Bioerosion of siliceous rocks driven by rock-boring freshwater insects

Macrobioerosion of mineral substrates in fresh water is a little-known geological process. Two examples of rock-boring bivalve molluscs were recently described from freshwater environments. To the best of our knowledge, rock-boring freshwater insects were previously unknown. Here, we report on the discovery of insect larvae boring into submerged siltstone (aleurolite) rocks in tropical Asia. These larvae belong to a new mayfly species and perform their borings using enlarged mandibles. Their traces represent a horizontally oriented, tunnel-like macroboring with two apertures. To date, only three rock-boring animals are known to occur in fresh water globally: a mayfly, a piddock, and a shipworm. All the three species originated within primarily wood-boring clades, indicating a simplified evolutionary shift from wood to hardground substrate based on a set of morphological and anatomical preadaptations evolved in wood borers (e.g., massive larval mandibular tusks in mayflies and specific body, shell, and muscle structure in bivalves)

Investigation of Relationships in the Children's Team in the Process of Sports Gaming

The article presents the results of studying the children's readiness (in the age of 5-7 years old) to interact with peers and adults in the elementary sports and gaming activities. The study was carried out within the framework of the pilot program of the Russian Academy of Education, based on the pre-school educational institutions in the city of Belgorod. To study the relationship in the children's team we used observation, sociometric technique, and diagnostic game situation. The analysis of results obtained showed the presence of problems of readiness to interact with peers and the formation of a communicative component of social experience in children in the age of 5-7 years old. Namely: insufficient level of children's independence, limited ideas about the possibility of using the sports and gaming activities in their own experience, low level of social and normative behavior. The results of the study confirmed the data previously presented in the publications on the growth in the number of preschool children not capable to interpersonal interaction

Assessment of Caspian Seal By-Catch in an Illegal Fishery Using an Interview-Based Approach.

The Caspian seal (Pusa caspica) has declined by more than 90% since 1900 and is listed as endangered by IUCN. We made the first quantitative assessment of Caspian seal by-catch mortality in fisheries in the north Caspian Sea by conducting semi-structured interviews in fishing communities along the coasts of Russia (Kalmykia, Dagestan), Kazakhstan and Turkmenistan. We recorded a documented minimum by-catch of 1,215 seals in the survey sample, for the 2008-2009 fishing season, 93% of which occurred in illegal sturgeon fisheries. Due to the illegal nature of the fishery, accurately quantifying total fishing effort is problematic and the survey sample could reflect less than 10% of poaching activity in the north Caspian Sea. Therefore total annual by-catch may be significantly greater than the minimum documented by the survey. The presence of high by-catch rates was supported independently by evidence of net entanglement from seal carcasses, during a mass stranding on the Kazakh coast in May 2009, where 30 of 312 carcasses were entangled in large mesh sturgeon net remnants. The documented minimum by-catch may account for 5 to 19% of annual pup production. Sturgeon poaching therefore not only represents a serious threat to Caspian sturgeon populations, but may also be having broader impacts on the Caspian Sea ecosystem by contributing to a decline in one of the ecosystem's key predators. This study demonstrates the utility of interview-based approaches in providing rapid assessments of by-catch in illegal small-scale fisheries, which are not amenable to study by other methods

Map of northern Caspian showing settlements in which interviews were conducted (triangles), by-catch sectors.

<p>(UR - Ural; KU - Kulaly; KA – Kalmykia; DA – Dagestan; delimited by lines).</p

Comparison of by-catch rates (seals/boat/season) among seasons.

<p>N – number of reports with quantitative data; Winter-Spring: February-April; Autumn: September-November; Mean, Median and SD (standard deviation), refer to seals/boat/season; Range refers to reported minimum by-catch in the sample.</p

Breakdown of minimum reported by-catch in 2008–2009 by area and season.

<p>N – number of reports with quantitative data; Winter-Spring: February-April; Autumn: September-November; autumn-spring: fishing in either September-November, or after ice melt, but exact period not given; Not specified: no season information given by interviewee.</p

Results of fishermen interviews on seal by-catch in 2009 including reports of usage of different types of fishing gear, by-catch and hunting, seal depredation and usage of seal products.

<p>Results of fishermen interviews on seal by-catch in 2009 including reports of usage of different types of fishing gear, by-catch and hunting, seal depredation and usage of seal products.</p

Discovery of a silicate rock-boring organism and macrobioerosion in fresh water

Macrobioerosion is a common process in marine ecosystems. Many types of rock-boring organisms break down hard substrates, particularly carbonate rocks and calcareous structures such as dead corals and shells. In paleontology, the presence of rocks with boreholes and fossil macroboring assemblage members is one of the primary diagnostic features of shallow marine paleo-environments. Here we describe a silicate rock-boring organism and an associated community in submerged siltstone rock outcrops in Kaladan River, Myanmar. The rock-boring mussel Lignopholas fluminalis is a close relative of the marine piddocks, and its borings belong to the ichnospecies Gastrochaenolites anauchen. The neotectonic uplift of the area leading to gradual decrease of the sea level with subsequent shift from estuarine to freshwater environment was the most likely driver for the origin of this community. Our findings highlight that rocks with macroborings are not an exclusive indicator of marine paleo-ecosystems, but may also reflect freshwater habitats

Discovery of a silicate rock-boring organism and macrobioerosion in fresh water

International audienceMacrobioerosion is a common process in marine ecosystems. Many types of rock-boring organisms break down hard substrates, particularly carbonate rocks and calcareous structures such as dead corals and shells. In paleontology, the presence of rocks with boreholes and fossil macroboring assemblage members is one of the primary diagnostic features of shallow marine paleo-environments. Here we describe a silicate rock-boring organism and an associated community in submerged siltstone rock outcrops in Kaladan River, Myanmar. The rock-boring mussel Lignopholas fluminalis is a close relative of the marine piddocks, and its borings belong to the ichnospecies Gastrochaenolites anauchen. The neotectonic uplift of the area leading to gradual decrease of the sea level with subsequent shift from estuarine to freshwater environment was the most likely driver for the origin of this community. Our findings highlight that rocks with macroborings are not an exclusive indicator of marine paleo-ecosystems, but may also reflect freshwater habitats