| observations on baiji (lipotes vexillifer) and finless porpoise (neophocaena asiaeorientalis) in the lower reaches of the chang jiang. | lipotes usually occurs in pairs or in small loose groups. the calves are born in march-april. the finless porpoises are usually seen in groups of five or six individuals. the blow of lipotes lasts 0.2-0.6 sec and that of neophocaena 0.2-0.5 sec. in lipotes, a short dive would take 10-20 sec and a long dive up to 1-2 min (average value being 31 sec). in neophocaena a long dive would reach a maximum of 65 sec with an average of 17.5 sec. lipotes has a pair of functional eyes. the selective seconda ... | 1980 | 7414316 |
| evoked-potential audiogram of the yangtze finless porpoise neophocaena phocaenoides asiaeorientalis. | | 2005 | 15957743 |
| preliminary hazard assessment of polychlorinated biphenyls, polybrominated diphenyl ethers, and polychlorinated dibenzo-p-dioxins and dibenzofurans to yangtze finless porpoise in dongting lake, china. | yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis), a protected endangered species, is the sole freshwater subspecies of finless porpoise, living only in the middle and lower reaches of the yangtze river, china, and its appended lakes. its population has decreased sharply to 1,400 because of human activities, including environmental contamination. in the present study, polychlorinated biphenyls (pcbs), polybrominated diphenyl ethers (pbdes), and polychlorinated dibenzo-p-dioxins ... | 2008 | 18333690 |
| detection of helicobacter in the fecal material of the endangered yangtze finless porpoise neophocaena phocaenoides asiaeorientalis. | in animals, infection by the epsilonproteobacteria helicobacter spp. and h. cetorum is widespread. it has been suggested that h. cetorum may cause gastritis in cetaceans. the aim of our study was to investigate the presence of helicobacter spp. in the fecal material of the endangered yangtze finless porpoise neophocaena phocaenoides asiaeorientalis. the fecal material of 12 porpoises living in the wild in poyang lake and 1 porpoise living in captivity at the wuhan baiji dolphinarium were examine ... | 2011 | 21932536 |
| chromosomal rearrangements and karyotype evolution in carnivores revealed by chromosome painting. | chromosomal evolution in carnivores has been revisited extensively using cross-species chromosome painting. painting probes derived from flow-sorted chromosomes of the domestic dog, which has one of the most rearranged karyotypes in mammals and the highest dipoid number (2n=78) in carnivores, are a powerful tool in detecting both evolutionary intra- and inter-chromosomal rearrangements. however, only a few comparative maps have been established between dog and other non-canidae species. here, we ... | 2012 | 22086079 |
| de novo assembly and characterization of narrow-ridged finless porpoise renal transcriptome and identification of candidate genes involved in osmoregulation. | during the evolutionary transition from land to water, cetaceans have undergone numerous critical challenges, with osmoregulation being the major one. two subspecies of the narrow-ridged finless porpoise (neophocaena asiaeorientalis), the freshwater yangtze finless porpoise (n. a. asiaeorientalis, naa) and the marine east asian finless porpoise (n. a. sunameri, nas), provide excellent subjects to understand the genetic basis of osmoregulatory divergence between freshwater and marine mammals. the ... | 2015 | 25608655 |
| organization and characteristics of the major histocompatibility complex class ii region in the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis). | little is known about the major histocompatibility complex (mhc) in the genome of yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) (yfp) or other cetaceans. in this study, a high-quality yfp bacterial artificial chromosome (bac) library was constructed. we then determined the organization and characterization of yfp mhc class ii region by screening the bac library, followed by sequencing and assembly of positive bac clones. the yfp mhc class ii region consists of two segreg ... | 2016 | 26932528 |
| isolation of culturable aerobic bacteria and evidence of kerstersia gyiorum from the blowhole of captive yangtze finless porpoises. | bacterial respiratory illnesses are problematic in aquatic mammals such as the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis; yfp), which is now at a critically endangered status. yet little is known about the bacteria inhabiting the respiratory tract of yfps. in this study, we preliminarily characterized the culturable aerobic bacteria from blow samples of captive yfps. the bacterial diversity was assessed through cultivation by direct exhalation onto columbia blood agar ... | 2016 | 27251558 |
