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This article explores the use of a virtual simulation experimental platform for teaching PLC programming in the context of elevators. The platform allows students to learn and practice programming skills using a stepwise sequence method, which enhances their interest in learning and improves the effectiveness of classroom teaching. The article also discusses the use of modular and structured programming ideas in elevator program design, which aligns with the cultivation of engineering quality. Overall, the virtual simulation technology provides a valuable tool for practical teaching and enhances students' theoretical knowledge and innovation abilities. [Extracted from the article]

The Amazon River dolphin Inia geoffrensis occurs throughout the basins of the Amazon and Orinoco Rivers and is categorized as Endangered on the IUCN Red List. Using satellite tracking data from eight dolphins (one female and seven males) in the Peruvian Amazon, we demonstrate that these dolphins inhabit a variety of habitat types and have core areas and home range areas of variable magnitudes. To gain a better understanding of how threats affect these dolphins, we examined the distance of dolphin records to locations of current and potential future anthropogenic threats. On average, dolphin home ranges overlapped with fisheries by 89%. Dolphins were found at an average distance of 252 km from the nearest proposed dam and 125 km from the nearest proposed dredging site. Given that many of these threats are still in the planning stage, we advise the government to consider the negative effects these activities have already had on other riverine species before proceeding. Additionally, efforts should be made to expand river dolphin tracking programmes to span multiple seasons, to track more females at our study sites and to increase the numbers tracked overall in other areas to improve our knowledge of the species' movement patterns. [ABSTRACT FROM AUTHOR]

Inia geoffrensis is an endangered species of the Amazon River basin, but there has been limited research regarding its health, particularly in describing normal cell morphology by traditional techniques. This study aimed to identify the peripheral blood cells of I. geoffrensis through microscopic evaluation. Blood smears were collected from wild adults and stained with Wright's stain. We differentiated leukocyte cells (neutrophils, eosinophils, lymphocytes, and monocytes) and platelets. Additionally, we observed signs of inflammatory reactions in cell morphology by incrementing cell size and active cytoplasm in neutrophils, eosinophils, lymphocytes, and platelets. These findings provide important considerations for hemogram interpretation in future research and individual clinical cases in Amazon River dolphins. Also, our study delivers baseline information for future characterization and understanding of hemogram and leukogram changes in response to disease and health assessment for dolphin species. [ABSTRACT FROM AUTHOR]

Copyright of Revue d'études Autochtones is the property of Societe Recherches Autochtones au Quebec and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

À partir d’un corpus de récits recueillis auprès d’enfants et d’adultes dans des villages du bas-Tapajós (Amazonie brésilienne, état du Pará), j’analyserai, dans cet article, le paysage narratif local à la lumière de l’histoire régionale. Les deux personnages les plus récurrents des récits, le Jurupari, un monstre sylvestre qui dévore les chasseurs imprudents, et le Boto, un dauphin enchanté qui se transforme en un beau jeune homme blanc pour séduire ses victimes, sont associés respectivement, par les populations locales, à une figure stéréotypée de l’« Indien » et au monde des « Blancs » et des téléromans. Je propose une lecture conjointe de ces deux figures en montrant comment les villageois se situent face à elles, selon un jeu d’identification et de mise à distance qui n’est pas exempt d’ambiguïtés.

River dolphins from the genus Inia are widely distributed in the Amazon, Orinoco and Tocantins River basins. Current knowledge on the dietary habits of these species is poor and based on stomach contents from stranded animals. We used carbon and nitrogen stable isotopes to evaluate the diet preferences and trophic niche of the boto (Inia geoffrensis geoffrensis) and the bufeo (I. g. boliviensis) in three rivers from the Amazon and Tocantins basins. Samples were obtained from skin biopsies taken from social animals near fish markets during a tagging program or from dart biopsies of wild individuals. Prey isotopic data were obtained from fish collected during the surveys, catches by local fishermen or published data. Contribution of prey to consumer diet was calculated through isotope mixing models and trophic niches were represented by the isotopic niche area. Piscivore prey was the main item in the diet of bufeos and botos from Tapajós and Tocantins River wild group, whereas botos from Tocantins market group showed differences in diet and a lower trophic position probably mediated by human feeding near markets. Isotopic niche area was greater for Tapajós botos than for Tocantins market group botos and bufeos, which can be an effect of the homogenization of the human-mediated diet and low samples sizes, in the case of the market group and bufeos, respectively. Results presented here, represent a first attempt toward a better understanding of the trophic ecology of this endemic and threatened species through stable isotope analysis. [ABSTRACT FROM AUTHOR]

