Marine Mammals: Why Dolphins, Whales, and Seals Are Not Fish

Dolphins, whales, and seals are mammals, not fish. They breathe air through lungs, give live birth, nurse their young with milk, and maintain a constant body temperature. Fish, by contrast, are aquatic vertebrates that typically breathe through gills, lay eggs, and are cold-blooded. This distinction matters for anyone who studies animal biology, works with marine species, or makes decisions about animal care and conservation. The confusion is understandable because marine mammals share their habitat with fish and have evolved streamlined bodies that resemble fish. However, the biological differences are fundamental and affect everything from how these animals breathe to how they raise their offspring.

What Defines a Mammal

Mammals belong to the class Mammalia, a group of vertebrates distinguished by several shared characteristics. These traits are present across all mammals, whether they live on land, in the air, or in the ocean.

Key Mammalian Traits

All mammals share three defining features. First, they have mammary glands that produce milk to nourish their young. Second, they have hair or fur at some stage of their life. Third, they are endothermic, meaning they generate their own body heat internally. These traits are present in marine mammals just as they are in terrestrial mammals like cattle, sheep, and goats.

The presence of mammary glands is particularly important. Marine mammal mothers nurse their calves and pups with milk that is rich in fat and nutrients. This investment in offspring care is a hallmark of mammalian reproduction. The imaging and diagnostic tools for cetacean mammary gland assessment review notes that cetacean mammary glands play a fundamental role in providing vital nutrients for the growth of offspring, even though research on their morphology and physiology remains limited compared to studies of ovaries and reproductive tracts.

Hair is another defining feature. Dolphins and whales have small amounts of hair, often only present at birth or around the blowhole. Seals have a dense fur coat that provides insulation. This hair is a remnant of their terrestrial ancestry and confirms their place within the mammalian lineage.

Respiration and Circulation

Mammals breathe air through lungs. Marine mammals must surface to inhale oxygen, and they cannot extract oxygen from water through gills. This is a critical difference from fish. A dolphin or whale will drown if it cannot reach the surface, while a fish would suffocate if removed from water.

The respiratory system of marine mammals is adapted for prolonged dives. They can store large amounts of oxygen in their muscles and blood, and they have a high tolerance for carbon dioxide. Research on adaptation of mammals to hypoxia explains that oxygen plays a pivotal role in the metabolism and activities of mammals, and that organisms living in deep ocean habitats face hypoxic stresses. Marine mammals have evolved specific strategies to cope with these stresses, including changes in physiology, gene expression regulation, and genetic mutations.

The circulatory system of marine mammals is also specialized. During a dive, blood is shunted away from peripheral tissues and directed toward the brain and heart. This dive response helps conserve oxygen and allows marine mammals to remain submerged for extended periods. A review of the multi-level adaptations for maximizing aerobic dive duration in marine mammals describes how these adaptations operate from the biochemical level up to behavioral strategies.

Reproduction and Parental Care

Marine mammals give live birth. Unlike fish, which typically lay eggs, marine mammals carry their young in the womb and deliver fully formed offspring. The young are dependent on their mothers for milk and protection during the early stages of life.

This reproductive strategy has significant implications for population dynamics. Marine mammal populations grow slowly because females invest heavily in each offspring. A female dolphin may give birth to a single calf every few years, and the calf may stay with its mother for several years. This slow reproductive rate makes marine mammal populations vulnerable to overexploitation and environmental changes.

The social behavior of marine mammals reflects their complex cognitive abilities. Killer whales, for example, live in stable social groups with intricate relationships. A study on infanticide in a mammal-eating killer whale population documented an adult male killer whale and his post-reproductive mother killing a neonate belonging to an unrelated female. The researchers suggested that infanticide is a sexually selected behavior in killer whales that could provide subsequent mating opportunities for the infanticidal male and inclusive fitness benefits for his mother. This level of social complexity is characteristic of mammals, not fish.

