Molecular identification of a papilloma virus from cutaneous lesions of captive and free-ranging Florida manatees

Cutaneous papillomatous lesions were biopsied from three captive Florida manatees (Trichechus manatus latirostris) at Homosassa Springs State Wildlife Park (HSSWP), Homosassa, Florida, USA, and from six free-ranging Florida manatees from Crystal and Homosassa rivers, Florida. Total DNA extracted from these lesions was assayed for the presence of papilloma virus genomes using the polymerase chain reaction (PCR) with primers that target the L1 capsid protein gene. The amplification generated DNA fragments 458 base pairs in length that encompassed a highly conserved domain within the L1 capsid protein and translated into identical polypeptides of 152 amino acids, suggesting the involvement of a single papilloma virus genotype. Multiple amino acid sequence and phylogenetic analyses of the L1 fragment indicated that the Florida manatee papilloma virus is a unique and quite distinct papillomavirus from other known papilloma viruses. The emergence of this new pathogen raises concerns about its potential impact on the already endangered Florida manatee.     

Activity patterns and spatial use of facility by a group of captive female manatees (Trichechus manatus latirostris)

As a means to compare and contrast to free‐ranging Florida manatees, we examined the behavior and movement patterns of nine adult‐female captive manatees at Homosassa Springs Wildlife State Park (HSWSP). HSWSP has a unique manatee exhibit that consists of a natural river and a man‐made pool. Because the manatees are exposed to a natural environment including natural food resources, the study of various aspects of behavioral and physiological parameters of the captive manatees is especially valuable with this group. We determined activity pattern and spatial use of the facility by manatees over three allotted periods of a day (noon, mid‐afternoon, and late‐afternoon) and three seasons (winter, spring, and summer). Behavioral strategies of the manatees were: 1) to remain “inactive,” probably to conserve energy, during the day while the park provisioned food; 2) to alter locations during the course of the afternoon, apparently with the direction of the sun, possibly to assist with thermoregulation; and 3) to change location seasonally where and when food resources became abundant, showing a strong interest in natural vegetation as it became available. Spatial use and activity pattern of the HSWSP captive manatees apparently were influenced by energy constraints and nutrient intake by provisioned food availability over the day and natural vegetation over the study period. The behavior of the female group of manatees may have been affected by the single‐sex living arrangement. In addition, these manatees are subject to a largely invariable temperature (ca. 23°C) that may have created thermal stress and immunological suppression over time. This study demonstrated that for these captive manatees the activity patterns and spatial use were comparable to that of free‐ranging manatees in relation to the availability of food resources. Zoo Biol 0:1–17, 2006. © 2006 Wiley‐Liss, Inc.     

MORBILLIVIRUS INFECTION IN MANATEES

The first evidence of exposure of free-ranging Florida manatees ( Trichechus manatees latirostris ) to a morbillivirus is reported. Blood samples were collected from 148 Florida manatees between 1977 and 1994. The sample included manatees that were under rehabilitation (n = 97), free-ranging (n = 40) and fresh necropsy specimens (n = 11). Serum from six animals (4%) neutralized porpoise and dolphin morbilliviruses to a higher titer than any other member of the Morbillivirus genus. Antibodies were not detected in sera from 12 free-ranging Antillean manatees ( T. manatus manatus ) from Guyana sampled in 1992 or from 12 hand-reared Amazonian manatees ( T. inunguis ) sampled in 1984. Immunoprecipitation studies using radio-labelled canine distemper virus protein and serum from Florida manatees showed precipitation of the nucleo-capsid (N) protein. The combination of low antibody titers and absence of clinical disease suggest that the Florida manatee is a dead-end host. Sporadic infection may occur following contact with another species in which infection is enzootic. Morbillivirus could, either by fatal infection or more insidious effects on the immune system or reproduction, pose a problem to this already threatened species.     