Acoustic characteristics of bubble production by an odontocete were documented for the first time. Bubble sounds produced by the Amazon river dolphin (Inia geoffrensis) were recorded incidentally as part of a survey of fish sounds in the Pacaya-Samiria National Reserve of Peru on six dates between 4 and 24 July 2012. Dolphins were observed to periodically produce large clouds of bubbles underneath or near the survey boat (averaging 7/survey or 8/h) as it drifted through areas of actively foraging dolphins. The bubble production was classified as bubble bursts due to theirsimilarity to bubble bursts produced by other ceta ceans. Bubble burst sounds had a mean peak frefuncquency of 402 Hz and duration of 8.9 s (n = 51) Bubble bursts were temporally clustered with an average interval of 169 s (0.1 to 1,187 s) between bursts. Bubble bursts were disproportionately more likely to be present when fish sounds were also present, but it is not known if the association was due to predation or other factors. A review of the literature finds similar bubble production has been reported in at least 14 other species of cetaceans (4 mysticetes and 10 odontocetes). Most are commonly associated with play, surprise, agonistic, and foraging behaviors. We discuss each of these possibilities and conclude that Amazon river dolphin bubble burst behavior is most likely indirelated to foraging or aggressive behavior because the behavior occurred in feeding areas and Mayappeared to be directed at the drifting boat. We Collado & Wartzok, 2007; Gomez-Salazar et al., further propose a novel hypothesis that the bubble Mayappeared to be directed at the drifting boat. We Collado & Wartzok, 2007; Gomez-Salazar et al., further propose a novel hypothesis that the bubble bursts are a hunting strategy used to disperse prey associated with floating vegetation mats and other forms of drifting materials used by fishes for shel ter. Future research is needed to better understand the behavior associated with bubble production by the Amazon river dolphin. [ABSTRACT FROM AUTHOR]

The Amazon river dolphin, or boto (Inia geoffrensis), is an endangered species, distributed over an extensive area of the Amazon–Orinoco basin. Here, we analyzed the acoustic behavior of a previously unstudied population of botos at the Juami-Japurá Ecological Station, Amazonas. We categorized call types according to their visual and acoustical parameters. Random forest decision trees were used to assess the validity of our classification. Six types of narrowband pulsed sounds were found, of which four are being described for the first time for the species. The vocalizations analyzed had mean maximum frequency of 25.7 kHz and mean minimum frequency of 1.1 kHz. The narrowband pulsed sounds are complex and different from those emitted by most members of the family Delphinidae. Although the acoustic repertoire of botos is not completely understood in functional terms, these pulsed sounds may play an important role in the social structure of the animals. [ABSTRACT FROM AUTHOR]

La similitud fonética y semántica entre un gran número de palabras de varios idiomas que sin embargo no se pueden reducir al mismo étimo le sugiere a Corominas (en el DCECH) un origen espontáneo en cada lengua, como resultado de la intención de reproducir por medios lingüísticos ciertas impresiones extra-lingüísticas. Tomando como punto de partida una selección de palabras categorizadas como ‘voces de origen expresivo’, analizamos la posibilidad y los límites de la creación léxica espontánea, en términos de fonosimbolismo y conceptos primarios expresados por onomatopeyas. Dado que el análisis comparativo de dichas palabras revela pautas semánticas y fonéticas recurrentes, no se puede rechazar por completo la idea de motivación lingüística (y en este sentido, intentamos rehabilitar la teoría de Hilmer, 1918), pero debemos situarla en el proto-románico, o, más probable, en el proto-indoeuropeo.

The dolphins Inia geoffrensis—boto and Sotalia fluviatilis—tucuxi are threatened cetaceans inhabiting river ecosystems in South America; population numbers are still lacking for many areas. This paper provides density and abundance estimations of boto and tucuxi in 15 rivers sampled during the past nine years as part of a multinational research alliance. Visual boat-survey data collection protocols and analyses have been developed since 2012 (based on Distance Sampling methods) and recently reviewed (2019) to improve robustness and comparability. Differences across the sampled rivers and the analyzed river basins (Amazon and Orinoco) pointed to a density/population size gradient with lower densities and abundances observed in the Orinoco basin (0.9–1.5 ind./km²), passing through the eastern Amazon basin (2–5 ind./km²), and the largest numbers found at the central Brazilian Amazon (lower Purus River—2012 (14.5 boto/km², N = 7672; 17.1 tucuxi/km², N = 9238)). However, in other parts of the central Amazon, the density of dolphins was smaller than expected for high productive whitewater rivers (1–1.7 ind./km² in the Japurá and Solimões rivers). We attributed these differences to specific features of the basin (e.g., hydro-geomorphology) as well as to the cumulative effects of anthropogenic activities.

DOI: 10.17014/ijog.4.2.61-70Three seepage gas samples collected from Boto Area, Bancak, Semarang, Central Java, were studied to determine their chemical characteristics using GC and GC-IRMS methods. They are composed 53 - 85% of methane predominantly. However, gas seep Site 3 sample has the highest N2 compound and the lesser extent to the samples Site 2 and Site 1 respectively. The two hydrocarbon gas seeps (Site 1, 2, and Site 3 samples) that are characterized by δ13C methane of -35.61‰ and -27.97‰, and values of δD methane of -112‰ and -109‰ respectively, are each isotopically distinct from all others suggesting, at least, they are derived from different maturity level. The Site 3 gas sample is suggested to be more mature than the others.

