15 best Difference Between Sharks and Bony Fish

Nov 20, 2023
Difference Between Sharks and Bony Fish

Sharks and Bony Fish: The key difference between sharks and bony fish is that the shark has an internal skeleton made from cartilage while bony fish has an internal skeleton made from calcified bones.

Fish are one of the five vertebrate groups belonging to Kingdom Animalia. They are multicellular aquatic organisms. There are more than 32,000 species in all aquatic environments that belong to this group. Most of the fish are carnivores or omnivores. Fish may have an internal skeleton made from bones or cartilage. There are three major groups of fish namely cartilaginous fish, Bony fish and lobe-finned fish.

What is the definition and classification of Sharks?

Figure-no-1: Sharks
  • Sharks are predatory fish belonging to the subclass Elasmobranchii and class Chondrichthyes. Their sleek bodies feature cartilaginous skeletons with multiple rows of sharp, replaceable teeth. For millions of years, sharks have existed and evolved into diverse species; currently, there are over 500 different kinds.
  • Sharks can be found throughout all oceans, from coastal waters to open sea environments. As top predators, they play a crucial role in marine ecology by helping regulate populations of other organisms in marine ecologies. Some shark species even act as apex predators with no natural enemies to contend with!
  • Fish species range in size from the dwarf lantern shark (which measures between 18-20 cm in length) to whale sharks which can grow to 40 feet (12 meters). Sharks possess various adaptations that facilitate hunting, such as excellent hearing and vision as well as their ability to detect electrical fields produced by other creatures.
  • While certain species, like the tiger and great white sharks, may occasionally come into contact with humans, most sharks do not pose a significant threat. Instead, sharks play an essential role in ocean ecology and need protection because they’re susceptible to overfishing and habitat destruction.

What is the definition and classification of Bony Fish?

Bony Fish
Figure no-2: Bony Fish
  • Osteichthyes is the name given to a group of fish that encompasses over 30,000 species and boasts predominantly bony skeletons as opposed to cartilage-rich structures found in sharks or other rays.
  • Bony fishes can be found in both freshwater and ocean environments. Bony fish come in an assortment of sizes, shapes, and adaptations that suit their habitats and lifestyles, from small tropical varieties with vibrant hues to larger predators that possess predatory behavior.
  • Bony fishes can be distinguished from one another by the presence of an operculum on their gills; it provides protection and aids respiratory function, enabling them to extract oxygen from water. Furthermore, these species possess a swimming bladder – an organ filled with gas that controls buoyancy and allows for movement within the water column – for controlling buoyancy control and position adjustment.
  • Bony fish’s scales provide protection and reduced friction while swimming. Scale sizes, shapes, and composition differ depending on the species. Fins come paired with one another: pectoral, pelvic, dorsal, and anal fins that serve to stabilize, maneuver and propel them. Bony fish typically reproduce by laying eggs outside of their female host; some species, however, are viviparous and give birth to live young. Furthermore, some varieties are herbivorous while others may be carnivorous.
  • Bonefish are an exceptionally diverse group, playing an essential role in aquatic ecosystems as prey for larger predator species and helping balance marine and freshwater environments.

Table Difference :

Characteristic Sharks Bony Fish
Skeletal Structure Cartilaginous skeleton Bony skeleton
Reproductive Strategies Oviparity, viviparity, ovoviviparity Mostly oviparity (laying eggs)
Scale Types Placoid scales (dermal denticles) Cycloid, ctenoid, or ganoid scales
Feeding Behavior Primarily carnivorous Varied herbivory, omnivory, carnivory
Sense of Smell Highly developed Good, but not as pronounced as sharks
Respiratory System Gill slits Gill slits
Tail Shape Heterocercal (upper lobe larger) Homocercal (equal lobes)
Lateral Line System Present Present
Tooth Structures Various types based on feeding habits Varied, depending on feeding habits
Habitat and Distribution Oceans, various depths, and habitats Freshwater and marine environments

Physical Characteristics

The physical characteristics of sharks and bony fish play an important role in distinguishing between them, with key differences including these below.


  • Their bones are made up of cartilaginous material, making their skeletons lighter and more flexible than that of other fish species. Cartilage provides tough yet flexible connective tissues.
  • Sharks possess two-lobed tails called heterocercal tails; usually, the upper lobe is larger than its counterpart below it for enhanced swimming efficiency and lift. Pectoral fins located on either side of their bodies provide stability and lift to improve maneuverability and can even feature triangular shapes that increase maneuverability.
  • Sharks are unique among aquatic creatures in that they possess placoid or dermal denticles – unique scales found within their skin that appear as teeth-like projections – to help provide protection and reduce drag in the water. Their rough scales improve hydrodynamics.

Bony Fish:

  • Bony fish have a rigid and stable skeleton constructed of calcium-rich bone. This structure provides greater rigidity than sharks’ cartilaginous structure.
  • Bony Fish have equal-sized tails that allow for efficient movement through water. Pectoral, dorsal, and pelvic fins help balance maneuverability, stability and provide balance when swimming through.
  • Scales on bony fish come in various forms, such as cycloid and ctenoid scales which overlap like shingles; ganoid scales found on certain bony primitive fish species have thicker scales with diamond or rhomboidal patterns on them.
  • Variations and exceptions exist among each group of fish; sharks for example may exhibit modified or unique features that set them apart from traditional sharks, while bony fish exhibit different body shapes, fins, and scale variations depending on the species they belong to and their ecological niche.


