| determination of hbcd, pbdes and meo-bdes in california sea lions (zalophus californianus) stranded between 1993 and 2003. | blubber samples from male california sea lions (zalphophus californianus) stranded between 1993 and 2003 were analyzed for 27 polybrominated diphenyl ether (pbde) congeners, three isomers of hexabromocyclododecane (hbcd) and 14 methoxylated polybrominated diphenyl ether (meo-bde) congeners. total pbdes ranged from 450 ng/g to 4740 ng/g wet mass and total hbcd ranged from < 0.3 ng/g to 12 ng/g wet mass. the concentration of hbcd increased from 0.7 ng/g to12.0 ng/g wet mass in sea lion blubber bet ... | 2006 | 16293266 |
| surgical resection of an orbital fat prolapse in a california sea lion (zalophus californianus). | a 23-year-old captive female california sea lion (zalophus californianus) developed an inferiotemporal subconjunctival swelling of the right eye. surgical excision of the mass was performed and a diagnosis of orbital fat prolapse was confirmed histopathologically. there was no recurrence of orbital fat prolapse at 15 months post operatively. this is the first known case of orbital fat prolapse in the california sea lion. | 2005 | 16008709 |
| right ear advantage for conspecific calls in adults and subadults, but not infants, california sea lions (zalophus californianus): hemispheric specialization for communication? | this paper explores functional hemispheric asymmetries in the perception of auditory signals in a marine mammal species, the sea lion. using a head-orienting task toward sounds we found a right ear--left hemisphere--advantage for conspecific calls in adult and subadult california sea lions (zalophus californianus) that was absent in infants. non-conspecific sounds did not elicit lateralized reactions in any age group. these findings show that maturational steps regarding communication in the bra ... | 2005 | 15845100 |
| seasonal prevalence and intensity of hookworms (uncinaria spp.) in california sea lion (zalophus californianus) pups born in 2002 on san miguel island, california. | intestines of california sea lion (zalophus californianus) pups (n= 204), born in 2002 on san miguel island, california, were examined for hookworms (uncinaria spp.) as part of a seasonal mortality study from june through december 2002 and january 2003. the investigation was planned to coincide with most of the previously established hookworm infection period of the pups. prevalence of hookworms in dead pups was 100% for each month of the study. the geometric mean intensity of infections per mon ... | 2005 | 15824900 |
| penetration of the small intestine of a california sea lion (zalophus californianus) pup by adult hookworms (uncinaria spp). | during a study on the mortality of california sea lion (zalophus californianus) pups born on san miguel island, california in 2002, two adult female hookworms (uncinaria spp) were found penetrating the serosal surface of the intestinal wall and protruding into the peritoneal cavity of one pup. documentation and a description of this unexpected finding and associated lesions are presented here. also, adult hookworms were found in the peritoneal fluid of two other dead z. californianus pups. | 2004 | 15115001 |
| acute haemorrhagic leucoencephalitis in a californian sea lion (zalophus californianus). | | 2004 | 15029968 |
| auditory and behavioral responses of california sea lions (zalophus californianus) to single underwater impulses from an arc-gap transducer. | a behavioral response paradigm was used to measure underwater hearing thresholds in two california sea lions (zalophus californianus) before and after exposure to underwater impulses from an arc-gap transducer. preexposure and postexposure hearing thresholds were compared to determine if the subjects experienced temporary shifts in their masked hearing thresholds (mtts). hearing thresholds were measured at 1 and 10 khz. exposures consisted of single underwater impulses produced by an arc-gap tra ... | 2003 | 14514220 |
| two distinct carcinomas of mammary gland origin in a california sea lion. | two histologic types of mammary cancer were encountered in an aged captive california sea lion (zalophus californianus). a cancer with myoepithelial cell proliferation, which had metastasized to distant viscera, was located in the left cranial mammary region. another cancer without myoepithelial cell proliferation was located in the right posterior mammary region, formed secondary nodules, and had metastasized to a regional lymph node. the presence of two different neoplasms in this sea lion is ... | 2003 | 12685092 |
| mental rotation of perspective stimuli in a california sea lion (zalophus californianus). | the time it takes humans to discriminate rotated objects from their mirror images increases linearly with the rotation angle. this phenomenon is probably due to an analogue mode of visual information processing during which an object's mental representation is rotated in a time-consuming process called mental rotation. as the speed of mental rotation in humans depends on rotation axis, we tested the ability of a california sea lion to mentally rotate perspective line drawings of three-dimensiona ... | 2003 | 12660446 |