The Major Groups of Marine Mammals

Marine mammals are not a single taxonomic group. They are divided into three main orders based on their evolutionary history and physical characteristics.

Cetaceans: Whales, Dolphins, and Porpoises

Cetaceans are fully aquatic mammals that never come onto land. They include the largest animals on Earth, such as the blue whale, as well as smaller species like the bottlenose dolphin. Cetaceans are divided into two suborders: baleen whales and toothed whales.

Baleen whales have plates of baleen in their mouths instead of teeth. They filter small organisms like krill and plankton from the water. Toothed whales, which include dolphins and porpoises, have teeth and hunt larger prey like fish and squid.

Cetaceans have evolved a range of adaptations for aquatic life. Their bodies are streamlined and fusiform, reducing drag as they move through water. Their forelimbs have become flippers, and their hind limbs have been lost entirely. The tail has become a horizontal fluke that provides propulsion through vertical movement.

The skin of cetaceans is smooth and hairless, reducing friction. They have a thick layer of blubber beneath the skin that provides insulation and energy storage. This blubber layer is essential for maintaining body temperature in cold ocean waters.

Pinnipeds: Seals, Sea Lions, and Walruses

Pinnipeds are semi-aquatic marine mammals that spend time both in the water and on land. They include seals, sea lions, and walruses. Pinnipeds have flippers for both forelimbs and hind limbs, and they are generally more agile on land than cetaceans.

Seals and sea lions differ in several ways. True seals have no external ear flaps and move on land by undulating their bodies. Sea lions have external ear flaps and can walk on their hind flippers. Walruses are distinguished by their long tusks and are found in Arctic regions.

Pinnipeds rely on their fur and blubber for insulation. They are excellent divers and can remain submerged for extended periods while hunting for fish and other prey. Their whiskers, or vibrissae, are highly sensitive and help them detect prey in murky water.

Sirenians: Manatees and Dugongs

Sirenians are fully aquatic herbivorous mammals. They include manatees and dugongs, which are found in warm coastal waters and rivers. Sirenians are sometimes called sea cows because they graze on aquatic vegetation.

Sirenians have a large, rounded body with a paddle-like tail. They have forelimbs that function as flippers but no hind limbs. Unlike cetaceans and pinnipeds, sirenians are slow-moving and spend much of their time feeding on seagrass beds.

Sirenians are the only herbivorous marine mammals. Their digestive system is adapted for processing plant material, and they have a complex stomach that aids in fermentation. This dietary specialization sets them apart from the carnivorous cetaceans and pinnipeds.

At a Glance: Marine Mammals Versus Fish

The following table compares dolphins, sharks, and fish across key biological features. This comparison highlights the fundamental differences between marine mammals and fish.

This table demonstrates that dolphins share more biological features with terrestrial mammals like cattle and horses than with sharks or bony fish. The similarities between dolphins and fish are the result of convergent evolution, where unrelated species develop similar body shapes because they live in the same environment.

Adaptations to Aquatic Life

Marine mammals have evolved a remarkable set of adaptations that allow them to thrive in water. These adaptations affect their physiology, anatomy, and behavior.

Thermoregulation in Cold Water

Water conducts heat away from the body about 25 times faster than air. Marine mammals must therefore have effective mechanisms for retaining body heat. The primary adaptation is blubber, a thick layer of fat beneath the skin that insulates the body and stores energy.

The thickness of blubber varies by species and by the temperature of their habitat. Arctic species like the bowhead whale have blubber that can be over 50 centimeters thick. Temperate and tropical species have thinner blubber layers.

Marine mammals also have countercurrent heat exchange systems in their flippers and flukes. Blood vessels in these extremities are arranged so that warm arterial blood flowing to the extremity passes close to cold venous blood returning to the body. This arrangement transfers heat from the arterial blood to the venous blood, reducing heat loss at the body surface.

Research on adaptations to marine versus terrestrial low temperature environments has examined how organisms adapt to cold environments. While this study focused on bacteria, it illustrates the principle that marine and terrestrial cold environments impose different constraints on organisms. Marine mammals have evolved specific adaptations to the marine cold environment, including their blubber layer and countercurrent heat exchange systems.