Sharks and bony fish reproduce differently, in terms of reproductive modes, strategies, offspring development strategies, etc. Here are some important points about their reproductive biology.


There are various methods of reproduction among sharks, including oviparity and viviparity.

  • Oviparity: Certain shark species produce eggs that are fertilized inside and placed into egg cases. Once fertilized, these purses can then be attached to structures or placed anywhere in their environment for safekeeping.
  • Viparity: Some shark species are viviparous, meaning that they give live birth to their offspring. The embryos develop internally while the mother provides nourishment via placental attachment or by passing along nutrients derived from an unfertilized egg.
  • Ovoviviparity: Many shark species exhibit ovoviviparity. In this reproductive mode, embryos are fed directly by their yolk sac rather than from their mother during gestation and delivery of live offspring by live birth.

Sharks are known for their slow growth, low fecundity, and late maturity. This allows them to dedicate much of their energy toward producing few, well-developed young. Some species even experience lengthy gestation periods which allows more development before birth.

Bony Fish:

  • Modes of Reproduction: Most bony fish species are oviparous, meaning that their eggs are laid externally.
  • External Fertilization: Bony fish release their eggs and sperm into the water where they are fertilized externally. Some species of bony fish, like certain types of cichlids, construct nests in which eggs are laid and protected until hatching by either parent.
  • Reproductive Strategies: Bony fish tend to reproduce at a faster rate than sharks; however, sharks produce more eggs at a lower cost per egg and tend to take longer gestation/incubation periods than bony fish.

Reproduction strategies and methods vary among species, depending on factors like habitat, ecological niche, or evolutionary history. Certain sharks and bony fish species may have specific reproductive strategies or adaptations based on these variables.

Feeding behavior and teeth have an intricate connection

Sharks and bony fish exhibit different feeding behaviors due to differences in their teeth and feeding mechanisms. Below is a breakdown of this difference by feeding behaviors, teeth size differences, and other factors.

  1. Sharks, commonly known as carnivorous predators, consume marine organisms for sustenance. Diet varies depending on species and ecological niche. As such, sharks have evolved into efficient hunters in their marine environment.
  2. Sharks exhibit various feeding behaviors, from scavenging and filter feeding to active predation. Some species specialize in targeting certain prey items while others have more general diets.
  3. Sharks possess an array of teeth types tailored specifically to their feeding habits. Common shark tooth types are included among them.
  4. Sharks equipped with serrated teeth can quickly tear, slice, and grasp prey with ease.
  5. Some sharks possess flattened pavement-like teeth designed to crush hard-shelled predators such as crabs and mollusks.
  6. Some shark species possess sharp and pointed teeth designed to impale and capture swimming prey quickly and securely.
  7. Bony fish possess a diverse feeding strategy that is reflective of their habitat and diet preferences, adapting for herbivory or omnivory as needed.

Bony fish vary in their tooth structure depending on their feeding habits, for instance; examples could include:

  1.  Predatory bony fish boasts sharp and pointed teeth designed for capturing prey and grasping it quickly and securely.
  2. Herbivorous species of fish possess blunt, herbivorous-style teeth designed to graze on vegetation and scrape algae off surfaces.
  3. Certain species possess special teeth to accommodate their unique feeding habits. Fish with fine comb-like structures on their mouths that filter water organisms with fine filters such as planktonic creatures may possess these specialized teeth.
  4. Some bony fish possess additional teeth found in the throat area that serve to grind food once consumed. These pharyngeal or pharyngeal teeth serve to aid in crushing it further after ingestion.
  5. Attracting sharks and bony fish requires understanding their tooth structures and feeding behaviors which reflect the variety of food sources and ecological niches available in aquatic environments. Understanding these adaptations provides valuable insights into the feeding ecology of these fish species as well as their ecological roles.

Habitat and Distribution

Habitat and distribution vary for different shark and bony fish species.

Here are a few key points on their habitat and distribution:

  1. Sharks in Oceans: Sharks can be found throughout marine environments including temperate, tropical, and cold water waters. Certain species have adapted specifically to certain oceanic regions while others have wider distributions.
  2. Habitat Preferences: Different shark species possess distinct ecological niches and feeding habits that determine their ideal environments.
  3. Coastal Habitats: Tiger and bull sharks have long been observed lingering around coastal environments like bays, estuaries, and mangrove forests.
  4. Open Ocean: Certain shark species like oceanic whitetip and blue sharks thrive in open ocean environments and are known for long-distance migrations.
  5. Bony Fish Freshwater and Marine Environments: Bony fish inhabit both freshwater and marine environments worldwide, from rivers, lakes, streams, and ponds to seabed ecosystems.