| inbreeding: disease susceptibility in california sea lions. | | 2003 | 12621424 |
| lingual squamous cell carcinoma in a california sea lion (zalophus californianus). | a 28-yr-old female california sea lion (zalophus californianus) in a commercial aquarium developed an ulcerated lingual tumor and died. necropsy revealed a moderately differentiated squamous cell carcinoma. immunohistochemical staining and electron microscopic studies revealed that the tumor cells were strongly positive with anti-keratin-cytokeratin antibody and had abundant tonofibrils and desmosomes. the neoplasm had metastasized to a mandibular lymph node. | 2002 | 12564535 |
| maneuverability by the sea lion zalophus californianus: turning performance of an unstable body design. | maneuverability is critical to the performance of fast-swimming marine mammals that use rapid turns to catch prey. overhead video recordings were analyzed for two sea lions (zalophus californianus) turning in the horizontal plane. unpowered turns were executed by body flexion in conjunction with use of the pectoral and pelvic flippers, which were used as control surfaces. a 90 degree bank angle was used in the turns to vertically orient the control surfaces. turning radius was dependent on body ... | 2003 | 12517984 |
| organochlorine pollutants [corrected] in california sea lions revisited. | dichlorodiphenyltrichloroethane (ddt) and polychlorinated biphenyls (pcbs) are ubiquitous environmental contaminants that have been banned in most countries, but considerable amounts continue to cycle the ecosphere. top trophic level predators, like sea birds and marine mammals, bioaccumulate these lipophilic compounds, reflecting their presence in the environment. | 2002 | 12479795 |
| long-term memory for concepts in a california sea lion ( zalophus californianus). | an adult california sea lion ( zalophus californianus) with extensive experience in performing discrimination learning tasks was tested to evaluate her long-term memory for two previously learned concepts. an associative concept, that of equivalence classification, was retested after a retention interval of approximately 1 year. the sea lion had originally shown emergent equivalence classification with nonsimilarity-based classes of stimuli in a simple discrimination repeated-reversal procedure ... | 2002 | 12461600 |
| molecular characterization of expressed dqa and dqb genes in the california sea lion ( zalophus californianus). | to date, there are no published mhc sequences from the california sea lion (zalophus californianus), a thriving species that, by feeding high on the marine food web, could be a sentinel for disturbances in marine and coastal ecosystems. in this study, degenerate primers and race technology were used to amplify near-full-length (mhczaca- dqb) and full-length (mhczaca- dqa) expressed class ii mhc gene products from the peripheral blood mononuclear cells of two california sea lions in rehabilitatio ... | 2002 | 12185537 |
| changes in auditory sensitivity with depth in a free-diving california sea lion (zalophus californianus). | all current data on underwater hearing in pinnipeds are based on tests conducted in small tanks, and may not accurately represent the auditory functioning of free-ranging animals, especially if hearing sensitivity changes with water depth. underwater auditory thresholds were determined for a california sea lion at depths ranging from 10 to 100 meters. the following results were obtained: (1) false alarm probabilities (responding in the absence of a signal) decreased significantly with depth, ind ... | 2002 | 12141359 |
| scanning electron microscopy study of the tongue and lingual papillae of the california sea lion (zalophus californianus californianus). | we observed the three-dimensional structures on the external surface and the connective tissue cores (ctcs) of the california sea lion (zalophus californianus californianus), after exfoliation of the epithelium of the lingual papillae (filiform, fungiform, and vallate papillae), using scanning electron microscopy (sem) and conventional light microscopy. macroscopically, the tongue was v-shaped and its apex was rounded. at the posterior area of the tongue, five vallate papillae were arranged in a ... | 2002 | 11997883 |
| domoic acid toxicity in californian sea lions (zalophus californianus): clinical signs, treatment and survival. | eighty-one californian sea lions (zalophus californianus) with signs of domoic acid toxicity stranded along the coast of california in 1998 when there were blooms of the domoic acid-producing alga pseudonitzschia australis off-shore. in 2000, a further 184 sea lions stranded with similar clinical signs, but the strandings occurred both during detectable algal blooms and after the blooms had subsided. the clinical signs in these 265 californian sea lions included seizures, ataxia, head weaving, d ... | 2002 | 11995679 |