| population- and growth-related differences in helminthic fauna of finless porpoises (neophocaena asiaeorientalis) in five japanese populations. | a survey of helminths and ectoparasites, including epizoits, was conducted in narrow-ridged finless porpoises (neophocaena asiaeorientalis) from japanese five populations using dead stranded or incidentally caught animals. in total, 13 helminth species were found (6 nematodes, 4 trematodes, 2 cestodes and 1 acanthocephalan) in 137 porpoises. a new location record of stenurus nanjingensis and a new host record of tetrabothrius sp. were obtained. eight species of helminth were considered common in ... | 2017 | 28070088 |
| population genetic structure of the yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis): implications for management and conservation. | understanding the population genetic structure is a prerequisite for conservation of a species. the degree of genetic variability characteristic of the mitochondrial dna control region has been widely exploited in studies of population genetic structure and can be useful in identifying meaningful population subdivisions. to estimate the genetic profile of the yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis), an endangered freshwater population endemic to china, the complete mt ... | 2005 | 16144307 |
| isolation of robinsoniella peoriensis from the fecal material of the endangered yangtze finless porpoise, neophocaena asiaeorientalis asiaeorientalis. | the aim of this study was to determine the causative agent of diarrhea in an endangered yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis). from the fecal material collected from this porpoise robinsoniella peoriensis was isolated. | 2013 | 23298816 |
| the diel rhythms of biosonar behavior in the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) in the port of the yangtze river: the correlation between prey availability and boat traffic. | information on the habitat use of the critically endangered yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) is critical for its conservation. the diel biosonar behavior of the porpoise in the port areas of the yangtze river was examined along with simultaneous observations of fish density and boat traffic. biosonar pulses from the porpoises were detected for 1233 min (5.77%) over a 21,380 min duration of effective observations. in total, 190 (5.63%) buzzes (an indication o ... | 2014 | 24823945 |
| frequent and prolonged nocturnal occupation of port areas by yangtze finless porpoises (neophocaena asiaeorientalis): forced choice for feeding? | during the yangtze freshwater dolphin expedition 2012, yangtze finless porpoises (neophocaena asiaeorientalis) were acoustically monitored in 9 port areas at night. during 6566 min of nocturnal monitoring, porpoise sonar was detected for 488 min (7.43% of the total time). of all 81 encounters, the longest echolocation span obtained was 102.9 min, suggesting frequent and prolonged porpoise occupation of the port areas. a combined total of 2091 click trains were recorded, with 129 (6.2%) containin ... | 2015 | 24920210 |
| genetic diversity and population structure of the critically endangered yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) as revealed by mitochondrial and microsatellite dna. | ecological surveys have indicated that the population of the critically endangered yangtze finless porpoise (yfp, neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. genetic conservation of this population will be an important component of the long-term conservation effort. we used a 597 base pair mitochondrial dna (mtdna) control region and 11 microsatellite loci to analyze the genetic diversity a ... | 2014 | 24968271 |
| effects of fish community on occurrences of yangtze finless porpoise in confluence of the yangtze and wanhe rivers. | the yangtze finless porpoise is a subspecies of narrow-ridged finless porpoise endemic to the middle and lower reaches of the yangtze river and the adjoining poyang and dongting lakes. with the depletion of fish stocks in the yangtze river in recent decades, food availability has become the most important factor affecting the survival of this subspecies. despite this, the relationships between fish community and occurrences of porpoise are far from being fully understood. therefore, during septe ... | 2015 | 25619818 |
| mitochondrial genome of the neophocaena asiaeorientalis asiaeorientalis (phocaenidae: neophocaena). | yangtze finless porpoise, neophocaena asiaeorientalis asiaeorientalis, is a cetacea animal which has been reclassified as a critically endangered species by iucn in 2013. in this study, we determined the complete mitochondrial genome of n. a. asiaeorientalis for use in future phylogenetic analyses. the complete mitochondrial genome of n. a. asiaeorientalis (16,385 bp in length) contained 37 genes (13 protein-coding genes, 2 rrna genes, and 22 trna genes) and a non-coding region (d-loop). additio ... | 2016 | 25703854 |