THE USE OF STABLE CARBON ISOTOPE ANALYSIS FOR DETERMINING THE DIETARY HABITS OF THE FLORIDA MANATEE, TRICHECHUS MANATUS LATIROSTRIS

The sloughed skin from three captive manatees at Lowry Park Zoological Garden (Tampa, Florida) was examined over a period of one year to determine its stable carbon isotopic composition (δ¹³C). The food consumed by these manatees in a controlled diet was also sampled and its δ¹³C values determined. The sloughed skin δ¹³C values from the captive manatees were enriched by an average of +4.1%0 relative to lettuce (generally >98% of the diet) the animals consumed. δ¹³C values of the skin were shown to be related to changes in δ¹³C values of the lettuce.
The stable carbon isotopic composition of internal tissues (liver, kidney, and blubber) and skin from dead, stranded manatees was also determined. These values were compared to values of vegetation that manatees are known to eat in the wild. The δ¹³C values of the internal tissues and skin of wild manatees were consistent with the range of δ¹³C values of their expected diet.     

Prevalence, Emergence, and Factors Associated with a Viral Papillomatosis and Carcinomatosis Syndrome in Wild, Reintroduced, and Captive Western Barred Bandicoots (Perameles bougainville)

Once widespread across western and southern Australia, wild populations of the western barred bandicoot (WBB) are now only found on Bernier and Dorre Islands, Western Australia. Conservation efforts to prevent the extinction of the WBB are presently hampered by a papillomatosis and carcinomatosis syndrome identified in captive and wild bandicoots, associated with infection with the bandicoot papillomatosis carcinomatosis virus type 1 (BPCV1). This study examined the prevalence and distribution of BPCV1 and the associated syndrome in two island and four mainland (reintroduced and captive) WBB populations in Western Australia, and factors that may be associated with susceptibility to this syndrome. BPCV1 and the syndrome were found in the wild WBB population at Red Cliff on Bernier Island, and in mainland populations established from all or a proportion of founder WBBs from Red Cliff. BPCV1 and the syndrome were not found in the wild population on Dorre Island or in the mainland population founded by animals exclusively from Dorre Island. Findings suggested that BPCV1 and the syndrome were disseminated into mainland WBB populations through the introduction of affected WBBs from Red Cliff. No difference in susceptibility to the syndrome was found between Dorre Island, Bernier Island, and island-cross individuals. Severity of lesions and the number of affected animals observed in captivity was greater than that observed in wild populations. This study provided epidemiological evidence to support the pathological and molecular association between BPCV1 infection and the papillomatosis and carcinomatosis syndrome and revealed increasing age as an additional risk factor for this disease.     

Social interactions in captive female Florida manatees

The Florida manatee (Trichechus manatus latirostris) is considered a semi‐social species with strong bonds developed primarily between mother and offspring. Some field studies suggest sociality may be more developed and such social relationships may facilitate survival. Seven facilities in Florida house manatees, many of which were brought into captivity because of injury or illness sustained in the wild. Decisions to release such manatees consider individual history and health. We examined social interactions in adult female captive manatees to assess level of association and implications for manatee care and release. We investigated the degree of contact among 20 manatees in captivity at four facilities housing two to nine adult female manatees. We used all contact behavior occurrences sampling and continuous recording for 180 continuous minutes per day over 3 consecutive days at each facility. Virtually all contacts were non‐aggressive. The number of contacts between manatees increased as the number of manatees per unit volume of water increased. Contacts did not fit a Poisson distribution, however, and were not random. When more than two manatees were present, manatees only associated with a subset of individuals in the aquarium. Relationships maintained in captivity indicate the potentially social nature of manatees, and suggest that further research is needed to examine the benefit of these relationships to the health and rehabilitation of manatees in captivity and conservation in the wild. Zoo Biol 24:135–144, 2005. © 2005 Wiley‐Liss, Inc.     

