Rhizobium lacunae sp. nov., Isolated From a Freshwater Pond

Bacterial strain designated CSW-27T was isolated from a freshwater pond in Taiwan. Cells were Gram-stain-negative, aerobic, oxidase-positive, catalase-negative, rod-shaped and motile by flagella. Strain CSW-27T grew at 20-40 oC (optimum, 30-37 oC), at pH 5-9 (optimum, pH 6-7) and in the presence of 0-4% NaCl (optimum, 0%). Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set revealed that strain CSW-27T was affiliated with species in the genus Rhizobium. Analysis of 16S rRNA gene sequences showed that strain CSW-27T had the highest similarity to Rhizobium straminoryzae CC-LY845T (98.5%) followed by Rhizobium capsici CC-SKC2T (96.9%). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain CSW-27T and the closely related Rhizobium species were 73.4-86.5, 66.0-88.8 and 13.3-22.1%, respectively. The principal fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, one uncharacterized aminophospholipid, three uncharacterized aminolipids and two uncharacterized lipids. The predominant polyamine was spermidine. The major isoprenoid quinone was Q-10. Genomic DNA G+C content of strain CSW-27T was 63.3%. These polyphasic taxonomic data indicited that strain CSW-27T should be considered as representing a novel species in the genus Rhizobium, for which the name Rhizobium lacunae sp. nov. is proposed with strain CSW-27T (=BCRC 81244T =LMG 31684T) as the type strain.

Environmental Accounting of the Yellow-Tail Lambari Aquaculture: Sustainability of Rural Freshwater Pond Systems

Freshwater pond aquaculture is the prevailing fish culture system worldwide, especially in developing countries. Climate change outcomes and inadequate environmental practices challenge its sustainability. This study applies emergy synthesis to assess the environmental performance of freshwater pond aquaculture in Brazil, aiming to identify and propose practices towards sustainability. As a study model, nine semi-intensive lambari farms operating at three levels of management were evaluated: low (LC), moderate (MC) and high (HC) control. Results showed that the main inputs for LC were services (27-46%), feed (7-39%), and water (15-21%), while for the MC and HC farms, they were feed (35-49% and 17-48%, respectively) and services (33-39% and 26-36%, respectively). All farms required more than 60% of their emergy from purchased inputs, resulting in low emergy sustainability index (ESI = 0.1-0.5). Replacing animal protein and oil on diet composition by vegetal sources, using superficial water instead of springwater, increasing juvenile productivity, and controlling pond fertilization can lead all systems to higher efficiency and resilience, increasing sustainability.

ROBOT APUNG PEMBERI PAKAN IKAN KOLAM AIR TAWAR BERBASIS ARDUINO

The need for fish is increasing every year. Because it is increasing every year, fish farming must be increased in line with the use of improved fish farming technology. So that it requires an adequate technological structure and mechanization. Based on this background, the arduino-based floating robot for feeding freshwater pond fish is designed to be able to apply technology that is useful in feeding farmed fish. The arduino based floating robot fish feeding freshwater fish pond using Arduino Mega 2560 as its microcontroller, 4 Sharp 2Y0A21 sensors that function to detect pond walls, RTC functions as a timer so that it can feed fish according to the time set on the tool, LCD functions as the information viewer of the tool, the L298N motor driver controls the DC motor and the servo motor functions as the opening or closing of the food valve on the appliance. In the test, the arduino based floating robot fish feeding freshwater fish pond is able to float in water and can feed fish based on the time available on the tool. The Sharp 2Y0A21 sensor as a pool wall detector has a distance reading in the range of 1 millimeter to 10 centimeter. The robot can avoid the pool wall with a span of 3 - 7 seconds, this is influenced, among others, by surging water, wind, sensor response, and DC motors.

The influence of a lost society, the Sadlermiut, on the environment in the Canadian Arctic

High latitude freshwater ecosystems are sentinels of human activity and environmental change. The lakes and ponds that characterize Arctic landscapes have a low resilience to buffer variability in climate, especially with increasing global anthropogenic stressors in recent decades. Here, we show that a small freshwater pond in proximity of the archaeological site “Native Point” on Southampton Island (Nunavut, Arctic Canada) is a highly sensitive environmental recorder. The sediment analyses allowed for pinpointing the first arrival of Sadlermiut culture at Native Point to ~ 1250 CE, followed by a dietary shift likely in response to the onset of cooling in the region ~ 1400 CE. The influence of the Sadlermiut on the environment persisted long after the last of their population perished in 1903. Presently, the pond remains a distorted ecosystem that has experienced fundamental shifts in the benthic invertebrate assemblages and accumulated anthropogenic metals in the sediment. Our multi-proxy paleolimnological investigation using geochemical and biological indicators emphasizes that direct and indirect anthropogenic impacts have long-term environmental implications on high latitude ecosystems.

