Nucleotide sequence of the D-loop region of the sperm whale (Physeter macrocephalus) mitochondrial genome

We have amplified, by the polymerase chain reaction, and have sequenced the D-loop region of the mitochondrial DNA from the sperm whale (Physeter macrocephalus). The sperm whale D-loop was aligned with D- loop sequences from four other cetaceans (Commerson's dolphin, orca, fin whale, and minke whale) and an out-group (cow). This alignment showed the sperm whale sequence to be larger than that of other cetaceans. In addition, some sequence blocks were highly conserved among all six species, suggesting roles in the functioning of mitochondrial DNA. Other blocks that were previously reported to be well conserved among cetaceans showed little sequence conservation with the sperm whale D-loop, which argues against the functional importance of these sequence blocks in cetaceans.      

The complete nucleotide sequence of the mitochondrial DNA of the fin whale,Balaenoptera physalus

Summary The composition of the mitochondrial DNA (mtDNA) of the fin whale,Balaenoptera physalus, was determined. The length of the molecule is 16,398 bp, and its organization conforms with that of other mammals. The general similarity between the mtDNA of the fin whale and the cow is greater than the similarity between the fin whale and other species (human, mouse, rat) in which the composition of the entire molecule has been described. The D-loop region of the mtDNA of the fin whale is 81% identical to the D-loop of dolphin DNA, and the central portion of the D-loop is similar to the bovine D-loop. The accumulation of transversions and gaps in the 12S and 16S rRNA genes was assessed by comparing the fin whale, cow, and human. The sequence difference between human and the whale and human and the cow was at the same level, indicating that the rate of evolution of the mtDNA rRNA genes is about the same in artiodactyls and cetaceans. In the 12S rRNA gene an accumulation rate of 0.05% per million years places the separation of cetaceans and artiodactyls at about 55 million years ago. The corresponding figure for human and either the whale or the cow is about 80 million years. In the 16S rRNA gene a 0.08% accumulation rate of transversions and gaps per million years yields concurring figures. A comparison between the cytochromeb gene of the fin whale and cytochromeb sequences in the literature, including dolphin (Stenella) sequences, identified the cetaceans as monophyletic and the artiodactyls as their closest relatives. The comparison between the cytochromeb sequences of the fin whale andStenella showed that differences in codon positions one or two were frequently associated with a change in another codon position.     

ISOLATION AND EXPRESSION OF THE INTERLEUKIN-2 GENE FROM THE KILLER WHALE, ORCINUS ORCA

Complementary DNA encoding interleukin-2 (IL-2) was isolated, cloned, and sequenced from the killer whale, Orcinus orca . The sequence of the killer whale IL-2 coding region consists of 455 nucleotides which translate into a polypeptide containing 151 amino acids. Killer whale IL-2 displays 88%, 88%, 87%, 87%, 85%, 84%, 80%, and 71% nucleotide sequence homology and 76%, 76%, 76%, 73%, 68%, 73%, 64%, and 56% amino acid homology with the cow, sheep, pig, red deer, horse, human, manatee, and mouse, respectively. High levels of killer whale recombinant IL-2 were generated by transiently transfecting killer whale IL-2/pCMV Blue plasmid DNA into cultured monkey kidney cells (Cos-1). Generation of this recombinant IL-2 will allow the development of assays useful for assessing IL-2 levels in the serum and from isolated lymphocytes of killer whales and possibly other species of cetaceans. A major contribution and significance of the in vitro expression of killer whale IL-2 exists in its potential to be used as a therapeutic agent.     

Call types of Bigg’s killer whales (Orcinus orca) in western Alaska: using vocal dialects to assess population structure

Bigg’s killer whales (Orcinus orca; i.e. ‘transient’ ecotype), as apex predators, are important to the dynamics of marine ecosystems, but little is known about their population structure in western Alaska. Currently, all Bigg’s killer whales in western Alaska are ascribed to a single broad stock for management under the US Marine Mammal Protection Act. However, recent nuclear microsatellite and mitochondrial DNA analyses indicate that this stock is likely comprised of genetically distinct sub-populations. In accordance with what is known about killer whale vocal dialects in other locations, we used the spatial distribution of group-specific call types to investigate the population structure of Bigg’s killer whales in this part of Alaska. Digital audio recordings were collected from 33 Bigg’s killer whale encounters throughout the Aleutian and Pribilof Islands in the summers of 2001–2007 and 2009–2010. Recorded calls were qualitatively classified into discrete types and then quantitatively described using 12 structural and time-frequency measures. Resulting call categories were validated using a random forest approach. A total of 36 call types and subtypes were identified across the entire study area, and regional patterns of call type use revealed three distinct dialects which correspond to proposed genetic delineations. Our results suggest that there are at least three acoustically and genetically distinct sub-populations in western Alaska, and we present an initial catalogue for this area describing the regional vocal repertoires of Bigg’s killer whale call types.     