The immune system of marine mammals also functions at low temperatures. A study on cold-tolerant phagocytic activity in polymorphonuclear leucocytes of marine mammals found that bottlenose dolphin neutrophils maintained stable phagocytic activity even at low temperatures, while terrestrial mammal neutrophils showed a temperature-dependent decline. Spotted seal neutrophils retained robust activity against certain particles at low temperatures. These findings suggest that marine mammal immune cells have undergone evolutionary adaptation to enable effective biological defense in cold marine environments.

Oxygen Storage and Dive Physiology

Marine mammals are exceptional divers. Some species can remain submerged for over an hour and reach depths of more than 1,000 meters. These diving abilities require specialized physiological adaptations.

Marine mammals have a high concentration of myoglobin in their muscles. Myoglobin is an oxygen-binding protein that stores oxygen in muscle tissue. The concentration of myoglobin in marine mammal muscles is significantly higher than in terrestrial mammals, allowing them to carry a large oxygen reserve on each dive.

During a dive, marine mammals reduce their heart rate and redirect blood flow to vital organs. This dive response conserves oxygen and allows the animal to extend its time underwater. The spleen also plays a role by releasing red blood cells into circulation during a dive, increasing the blood's oxygen-carrying capacity.

Research on convergent evolution in high-altitude and marine mammals has examined molecular adaptations to hypoxia in these two groups. Both high-altitude and marine mammals face challenges related to low oxygen availability, and they have evolved similar genetic adaptations to cope with these conditions.

Sensory Systems

Marine mammals have evolved specialized sensory systems that function effectively in water. Toothed whales and dolphins use echolocation to navigate and find prey. They emit high-frequency clicks and listen for the echoes that bounce off objects in their environment. This biosonar system allows them to hunt in dark or murky water where vision is limited.

Pinnipeds rely heavily on their whiskers, or vibrissae, to detect prey. The whiskers are highly innervated and can detect the water movements created by swimming fish. This tactile sense is particularly important in low-visibility conditions.

Marine mammals have eyes that are adapted for underwater vision. Their eyes have a spherical lens that focuses light efficiently in water, and they have a high concentration of rod cells for low-light vision. Some species also have adaptations that protect their eyes from the pressure changes experienced during deep dives.

Evolutionary History

The evolutionary history of marine mammals explains why they share more characteristics with terrestrial mammals than with fish. Marine mammals evolved from land-dwelling ancestors that returned to the ocean over millions of years.

From Land to Sea

The ancestors of cetaceans were terrestrial hoofed mammals that lived about 50 million years ago. These early ancestors gradually adapted to a semi-aquatic lifestyle, spending more time in the water and developing features suited for swimming. Over time, their bodies became more streamlined, their limbs transformed into flippers, and their nostrils moved to the top of their heads to form a blowhole.

Pinnipeds evolved from bear-like or otter-like ancestors that lived about 25 million years ago. These ancestors adapted to a semi-aquatic lifestyle, developing flippers and a streamlined body for efficient swimming. Sirenians evolved from elephant-like ancestors and are more distantly related to other marine mammals.

The process of adaptation to aquatic life involved changes at the genetic level. Research on molecular characterization of positively selected genes contributing aquatic adaptation in marine mammals has identified genes that underwent positive selection during the transition from land to sea. These genetic changes affected traits such as oxygen storage, thermoregulation, and sensory perception.

Convergent Evolution

The similar body shapes of marine mammals and fish are the result of convergent evolution. Convergent evolution occurs when unrelated species evolve similar traits because they face similar environmental pressures. The streamlined body, flippers, and tail fins of marine mammals and fish are examples of convergent evolution.

Despite these similarities, the underlying anatomy is different. A dolphin's flipper contains the same bones as a human hand, while a fish's fin contains a different skeletal structure. The tail of a dolphin moves up and down, while the tail of a fish moves side to side. These differences reflect the different evolutionary histories of the two groups.