Winter Habitat Preferences for Florida Manatees and Vulnerability to Cold

To survive cold winter periods most, if not all, Florida manatees rely on warm-water refuges in the southern two-thirds of the Florida peninsula. Most refuges are either warm-water discharges from power plant and natural springs, or passive thermal basins that temporarily trap relatively warm water for a week or more. Strong fidelity to one or more refuges has created four relatively discrete Florida manatee subpopulations. Using statewide winter counts of manatees from 1999 to 2011, we provide the first attempt to quantify the proportion of animals using the three principal refuge types (power plants, springs, and passive thermal basins) statewide and for each subpopulation. Statewide across all years, 48.5% of all manatees were counted at power plant outfalls, 17.5% at natural springs, and 34.9 % at passive thermal basins or sites with no known warm-water features. Atlantic Coast and Southwest Florida subpopulations comprised 82.2% of all manatees counted (45.6% and 36.6%, respectively) with each subpopulation relying principally on power plants (66.6% and 47.4%, respectively). The upper St. Johns River and Northwest Florida subpopulations comprised 17.8% of all manatees counted with almost all animals relying entirely on springs (99.2% and 88.6% of those subpopulations, respectively). A record high count of 5,076 manatees in January 2010 revealed minimum sizes for the four subpopulations of: 230 manatees in the upper St. Johns River; 2,548 on the Atlantic Coast; 645 in Northwest Florida; and 1,774 in Southwest Florida. Based on a comparison of carcass recovery locations for 713 manatees killed by cold stress between 1999 and 2011 and the distribution of known refuges, it appears that springs offer manatees the best protection against cold stress. Long-term survival of Florida manatees will require improved efforts to enhance and protect manatee access to and use of warm-water springs as power plant outfalls are shut down.     

PREHENSILE USE OF PERIORAL BRISTLES DURING FEEDING AND ASSOCIATED BEHAVIORS OF THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS)

The use of perioral bristles (modified vibrissae) by 17 captive Florida manatees and approximately 20 wild manatees was analyzed. Captive manatees were fed six species of aquatic vegetation normally eaten in the wild (four freshwater species and two seagrasses). Inanimate objects were placed in the holding tanks with manatees at Lowry Park Zoological Gardens (Tampa, FL) to determine the degree to which perioral bristles were used in exploration and to define the range of manipulative behavior. In addition, behavioral observations were made on the use of perioral bristles during social interactions with conspecifics. Observations were recorded using a Hi8-format video camera. Florida manatees possess an unusually large degree of fine motor control of the snout and perioral bristles. The large and robust perioral bristle fields of the upper lip were used in a prehensile manner during feeding. Bristle use by manatees feeding on submerged vegetation differed from that seen during feeding on floating vegetation. Other behavioral use of the perioral bristles shows variation depending upon the situation encountered. The degree of plasticity of perioral bristle use supports our hypothesis that the vibrissal-muscular complex of the Florida manatee has evolved to increase the efficiency of grazing and browsing on aquatic vegetation and to fully maximize the potential of the manatee as a generalist feeder. The manipulative and sensitive nature of the manatee snout is likely a manifestation of a complex sensory and motor system which has evolved for marine mammal aquatic herbivores living in shallow turbid habitats.     

TRENDS IN MANATEE (TRICHECHUS MANATUS LATIROSTRIS) COUNTS AND HABITAT USE IN TAMPA BAY, 1987–1994: IMPLICATIONS FOR CONSERVATION

Aerial surveys ( n = 88) were used to document locations and count sightings of manatees ( Trichechus manatus latirostris ) in the inshore waters of Tampa Bay, Florida, between November 1987 and May 1994. We made 5,358 sightings of manatees in 1,958 groups. Calves represented 8% of the manatees sighted. Counts were significantly higher in winter ( = 79, n = 29 flights) than in non-winter ( = 46, n = 47) months. Counts of manatees in winter increased significantly during the study, but warm-season counts did not. Regression models demonstrated a relationship between counts and environmental factors. Year-round counts were related to air temperatures and seasons, with highest counts in winter. However, in the winter season, counts were significantly correlated only with wind speed, not air temperature. Yearround counts were predicted to be curvilinear with highest counts at 15°C average air temperature. Areas used differed with season: in cold weather, 76% of all sightings occurred in zones with warm-water sources. High-use areas were identified for summer months. Spatial filter analysis was used to compare manatee density in high-use areas between two two-year time periods. The data indicate that (1) manatee use of Tampa Bay was high and increasing in winter, (2) there are particular zones of the bay where conservation of manatees and habitat should be a priority, and (3) sufficient information has been collected for management agencies to develop and implement manatee protection plans.     