Temporal variation in dwarf sperm whale (Kogia sima) habitat use and group size off Great Abaco Island, Bahamas

Dwarf sperm whales (Kogia sima) are among the most commonly stranded yet least known pelagic cetaceans. Few studies have occurred at sea, and none have quantified temporal and spatial variation in dwarf sperm whale abundance and group size. We assessed seasonal and spatial variation in dwarf sperm whale group size and abundance off Great Abaco Island, Bahamas using surveys within a 126 km² study area with depths between 2 and 1,600 m. After correcting for survey effort and variation in sighting efficiency among sea states, we found that dwarf sperm whale group size and habitat use varied seasonally. In summer, dwarf sperm whale groups were small (median = 2.5, range = 1–8) and were found only in the two deep habitats within the study area (slope 400–900 m, deep 900–1,600 m). In winter, group sizes increased (median = 4, range = 1–12) and sightings were almost six times higher in the slope habitat, where vertical relief is highest, than other habitats. Our results suggest that studies of pelagic cetaceans and conservation plans must explicitly account for seasonal variation in group size and habitat use.     

Hydrodynamic performance of the flippers of large‐bodied cetaceans in relation to locomotor ecology

Cetaceans evolved flippers that are unique in both size and shape probably due to selection pressures associated with foraging and body size. Flippers function as control surfaces for maneuverability and stability. Flippers of cetaceans and engineered hydrofoils are similar with streamlined cross‐sections and wing‐like planforms, which affect lift, drag and hydrodynamic efficiency. Scale models of the flippers from large‐bodied (body length > 6 m) cetaceans (fin whale, killer whale, sperm whale) were constructed from computed tomography (CT) scans of flippers. Flipper planforms were highly tapered for the fin whale, a rounded, paddle‐like design for the killer whale, and a square geometry for the sperm whale. Hydrodynamic properties of the models at varying angles of attack (?40º to 40^o) were determined in a water tunnel with a multi‐axis load cell. The flippers were found to have hydrodynamic characteristics similar to engineered wings. Differences in flipper morphology of large‐bodied cetaceans and their hydrodynamic performance are associated with the requirements of aquatic locomotion involved with ecology of the whales. The flippers of the killer whale provided the greatest maneuverability, whereas the flippers of the fin whale had low drag for lunging and the flippers of the sperm whale provided lift for diving.     

Rod Monochromacy and the Coevolution of Cetacean Retinal Opsins

Cetaceans have a long history of commitment to a fully aquatic lifestyle that extends back to the Eocene. Extant species have evolved a spectacular array of adaptations in conjunction with their deployment into a diverse array of aquatic habitats. Sensory systems are among those that have experienced radical transformations in the evolutionary history of this clade. In the case of vision, previous studies have demonstrated important changes in the genes encoding rod opsin (RH1), short-wavelength sensitive opsin 1 (SWS1), and long-wavelength sensitive opsin (LWS) in selected cetaceans, but have not examined the full complement of opsin genes across the complete range of cetacean families. Here, we report protein-coding sequences for RH1 and both color opsin genes (SWS1, LWS) from representatives of all extant cetacean families. We examine competing hypotheses pertaining to the timing of blue shifts in RH1 relative to SWS1 inactivation in the early history of Cetacea, and we test the hypothesis that some cetaceans are rod monochomats. Molecular evolutionary analyses contradict the “coastal” hypothesis, wherein SWS1 was pseudogenized in the common ancestor of Cetacea, and instead suggest that RH1 was blue-shifted in the common ancestor of Cetacea before SWS1 was independently knocked out in baleen whales (Mysticeti) and in toothed whales (Odontoceti). Further, molecular evidence implies that LWS was inactivated convergently on at least five occasions in Cetacea: (1) Balaenidae (bowhead and right whales), (2) Balaenopteroidea (rorquals plus gray whale), (3) Mesoplodon bidens (Sowerby''s beaked whale), (4) Physeter macrocephalus (giant sperm whale), and (5) Kogia breviceps (pygmy sperm whale). All of these cetaceans are known to dive to depths of at least 100 m where the underwater light field is dim and dominated by blue light. The knockout of both SWS1 and LWS in multiple cetacean lineages renders these taxa rod monochromats, a condition previously unknown among mammalian species.     