The question of adaptations to polar environments in marine mammals has been a topic of scientific inquiry since at least the 1960s. Marine mammals that live in polar regions face extreme cold and seasonal changes in food availability. Their adaptations to these conditions include thick blubber, reduced heat loss, and seasonal migration patterns.

Why the Distinction Matters

Understanding that marine mammals are not fish has practical implications for conservation, management, and animal care.

Conservation and Management

Marine mammals and fish are managed under different legal and regulatory frameworks. In many countries, marine mammals are protected by specific legislation that recognizes their unique biological and social characteristics. These protections may include restrictions on hunting, fishing bycatch reduction measures, and habitat protection.

The slow reproductive rate of marine mammals makes them particularly vulnerable to population declines. A dolphin population that loses individuals to bycatch or habitat degradation may take decades to recover. Conservation efforts must account for these biological realities.

Marine mammals also face health threats that are distinct from those affecting fish. Candida infections in marine mammals have been recognized as significant pathogens in cetaceans and pinnipeds. The spread of antifungal-resistant strains poses threats to animal health and raises One Health concerns. Cetaceans are most vulnerable to respiratory and disseminated mycoses due to their distinct anatomical characteristics, while pinnipeds commonly experience mucocutaneous infections. Localized infections may progress to fatal systemic disease, with mortality rates approaching 100% in severe cases despite therapeutic treatment.

Animal Care and Veterinary Medicine

Veterinarians who work with marine mammals require specialized knowledge that differs from fish medicine. Marine mammals have unique anatomical and physiological features that affect diagnosis and treatment. For example, the mammary glands of cetaceans present particular challenges for assessment. The review of imaging and diagnostic tools for cetacean mammary gland assessment describes how tools such as mammography, CT, MRI, and ultrasonography might be adapted for use in marine mammal medicine.

Marine mammals are also susceptible to infectious diseases that do not affect fish. Cetacean morbilliviruses have emerged as significant pathogens affecting cetacean populations worldwide. The genome sequence of Fraser's dolphin morbillivirus, isolated from a stranded Fraser's dolphin in Hawai'i, showed a genomic organization similar to other morbilliviruses and phylogenetic analysis demonstrated that it is a distinct member of the genus Morbillivirus.

Public Education and Awareness

Public understanding of marine mammals affects how people interact with these animals. People who understand that dolphins are mammals are more likely to recognize that dolphins need to breathe air and may be disturbed by close approach from boats. People who understand that seals are mammals are more likely to recognize that seal pups on the beach may be waiting for their mothers to return and should not be approached or moved.

Educational programs that clarify the distinction between marine mammals and fish can help reduce harmful interactions and promote responsible wildlife viewing. These programs can also foster greater appreciation for the unique adaptations that allow marine mammals to thrive in aquatic environments.

Common Misconceptions

Several misconceptions about marine mammals persist despite scientific evidence to the contrary. Addressing these misconceptions is important for accurate understanding and informed decision-making.

Misconception: Dolphins Are Fish Because They Live in Water

Living in water does not make an animal a fish. Many animals that live in water are not fish, including marine mammals, sea turtles, and marine invertebrates. Classification is based on evolutionary relationships and shared characteristics, not on habitat.

Dolphins share more characteristics with humans and other mammals than with fish. They breathe air, give live birth, nurse their young, and have hair at some stage of their life. These characteristics place them firmly within the class Mammalia.

Misconception: Whales Are Too Large to Be Mammals

Size does not determine classification. The blue whale is the largest animal that has ever lived, but it is still a mammal. Its size is an adaptation to the aquatic environment, where the buoyancy of water supports a massive body.

The blue whale shares all the defining characteristics of mammals. It breathes air through lungs, gives live birth, nurses its young with milk, and has a small amount of hair. Its enormous size is a result of evolutionary adaptation to its environment, not a reason to classify it differently.