| acoustic property reconstruction of a neonate yangtze finless porpoise's (neophocaena asiaeorientalis) head based on ct imaging. | the reconstruction of the acoustic properties of a neonate finless porpoise's head was performed using x-ray computed tomography (ct). the head of the deceased neonate porpoise was also segmented across the body axis and cut into slices. the averaged sound velocity and density were measured, and the hounsfield units (hu) of the corresponding slices were obtained from computed tomography scanning. a regression analysis was employed to show the linear relationships between the hounsfield unit and ... | 2015 | 25856588 |
| fecal bacterial composition of the endangered yangtze finless porpoises living under captive and semi-natural conditions. | intestinal microbiota is essential to the health and physiology of host animals. we undertook the first microbiological study of the fecal bacterial composition from critically endangered (cr) yangtze finless porpoises (neophocaena asiaeorientalis asiaeorientalis; yfps) living under captive and semi-natural conditions using both high-throughput sequencing method and 16s rrna gene clone library method. as determined by high-throughput sequencing of v3-v4 regions of the 16s rrna gene, semi-natural ... | 2016 | 26620537 |
| behavioral laterality in yangtze finless porpoises (neophocaena asiaeorientalis asiaeorientalis). | the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) is a critically endangered species with less than 1000 individuals expected to be left in the wild. while many studies have been conducted on laterality among several cetacean species, no studies investigating the yangtze finless porpoise have been conducted. using event sampling methods, several behaviors such as flipper-body touching, object touching, barrel-rolls, side swimming, and swimming direction were recorded fro ... | 2017 | 28454916 |
| parasitic infections in the east asian finless porpoise neophocaena asiaeorientalis sunameri living off the chinese yellow/bohai sea coast. | parasitic disease is among the major causes of health problems in marine mammals. however, little information on parasitic species composition and infection levels in finless porpoises (neophocaena spp.) is available. in this study, we report the first systematic survey on parasitic infections in the east asian finless porpoise n. asiaeorientalis sunameri (eafp) living off the chinese yellow/bohai sea coast. using both morphological and molecular methods, 5 parasitic helminths were identified: c ... | 2017 | 28627493 |
| b-mode ultrasonographic evaluation of the testis in relation to serum testosterone concentration in male yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) during the breeding season. | the use of ultrasonography as a noninvasive tool for assessing the reproductive status of the male yangtze finless porpoise (yfp; neophocaena phocaenoides asiaeorientalis) was validated by correlating ultrasonographically determined testicular volume (tv) and testicular parenchyma pixel intensity (pi) with serum testosterone (t) concentration. the testes of 13 free-ranging male yfps from the tian-e-zhou reserve and three captive animals from the baiji dolphinarium (wuhan, china) were examined ul ... | 2010 | 19945744 |
| the source parameters of echolocation clicks from captive and free-ranging yangtze finless porpoises (neophocaena asiaeorientalis asiaeorientalis). | the clicks of yangtze finless porpoises (neophocaena asiaeorientalis asiaeorientalis) from 7 individuals in the tank of baiji aquarium, 2 individuals in a netted pen at shishou tian-e-zhou reserve and 4 free-ranging individuals at tianxingzhou were recorded using a broadband digital recording system with four element hydrophones. the peak-to-peak apparent source level (asl_pp) of clicks from individuals at the baiji aquarium was 167 db re 1 μpa with mean center frequency of 133 khz, -3db bandwid ... | 2015 | 26053758 |
| hearing pathways in the yangtze finless porpoise, neophocaena asiaeorientalis asiaeorientalis. | how an animal receives sound may influence its use of sound. while 'jaw hearing' is well supported for odontocetes, work examining how sound is received across the head has been limited to a few representative species. the substantial variation in jaw and head morphology among odontocetes suggests variation in sound reception. here, we address how a divergent subspecies, the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) hears low-, mid- and high-frequency tones, as well ... | 2014 | 24143026 |
| assembly and characterization of the mhc class i region of the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis). | the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis; yfp) is the sole freshwater subspecies of n. asiaeorientalis and is now critically endangered. major histocompatibility complex (mhc) is a family of highly polymorphic genes that play an important immunological role in antigen presentation in the vertebrates. currently, however, little is known about mhc region in the genome of the yfp, which hampers conservation genetics and evolutionary ecology study using mhc genes. in ... | 2016 | 26585324 |