The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour. We analysed frequency contours of 727 signals (sampled at 10 ms temporal resolution). These contours were analyzed using an adaptive resonance theory neural network combined with dynamic time-warping (ARTwarp). Using a critical similarity value of 96%, frequency contours were categorized into 237 sound-types. The most common types were emitted when calves were present suggesting a key role in mother-calf communication. Our findings show that the acoustic repertoire of river dolphins is far from simple. Furthermore, the calls described here are similar in acoustic structure to those produced by social delphinids, such as orcas and pilot whales. Uncovering the context in which these signals are produced may help understand the social structure of this species and contribute to our understanding of the evolution of acoustic communication in whales.

The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour. We analysed frequency contours of 727 signals (sampled at 10 ms temporal resolution). These contours were analyzed using an adaptive resonance theory neural network combined with dynamic time-warping (ARTwarp). Using a critical similarity value of 96%, frequency contours were categorized into 237 sound-types. The most common types were emitted when calves were present suggesting a key role in mother-calf communication. Our findings show that the acoustic repertoire of river dolphins is far from simple. Furthermore, the calls described here are similar in acoustic structure to those produced by social delphinids, such as orcas and pilot whales. Uncovering the context in which these signals are produced may help understand the social structure of this species and contribute to our understanding of the evolution of acoustic communication in whales. [ABSTRACT FROM AUTHOR]

Infanticide by males is a phenomenon common in species in which the reproductive output of large numbers of females can be monopolized by a small number of males. It is thought to increase a male’s fitness, at the expense of the fitness of the infant’s parents, by bringing females into season more quickly. Infanticide by males has been recorded in just three cetacean species. We report aggressive behavior suggestive of infanticide in a fourth, the Amazon river dolphin (Inia geoffrensis). We observed and photographed a series of attacks on a neonate Amazon river dolphin by a large male, with apparent protective behavior by the mother. Although infanticide was not confirmed, the forceful, aggressive behaviors were highly suggestive of infanticidal behavior and represent another important data point for comparative studies of infanticide in mammals. Amazon river dolphins may have a polygynous, polyandrous, or promiscuous mating system, the latter two of which are not the norm in species in which the reproductive output of large numbers of females are monopolized by a small number of males. However, sexual dimorphism, high rates of aggression by males, socio-sexual object-carrying displays by males, and a long interbirth interval suggest that successful male Amazon river dolphins may be able to monopolize a large proportion of mating opportunities, and it is plausible that male dolphins can improve their reproductive success by bringing females into estrous sooner by killing the offspring of other males. [ABSTRACT FROM AUTHOR]

Reproductive parameters of the Amazon river dolphin, or boto Inia geoffrensis, were estimated from a population of individually recognizable animals in the Brazilian Amazon throughout 24 years. Gestation lasts 12.3–13 months, and calves are nursed for 1.5–5.8 years. The mean inter-birth interval is 4.6 years, and there is no evidence of reproductive senescence. Females first give birth at a mean age of 9.7 years and become sexually mature at body lengths of 180–200 cm. Body length at birth averages 84 cm. The annual pregnancy rate was ~0.4, but the annual birth rate was 0.22; therefore, almost half of pregnancies do not result in a calf seen by our research team. Entanglement of neonates in monofilament gillnets might account, at least in part, for these losses. Births can occur year round, but peak at low water, when botos and their newborn calves are concentrated on river margins. Despite profound physical and behavioural adaptations over millions of years to a life in shallow, fresh waters and complex habitats, the boto has remarkably similar reproductive characteristics to those of its marine counterparts, dolphins of the family Delphinidae. The fundamental reproductive characteristics of small odontocetes have apparently been robust to change over a very considerable evolutionary timespan. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Filología Románica is the property of Universidad Complutense de Madrid and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to characterize the structures of the posterior respiratory system of two species of river dolphins: Inia geoffrensis and Sotalia fluviatilis. The respiratory tract of both species was evaluated using macro and microscopic techniques. Four macroscopic anatomical structures were identified: Trachea, main bronchus, tracheal bronchus and lung. The presence of the exuberant tracheal bronchus suggested ease of gas exchanges. Histological analysis revealed the presence of alveolar ducts and myoelastic sphincter in these Amazonian cetaceans. The posterior respiratory portion of the Amazonian dolphins presents similarity with other odontocetes and the knowledge of this structure can also help contribute to the understanding of the physiology of diving and how these species are adapted to their habitat. [ABSTRACT FROM AUTHOR]

We present results of the first simultaneous visual and acoustic surveys for Amazon River dolphins (Inia geoffrensis) and tucuxi (Sotalia fluviatilis), undertaken in Yarinacocha Lagoon, Ucayali, Peru (length = 20 km, area = 12 km2). A total of 324 Sotalia observations and 44 Inia observations were recorded in boat-based transects. Based upon total survey effort, we estimated Sotalia had a mean density ± SE of 1.98 ± 4.6 ind km-2 and an overall abundance of 34 individuals (95% CI: 28 to 40). Average density for Inia was 0.2 ± 1.2 ind km-2 with overall abundance estimated at 3 individuals (95% CI: 0 to 8). Visual surveys observed more Sotalia individuals during earlier hours of the day and during the dry season. Preliminary acoustic surveys undertaken with C-POD passive acoustic monitoring devices indicated a diel pattern in detections of cetacean vocalization with more diurnal activity and with detections ceasing from midnight until 10:00 AM. This work highlights the possibility of monitoring both river dolphin species through visual and acoustic surveys to generate baseline information on abundance trends and distribution patterns in the Ucayali region, an area with high levels of human disturbance. [ABSTRACT FROM AUTHOR]