| standard metabolic rate at the surface and during trained submersions in adult california sea lions (zalophus californianus). | the metabolic rate (mr) of four adult california sea lions (zalophus californianus), two males and two females, was quantified during trained submersion and stationing behavior in laboratory tanks. mr was measured, at rest and for single submersions of increasing duration (1-7 min), by measuring oxygen consumption using open-circuit, indirect calorimetry. standard mr was measured under conditions defined for basal mr and was found to be 1.9 to 3 times that predicted for terrestrial animals of si ... | 2001 | 11606601 |
| equivalence classification by california sea lions using class-specific reinforcers. | the ability to group dissimilar stimuli into categories on the basis of common stimulus relations (stimulus equivalence) or common functional relations (functional equivalence) has been convincingly demonstrated in verbally competent subjects. however, there are investigations with verbally limited humans and with nonhuman animals that suggest that the formation and use of classification schemes based on equivalence does not depend on linguistic skills. the present investigation documented the a ... | 2001 | 11599636 |
| use of medetomidine-zolazepam-tiletamine with and without atipamezole reversal to immobilize captive california sea lions. | from june 1998 to august 1999, 39 california sea lions (zalophus californianus) were immobilized at a rehabilitation center in northern california (usa) using medetomidine plus zolazepam and tiletamine (mzt), alone and in combination with isoflurane, with atipamezole reversal. animals were given 70 microg/kg medetomidine with 1 mg/kg of a 1:1 solution of tiletamine and zolazepam intramuscularly. mean (+/-sd) time to maximal effect was 5+/-3 min. at the end of the procedure, animals were given 20 ... | 2001 | 11504231 |
| immobilization of california sea lions using medetomidine plus ketamine with and without isoflurane and reversal with atipamezole. | the use of medetomidine and ketamine, alone and in combination with isoflurane, with atipamezole reversal was evaluated for immobilizing 51 california sea lions (zalophus californianus) for a variety of medical procedures at a rehabilitation center in northern california (usa) between may 1997 and august 1998. animals were given 140 microg/kg medetomidine with 2.5 mg/kg ketamine intramuscularly. mean (+/-sd) time to maximal effect was 8+/-5 min. at the end of the procedure, animals were given 20 ... | 2000 | 10682753 |
| detection of domoic acid in northern anchovies and california sea lions associated with an unusual mortality event. | the occurrence of an unusual mortality event involving california sea lions (zalophus californianus) along the central california coast in may 1998 was recently reported. the potent neurotoxin domoic acid (da), produced naturally by the diatom pseudo-nitzschia australis and transmitted to the sea lions via planktivorous northern anchovies (engraulis mordax), was identified as the probable causative agent. details of da analyses for anchovy tissues and sea lion feces are described. domoic acid le ... | 1999 | 10647509 |
| mortality of sea lions along the central california coast linked to a toxic diatom bloom. | over 400 california sea lions (zalophus californianus) died and many others displayed signs of neurological dysfunction along the central california coast during may and june 1998. a bloom of pseudo-nitzschia australis (diatom) was observed in the monterey bay region during the same period. this bloom was associated with production of domoic acid (da), a neurotoxin that was also detected in planktivorous fish, including the northern anchovy (engraulis mordax), and in sea lion body fluids. these ... | 2000 | 10638756 |
| functional equivalence in a california sea lion: relevance to animal social and communicative interactions. | laboratory investigations into equivalence class formation suggest how animals in social and communicative contexts learn to place dissimilar individuals, signals, responses and social reinforcers into the same functional class. kastak & schusterman (1994, anim. learn. behav., 22, 427-435) demonstrated that a california sea lion performed generalized identity matching-to-sample; that is, it chose visual stimulus a conditionally upon an identical sample a (aa matching), chose stimulus b condition ... | 1998 | 9632496 |
| isoflurane anesthesia in free ranging sea lion pups. | california sea lion pups, zalophus californianus, (n = 115), were captured and anesthetized for (mean +/- sd) 17.6 +/- 7.8 min on san miguel island, california (usa) in november of 1992. mask isoflurane anesthesia allowed intubation in 7.1 +/- 2.74 min. pups recovered and walked in 7.32 +/- 4.8 min. mask anesthesia in pups resulted in relaxation in 45 +/- 14 sec. safe, brief anesthesia was delivered in support of weighing, medical evaluation, and short surgical procedures. recovery character of ... | 1997 | 9131549 |