Misconception: Seals Are Fish Because They Have Flippers

Flippers are an adaptation for swimming, not a characteristic that defines fish. Many animals have flippers, including sea turtles and penguins, and none of these animals are fish. Seals are mammals that have evolved flippers for efficient movement in water.

Seals have fur, give live birth, and nurse their young with milk. They are warm-blooded and breathe air. These characteristics are shared with other mammals and distinguish seals from fish.

How to Identify a Marine Mammal

Identifying whether an animal is a marine mammal or a fish can be done by observing several key characteristics. These observations can be made from a distance and do not require close contact with the animal.

Observing Respiration

Marine mammals must surface to breathe. A dolphin or whale will come to the surface and exhale through its blowhole, creating a visible spout of water vapor. Fish do not surface to breathe and do not produce such spouts.

Seals and sea lions also surface to breathe, but they do not have blowholes. They breathe through their nostrils, which are located on the front of their snout. When a seal surfaces, it may be visible with its head above the water.

Observing Body Movement

Marine mammals move through water differently than fish. Dolphins and whales propel themselves with vertical movements of their tail flukes. Fish propel themselves with side-to-side movements of their tail fins.

When a dolphin surfaces, it may arch its back and tail as it dives. This movement pattern is distinct from the swimming behavior of fish. Seals and sea lions use their front flippers for propulsion and may be seen porpoising through the water.

Observing Social Behavior

Marine mammals often exhibit social behaviors that are not typical of fish. Dolphins may be seen riding the bow waves of boats, leaping out of the water, and interacting with each other at the surface. Whales may be seen breaching, spyhopping, and lobtailing.

These behaviors are beyond for display. They serve social, communicative, and foraging functions. The complexity of these behaviors reflects the advanced cognitive abilities of marine mammals.

Practical Assessment Steps

For students, researchers, and professionals who need to confirm whether an animal is a marine mammal, the following assessment steps provide a systematic approach.

Step 1: Observe Respiration

Watch the animal at the surface. If it surfaces to breathe air and exhales visibly, it is likely a marine mammal. If it remains submerged and shows no need to surface, it may be a fish.

Step 2: Examine Body Covering

If you can see the animal closely, examine its skin. Marine mammals have smooth skin with little or no visible scales. Fish have scales that are visible to the naked eye. Marine mammals may have hair or fur, while fish do not.

Step 3: Assess Reproductive Behavior

If you observe an adult with young, note whether the young appears to be nursing. Marine mammal mothers nurse their young with milk. Fish do not produce milk and do not nurse their young.

Step 4: Consider the Tail

If you can see the tail, note its orientation. Marine mammals have horizontal tail flukes that move up and down. Fish have vertical tail fins that move side to side.

Step 5: Record Your Observations

Document your observations with notes, photographs, or video. Record the date, time, location, and environmental conditions. This information is valuable for research and conservation efforts.

Records and Measurements

Accurate records are essential for research and conservation of marine mammals. The following types of records are commonly maintained by researchers and wildlife managers.

Sighting Records

Sighting records document when and where marine mammals are observed. These records include the species, number of individuals, behavior, and environmental conditions. Sighting records are used to track population distribution and abundance.

Photo-identification is a common method for tracking individual marine mammals. Photographs of distinctive markings, such as the dorsal fin of a dolphin or the pigmentation pattern of a whale, allow researchers to identify and track individuals over time. The bridle mark system on bottlenose dolphins describes pigmented facial features that supplement photo-identification efforts.

Health Records

Health records document the physical condition of individual animals. These records may include body condition scores, measurements, and observations of injuries or lesions. Health records are important for monitoring population health and detecting disease outbreaks.

Skin lesions in dolphins can indicate health problems. An exploratory investigation into microbial and cyanobacterial presence on skin epibiota and orofacial lesions in estuarine common bottlenose dolphins found that samples from algal sheens and orofacial lesions demonstrated higher bacterial diversity than reported in normal bottlenose dolphin skin microbiomes. Previously unreported bacterial genera were identified, including genera containing pathogenic species.