REACTION OF FIN WHALES BALAENOPTERA PHYSALUS TO AN EARTHQUAKE

ABSTRACT

Whales living within seismically active regions are subject to intense disturbances from strong sounds produced by earthquakes that can kill or injure individuals. Nishimura & Clark (1993) relate the possible effects of underwater earthquake noise levels in marine mammals, adducing that T-phase source signal level (10- to 30- Hz range) can exceed 200 dB re: 1 μPa at 1 m, for a magnitude 4–5 earthquake, sounds audible to fin whales which produce low frequency sounds of 16–20/25–44 Hz over 0.5–1s, typically of 183 dB re: 1 μPa at 1 m. Here we present the response of a fin whale to a 5.5 Richter scale earthquake that took place on 22 February 2005, in the Gulf of California. The whale covered 13 km in 26 min (mean speed = 30.2 km/h). We deduce that the sound heard by this whale might have triggered the costly energy expenditure of high speed swimming as a seismic-escape response. These observations support the hypothesis of Richardson et al. (1995) that cetaceans may flee from loud sounds before they are injured, when exposed to noise in excess of 140 dB re: 1 μPa 1 m.     

Collection and processing of hematopoietic progenitor cell products at risk of presenting with cold agglutination

Background aimsCold agglutinins are commonly identified in transfusion laboratories and are defined by their ability to agglutinate erythrocytes at 3–4°C, with most demonstrating a titer >64. Similarly, cryoglobulins can precipitate from plasma when temperatures drop below central body temperature, resulting in erythrocyte agglutination. Thankfully, disease associated from these autoantibodies is rare, but unfortunately, such temperature ranges are routinely encountered outside of the body's circulation, as in an extracorporeal circuit during hematopoietic progenitor cell (HPC) collection or human cell therapy laboratory processing. When agglutination occurs ex vivo, complications with the collection and product may be encountered, resulting in adverse events or product loss. Here, we endeavor to share our experience in preventing and responding to known cases at risk of or spontaneous HPC agglutination in our human cell therapy laboratory.Case reportsFour cases of HPC products at risk for, or spontaneously, agglutinating were seen at our institution from 2018 to 2020. Planned modifications occurred, including ambient room temperature increases, tandem draw and return blood warmers, warm product transport and extended post-thaw warming occurred. In addition, unplanned modifications were undertaken, including warm HPC product processing and plasma replacement of the product when spontaneous agglutination of the product was identified. All recipients successfully engrafted after infusion.ConclusionsWhile uncommon, cold agglutination of HPC products can disrupt standard processes of collection and processing. Protocol modifications can circumvent adverse events for the donor and minimize product loss. Such process modifications should be considered in individuals with known risks for agglutination going to HPC donation/collection.     

Prolonged exposure to particulate Cr(VI) is cytotoxic and genotoxic to fin whale cells