Three seepage gas samples collected from Boto Area, Bancak, Semarang, Central Java, were studied to determine their chemical characteristics using GC and GC-IRMS methods. They are composed 53 - 85% of methane predominantly. However, gas seep Site 3 sample has the highest N2 compound and the lesser extent to the samples Site 2 and Site 1 respectively. The two hydrocarbon gas seeps (Site 1, 2, and Site 3 samples) that are characterized by δ13C methane of -35.61‰ and -27.97‰, and values of δD methane of -112‰ and -109‰ respectively, are each isotopically distinct from all others suggesting, at least, they are derived from different maturity level. The Site 3 gas sample is suggested to be more mature than the others. [ABSTRACT FROM AUTHOR]

Toothed whales have evolved to live in extremely different habitats and yet they all rely strongly on echolocation for finding and catching prey. Such biosonar-based foraging involves distinct phases of searching for, approaching and capturing prey, where echolocating animals gradually adjust sonar output to actively shape the flow of sensory information. Measuring those outputs in absolute levels requires hydrophone arrays centred on the biosonar beam axis, but this has never been done for wild toothed whales approaching and capturing prey. Rather, field studies make the assumption that toothed whales will adjust their biosonar in the same manner to arrays as they will when approaching prey. To test this assumption, we recorded wild botos (Inia geoffrensis) as they approached and captured dead fish tethered to a hydrophone in front of a star-shaped seven-hydrophone array. We demonstrate that botos gradually decrease interclick intervals and output levels during prey approaches, using stronger adjustment magnitudes than predicted from previous boto array data. Prey interceptions are characterised by high click rates, but although botos buzz during prey capture, they do so at lower click rates than marine toothed whales, resulting in a much more gradual transition from approach phase to buzzing. We also demonstrate for the first time that wild toothed whales broaden biosonar beamwidth when closing in on prey, as is also seen in captive toothed whales and bats, thus resulting in a larger ensonified volume around the prey, probably aiding prey tracking by decreasing the risk of prey evading ensonification. [ABSTRACT FROM AUTHOR]

Discute as relações entre folclore e medicina popular na Amazônia, tendo como referencial de análise o conto "Filhos do boto", de Canuto Azevedo. Aponta que os contos folclóricos estão saturados de elementos da realidade cultural e podem ser utilizados como testemunhos históricos que expressam embates entre diferentes tradições. Os registros folclóricos são fruto do diálogo muitas vezes conflituoso entre folcloristas, cientistas sociais, médicos, pajés e seus seguidores, e sua análise deve ser acompanhada de reflexão sobre as condições de sua produção. Neste caso específico, trata-se de refletir, com base no imaginário de sedução e cura em torno do boto, sobre a possibilidade de ampliar o conhecimento sobre a medicina popular praticada na Amazônia, região de forte presença da pajelança cabocla.This discussion of the relations between folklore and popular medicine in the Amazon takes Canuto Azevedo's story "Filhos do boto" (Children of the porpoise) as an analytical reference point. Replete with elements of cultural reality, folk tales can serve as historical testimonies expressing clashes between different traditions. Folk records are fruit of what is often a quarrelsome dialogue between folklorists, social scientists, physicians, and pajés and their followers, and their analysis should take into account the conditions under which they were produced. Based on the imaginary attached to the figure of the porpoise - a seductive creature with healing powers - the article explores how we might expand knowledge of popular medicine as practiced in the Amazon, where the shamanistic rite known as pajelança cabocla has a strong presence.

Franciscana dolphins were used as source of information on the bioavailability of cadmium in the neritic waters off South Brazilian Coast. Liver samples obtained from 44 individuals incidentally captured off Rio Grande do Sul State were analyzed by electrothermal AAS. Cadmium concentrations, age, total weight and length of the analyzed dolphins varied between 39 and 4144 µg.kg-1 (wet weight), one and five years, 17.5 and 49.2 kg, and between 105.3 and 156.8 cm, respectively. Concerning hepatic cadmium concentrations of franciscanas, there was no significant difference between data raised by the present study and information from literature, regarding Rio de Janeiro State. The low cadmium concentrations observed may be attributed to the fact that loliginid squids constitute the main cephalopod prey for franciscanas. This study corroborates investigations on cadmium levels in Brazilian squids and strengthened the hypothesis that cephalopods of Loliginidae Family do not constitute important vectors of the transfer of cadmium to cetaceans.Franciscanas foram utilizadas como fonte de informação sobre a biodisponibilidade de cádmio em águas neríticas da Costa Sul do Brasil. Amostras de fígado, obtidas de 44 indivíduos capturados acidentalmente ao largo da costa do Rio Grande do Sul, foram analisadas através de EAA eletrotérmica. Concentrações de cádmio, idade, peso e comprimento totais dos golfinhos analisados variaram entre 39 e 4144 µg.kg-1 (peso úmido), um e cinco anos, 17,5 e 49,2 kg, e entre 105,3 e 156,8 cm, respectivamente. Em relação às concentrações hepáticas de cádmio em franciscanas, não houve diferença significativa entre os dados gerados pelo presente estudo e informação proveniente da literatura, referente ao Estado do Rio de Janeiro. As baixas concentrações de cádmio observadas podem ser atribuídas ao fato de as lulas da Família Loliginidae constituírem a principal presa para franciscanas, dentre os cefalópodes. Este estudo corrobora investigações sobre níveis de cádmio em lulas brasileiras e reforça a hipótese de que cefalópodes loliginídeos não constituem vetores importantes da transferência de cádmio para cetáceos.