Stranding Records

Stranding records document marine mammals that wash ashore, either dead or alive. These records are important for monitoring mortality events and detecting emerging threats. Stranded animals may be examined to determine the cause of death and to collect samples for research.

Stranding networks rely on trained responders who can safely handle stranded animals and collect appropriate data. Members of the public who encounter a stranded marine mammal should report it to the appropriate authorities and avoid touching or moving the animal.

Common Failure Patterns in Identification

Misidentification of marine mammals can lead to management errors and public safety issues. The following failure patterns are common.

Failure to Recognize That Marine Mammals Need Air

People who do not understand that marine mammals breathe air may not recognize the signs of distress when an animal is unable to surface. This can lead to delayed rescue efforts for entangled or stranded animals.

Failure to Distinguish Between Species

Different species of marine mammals have different habitat requirements and conservation status. Confusing one species for another can lead to incorrect management decisions. For example, confusing a harbor seal with a sea lion may result in inappropriate handling or relocation.

Failure to Recognize Disease Signs

Marine mammals can carry diseases that are transmissible to humans and other animals. People who do not recognize disease signs may approach sick animals and put themselves at risk. The review of Candida infections in marine mammals notes that localized mucocutaneous infections may progress to fatal systemic disease and that immunosuppression, long-term antibiotic treatment, environmental stress factors, and deterioration of water quality are important predisposing factors.

Welfare and Safety Context

Marine mammals are protected by various laws and regulations in many countries. These protections reflect the biological and social characteristics of marine mammals and the need to conserve them for future generations.

Legal Protections

In the United States, marine mammals are protected by the Marine Mammal Protection Act of 1972. This law prohibits the taking of marine mammals, which includes hunting, killing, capturing, and harassing them. Similar protections exist in other countries.

The legal protections for marine mammals are based on the recognition that these animals have unique biological characteristics, including their slow reproductive rates and complex social behaviors. These characteristics make them vulnerable to population declines from human activities.

Public Safety Considerations

Marine mammals are wild animals and can be dangerous. They are large, powerful, and may behave unpredictably, especially when threatened or when protecting their young. Members of the public should maintain a safe distance from marine mammals and should not attempt to feed or touch them.

Stranded marine mammals may be sick or injured and may carry diseases that can be transmitted to humans. Members of the public should not approach stranded animals and should report them to the appropriate authorities.

Professional Escalation Criteria

Wildlife professionals and veterinarians should escalate concerns about marine mammals to appropriate authorities when they observe signs of distress, disease, or unusual mortality. The following criteria indicate a need for professional intervention:

• A marine mammal that is stranded and unable to return to the water
• A marine mammal that appears sick, injured, or emaciated
• A marine mammal that is entangled in fishing gear or other debris
• A marine mammal that is behaving abnormally, such as swimming in circles or beaching itself repeatedly
• A marine mammal that is in an area where it is at risk of harm from human activities

When these signs are observed, the appropriate authorities should be notified immediately. Trained responders can assess the situation and determine the best course of action.

Frequently Asked Questions

Are dolphins mammals?

Yes, dolphins are mammals. They belong to the order Cetacea, which includes whales and porpoises. Dolphins breathe air through lungs, give live birth, nurse their young with milk, and have hair at some stage of their life. These characteristics place them in the class Mammalia, not in the class of fish.

Are seals mammals?

Yes, seals are mammals. They belong to the order Pinnipedia, which also includes sea lions and walruses. Seals have fur, give live birth, and nurse their young with milk. They are warm-blooded and breathe air through lungs. These characteristics distinguish them from fish.

Why do dolphins look like fish if they are mammals?

Dolphins look like fish because of convergent evolution. Convergent evolution occurs when unrelated species evolve similar traits because they face similar environmental pressures. The streamlined body, flippers, and tail of dolphins are adaptations for swimming that evolved independently from the similar features of fish. Despite these similarities, dolphins and fish have different evolutionary histories and different underlying anatomy.