BackgroundHexavalent chromium [Cr(VI)] is a human lung carcinogen and global marine pollutant. High Cr concentrations, resembling the ones observed in occupationally exposed workers, have been observed in fin whales (Balaenoptera physalus) in the Gulf of Maine. This outcome suggests Cr might be disrupting the health of fin whale populations. Indeed, Cr in acute (24 h) exposure does cause toxicity in fin whale cells. However, human cell culture data indicate prolonged exposures (120 h) induce a higher amount of toxicity compared to 24 h exposure due to an inhibition of homologous recombination repair. However, whether prolonged exposure causes similar outcomes in fin whale cells is unknown.ObjectiveDue to the importance of assessing prolonged exposure toxicity, this study focuses on characterizing acute and prolonged exposure of Cr(VI) in male and female fin whale cells.MethodsCytotoxicity was measured by the clonogenic assay, also known as colony forming assay, which measures the ability of cells to proliferate and form colonies after the treatment. DNA double strand breaks were analyzed by neutral comet assay. Clastogenicity was measured using the chromosome aberration assay. Intracellular Cr levels were measured with Graphite Furnace Atomic Absorption Spectrometry (GFAAS) with Syngistix Software.ResultsIn this study, we demonstrate that particulate Cr(VI) induces cytotoxicity and genotoxicity in a treatment-dependent manner after 24 h and 120 h exposures. Cytotoxicity levels were generally low with relative survival above 64 %. DNA double strand break data and chromosome aberration data were elevated after a 24 h exposure, but decreased after a 120 h exposure. While cytotoxicity was similar after 24 h and 120 h exposures, less DNA double strand breaks and chromosomal instability occurred with prolonged exposure.ConclusionParticulate Cr(VI) is cytotoxic and genotoxic to fin whale cells after acute and prolonged exposures. The reduction of genotoxicity we have observed after 120 h exposure may be partly explained by lower intracellular Cr levels after 120 h. However, the decrease in intracellular levels is not reflected by a similar decrease in chromosome aberrations suggesting other mechanisms may be at play. Male fin whale cells appear to be more susceptible to the genotoxic effects of particulate Cr(VI) while female cells are less susceptible possibly due to increased cell death of damaged cells, but more work is needed to clarify if this outcome reflects a sex difference or interindividual variability. Overall, the study shows particulate Cr(VI) does induce toxicity at both acute and prolonged exposures in fin whales cells indicating Cr(VI) exposure is a health risk for this species.     

Cytoplasmic and Mitochondrial Creatine Kinases from the Skeletal Muscle of Sperm Whale (Physeter macrocephalus). Molecular Cloning and Enzyme Characterization

We have amplified two cDNAs, coding for creatine kinases (CKs), from the skeletal muscle of sperm whale Physeter macrocephalus by PCR, and cloned these cDNAs into pMAL plasmid. These are the first CK cDNA and deduced amino acid sequences from cetaceans to be reported. One of the two amino acid sequences is a cytoplasmic, muscle-type isoform (MCK), while the other was identified as a sarcomeric, mitochondrial isoform (sMiCK) that included a mitochondrial targeting peptide. The amino acid sequences of sperm whale MCK and sMiCK showed 94–96% sequence identity with corresponding isoforms of mammalian CKs, and all of the key residues necessary for CK function were conserved. The phylogenetic analyses of vertebrate CKs with three independent methods (neighbor-joining, maximum-likelihood and Bayes) supported the clustering of sperm whale MCK with Bos and Sus MCKs, in agreement with the contemporary view that these groups are closely related. Sperm whale MCK and sMiCK were expressed in Escherichia coli as a fusion protein with maltose-binding protein, and the kinetic constants (K _m, K _d and k _cat) were determined for the forward reaction. Comparison of kinetic constants with those of human and mouse CKs indicated that sperm whale MCK has a comparable affinity for creatine (K _m^Cr = 9.38 mM) to that of human MCK, and the sMiCK has two times higher affinity for creatine than the human enzyme. Both the MCK and sMiCK of sperm whale display a synergistic substrate binding (K _d /K _m = 3.1–7.8) like those of other mammalian CKs.     

cDNA-derived amino acid sequences of myoglobins from nine species of whales and dolphins

We determined the myoglobin (Mb) cDNA sequences of nine cetaceans, of which six are the first reports of Mb sequences: sei whale (Balaenoptera borealis), Bryde's whale (Balaenoptera edeni), pygmy sperm whale (Kogia breviceps), Stejneger's beaked whale (Mesoplodon stejnegeri), Longman's beaked whale (Indopacetus pacificus), and melon-headed whale (Peponocephala electra), and three confirm the previously determined chemical amino acid sequences: sperm whale (Physeter macrocephalus), common minke whale (Balaenoptera acutorostrata) and pantropical spotted dolphin (Stenella attenuata). We found two types of Mb in the skeletal muscle of pantropical spotted dolphin: Mb I with the same amino acid sequence as that deposited in the protein database, and Mb II, which differs at two amino acid residues compared with Mb I. Using an alignment of the amino acid or cDNA sequences of cetacean Mb, we constructed a phylogenetic tree by the NJ method. Clustering of cetacean Mb amino acid and cDNA sequences essentially follows the classical taxonomy of cetaceans, suggesting that Mb sequence data is valid for classification of cetaceans at least to the family level.     