| heart rate and plasma lactate responses during submerged swimming and trained diving in california sea lions, zalophus californianus. | california sea lions, zalophus californianus, were trained to elicit maximum voluntary breath holds during stationary underwater targeting, submerged swimming, and trained diving. lowest heart rate during rest periods was 57 bpm. the heart rate profiles in all three protocols were dominated by a bradycardia of 20-50 bpm, and demonstrated that otariid diving heart rates were at or below resting heart rate. venous blood samples were collected after submerged swimming periods of 1-3 min. plasma lac ... | 1997 | 9051904 |
| coccidioidomycosis in free-living california sea lions (zalophus californianus) in central california. | coccidioidomycosis is described in seven california sea lions (zalophus californianus) admitted to the marine mammal center, sausalito, california (usa), between january 1986 and december 1994. diagnoses were confirmed by histology in all seven cases, culture in three cases, and serology in one case. these are believed to be the first published cases of coccidioidomycosis in free-ranging california sea lions. | 1996 | 9359077 |
| metastatic carcinoma of probable transitional cell origin in 66 free-living california sea lions (zalophus californianus), 1979 to 1994. | sixty-six (18%) cases of widely metastatic carcinoma of probable transitional cell origin were identified in 370 california sea lions (zalophus californianus) stranded alive along the central california (usa) coast, between january 1979 and december 1994. live animals were usually emaciated and anorectic, with perineal edema and occasionally hind-flipper paralysis or paresis. large yellow caseous masses were observed in the sub-lumbar lymph nodes, often extending around the ureters resulting in ... | 1996 | 8722262 |
| tactile size discrimination by a california sea lion (zalophus californianus) using its mystacial vibrissae. | the capability of a blindfolded california sea lion (zalophus californianus) to discriminate diameter differences of circular discs by means of active touch with its mystacial vibrissae was studied. using a forced choice paradigm the sea lion was required to choose the larger of two simultaneously presented perspex discs. absolute difference thresholds (delta d) were determined for 3 standard discs (1.12 cm phi, 2.52 cm phi, 8.74 cm phi) by the psychophysical method of constants. increasing disc ... | 1994 | 7807420 |
| the bronchial tree and lobular division of the lung of the california sea lion (zalophus californianus). | in the california sea lion (zalophus californianus), the position of the tracheal bifurcation is fairly cranial compared with those of mammals in general. the right lung has the dorsal, ventral, medial and lateral bronchiole systems. the cranial lobe is formed by the first bronchiole of the dorsal bronchiole system. the middle lobe is formed by the first bronchiole of the lateral bronchiole system. the accessory lobe is formed by the first bronchiole of the ventral bronchiole system. the caudal ... | 1993 | 8399752 |
| acute hepatic necrosis associated with a sarcocystis-like protozoa in a sea lion (zalophus californianus). | | 1992 | 1457561 |
| relationship between heart rate and oxygen consumption during steady-state swimming in california sea lions. | heart rate (fh) and rate of oxygen uptake (vo2) were measured in six subadult california sea lions zalophus californianus while they were at rest and while they were swimming for 15 min at controlled speeds of up to 1.4 m s-1 and pulling loads of up to 3 kg. there was a good linear relationship between fh and vo2 in all six sea lions. the slopes of the individual regression lines varied between 2.66 and 4.36 beats ml-1 o2 kg-1, the intercepts varied between 48.2 and 63.0 beats min-1 and r2 varie ... | 1992 | 1402612 |
| color vision in the california sea lion (zalophus californianus). | three california sea lions were trained to discriminate between a colored stimulus and two shades of gray in a 3-fold simultaneous choice situation. the colors blue, green and red were tested against shades of gray varying from low to high relative brightness. all animals distinguished blue from gray; two animals also distinguished green from gray; but none discriminated between red and gray. our data suggest that california sea lions have dichromatic color vision. their ability to discriminate ... | 1992 | 1604834 |
| pinniped splenic volumes. | splenic volume was measured by computerized axial tomography in three harbor seals (phoca vitulina) and two california sea lions (zalophus californianus). volumes ranged from 228 to 679 ml, representing 0.8-3.0% of calculated percentage body mass. despite possible variation in the state of splenic contraction during the examination, these values are in the upper range of reported mammalian splenic volumes (as % of body mass). this reinforces the pinniped splenic erythrocyte storage concept. | 1992 | 1539742 |