| analysis of the bacterial diversity in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. | the aim of this study was to determine the bacteria present in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. fecal samples were collected from 12 yangtze finless porpoises living in the wild at poyang lake, located in jiangxi province, china. to determine the bacterial diversity, a 16s rrna gene clone library using the bacterial pcr primers fd1 and rp2, was prepared. a total of 138 near-full-length sequences were analyzed and 39 operatio ... | 2011 | 22201021 |
| estimation of the detection probability for yangtze finless porpoises (neophocaena phocaenoides asiaeorientalis) with a passive acoustic method. | yangtze finless porpoises were surveyed by using simultaneous visual and acoustical methods from 6 november to 13 december 2006. two research vessels towed stereo acoustic data loggers, which were used to store the intensity and sound source direction of the high frequency sonar signals produced by finless porpoises at detection ranges up to 300 m on each side of the vessel. simple stereo beam forming allowed the separation of distinct biosonar sound source, which enabled us to count the number ... | 2008 | 18537391 |
| first human-caused extinction of a cetacean species? | the yangtze river dolphin or baiji (lipotes vexillifer), an obligate freshwater odontocete known only from the middle-lower yangtze river system and neighbouring qiantang river in eastern china, has long been recognized as one of the world's rarest and most threatened mammal species. the status of the baiji has not been investigated since the late 1990s, when the surviving population was estimated to be as low as 13 individuals. an intensive six-week multi-vessel visual and acoustic survey carri ... | 2007 | 17686754 |
| the ontogeny of echolocation in a yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis). | acoustic and concurrent behavioral data from one neonatal male yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) in captivity were presented. the calf click train was first recorded at 22 days postnatal, and the frequency of hydrophone-exploration behavior with head scanning motions in conjunction with emissions of click trains by the calf increased gradually with age. the echolocation clicks in the first recorded click train were indistinguishable from those of adults. calf ec ... | 2007 | 17672621 |
| serum concentrations of gonadotropins and steroid hormones of neophocaena phocaenoides asiaeorientalis in middle and lower regions of the yangtze river. | as a relatively isolated and unique freshwater population, the yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) is the most endangered subpopulation of this species. the objective of this study was to improve our understanding of their reproductive endocrinology by measuring (radioimmunoassay) serum concentrations of fsh, lh, estradiol (e(2)), progesterone (p(4)) and testosterone (t(2)) in free-ranging animals. blood samples were collected from 66 yangtze finless porpoises (41 ... | 2007 | 17196248 |
| range-wide yangtze freshwater dolphin expedition: the last chance to see baiji? | there are two species of fresh water cetaceans surviving in the yangtze river system in china: baiji (lipotes vexillifer) and yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis). as a result of the expansion of human activities on the river, their distribution ranges appear to be decreasing and in the case of the baiji, are even being restricted to several sections. the baiji is the world's most critically endangered cetacean species with a population estimated at only a few tens ... | 2006 | 17120833 |
| passive acoustic survey of yangtze finless porpoises using a cargo ship as a moving platform. | in order to periodically investigate the population and distribution of the yangtze finless porpoise (neophocaena asiaeorientalis asiaeorientalis) in its main distribution range in the yangtze river, a passive acoustic system deployed on a cargo ship as a moving platform, rather than a dedicated research ship, was developed. a stereo acoustic event data-logger (a-tag) was installed on the cargo ship to passively detect phonating animals. in three surveys carried out in the yangtze river from wuh ... | 2011 | 21973384 |
| establishment and characterization of fibroblast cell lines from the skin of the yangtze finless porpoise. | the yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis), as the sole freshwater subspecies of n. phocaenoides, is endemic to the yangtze river and its adjacent lakes. its population has declined significantly over recent decades. in this study, we established a skin-derived finite fibroblast cell line of the yangtze finless porpoise, named yfp-sf1, using primary cell culture methods, and an immortalized cell line, t-yfp-sf1, through co-transfection (gfp and sv40 t antigens) techn ... | 2011 | 21959845 |