Tuberculosis (Mycobacterium microti) in wild field vole populations

Vole tuberculosis (TB; Mycobacterium microti) is an understudied endemic infection. Despite progressing slowly, it causes severe clinical pathology and overt symptoms in its rodent host. TB was monitored for 2 years in wild field voles in Kielder Forest, UK. The prevalence of characteristic cutaneous TB lesions was monitored longitudinally at 4 sites, with individuals live-trapped and repeatedly monitored. A prevalence of 5.2% of individuals with lesions was recorded (n=2791). In a cross-sectional study, 27 sites were monitored bi-annually, with TB assessed by post-mortem examination for macroscopic lesions, and by culture and histopathology. Seventy-nine voles (10.78%; n=733) were positive for mycobacteria, with the highest prevalence in spring (13.15%; n=327). TB prevalence varied, with between 0% and 50% of voles infected per site. Prevalence increased with age (mass), and apparent seasonality was due to a higher proportion of older animals in spring. Survival analysis supported this result, with cutaneous lesions only manifesting in the advanced stages of infection, and therefore only being found on older voles. The body condition of individuals with lesions declined at the time when the lesion was first recorded, when compared to individuals without lesions, suggesting there may be an acute phase of infection during its advanced stage. Although predicted survival following the appearance of a cutaneous lesion was lower than for uninfected individuals, this was not significant.     

AGE DETERMINATION IN MANATEES USING GROWTH-LAYER-GROUP COUNTS IN BONE

Growth layers were observed in histological preparations of bones of known-age, known minimum-age, and tetracycline-marked free-ranging and captive Florida manatees ( Trichechus manatus latirostris ), substantiating earlier preliminary findings of other studies. Detailed analysis of 17 new case histories showed that growth-layer group (GLG) counts in the periotic bone were consistent with known age, or time since tetracycline administration, but were less reliable in other bones. GLG counts were also made in periotic bones of 1,196 Florida manatees of unknown age found dead from 1974 through 1991. These counts were conducted in order to assess variability and to determine relationships among estimated age, size, sex, and degree of bone resorption. Resorption can interfere with accuracy of GLG counts. This effect does not occur until ages greater than about 15 yr and body lengths greater than 300 cm are attained. GLGs were also observed in periotic bones of Antillean manatees ( Trichechus manatus manatus ) but were not validated against known-age specimens. Use of GLG counts in the periotic bone is suitable for application to studies of population dynamics and other age-related aspects of manatee biology.     

Serologic and molecular evidence for Testudinid herpesvirus 2 infection in wild Agassiz's desert tortoises, Gopherus agassizii

Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.     

AERIAL VIDEOGRAMMETRY FROM A TETHERED AIRSHIP TO ASSESS MANATEE LIFE-STAGE STRUCTURE

Aerial videogrammetry from an airship tethered to a boat was used to assess the life-stage structure of manatees in the Blue Waters area of the Homosassa River on the west coast of central Florida. Individual frames of videos were loaded onto a computer and lengths of manatees measured using graphics software. All images of manatees were measured independently by three observers. Measurements were transformed to total manatee lengths by calculating the ratio between the measurements of a reference object of known length and the measurement of the manatee. Length estimates were highly variable but were unbiased with respect to observer. Results of an analysis of variance suggested that the hypothesis that lengths differed among days and among observers should not be rejected. Life-stage structures were represented in three schemes. One scheme-which included four life stages: dependent calves, juveniles, animals in tramsition between juvenile and adult, and adults-was included to provide the most information without sacrificing confidence in the life-stage distribution. Overall, the video system was effective at capturing images of manatees for life-stage characterization and, with improvements in image resolution, could become a valuable tool for photo-identification in sight-resight experiments.     