| the effect of submergence on heart rate and oxygen consumption of swimming seals and sea lions. | respiratory, metabolic, and cardiovascular responses to swimming were examined in two species of pinniped, the harbor seal (phoca vitulina) and the california sea lion (zalophus californianus). 1. harbor seals remained submerged for 82-92% of the time at swimming speeds below 1.2 m.s-1. at higher speeds, including simulated speeds above 1.4 m.s-1, the percentage of time spent submerged decreased, and was inversely related to body weight. in contrast, the percentage of time spent submerged did no ... | 1991 | 2045544 |
| artificial language comprehension and size transposition by a california sea lion (zalophus californianus). | a variation of the conditional discrimination procedure defines relations between stimuli (for example, gestural signs and their referents), and it has been used to study language comprehension in california sea lions. the animals followed instructions given by a trainer's gestures designating properties of size, brightness, and location (adjectives), types of objects (nouns), and actions (verbs). the signs can be combined and recombined according to a conditional sequence or syntax. in this stu ... | 1986 | 3802779 |
| diskospondylitis in a california sea lion. | | 1986 | 3505958 |
| metastatic squamous cell carcinoma in a beached california sea lion (zalophus californianus). | | 1986 | 3712660 |
| nutritional myopathy in a captive california sea lion. | | 1985 | 4077648 |
| polyradiculoneuritis in a california sea lion. | | 1984 | 6511605 |
| viral hepatitis (adenovirus) in a california sea lion. | a juvenile california sea lion (zalophus californianus) died 28 days after admission to the california marine mammal center. necropsy revealed hemorrhagic fluid in the stomach and hepatomegaly. histologically, there was evidence of multifocal necrotizing hepatitis and acute suppurative bronchopneumonia. amphophilic intranuclear inclusions were found, and electron microscopy revealed virions morphologically classifiable as adenovirus. | 1981 | 6276345 |
| upper airway of the california sea lion: an anesthetist's perspective. | | 1981 | 6908776 |
| metastatic adenocarcinoma in two california sea lions, zalophus c. californianus. | two california sea lions (zalophus californianus californianus) came to necropsy with morphologically identical metastatic tumors. these were glandular epithelial origin and were widespread throughout the visceral organs. both animals were found beached and dead within two months and were only 220 km apart. | 1980 | 7431526 |
| pancreatic duct adenoma and strangulation of the small intestine in a california sea lion (zalophus californianus). | a 16 year-old female california sea lion (zalophus californianus) died in a zoological garden following a period of insidious weight loss. necropsy revealed a loop of intestine strangulated by a fibrous ring connected to a pancreatic mass. histopathologic diagnosis of the latter was pancreatic duct adenoma. | 1978 | 739584 |
| the upper limit of underwater auditory frequency discrimination in the california sea lion. | | 1978 | 690337 |
| metallothionein and the subcellular localization of mercury and cadmium in the california sea lion. | | 1977 | 17507 |
| discrimination of pure-tone intensities by the california sea lion. | | 1976 | 1010891 |
| coccidioidomycosis in a california sea lion (zalophus californianus). | coccidioidomycosis in an adult male california sea lion (zalophus californianus) is described. the animal was housed in a zoo in tucson, arizona, for approximately 5 years. this is believed to be the first reported case of coccidioidomycosis in a marine mammal. | 1976 | 16498880 |
| air temperature and direct parititional calorimetry of the california sea lion (zalophus californianus). | | 1976 | 3339 |
| underwater localization of pulsed pure tones by the california sea lion(zalophus californianus). | | 1975 | 1184845 |
| thermal insulation of the california sea lion during exposure to heat. | | 1975 | 237696 |
| conditioned bardycardia in the sea lion zalophus californianus. | | 1975 | 1134577 |
| detection of underwater signals by a california sea lion and a bottlenose porpoise: variation in the payoff matrix. | | 1975 | 1141502 |
| underwater localization of click and pulsed pure-tone signals by the california sea lion (zalophus californianus). | | 1975 | 1117093 |
| evidence of duplicity in the retina of the california sea lion (zalophus californianus). | | 1975 | 234062 |
| auditory sensitivity of a california sea lion to airborne sound. | | 1974 | 4424866 |
| california sea lion myoglobin. complete covalent structure of the polypeptide chain. | | 1974 | 4850855 |
| evaporative heat loss in the california sea lion and harbor seal. | | 1974 | 4151637 |
| behavioral thermoregulation in the california sea lion. | | 1974 | 4815152 |
| conductive heat loss to sand in california sea lions and a harbor seal. | | 1974 | 4149005 |