| accumulation of butyltin compounds in finless porpoises (neophocaena asiaeorientalis) from korean coast: tracking the effectiveness of tbt regulation over time. | the concentrations of butyltin compounds (bts) were measured in the livers of finless porpoises (neophocaena asiaeorientalis) caught off the korean coast in 2003 and 2010, to assess the effectiveness of legislative action against bts. the concentrations of bts ranged from 65.1 to 1432 (average: 370) ng/g wet weight, within the ranges reported by previous studies. the levels of bts in almost all the samples exceeded the suggested threshold value, implying potential adverse health effects from the ... | 2013 | 23207253 |
| auditory temporal resolution and evoked responses to pulsed sounds for the yangtze finless porpoises (neophocaena phocaenoides asiaeorientalis). | temporal cues are important for some forms of auditory processing, such as echolocation. among odontocetes (toothed whales, dolphins, and porpoises), it has been suggested that porpoises may have temporal processing abilities which differ from other odontocetes because of their relatively narrow auditory filters and longer duration echolocation signals. this study examined auditory temporal resolution in two yangtze finless porpoises (neophocaena phocaenoides asiaeorientalis) using auditory evok ... | 2011 | 21909973 |
| noise-induced temporary threshold shift and recovery in yangtze finless porpoises neophocaena phocaenoides asiaeorientalis. | in yangtze finless porpoises neophocaena phocaenoides asiaeorientalis, the effects of fatiguing noise on hearing thresholds at frequencies of 32, 45, 64, and 128 khz were investigated. the noise parameters were: 0.5-oct bandwidth, -1 to +0.5 oct relative to the test frequency, 150 db re 1 μpa (140-160 db re 1 μpa in one measurement series), with 1-30 min exposure time. thresholds were evaluated using the evoked-potential technique allowing the tracing of threshold variations with a temporal reso ... | 2011 | 21786923 |
| ethogram of yangtze finless porpoise calves (neophocaena phocaenoides asiaeorientalis). | underwater behavioral patterns of one yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) calf in captivity and those performed on the water surface by two calves in semi-natural environment were focally followed and continuously recorded until one year postpartum to construct the ethogram. the results indicate that 1) the three calves could display diverse and active behavioral patterns; 2) soon after birth, patterns critical for survival appeared first; 3) playful and social pa ... | 2010 | 20979255 |
| trace element concentrations, risks and their correlation with metallothionein genes polymorphism: a case study of narrow-ridged finless porpoises (neophocaena asiaeorientalis) in the east china sea. | the concentration of trace elements (tes) and their risk to narrow-ridged finless porpoises (neophocaena asiaeorientalis) are still unclear. the present study determined the concentration of typical tes in liver, kidney, and muscle tissues from porpoises in the east china sea, assessed potential health risk of tes to porpoises, and explored the relationship between te concentration and metallothionein genes (mts) polymorphism. it was found that zn, cu, mn, cd and hg were highly accumulated in li ... | 2017 | 27697338 |
| using environmental dna to assess population-wide spatiotemporal reserve use. | scientists increasingly rely on protected areas to assist in biodiversity conservation, yet the efficacy of these areas is rarely systematically assessed, often because of underfunding. still, adaptive management strategies to maximize conservation success often rely on understanding the temporal and spatial dynamism of populations therein. examination of environmental dna (edna) is a time and cost-effective way to monitor species' distribution, and quantitative polymerase chain reaction (qpcr) ... | 2017 | 28221696 |
| widespread passive acoustic detection of yangtze finless porpoise using miniature stereo acoustic data-loggers: a review. | data on distribution, abundance, ecology, and behavior are essential for conservation and management of endangered animals in the wild. yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) is an endangered small odontocete species, living exclusively in the yangtze river and its connecting poyang and dongting lakes. frequent production of high-frequency bio-sonar signals allows the animal to be detectable using passive acoustic methods. recently, a stereo acoustic event data-logge ... | 2010 | 20815482 |