Deliberate killing for use as bait in a regional catfish ( Calophysus macropterus) fishery is the primary threat affecting the survival of the Amazon river dolphin, or boto ( Inia geoffrensis). Establishing and improving freshwater protected areas has been suggested as a possible course of action to protect the species. However, the ecology of the boto is poorly understood and more information is needed on the species' habitat use and movement patterns to ensure that spatial protection initiatives meet conservation needs. In this study, mark-recapture/resight data collected in and near the Mamirauá Sustainable Development Reserve, a várzea in the Brazilian Amazon, was used to examine transition probabilities of botos between various habitat types. Our findings suggest that it is imperative that spatial protection initiatives focused on the boto take into account the importance of várzea habitat and bay systems for individuals in early life stages. Moreover, because botos frequently occupy the main rivers, particularly during the low water period, protecting areas of the main river waters adjacent to várzeas could aid in the protection of hunted populations. [ABSTRACT FROM AUTHOR]

We monitored the underwater behavior of botos (Inia geoffrensis) using stereo acoustic data loggers to observe their local habitat use and its diel changes at the Mamiraua Sustainable Development Reserve, Brazil. A-tags were set at five sites in three different habitat types: Lake (low current), Channel (middle current), and Junction (junction of two channels). The presence index during nighttime was significantly greater than during daytime in the Lake and Junction. Underwater movement was estimated from the changing pattern (trajectory) of the relative angle of the sound source from A-tags. A staying-type trajectory was dominant in the Lake, although the prevalence of moving-type trajectory increased at night. More than 80% of detected trajectories were the staying type in the Junction, while moving- type trajectories dominated in the Channel. The frequency of click trains was greatest in the Lake, followed by the Junction and Channels. The average interpulse interval, which reflects the mean target distance of echolocation, was shortest in the Lake, followed by the Junction and Channel. These results suggest that the botos used the Lake as their primary habitat for active behaviors like foraging, especially at night, and the Junction as their primary habitat for relatively inactive behaviors at night. [ABSTRACT FROM AUTHOR]

Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3±6.1 dB re. 1 μPa, mean SLEFD of 132.1±6.0 dB re. 1 µPa2s, mean Fc of 101.2±10.5 kHz, mean BWRMS of 29.3±4.3 kHz and mean ICI of 35.1±17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6–10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9–25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars. [ABSTRACT FROM AUTHOR]

Odontoceti emit broadband high-frequency clicks on echolocation for orientation or prey detection. In the Amazon Basin, two odontoceti species, boto (Amazon River dolphin, Inia geoffrensis) and tucuxi (Sotalia fluviatilis), live sympatrically. The acoustic characteristics of the echolocation clicks of free-ranging botos and tucuxis were measured with a hydrophone array consisting of a full-band and an acoustic event recorder (A-tag). The clicks of the two species were short-duration broadband signals. The apparent source level was 201 dB 1 µPa peak-to-peak at 1 m in the botos and 181 dB 1µPa peak-to-peak at 1 m in the tucuxis, and the centroid frequency was 82.3 kHz in the botos and 93.1 kHz in the tucuxis. The high apparent source level and low centroid frequency are possibly due to the difference in body size or sound production organs, especially the nasal structure, the sound source of clicks in odontoceti. [ABSTRACT FROM AUTHOR]

Indo-Pacific humpback dolphins have historically inhabited the northern waters off Lantau Island, Hong Kong; however their numbers have significantly decreased over the past decade, while human pressure has simultaneously increased. Based on a spatio-temporal analysis using a Geographic Information System (GIS), this study aims to assess the cumulative human impacts of local activities on this dolphin population since 1996. After introducing and discussing the multiple approaches, difficulties, and limitations to cumulative effects assessments (CEA), this paper outlines our proposed CEA methodology. Our methodology involves mapping and analysis of anthropogenic marine impacts in relation with historical dolphin distributions in the area. Local scale results show evidence of a relationship between the addition of new high-speed ferry (HSF) routes into the cumulative environment and the decrease in dolphins in a specific region known as the Brothers Islands. These results coincide with past research showing that whales and dolphins are significantly disrupted in the presence of high vessel traffic, which continues to grow in the northern waters off Lantau Island, Hong Kong and in many other places around the world. [ABSTRACT FROM AUTHOR]

