at progressive speeds over a 5-week period. Comparisons made between exercised (EX) and sedentary animal groups revealed (i) significantly higher number of MSCs in EX animals, (ii) elevated alkaline phosphatase (ALP) activity, (iii) increased level of osteopontin (OPN) and osteocalcin (OCL), and (iv) reduced marrow cavity fat. The results obtained support the thesis that EX may play a substantial role in the regeneration of mesenchymal tissues. Therefore, EX may represent a novel, nonpharmacological strategy of slowing down age-related decline of the musculoskeletal functions.

Sessile and sedentary macrofauna from the Pirapama Shipwreck, Pernambuco, Brazil

Shipwrecks are considered artificial reef environments - structures immersed in aquatic environments (especially marine ones) that provide fauna with shelter, hard substrates, food and nursery areas. This study aimed to survey the benthic animal biodiversity of the Pirapama shipwreck, located 23 m deep and six miles off Recife harbor. From 2001 to 2007, species were observed, photographed and collected through scuba diving. The material was later sorted and identified in the laboratory. A total of 76 sessile and sedentary animal taxa were recorded belonging to the following phyla: Porifera (Demospongiae and Calcarea), Cnidaria (Hydrozoa and Anthozoa), Mollusca (Bivalvia and Gastropoda), Annelida (Polychaeta), Arthropoda (Cirripedia), Bryozoa (Gymnolaemata), Echinodermata (Asteroidea and Echinoidea), and Chordata (Ascidiacea). The greatest richness was for Porifera and Bryozoa - 13 listed species for each. Eleven new occurrences were recorded for the state of Pernambuco, the hydroid Halopteris polymorpha and ten bryozoan species, one of them being the first record for Brazil (Scrupocellaria curacaoensis). The Pirapama's biodiversity was considered typical when compared to other shipwrecks that have been studied around the world.

Reinterpretation of Climactichnites Logan 1860 to include subsurface burrows, and erection of Musculopodus for resting traces of the trailmaker

Based on a thorough examination of field and museum Climactichnites specimens, two species of this trace are recognized, each representing a unique behavioral variant produced by a soft-bodied animal in Late Cambrian intertidal environments. C. wilsoni represents surface-produced trails, whereas C. youngi is re-erected for burrows produced below the surface. Burrowing behavior is supported by: 1) the presence of C. youngi within, rather than on, the surface of beds; 2) the orientation of some burrows inclined to bedding; and 3) the occasional presence of distinct burrow fills. Burrows can also be distinguished morphologically from surface traces by the absence of lateral ridges and the presence of fine, mm-scale striations or grooves superimposed on the transverse bars and furrows. Burrowing behavior for the Climactichnites trailmaker was previously unknown and thus represents a new, although not entirely unexpected, behavior for this mollusk or mollusk-like animal. The body impression of the sedentary animal is removed to Musculopodus sedentarius n. igen. and isp. In the future, Musculopodus may be expanded to include the resting traces of other soft-bodied animals known from the fossil record. Currently, Climactichnites is known only from very shallow to emergent strata of North America; reports of this fossil in other parts of the world are misidentified trails produced by other animals.

Billings' second operculum: a late Early Ordovician Maclurites (Gastropoda) from western Newfoundland and the Canadian Arctic

An operculum of Maclurites, first described by Billings in 1865, is redescribed from the original material collected at Cape Norman, northwestern Newfoundland, and from additional specimens from Ellesmere Island, Canadian Arctic. Based on indirect evidence, a very late to latest Early Ordovician age is assigned to the strata of the St. George Group that contains this fossil. This operculum has a paleoequatorial distribution. On the basis of its geometry, the operculum is interpreted as having a "concentric" growth pattern rather than a spiral one. If so, the complex coiling pattern assumed for Maclurites may be in error. Speculation on functional morphology explains the shape of the operculum without recourse to any assumed coiling during growth and reinforces the interpretation of Maclurites as an exceedingly sedentary animal.

Effect of a mild exercise program on myocardial function and the development of hypertrophy

Cardiac function and the development of myocardial hypertrophy were studied in rats conditioned by an exercise program consisting of 8 wk of running on a treadmill. At the end of the training period a group of exercised and sedentary rats was subjected to hemodynamic evaluation under general anesthesia. Except for a slight elevation in the heart rates of the exercised animals there were no significant differences between the exercised and sedentary rats at rest. Following an increase in afterload or a period of hypoxia, the cardiac index of the exercised animals remained significantly higher than that of the sedentary controls. These differences were related to changes in stroke volume. Another group of exercised and sedentary animals underwent either constriction of the ascending aorta or a sham operation. Sedentary rats developed significant hypertrophy at 3 days but had no hypertrophy at 1 day after aortic constriction. Exercised rats, however, developed significant myocardial hypertrophy by 1 day after pressure overload. These data suggest that the heart from an exercised animal is better able to tolerate increases in afterload and hypoxia and can respond with compensatory myocardial hypertrophy more rapidly than the heart of a sedentary animal.

Oxygen dissociation curves of the blood of larval and adult lampreys (Lampetra fluviatilis)

1. An electrolytic method was used to plot the oxygen dissociation curves of whole blood from both the larva and adult of the lamprey Lampetra fluviatilis at a temperature of 10 degrees C and over a pH range of 6-5-8-1. 2. Larval blood has a far higher affinity for oxygen than that of adults, the respective calculated P50's at a pH of 7–75 being 1-9 and 10-7 mmHg. 3. The high affinity of larval blood is of use to a relatively sedentary animal living in burrows, and the increased oxygen delivery pressure brought about by the shift of the curve to the right in the adult is of advantage to an animal exhibiting greater activity. 4. The n value obtained from the Hill plots increased with increasing saturation and were lower in larvae than adults at the same level of blood saturation. 5. The Bohr effect in larvae at 10 degrees C over the pH range 6-5-8-1 was --0-25, a value which did not differ significantly from the −0-22 found in adults.

Some parameters of growth in the common intertidal barnacle, Balanus balanoides (L.)

It is difficult to determine the weight or nitrogen content of the living tissues of an operculate barnacle without destroying it. It has been customary, there-fore, in ecological work to express growth in terms of various parameters determined from repeated measurements of the shell. Moore (1934) employed shell volume calculated from the height and basal diameters; others (Costlow & Bookhout, 1953, 1956; Mawatari, Hirosaki & Kobayashi, 1954a, b) have used the area of the basis. Most commonly, however, in growth-rate studies the length of the basis measured through the rostro-carinal axis has been used (Hatton, 1938; Barnes & Powell, 1953). Recently, working with animals cultured in the laboratory when the cast of an individual could be obtained subsequent to ecdysis, Costlow & Bookhout (1957) have used the size of the mouthparts as a measure of growth after first establishing their relation to body size. The space, both areal and volumetric, occupied by a sedentary animal is of primary importance in studies of its ecology and measurements of shell-size are, therefore, adequate for many purposes. For some aspects of growth and ecology it is, nevertheless, very desirable that the relation between such parameters and others, more directly connected with the living material, should be established.