| premature births in california sea lions: association with high organochlorine pollutant residue levels. | premature pupping in california sea lions has been noted on the breeding islands since 1968. organochlorine pesticides and polychlorinated biphenyl residues were two to eight times higher in tissues of premature parturient females and pups than in similar tissues of full-term parturient females and pups collected on san miguel island in 1970. | 1973 | 4199282 |
| heartworms in captive california sea lions. | | 1973 | 4795400 |
| oxygen uptake of the california sea lion and harbor seal during exposure to heat. | | 1973 | 4726508 |
| innervation of the vibrissae of the california sea lion, zalophus californianus. | | 1973 | 4723405 |
| underwater audiogram of the california sea lion by the conditioned vocalization technique. | conditioning techniques were developed demonstrating that pure tone frequencies under water can exert nearly perfect control over the underwater click vocalizations of the california sea lion (zalophus californianus). conditioned vocalizations proved to be a reliable way of obtaining underwater sound detection thresholds in zalophus at 13 different frequencies, covering a frequency range of 250 to 64,000 hz. the audiogram generated by these threshold measurements suggests that under water, the r ... | 1972 | 5033891 |
| respiratory variation of heart rate in the california sea lion. | | 1972 | 5058365 |
| leptospirosis in a california sea lion. | | 1972 | 4481104 |
| aerial and underwater visual acuity in the california sea lion (zalophus califernianus) as a function of luminance. | | 1971 | 5288866 |
| ddt in california sea lions. | | 1971 | 4942890 |
| behavioral control of body temperature in the unrestrained california sea lion. | | 1971 | 5134250 |
| development of a fatted male phenomenon in california sea lions. | | 1971 | 5170706 |
| verminous pneumonia in the california sea lion (zalophus californianus). | | 1971 | 5167763 |
| conditioned vocalizations as a technique for determining visual acuity thresholds in sea lions. | aerial visual acuity and underwater visual acuity were measured in two sea lions (zalophus californianus) by training them to emit click bursts if they saw a striped target or to remain silent if they saw a gray target. the closest grating spacings that could be resolved both in air and under water subtended a visual angle of 5.5 minutes of arc at a distance of 5.5 meters. | 1970 | 5424799 |
| anesthesia and restraint for the california sea lion, zalophus californianus. | | 1969 | 5388165 |
| barking, dominance, and territoriality in male sea lions. | experiments in which male sea lions (zalophus californianus) were removed and reintroduced into a social group demonstrate that barking by larger males restricts movement and barking by other smaller males. barking and aggression were primarily directed toward animals of most nearly equal size. two 6-year-olds seeking to establish and maintain territorial status used aggressive tactics similar to those observed in breeding males in the field. | 1968 | 5689412 |
| attention shift and errorless reversal learning by the california sea lion. | repeated combinations of a previously well-learned size clue preference with the previously negative form cue followed by gradual reduction of the size cue resulted in nearly errorless performance by two sea lion. on a series of nine form-discriminination reversals. systematic insertion of probe trials, during which the size cue was not present, revealed that attention was primarily focused on the size dimension during early stages of training, when size differences were large, and then was grad ... | 1967 | 6022233 |
| underwater vocalization by sea lions: social and mirror stimuli. | underwater vocal response of three sea lions (zalophus californianus) increased under conditions of social interaction. when confronted by their mirror images, two animals increased their number of vocalizations, which included "whinny" sounds, barks, buzzing, and varying patterns of click trains. click vocalizations showed habituation and recovery when the animals were in the presence of the mirror stimulus. | 1966 | 5916951 |
| serial discrimination-reversal learning with and without errors by the california sea lion. | a sea lion under water performed virtually without errors on a series of three form-discrimination reversals. significant training requirements were the combining of a previously well-established size cue preference with the nonpreferred form cue, followed by the gradual reduction of the size cue until it was completely eliminated. orienting responses reached a peak and then decreased during progressive-dimensional-change training, suggesting critical stages in the transition of attention from t ... | 1966 | 5964516 |