Negative interactions between fishers and the Amazon River dolphin ( Inia geoffrensis), or boto, have increased substantially in the last few decades. Herein, we investigate these interactions with focus on assessing fisher perceptions, attitudes, and behaviors toward botos. Moreover, we evaluate the effect that the Mamirauá Sustainable Development Reserve (MSDR) in the Brazilian Amazon, and related programs, has had on fisher attitudes and behaviors toward botos. The results suggest that interactions between fishers and botos, such as depredation and incidental entanglement, are frequent, and that the illegal harvest for botos, for use as bait, occurs in the majority of the study communities. However, the assessment revealed that most fishers have positive attitudes toward botos and that these attitudes have been influenced by participation in the MSDR activities such as research and ecotourism. Our results also highlight the importance of community-based enforcement in addressing the issue of boto harvesting. The MSDR programs have successfully promoted positive attitudes toward botos and have likely played a role in limiting boto mortality through behavioral controls, though the scope of influence of these programs has been restricted to a small geographical area. The current extent of these programs is insufficient to prevent the decline of the boto population; therefore, we suggest the MSDR model be used to improve and expand boto conservation efforts with communities in the region. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the distribution of botos, Inia geoffrensis, along a 530 km stretch in the middle reaches of the Araguaia River (central Brazil). Data collection was conducted in May (lowering water season) and September (dry season) of 2009. The location and group size of botos were recorded, and the relative density was calculated. The river was divided into nine areas according to geomorphological features; these areas were later grouped into two (low and high) levels of sediment input. The study area was categorized into six types of shoreline habitats: vegetated bank, non-vegetated bank, beach, confluence, bay, and island. A total of 195 sightings (239 botos) were recorded, with the highest density of sightings found in habitats in which tributaries entered the Araguaia River (confluence) followed by the bay habitat. The group size varied from one to three individuals, and single individuals were predominant. The segment with high sediment input also had a higher density of botos compared with the low-sediment segment. Botos-preferred habitats and human activities have a great overlap in Araguaia River. Restrictions of certain human activities, and tourism management would reduce both the intentional and accidental harm of botos in the Araguaia River. [ABSTRACT FROM AUTHOR]

In the Amazon Basin, the use of the pink dolphin or boto (Inia geoffrensis) for bait in the piracatinga (Calophysus macropterus) fishery was first detected in the year 2000. Since then, this artisanal fishery has become more prevalent as it requires only a few hours of work per night and provides immediate cash earnings. It is thus an attractive addition to (or replacement for) traditional fishing. Previous reports have noted the use of botos as bait, but stated that the most common bait used are caimans (Melanosuchus niger, Caiman crocodilus). Estimates of the number of dolphins killed based on fish landings have been proposed and an apparent decrease in sighting/survival of an artificially-marked boto population was observed. Although stocks/population estimates, trends and actual numbers of hunted dolphins are unknown, the conservation impacts of this activity are of concern. Between October 2010 and November 2011, research was conducted within an area with serious conflicts between dolphins and fishermen as well as intense fishing for piracatinga, i.e. in the lower Japurá River, on the border with the Mamirauá and Amanã Sustainable Development Reserves, where both boto and tucuxi (Sotalia fluviatilis) are used for bait. One-hundred and fifty-seven monitoring surveys were carried out in eight key communities, confirming 114 piracatinga fishing events through direct monitoring and incognito surveys of fishing gear (gaiolas). Empirical evidence of the activity in gaiolas comprised pieces of bait, carcass remains, piracatinga provoked vomits and dolphin fished carcasses. Of those, 31.2% (n = 35) involved cetacean bait (91.4% I. geoffrensis, 8.58% S. fluviatilis), 68.7% (n = 77) caiman bait (96% M. niger, 4% C. crocodilus), and two fishing events used both types. These percentages may be higher/lower in other areas within and outside the Reserves. Given the increasing trend of the piracatinga fishery, the authors believe that precautionary measures for the conservation of Amazonian dolphins are urgently needed. Development of practical short-term solutions (e.g. offal-baited fish traps) and multispecies management together with law enforcement, incentives and educational programmes could allow the future transition of riverine communities from the piracatinga fishery to sustainable, higher income activities. [ABSTRACT FROM AUTHOR]

The article discusses various toothed whales found in freshwater habitats including the Amazon River dolphin, the Indus and Ganges river dolphins, and the Yangtze river dolphin. It says that the said genera of dolphins are identified as part of different families due to their molecular and morphological differences. It mentions that the existing habitat of freshwater dolphins might be attributed to the independent episodes of freshwater colonization. It states that various fragment fossil specimens such as jaw or isolated tooth fragments were discovered and believed to be related to existing genera of river dolphins. It cites the Platanistinae fossil record from the early Miocene period which was found at the coastal deposits of Oregon.