| variation in sexual behaviors in a group of captive male yangtze finless porpoises (neophocaena phocaenoides asiaeorientalis): motivated by physiological changes? | most male mammals in temperate regions demonstrate seasonal sexual behaviors that coincide with seasonal variations in gonadal activities and androgen hormones. the yangtze finless porpoise is a temperate freshwater cetacean species and an obvious seasonal breeder. to investigate the relationship between sexual behavior and gonadal activity in this animal, testicular size (volume) and structure (ultrasonogram pixel intensity) of two adult male porpoises (af, ab) and one sub-adult male (tt) were ... | 2010 | 20708252 |
| high mhc dqb variation and asymmetric allelic distribution in the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. | the endangered yangtze finless porpoise is found in the middle and lower reaches of the yangtze river and its adjoining big lakes. to explore the major histocompatibility complex (mhc) genetic diversity and allelic distribution patterns across its range, we investigated variation at dqb exon 2. from 76 porpoises, we identified 18 dqb sequences. the freshwater yangtze populations had much higher allelic diversity than marine populations. among these freshwater populations, the middle-reach popula ... | 2010 | 20087659 |
| ultrastructure of the spermatozoa of the yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis). | semen sample was collected from two captive adult yangtze finless porpoises (neophocaena phocaenoides asiaeorientalis) during physical examination. one individual was aged about 9 years with body length 143 cm (total length) and body weight 46.1 kg in 2003. the age of the other was unknown and its body length was 147 cm and body weight was 43 kg in 2004. ultrastructure of their spermatozoa was examined using scanning and transmission electron microscope. the sperm concentration was 4.17 x 10(9) ... | 2009 | 19519735 |
| comparison of stationary acoustic monitoring and visual observation of finless porpoises. | the detection performance regarding stationary acoustic monitoring of yangtze finless porpoises neophocaena phocaenoides asiaeorientalis was compared to visual observations. three stereo acoustic data loggers (a-tag) were placed at different locations near the confluence of poyang lake and the yangtze river, china. the presence and number of porpoises were determined acoustically and visually during each 1-min time bin. on average, porpoises were acoustically detected 81.7+/-9.7% of the entire e ... | 2009 | 19173440 |
| accumulation and temporal changes of pcdd/fs and dioxin-like pcbs in finless porpoises (neophocaena asiaeorientalis) from korean coastal waters: tracking the effectiveness of regulation. | temporal trend studies are useful to evaluate the effectiveness of regulations on local pollutants. the emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (pcdd/fs) and dioxin-like polychlorinated biphenyls (pcbs) has been regulated by the korean government in accordance with the stockholm convention. the accumulation and temporal trends of pcdd/fs and dioxin-like pcbs were investigated in finless porpoises (neophocaena asiaeorientalis) collected in korean waters. median concentrati ... | 2016 | 26971816 |
| parentage-based group composition and dispersal pattern studies of the yangtze finless porpoise population in poyang lake. | social behaviors are poorly known for the critically endangered yangtze finless porpoise (yfp, neophocaena asiaeorientalis asiaeorientalis). here, group composition and dispersal patterns of the yfp population living in the poyang lake were studied by parentage-based pedigree analyses using 21 microsatellite loci and a 597 bp segment of the mitochondrial dna control region. in this study, 21 potential mother-offspring pairs and six potential father-offspring pairs (including two potential parent ... | 2016 | 27529217 |
| sonar gain control in echolocating finless porpoises (neophocaena phocaenoides) in an open water. | source levels of echolocating free-ranging yangtze finless porpoise (neophocaena phocaenoides asiaeorientalis) were calculated using a range estimated by measuring the time delays of the signals via the surface and bottom reflection paths to the hydrophone, relative to the direct signal. peak-to-peak source levels for finless porpoise were from 163.7 to 185.6 db re: 1 micropa. the source levels are highly range, dependent and varied approximately as a function of the one-way transmission loss fo ... | 2006 | 17069278 |
| nonconstant quality of auditory filters in the porpoises, phocoena phocoena and neophocaena phocaenoides (cetacea, phocoenidae). | simultaneous tone-tone masking in conjunction with the envelope-following response (efr) recording was used to obtain tuning curves in porpoises phocoena phocoena and neophocaena phocaenoides asiaeorientalis. the efr was evoked by amplitude-modulated probes with a modulation rate of 1000 hz and carrier frequencies from 22.5 to 140 khz. equivalent rectangular quality qerb of the obtained tuning curves varied from 8.3-8.6 at lower (22.5-32 khz) probe frequencies to 44.8-47.4 at high (128-140 khz) ... | 2006 | 16708972 |