| shaping and discriminative control of underwater click vocalizations in a california sea lion. | a captive vea lion (zalophus californianus) which had never before produced clicking sounds in the laboratory was first conditioned to vocalize in air and subsequently learned to emit underwater clicks. clicking was brought under control by differential reinforcement procedures. vocalization as an indicator response may be useful in the comparative study of discriminative behavior. | 1965 | 5858032 |
| underwater visual discrimination by the california sea lion. | two captive sea lions (zalophus californianus) presented with a series of size-discrimination tasks showed preferences for the smaller of two targets and gave virtually errorless performances despite changes in the form and relative size of the targets. further tests revealed that they were capable of discriminating a size-difference ratio as small as 1.06:1. | 1965 | 14260381 |
| [studies on the kidney blood supply in sea-lions (zalophus californianus)]. | | 1963 | 14092219 |
| the corticoids of the adrenal of the california sea lion (zalophus californianus). | | 1961 | 13885607 |
| chronic aortitis in the california sea-lion, zalophus californianus. | | 1960 | 14405285 |
| pinniped phylogenetic relationships inferred using aflp markers. | amplified fragment length polymorphisms (aflps) are widely used for phylogenetic reconstruction in plants but their use in animal taxa has been limited, and in mammals rare. in addition, their use has been largely limited to shallow relationships amongst species or subspecies. here, we genotype 23 pinniped species for 310 aflp markers and find a strong phylogenetic signal, with individuals coclustering within species, and overall a good agreement between our phylogeny and those constructed using ... | 2009 | 19277054 |
| [radiographic observations of a healthy otter zalophus californianus and of an otter with parasitic pneumonia caused by parafilarioides decorus]. | | 2016 | 4461446 |
| underwater barking by male sea lio (zalophus californianus). | | 1969 | 5788987 |
| what california sea lions exposed to domoic acid might teach us about autism: lessons for predictive and preventive medicine. | autism spectrum disorder (asd) shares many biological and behavioral similarities with the deleterious effects of domoic acid (da) exposure. da is produced by marine algae and most commonly by species ofpseudo-nitzschia. humans and marine mammals can be exposed to da when they consume whole fish or shellfish. the mammalian fetus is highly sensitive to the deleterious effects of da exposure. both asd and exposures to toxic levels of da feature repetitive behaviors, challenges with social interact ... | 2017 | 29021833 |
| no evidence for clonal transmission of urogenital carcinoma in california sea lions (zalophus californianus). | urogenital carcinoma is a highly metastatic cancer affecting california sea lions (zalophus californianus). the disease has high prevalence amongst stranded animals, and is one of the most commonly observed cancers in wildlife. the genital localisation of primary tumours suggests the possibility that coital transmission of an infectious agent could underlie this disease. otarine herpesvirus type 1 has been associated with lesions, however a causative role for this virus has not been confirmed. w ... | 2017 | 28948233 |
| maternal-fetal disposition of domoic acid following repeated oral dosing during pregnancy in nonhuman primate. | domoic acid (da) is a marine algal toxin that causes acute and chronic neurotoxicity in animals and humans. prenatal exposure to da has been associated with neuronal damage and cognitive and behavioral deficits in juvenile california sea lions, cynomolgus monkeys and rodents. yet, the toxicokinetics (tk) of da during pregnancy and the maternal-fetal disposition of da have not been fully elucidated. in this study, we investigated the tk before, during, and after pregnancy and the maternal-fetal d ... | 2020 | 32360744 |
| bowman's layer in the cornea- structure and function and regeneration. | bowman's layer lies immediately posterior to the epithelial basement membrane (ebm) and anterior to the stroma proper in humans, chickens, quail, zebra fish, deer, giraffe, antelope, california sea lions, guinea pig and several other species. it is not found in dog, wolf, cat, tiger, lions, rabbit, pigs, cows, goats, or horses. developmental anomalies of bowman's layer are rare, but acquired damage to bowman's layer, or even complete destruction, is frequently seen in advanced bullous keratopath ... | 2020 | 32339517 |
| severe sea lion bites in urban cold-water swimmers. | a series of sea lion bites in open-water swimmers recently gained the attention of the national and international media. pinniped (the clade including seals and sea lions) bites historically have been in people who hunt or handle marine mammals. as populations of humans and pinnipeds continue to grow, interactions with animals by those participating in recreational activities are likely to become more frequent. | 2019 | 31708308 |