Validation and use of an indirect enzyme-linked immunosorbent assay for detection of antibodies to West Nile virus in American Alligators (Alligator mississippiensis) in Florida

In October 2002, West Nile virus (WNV) was identified in farmed American alligators (Alligator mississippiensis) in Florida showing clinical signs and having microscopic lesions indicative of central nervous system disease. To perform seroepidemiologic studies, an indirect enzyme-linked immunosorbent assay (ELISA) was developed to determine exposure of captive and wild alligators to WNV. To validate the test, a group of WNV-seropositive and -seronegative alligators were identified at the affected farm using hemagglutination inhibition (HAI) and the plaque reduction neutralization test (PRNT). The indirect ELISA utilized a rabbit anti-alligator immunoglobulins polyclonal antibody as the secondary antibody, and inactivated WNV-infected Vero cells were used as the coating antigen. For all samples (n=58), the results of the ELISA were consistent with the HAI and PRNT findings. Plasma was collected from 669 free-ranging alligators from 21 sites across Florida in April and October 2003. Four samples collected in April and six in October were positive for WNV antibodies using HAI, PRNT, and the indirect ELISA. This indicated that wild alligators in Florida have been exposed to WNV. These findings can be used as a baseline for future surveys.     

Seroprevalence of hantaviruses in small wild mammals trapped in South Korea from 2005 to 2010

The seroprevalence of Hantaan virus (HTNV) in wild rodents in South Korea was analyzed. Wild rodents were trapped in 18 cities in eight provinces during 2005-2007 and on three islands and four mountains during 2008-2010. Sera were collected from 629 out of 933 trapped wild animals and examined for immunoglobulin G antibodies to HTNV using indirect immunofluorescence assays. Apodemus agrarius (80.1%) was the most frequently captured species at almost all trapping sites. The overall prevalence of HTNV antibodies was 0.26 (162/629). Seropositive individuals were more frequent in cities (32.2%, n=410) than on islands (14.0%, n=57) or mountains (13.6%, n= 162). HTNV antibody-positive rate was higher in the fall (29.6%, n=253) than in the spring (23.1%, n=376). A. agrarius had the highest prevalence of HTNV antibodies (26.9%, n=561) of all tested species. Considering all the individuals, the prevalence of HTNV antibodies was higher in males (29.2%, n=250) than in females (22.3%, n=305). Our results show that HTNV is widely distributed throughout South Korea, and that HTNV infection of wild rodents is affected by their habitat, species, sex, and season.     

Detection of rabies virus antibodies in Brazilian free-ranging wild carnivores

Rabies virus is a pathogen of major concern in free-ranging wild carnivores in several regions of the world, but little is known about its circulation in Brazilian wild carnivores. Sera from 211 free-ranging wild carnivores, captured from 2000 to 2006 in four locations of two Brazilian biomes (Pantanal and Cerrado), were tested for rabies antibodies. Twenty-six individuals (12.3%) had neutralizing antibody titers ≥0.10 IU/ml. The four sampled locations had antibody-positive animals, suggesting that Rabies virus circulates in all of these regions. Results underscore the risk posed by rabies for conservation of Brazilian carnivores and the possibility of the animals acting as reservoirs for the Rabies virus.     

Seroepidemiology of parapoxvirus infections in captive and free-ranging California sea lions Zalophus californianus

Cutaneous nodular lesions caused by parapoxvirus infections are commonly observed in stranded pinnipeds following their arrival at rehabilitation facilities. An indirect enzyme-linked immunosorbent assay (ELISA) was developed and validated to determine exposure to parapoxviruses in California sea lions Zalophus californianus in captivity and in the wild. The diagnostic performance of this assay was evaluated using receiver-operating characteristic analysis. At a selected cut-off value, the calculated sensitivity was 100% (95% CI = 86 to 100%) and the specificity was 100% (95% CI = 87 to 100%). Analysis of sera collected from 26 affected sea lions during various stages of the disease revealed anti-parapoxvirus antibodies in all affected sea lions prior to the development of cutaneous pox lesions. This indicated that previous exposure to a parapoxvirus does not confer protection against clinical disease. In at least 7 cases, exposure to the virus occurred during hospitalization. Analysis of paired sera from 74 unaffected sea lions indicated subclinical infections in at least 3 animals. Finally, the prevalence of anti-parapoxviral antibodies in 761 free-ranging California sea lions captured and tested was 91% (95% CI = 89 to 93%). This indicated that infection with a parapoxvirus is a common occurrence in the wild and that the release of captive sea lions infected with parapoxvirus into the wild should not increase the risk of a parapoxvirus outbreak in free-ranging sea lions.     