In the Western Brazilian Amazon, interactions of boto (Inia geoffrensis) and tucuxi (Sotalia fluviatilis) dolphins with fishing activities are common, but the prevalence of incidental/intentional catches is not known. This article describes incidental mortality events and intentional killing of I. geoffrensis and S. fluviatilis entangled in artisanal fishing gear and the opportunistic use of carcasses as bait. Between October 2010 and November 2011, surveys were conducted in waters of the lower Japurá River, between the Mamirauá and Amanã sustainable development reserves. In order to obtain information on interactions and to try to establish a stranding/entanglement response program (SERP), informal conversations were exchanged with local inhabitants (n = 174). Intense carcass-search surveys (n = 171) along the river in the four hydrological seasons (e.g., low, rising, high, and falling waters) were conducted, comprising a total of 1,197 h of sampling effort. Twenty-five dolphin-fishing interaction events were recorded (11 I. geoffrensis and 14 S. fluviatilis), 19 in 2011 and six in 2012 (through SERP). A total of 11 necropsies (three I. geoffrensis and eight S. fluviatilis) were performed. Four individuals (two I. geoffrensis and two S. fluviatilis) exhibited evidence of physical violence before death, and two (one I. geoffrensis and one S. fluviatilis) died in abandoned gillnets. Two intentional killing events of I. geoffrensis incidentally entangled for bait use in the piracatinga (Calophysus macropterus) fishery were reported by fishermen, while three carcasses (two I. geoffrensis and one S. fluviatilis) with gillnet marks were also used in that activity. At least six of the S. fluviatilis entanglement events occurred in fishing gear used for tambaqui (Colossoma macropomum) and pirapitinga (Piaractus brachypomus) (90/100-mm mesh-size gillnet), two of the most important commercial fish species in the Amazon Basin. As seasonal fishing constitutes the main income for riverine human populations, the negative reactions that cetacean presence causes to people could have a catalyst effect for the transition from "incidental capture" to "intentional capture and competitor removal." Law enforcement and precautionary measures through good fishing practices inside dolphin critical foraging areas should be taken together with fisheries' managers and fishermen to start to develop multiple-species management and ensure sustainable fishing practices. [ABSTRACT FROM AUTHOR]

Aggression is often utilised in intraspecific competition to establish and maintain dominance hierarchies in social mammals. Here, we determine if aggressiveness in conditioned botos ( Inia geoffrensis) during interactions with humans under provisioning is influenced by the presence or absence of food rewards and if provisioning leads to the establishment of a dominance hierarchy among these generally solitary animals. Mean values of bites among the botos for sessions in which food rewards were delivered were significantly higher than sessions in which no food reward was delivered. No significant difference exists between the mean number of bites per individual during feeding sessions, but the mean number of bites increased significantly with time when animals were not fed. Supplant behaviours were used as a non-harming alternative to bites. The botos' provisioning is a case of instrumental conditioning, in which the conditioned botos expect to receive food from tourists, increasing competition among the animals when they are not fed. The provisioned botos exhibited an almost linear dominance hierarchy. Bites and supplant behaviours were used more frequently by dominant botos to prevent subordinates from obtaining food provisions. Interactions brought about by provisioning are likely to be harmful to the botos and potentially dangerous to humans. [ABSTRACT FROM AUTHOR]

Abstract: The Amazon River dolphin (Inia geoffrensis), or boto, is illegally harvested for use as bait in fisheries for the catfish Calophysus macropterus. To determine the effect of this harvest, we estimated apparent survival for a boto population in the central Brazilian Amazon where direct harvest is known to have occurred since 2000. For our analysis, we used capture and recapture/resighting data of 528 marked botos over a 17-year period (1994–2011). Time-dependent models estimated that apparent survival after the first reports of harvest (ϕ =0.899; SE=0.007) was significantly lower than in years prior to harvest (ϕ =0.968; SE=0.009). The decline in apparent survival suggests that current harvest rates exceed conservation limits and may be unsustainable. This issue requires the attention of natural resource managers from all countries of the Amazon basin, as the harvest is widespread and decline in survival could be mirrored in numerous locales. [Copyright &y& Elsevier]

The article presents a study which investigates the unusual behavior of botos or inia geoffrensis in the upper reaches of the Tocantins River, Brazil. It states that systematic and exploratory surveys of feeding activities and unusual behaviors, such as object carrying were conducted in the study using different methods including strip-transects, fixed-point observations, and point sampling. It notes that the study found that boats made prey more easily accessible for botos to locate.

The article presents information on the freshwater dolphins that are considered as one of the least known species of all cetacean populations and due to which researchers are eyeing to minimize their extinction process. It informs that the Amazon River dolphins were examined under a study using ultrasonography during the yearly capture expedition. It further informs that the age and maturity estimates were determined considering the body length, weight and external characteristics and useful data was fetched for morphologic characterization of the boto's testes.