| evaluation of serial blood lactate and the use of a point-of-care lactate meter in live-stranded pinnipeds. | live-stranded pinnipeds often present to rehabilitation centers systemically debilitated with dehydration and poor perfusion. in many terrestrial mammals, blood lactate elevation has been correlated with global tissue hypoxia and decreased circulating blood volume. serial blood lactate measurements in companion animals and humans have been used to guide fluid resuscitation therapy and evaluate prognosis. the primary objective of this study was to evaluate the prognostic value of serial blood lac ... | 2019 | 31120672 |
| transcriptional profiles of california sea lion peripheral nk and cd+8 t cells reflect ecological regionalization and infection by oncogenic viruses. | the california sea lion is one of the few wild mammals prone to develop cancer, particularly urogenital carcinoma (ugc), whose prevalence is currently estimated at 25% of dead adult sea lions stranded along the california coastline. genetic factors, viruses and organochlorines have been identified as factors that increase the risk of occurrence of this pathology. given that no cases of ugc have as yet been reported for the species along its distribution in mexican waters, the potential relevance ... | 2019 | 30915075 |
| proportional loss of parvalbumin-immunoreactive synaptic boutons and granule cells from the hippocampus of sea lions with temporal lobe epilepsy. | one in 26 people develop epilepsy and in these temporal lobe epilepsy (tle) is common. many patients display a pattern of neuron loss called hippocampal sclerosis. seizures usually start in the hippocampus but underlying mechanisms remain unclear. one possibility is insufficient inhibition of dentate granule cells. normally parvalbumin-immunoreactive (pv) interneurons strongly inhibit granule cells. humans with tle display loss of pv interneurons in the dentate gyrus but questions persist. to ad ... | 2019 | 30861128 |
| xanthine nephrolithiasis in juvenile captive giant otters (pteronura brasiliensis). | nephrolithiasis has been reported in several aquatic mammals including bottlenose dolphins (tursiops truncatus), small clawed otters (amblonyx cinereus), european river otters (lutra lutra), north american river otters (lontra canadensis), northern elephant seals (mirounga angustirostris), florida manatees (trichechus manatus latirostris), and california sea lions (zalophus californianus). compositions of calculi in previous cases were predominantly calcium oxalate or ammonium acid urate. xanthi ... | 2020 | 31926528 |
| epidemiology, genetic diversity and evolution of canine astrovirus. | astroviruses (astvs) are major causative agents of gastroenteritis in children and have been reported in many species. canine astrovirus (caastv), as an enteric pathogen, has been widely detected worldwide, but little is known about their genetic diversity and evolution, partly owing to a lack of genomic data. here, we sequenced 12 nearly full-length caastv genomes to address the gap in knowledge. we found 14 (13.2%) and 7 (3.35%) caastv-positive samples from pet dogs with and without diarrhoea, ... | 2020 | 32946195 |
| molecular and genome characterization of colistin-resistant escherichia coli isolates from wild sea lions (zalophus californianus). | using molecular and whole-genome sequencing tools, we investigated colistin-resistant escherichia coli isolates from wild sea lions. two unrelated e. coli colistin-resistant isolates, st8259 and st4218, were identified, both belonging to the b2 phylogroup and different serotypes. polymorphisms in pmra, pmrb, and phoq proteins were identified, and the role of pmrb and phoq in contributing to colistin resistance was determined by complementation assays. however, the mutations characterized in the ... | 2020 | 32897511 |
| stress-related and reproductive hormones in hair from three north pacific otariid species: steller sea lions, california sea lions and northern fur seals. | assessing the physiological impact of stressors in pinnipeds is logistically challenging, and many hormones are altered by capture and handling, limiting the utility of metabolically active tissues. hair is increasingly being used to investigate stress-related and reproductive hormones in wildlife populations due to less-invasive collection methods, being metabolically inert once grown and containing multiple biomarkers of ecological interest. we validated enzyme immunoassays for measuring aldos ... | 2020 | 32843968 |
| entanglement rates and haulout abundance trends of steller (eumetopias jubatus) and california (zalophus californianus) sea lions on the north coast of washington state. | entanglements affect marine mammal species around the globe, and for some, those impacts are great enough to cause population declines. this study aimed to document rates and causes of entanglement and trends in local haulout abundance for steller and california sea lions on the north coast of washington from 2010-2018. we conducted small boat surveys to count sea lions and document entangled individuals. rates of entanglement and entangling material occurrence were compared with records of stra ... | 2020 | 32841298 |