Widespread occurrence in Australian marsupials of neutralizing antibodies to a herpesvirus from a parma wallaby.

Serum neutralizing antibodies to a parma wallaby herpesvirus (PWHV) have been detected in a wide range of marsupials from different locations across Australia, including several islands. A study of 242 animals (mostly macropods) sampled in the wild showed that 23% had antibodies; a significantly higher frequency (41%) of 116 animals in captivity had antibodies, which were generally at higher levels than those of animals in the wild. Antibodies to PWHV were also detected among parma wallabies from a colony on Kawau Island, New Zealand. The highest antibody levels were found in a group of captive tammar wallabies during recurrent outbreaks of clinical infection. It is suggested that PWHV has evolved along with a marsupial host, and that the high antibody levels among captive animals reflects ease of virus transmission due to crowding, or to conditions of stress leading to expression of latent virus.     

Epizootiology of Brucella infection in Australian fur seals

Novel members of the bacterial genus Brucella have recently emerged as pathogens of various marine mammal species and as potential zoonotic agents. We investigated the epizootiology of Brucella infection in Australian fur seals (Arctocephalus pusillus doriferus) by establishing demographic and temporal variations in antibody prevalence, attempting isolation of the causative agent, and determining whether this potential pathogen is involved in frequent abortions observed in this pinniped species. Two competitive enzyme-linked immunosorbent assays (cELISAs), an indirect ELISA, and a fluorescence polarization assay (FPA) were used to test sera for Brucella antibodies. The FPA and cELISA proved suitable for use in this species. Significant differences in antibody prevalence were found between age classes of seals sampled between 2007 and 2009 at one colony. Pups sampled at this site (n=134) were negative for Brucella antibodies by all serologic tests but 17 of 45 (38%) of juveniles were antibody-positive. Antibody prevalence in adult females was significantly higher than in juveniles (P=0.044). Antibody prevalence for adult females between 2003 and 2009 varied significantly over time (P=0.011), and for individuals sampled between 2003 and 2005, the likelihood of pregnancy was greater in individuals positive for Brucella antibodies (P=0.034). Inflammatory lesions suggestive of infectious agents were found in 14 of 39 aborted Australian fur seal pups, but pathologic changes were not uniformly consistent for Brucella infection. Culture and PCR investigations on fetal tissues were negative for Brucella. Culture and PCR on selected fresh or frozen tissues from 36 juvenile and adult animals were also negative. We suspect that the prevalence of active infection with Brucella in Australian fur seals is low relative to antibody prevalence.     

Helminths of the Florida manatee, Trichechus manatus latirostris, with a discussion and summary of the parasites of sirenians

We examined 215 Florida manatees (Trichechus manatus latirostris) at necropsy to determine the helminth fauna. Six species were identified: Heterocheilus tunicatus (Nematoda: Ascaridoidea); Anoplocephala sp. (Cestoda: Cyclophyllidea); and 4 species of trematodes, Cochleotrema cochleotrema (Digenea: Opisthotrematidae), Chiorchis fabaceus (Digenea: Paramphistomatidae), Nudacotyle undicola (Digenea: Nudacotylidae), and Moniligerum blairi (Digenea: Opisthotrematidae). Seventy-three percent of the manatees examined were infected with at least 1 species of helminth. The mean number of species of helminths per infected manatee was 1.9 with a range of 1-4. Fifty-nine manatees were helminth-free; 30 of these were calves. No associations were found between the intensity of helminth infections and host sex, age class, season, and geographic location of recovery, or cause of death. Differences in parasite prevalence between age classes were highly significant for Chiorchis, Cochleotrema, and Heterocheilus, due to a low number of infected calves. A higher prevalence of Cochleotrema was found in manatees recovered from eastern Florida, and Heterocheilus was evident in significantly more manatees from western and souther Florida. Comparisons in the parasite fauna are made among Florida manatees and other sirenian populations, and a brief review of sirenian parasites is included.