Ultrastructure,biomechanical and chemical properties of the vestigial dentition of a Cuvier's beaked whale

Beaked whales are poorly known cetaceans with a peculiar dentition consisting of one or two pairs of mandibular tusks, sometimes accompanied by dozens of peg-like rudimentary teeth normally concealed in the gum tissue. This study investigated the ultrastructure, chemical and biomechanical properties of vestigial teeth in a specimen of Cuvier's beaked whale deposited in the Otago Museum collections. The juvenile individual had 49 needle-like vestigial teeth in situ on the lower jaws. Scanning electron microscopy images revealed a thin layer of semi-structured prismless enamel covering the teeth. Mechanical properties values were within the range of values reported for other cetaceans, suggesting relaxed biomechanical functional demands. Chemical analyses revealed preservation of the hydroxyapatite composition despite morphological simplification and vestigial nature. The presumed high incidence of vestigial teeth in Ziphius cavirostris, the small size and the degenerate nature of these structures are consistent with their interpretation as vestiges rather than atavisms.     

Interactions between Cetacean and Fisheries in the Southern Ocean

Soon after longlining on Patagonian toothfish (Dissostichus eleginoides) started in the Southern Ocean in the second half of the 1980s, interactions of cetaceans with these fisheries became apparent. The two species primarily involved were orcas (killer whales) (Orcinus orca) and male sperm whales (Physeter macrocephalus). Both species took substantial number of fish from the line primarily during day light hours. Catch rates of longliners declined to less than 50% when orcas occurred close to longline vessels while the loss to sperm whales was much less obvious. They were seen diving close to the line down to 400 m where they apparently took fish. Their impact on catch rates was much less notable. Sperm whales became frequently entangled in the line and part of the line was lost in a number of cases. Other cetaceans were rarely seen in the vicinity of longline vessels. They became entangled in the line only occasionally and one whale (presumably a minke whale) died.     

SEASONAL PATTERNS IN THE ABUNDANCE AND DISTRIBUTION OF CALIFORNIA CETACEANS, 1991–1992

This study presents a detailed seasonal comparison of the abundance and distribution of cetaceans within 100-150 nmi (185-278 km) of the California coast during 1991 and 1992. The results of a shipboard line-transect survey conducted in July-November 1991 ("summer") were compared to those from aerial line-transect surveys conducted in March-April 1991 and February-April 1992 ("winter"). Using a confidence-interval-based bootstrap procedure, abundance estimates for six of the eleven species included in the comparison exhibited significant (α= 0.05) differences between the winter and summer surveys. Pacific white-sided dolphins ( Lagenorhynchus obliquidens ), Risso's dolphins ( Grampus griseus ), common dolphins ( Delphinus spp.), and northern right whale dolphins ( Lissodelphis borealis ) were significantly more abundant in winter. The abundance of blue whales ( Balaenoptera musculuss ) and gray whales ( Eschrichtius robustus ) reflected well-documented migratory patterns. Fin whales ( B. physalus ) were significantly more abundant during summer. No significant differences in seasonal abundance were identified for Dall's porpoises ( Phocoenoides dalli ), bottlenose dolphins ( Tursiops truncatus ), killer whales ( Orcinus orca ), sperm whales ( Physeter macrocephalus ), or humpback whales ( Megaptera novaeangliae ). Significant north/south shifts in distribution were found for Dall's porpoises, common dolphins, and Pacific white-sided dolphins, and significant inshore/offshore differences were identified for northern right whale dolphins and humpback whales.     

Asymmetry of pectoral flipper use in the orca <Emphasis Type="Italic">Orcinus orca</Emphasis> (Linnaeus, 1758) from the Avachinskii Bay (Eastern Kamchatka)

Asymmetrical forelimb use is characteristic of many mammalian species. However, little is known about this phenomenon in cetaceans. We examined the asymmetry in pectoral flipper use by the wild orca Orcinus orca (Linnaeus, 1758). During observations from motor boats in the Avachinskii Bay (East Kamchatka) we recorded the use of flippers in slapping the water by individually identified resident (fish-eating) orcas. The studied individuals mostly used their right flipper. The revealed right-sided bias presumably reflects the pivotal role of the left brain hemisphere in the control of forelimb movements, which is consistent with the data that have been obtained for other cetacean species.     