Classical and molecular cytogenetic (18S rDNA, telomeric sequence, and LINE-1 retrotransposon probes) studies were carried out to contribute to an understanding of the organization of repeated DNA elements in the Amazon River dolphin (boto, Inia geoffrensis). Twenty-seven specimens were examined, each presenting 2n = 44 chromosomes, the karyotype formula 12m + 14sm + 6st + 10t + XX/XY, and fundamental number (FN) = 74. C-positive heterochromatin was observed in terminal and interstitial positions, with the occurrence of polymorphism. Interstitial telomeric sequences were not observed. The nucleolar organizer region (NOR) was located at a single site on a smallest autosomal pair. LINE-1 was preferentially distributed in the euchromatin regions, with the greatest accumulation on the X chromosome. Although the karyotype structure in cetaceans is considered to be conserved, the boto karyotype demonstrated significant variations in its formula, heterochromatin distribution, and the location of the NOR compared to other cetacean species. These results contribute to knowledge of the chromosome organization in boto and to a better understanding of karyoevolution in cetaceans. [ABSTRACT FROM AUTHOR]

1. Freshwater cetacean species, including the baiji ( Lipotes vexillifer), Amazon River dolphin ( Inia geoffrensis), Ganges/Indus River dolphins ( Platanista spp.) and Yangtze finless porpoise ( Neophocaena asiaeorientalis asiaeorientalis), apex predators in megariver ecosystems, face serious challenges owing to the deterioration of habitat quality. 2. We simulated population change of four freshwater cetacean species under increasing habitat deterioration. Carrying capacity ( K) was used to represent the habitat quality, and a logistic model was used to describe the rate of habitat deterioration ( dK). 3. An individual-based Leslie matrix model showed that population declines and extinctions in freshwater cetaceans under increasing habitat deterioration exhibit a consistent pattern irrespective of the initial level of K or population size. When dK is low, population abundance fluctuates stochastically around initial K, but a rapid increase in dK is accompanied by a sharp population decline, with a residual population ultimately declining continuously to extinction. 4. Simulations show that traditional census survey techniques used in cetacean species are unlikely to detect early signs of population decline before a critical level is reached. 5. Empirical data of the likely extinction of baiji strongly agree with our simulation exercise, implying that extinction of other freshwater cetacean species may occur sooner than previously considered. Hence, precautionary approaches for habitat restoration and landscape management should be implemented before freshwater cetacean population declines are detected, and ideally, before habitat quality begins to deteriorate. [ABSTRACT FROM AUTHOR]

Although mosques worldwide serve the same spiritual purposes, they are significantly different in structure from one area to another within and among localities, countries and continents of the world. Muslims used whatever was available to them in their environment and their limited experience in building mosques resulted in structural differences in mosques until the age of globalisation, when some world-class mosque structures were popularised among Muslims. This paper is an attempt to produce a historical survey of the architectural designs of mosques in Ilorin in the nineteenth and twentieth centuries. Through exploratory research, the paper gives a thematic history of Ilorin mosques’ architecture that started as a simple structure in the nineteenth century reflecting the immediate cultural setting, to become edifices in the twentieth century reflecting outside cultural influences, for the purpose of meeting the spiritual, social, physical and psychological needs of Muslims. [ABSTRACT FROM AUTHOR]

Living in groups is usually driven by predation and competition for resources. River dolphins do not have natural predators but inhabit dynamic systems with predictable seasonal shifts. These ecological features may provide some insight into the forces driving group formation and help us to answer questions such as why river dolphins have some of the smallest group sizes of cetaceans, and why group sizes vary with time and place. We analyzed observations of group size for Inia and Sotalia over a 9 yr period. In the Amazon, largest group sizes occurred in main rivers and lakes, particularly during the low water season when resources are concentrated; smaller group sizes occurred in constricted waters (channels, tributaries, and confluences) that receive an influx of blackwaters that are poor in nutrients and sediments. In the Orinoco, the largest group sizes occurred during the transitional water season when the aquatic productivity increases. The largest group size of Inia occurred in the Orinoco location that contains the influx of two highly productive whitewater rivers. Flood pulses govern productivity and major biological factors of these river basins. Any threats to flood pulses will likely have an effect on the functionality of these ecosystems and the species living in them. [ABSTRACT FROM AUTHOR]

This study is part of an on-going effort to evaluate and monitor river dolphin populations in South America. It comprises the largest initiative to estimate population size and densities of Inia and Sotalia dolphins using statistically robust and standardized methods. From May 2006 to August 2007, seven visual surveys were conducted in selected large rivers of Bolivia, Colombia, Brazil, Ecuador, Peru, and Venezuela in the Amazon and Orinoco river basins. Population sizes of Inia and Sotalia were estimated for different habitats (main river, tributary, lake, island, confluence, and channel). A total of 291 line and 890 strip transects were conducted, covering a distance of 2,704 linear kilometers. We observed 778 Inia geoffrensis, 1,323 Inia boliviensis, and 764 Sotalia fluviatilis. High-density areas were identified (within 200 m from the river banks, confluences, and lakes) and we propose that these constitute critical habitat for river dolphins. High densities of river dolphins seem to coincide with well-managed freshwater protected areas and should be considered as hot spots for river dolphins in South America. [ABSTRACT FROM AUTHOR]