Do marine mammals lay eggs?

No, marine mammals do not lay eggs. All marine mammals give live birth. This is a defining characteristic of mammals. Fish, by contrast, typically lay eggs, although some species of sharks give live birth.

Do marine mammals have gills?

No, marine mammals do not have gills. They breathe air through lungs and must surface to inhale oxygen. Fish have gills that extract oxygen from water. This is a fundamental difference between marine mammals and fish.

How long can marine mammals stay underwater?

The dive duration varies by species. Some species can remain submerged for over an hour, while others make shorter dives. Marine mammals have adaptations that allow them to store oxygen in their muscles and blood and to reduce their heart rate during dives. These adaptations allow them to extend their time underwater.

Do marine mammals have hair?

Yes, marine mammals have hair at some stage of their life. Dolphins and whales have small amounts of hair, often only present at birth or around the blowhole. Seals have a dense fur coat. The presence of hair is a defining characteristic of mammals.

Why is it important to know that marine mammals are not fish?

Knowing that marine mammals are not fish is important for conservation, management, and animal care. Marine mammals have different biological characteristics than fish, including slow reproductive rates and complex social behaviors. These characteristics affect how they should be managed and protected. Understanding the distinction also helps people interact safely and responsibly with marine mammals in the wild.

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References and Further Reading

• NCBI Literature Resources. National Center for Biotechnology Information.
• PubMed. National Library of Medicine.
• Adaptation of mammals to hypoxia.. Animal models and experimental medicine, 2021.
• Adaptations to marine versus terrestrial low temperature environments as revealed by comparative genomic analyses of the genus Psychrobacter.. FEMS microbiology ecology, 2018.
• Current Clinical Concepts: Heat Tolerance Testing.. Journal of athletic training, 2023.
• Exoskeleton Application to Military Manual Handling Tasks.. Human factors, 2022.
• Heat injury prevention--a military perspective.. Journal of strength and conditioning research, 2012.
• THE QUESTION OF ADAPTATIONS TO POLAR ENVIRONMENTS IN MARINE MAMMALS.. Federation proceedings, 1964.
• Stress, Cognition, Drones, and Adaptive Tasks.. Aerospace medicine and human performance, 2020.
• Emerging findings on trauma in the military.. Psychological trauma : theory, research, practice and policy, 2019.
• Genome sequence of Fraser's dolphin morbillivirus isolated from a stranded Fraser's dolphin (Lagenodelphis hosei) in Hawai'i.. 2026.
• Candida Infections in Marine Mammals: Epidemiology, Antifungal Resistance, and One Health Implications.. 2026.
• The Bridle Mark System on Bottlenose Dolphins (Tursiops truncatus): Pigmented Facial Features Supplement Photo-Identification. 2026.
• Discovery of cold-tolerant phagocytic activity in polymorphonuclear leucocytes (PMNs) of marine mammals.. 2026.
• Imaging and Diagnostic Tools for Cetacean Mammary Gland Assessment: Challenges and Future Directions for Marine Mammal Pathology, Medicine and Research.. 2025.
• An exploratory investigation into the microbial and cyanobacterial presence on skin epibiotia and orofacial lesions in estuarine common bottlenose dolphins (Tursiops truncatus) through metabarcoding.. 2026.
• Paramytha ossicola sp. nov. (Polychaeta, Ampharetidae) from mammal bones: Reproductive biology and population structure. 2017.
• Infanticide in a mammal-eating killer whale population. Scientific Reports, 2018.
• Convergent evolution in high-altitude and marine mammals: Molecular adaptations to pulmonary fibrosis and hypoxia. Zoological Research, 2024.
• Molecular characterization of positively selected genes contributing aquatic adaptation in marine mammals. Genes and Genomics, 2024.
• A review of the multi-level adaptations for maximizing aerobic dive duration in marine mammals: From biochemistry to behavior. Journal of Comparative Physiology B Biochemical Systemic and Environmental Physiology, 2014.

This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.