Cetaceans of Southeast Alaska: distribution and seasonal occurrence

Aim To assess the distribution, group size, seasonal occurrence and annual trends of cetaceans. Location The study area included all major inland waters of Southeast Alaska. Methods Between 1991 and 2007, cetacean surveys were conducted by observers who kept a constant watch when the vessel was underway and recorded all cetaceans encountered. For each species, we examined distributional patterns, group size, seasonal occurrence and annual trends. Analysis of variance (anova F) was used to test for differences in group sizes between multiple means, and Student’s t‐test was used to detect differences between pairwise means. Cetacean seasonal occurrence and annual trends were investigated using a generalized linear model framework. Results Humpback whales (Megaptera novaeangliae) were seen throughout the region, with numbers lowest in spring and highest in the fall. Fin whale (Balaenoptera physalus) and minke whale (Balaenoptera acutorostrata) distributions were more restricted than that reported for humpback whales, and the low number of sightings precluded evaluating seasonal trends. Three killer whale (Orcinus orca) eco‐types were documented with distributions occurring throughout inland waters. Seasonal patterns were not detected or could not be evaluated for resident and offshore killer whales, respectively; however, the transient eco‐type was more abundant in the summer. Dall’s porpoise (Phocoenoides dalli) were distributed throughout the region, with more sightings in spring and summer than in fall. Harbour porpoise (Phocoena phocoena) distribution was clumped, with concentrations occurring in the Icy Strait/Glacier Bay and Wrangell areas and with no evidence of seasonality. Pacific white‐sided dolphins (Lagenorhynchus obliquidens) were observed only occasionally, with more sightings in the spring. For most species, group size varied on both an annual and seasonal basis. Main conclusions Seven cetacean species occupy the inland waters of Southeast Alaska, with distribution, group size, seasonal occurrence and annual trends varying by species. Future studies that compare spatial and temporal patterns with other features (e.g. oceanography, prey resources) may help in identifying the key factors that support the high density and biodiversity of cetaceans found in this region. An increased understanding of the region’s marine ecology is an essential step towards ensuring the long‐term conservation of cetaceans in Southeast Alaska.     

The mitochondrial genome and ribosomal operon of Brachycladium goliath (Digenea: Brachycladiidae) recovered from a stranded minke whale

Members of the Brachycladiidae are known to cause pathologies implicated in cetacean strandings and it is important to develop accurate diagnostic markers to differentiate these and other helminths found in cetaceans. Brachycladium goliath (van Beneden, 1858) is a large trematode found, as adults, usually in the hepatic (bile) and pancreatic ducts of various cetaceans. Complete sequences were determined for the entire mitochondrial genome, and phylogenetically informative nuclear genes contained within the ribosomal operon, from a small piece of an individual worm taken from a common minke whale Balaenoptera acutorostrata Lacépède, 1804. Genomic DNA was sequenced using an Illumina MiSeq platform. The mtDNA is 15,229 bp in length consisting of 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 2 non-coding regions of which the larger is comprised of 4 tandemly repeated units (260 bp each). The ribosomal RNA operon is 9297 bp long. These data provide a rich resource of molecular markers for diagnostics, phylogenetics and population genetics in order to better understand the role, and associated pathology of helminth infections in cetaceans.     

The prevalence of Toxoplasma gondii antibodies in wild and captive cetaceans from Japan

The seroprevalence of Toxoplasma gondii was investigated in wild and captive cetaceans from Japan. Antibodies against T. gondii were examined by both latex agglutination test (LAT) and indirect hemagglutination test (IHAT) for 77 serum or plasma samples obtained from 59 individuals of 6 species, including 2 hybrids. Antibody titers greater than 1:64 in LAT and greater than 1:640 in IHAT, indicative of the presence of T. gondii, were found in 11.9% of 59 individuals. In 7 samples that showed a positive reaction by IHAT, T. gondii titers were examined for each immunoglobulin (Ig) fraction separated by sucrose gradient centrifugation. The antibody peaks in each fraction were divided into 3 types, thought to be a reaction of IgM (type 1), IgG (type 2), and IgM with IgG (type 3). Type 1 was found in serum from a bottle-nosed dolphin (Tursiops truncatus) and a killer whale (Orcinus orca) sampled soon after capture off the Japanese coast in 1988; it was concluded that infection in the wild had occurred less than 15 yr before the study was performed. The prevalence of putative IgM and IgG antibodies from a captive-bred T. truncatus suggested that T. gondii infection also occurred in the aquarium.