Integrative Studies on a New Ciliate Campanella sinica n. sp. (Protista, Ciliophora, Peritrichia) Based on the Morphological and Molecular Data, With Notes on the Phylogeny and Systematics of the Family Epistylididae

During an investigation on freshwater peritrichs, a new colonial sessilid ciliate, Campanella sinica n. sp., was isolated from aquatic plants in an artificial freshwater pond in Qingdao, China. Specimen observations of this species were performed both in vivo and using silver staining. C. sinica n. sp. is characterized by the appearance of the mature colony, which is up to 2 cm high and contains more than 1,000 zooids, the asymmetric horn-shaped zooids, strongly everted and multi-layered peristomial lip, the slightly convex peristomial disc, and the well-developed haplokinety and polykinety, which make more than four circuits of the peristome before descending into the infundibulum. The small subunit ribosomal DNA (SSU rDNA), 5.8s rDNA and its flank internal transcribed spacers (ITS1-5.8s rDNA-ITS2), and large subunit ribosomal DNA (LSU rDNA) are sequenced and used for phylogenetic analyses which reveal that the family Epistylididae Kahl, 1933 is non-monophyletic whereas the genus Campanella is monophyletic and nests within the basal clade of the sessilids. The integrative results support the assertion that the genus Campanella represents a separate lineage from other epistylidids, suggesting a further revision of the family Epistylididae is needed. We revise Campanella including the transfer into this genus of a taxon formerly assigned to Epistylis, which we raise to species rank, i.e., Campanella ovata (Nenninger, 1948) n. grad. & n. comb. (original combination Epistylis purneri f. ovataNenninger, 1948). In addition, we provide a key to the identification of the species of Campanella.

Morphology, Morphogenesis, and Molecular Phylogeny of a New Freshwater Ciliate, Quadristicha subtropica n. sp. (Ciliophora, Hypotrichia)

The morphology and the regulation of cortical pattern associated with the cell size, division, and phylogenetic position of a new hypotrichous ciliate, Quadristicha subtropica n. sp. collected from a freshwater pond in southern China, were investigated. Quadristicha subtropica n. sp. is characterized as follows: size in vivo 60–115 μm × 25–45 μm; 19–21 adoral membranelles; buccal cirrus near anterior end of endoral and paroral; cirrus IV/3 at about level of buccal vertex; right marginal row begins ahead of buccal vertex; 11–16 right and 12–19 left marginal cirri; and dorsal cilia about 5 μm long. The basic morphogenetic process in Q. subtropica n. sp. is consistent with that of the type species, Quadristicha setigera. Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal that the systematic position of Q. subtropica n. sp. is rather unstable with low support values across the tree and the genus Quadristicha is not monophyletic.

Lake-Level Changes and Their Paleo-Climatic Implications at the MIS12 Lower Paleolithic (Middle Pleistocene) Site Marathousa 1, Greece

Lithics and cut-marked mammal bones, excavated from the paleo-lake Marathousa 1 (MAR-1) sediments in the Megalopolis Basin, southern Greece, indicate traces of hominin activity occurring along a paleo-shoreline ca. 444,000 years (444 ka) ago. However, the local environment and climatic conditions promoting hominin activity in the area during the MIS12 glacial remain largely unknown. In order to reconstruct the paleo-environment including paleo-lake levels and governing paleo-climatic factors on a high temporal resolution, we analyzed a 6-meter-long sediment sequence from the archeological site MAR-1 and a Bayesian age model was computed for a better age constrain of the different sedimentary units. A multiproxy approach was applied using ostracods, sponge spicules, diatoms, grain sizes, total organic carbon, total inorganic carbon and conventional X-ray fluorescence analysis. The results from the site represent a protected region surrounded by high mountains under the constant influence of water, either as a shallow partly anoxic water body surrounded by reed belts (>463–457 ka, <434–427 ka), a riverine-lake deltaic system (∼457–448 ka), a floodplain (∼448–444 ka) or a seasonal freshwater pond (∼444–436 ka). The local changes of water levels resemble large trends and rhythms of regional records from the Mediterranean and appear to directly respond to sea surface temperature (SST) changes of the North Atlantic. In particular, when the SSTs are high, more moisture reaches the study area and vice versa. Additional water reaches MAR-1 through melting of the surrounding glaciers after brief warm phases during MIS12 in the Mediterranean realm, which leads to the formation of smaller fresh water ponds, where also the horizon of the excavated remains is placed. Such ponds, rich in ostracods and other microorganisms, provided mammals and humans valuable resources, such as potable water, a wide range of plant species and hunting opportunities. These deposits therefore bear a high archeological potential. The results from our study suggest that the Megalopolis Basin could have served as a refugium for hominins and other organisms due to its capacity to retain freshwater bodies during glacial and interglacial periods.