Bony fish species have evolved to thrive in various aquatic environments, including:

  1. Freshwater Fish: There are numerous species of bony fish that have adapted specifically for life in freshwater environments and exhibit resistance to low levels of salinity, providing suitable environments in which they can flourish.
  2. Coral Reefs: Coral reefs provide habitat to an incredible diversity of fish species, many with special adaptations that allow them to navigate and shelter within its intricate structures.
  3. Pelagic Fish: Many bony species, like tuna and mackerel, migrate widely and inhabit open ocean environments. When traveling together they form large schools.
  4. Distribution Patterns of Bony Fishes: Bony fish distribution can be affected by many different factors, including water temperature, salinity levels, food availability, and their interactions with their environment. Some species are limited to specific areas while others can be found worldwide.

Conservation and threats

Sharks and bony fish species face numerous threats that require conservation efforts to safeguard both populations and habitats.

Here are the main points about threats and conservation for both sharks and bony fish:

Humans face threats from sharks:

Due to their slow growth rate, late maturation, and low reproduction rates, shark populations are especially susceptible to overfishing. Targeted fishing for fins, meat, or other products and bycatch from fisheries targeting other species threaten shark populations worldwide.

Shark finning, or the practice of cutting away and throwing out shark fins into the ocean, poses an extremely grave danger. Demand for these fins for shark soup production fuels this practice worldwide.

  • Habitat Destruction: The degradation and destruction of marine environments such as coral reefs or coastal areas has a devastating impact on shark populations. Activities such as coastal development, pollution, and destructive fishing may disrupt these shark habitats and disrupt shark populations as a whole.
  • Climate Change: Climate changes impact shark populations by altering ocean temperatures, currents, and food sources, as well as altering prey species distribution and behavior – this may have a dramatic effect on shark numbers.
  • Bony Fish Threats: Unsustainable fishing techniques are leading to the reduction of many bony fish species populations, which has an adverse impact on ecosystems and food webs.
  • Habitat Degradation – Habitat degradation can pose a threat to bony fish populations, as its destruction or degradation reduces access to food, spawning grounds, and nursery areas as well as sources of spawning sites and nursery spaces.
  • Pollution poses a great threat to bony fish populations: Pollutants come from industrial and agricultural runoffs, oil spills, and plastic waste; toxic substances may accumulate in their tissues and impact reproductive ability and health negatively.
  • Fishing Regulations & Management: Sustainable fishing regulations such as size restrictions, catch limits, and gear modifications must be enforced to safeguard both shark and bony fish populations while preventing overfishing. This ensures the long-term survival of sharks & bony fish populations as well as prevents overfishing.
  • Protected areas and marine reserves: The establishment of marine protected zones and reserves is critical to providing crucial habitats for sharks and other marine life, providing refuge, encouraging biodiversity, and supporting ecosystem recovery.
  • International Agreements and Conservation Initiatives: International agreements such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), aim at regulating and monitoring the trade of endangered shark and bony fish species. Conservation initiatives raise awareness and conduct research with the aim of advocating policy changes through raising awareness.
  • Sustainable Seafood Options: By choosing sustainable seafood options, individuals can help the environment by supporting responsible fisheries and avoiding species listed as endangered or threatened, helping decrease demand for unsustainable practices.
  • Public Education and Awareness: Promoting public awareness and education about sharks, bonefish, and marine ecosystems is vital. Individuals can advocate for conservation by increasing their understanding of the ecological roles played by sharks and bony fish as well as the threats they face.

Conservation measures must be implemented in order to secure the long-term survival of sharks and bony fish populations, protect their habitats, and sustain marine ecosystems.

Human Interactions

Our interaction with sharks and other bony fish includes several components misconceptions, attacks on humans, safety measures for humans, economic value, and the aquarium trade.

Here are the main points about these interactions between people and these fish:

  • Misconceptions About Sharks: For years, sharks have been the target of misperceptions and negative portrayals that create fear and confusion about them. Media coverage and cultural perceptions contribute to perpetuating these misconceptions by portraying sharks as fierce predators.
  • Attacks: Shark attacks on humans may be relatively rare, yet they do happen. It is essential to keep in mind that sharks don’t hunt humans specifically as prey; most attacks occur as a result of misidentification or an incidental encounter between sharks and humans.
  • Human Safety Measures: Measures taken to protect humans in areas where sharks share aquatic environments with humans are called Human Safety Measures, including beach surveillance, shark warning systems, and public education about risky behavior as well as drumlines or shark nets in certain coastal regions.
  • Bony Fish: Attributes and Implications Bony fish play an essential part in aquaculture and fisheries industries globally, from commercial fishing operations and recreational fisheries, through recreational fishing activities and seafood trade, all contributing to their economic significance.
  • Sustainability Fishing: Maintaining healthy populations of bony fish through sustainable fisheries is vitally important. In order to guarantee long-term viability and prevent overexploitation, regulations, and management strategies have been put in place.
  • Aquarium Trade: Bony fish with distinct or vibrant hues are highly sought-after for aquarium trade, yet unsustainable collection and trading may cause adverse impacts to wild populations. Aquaculture and captive breeding of aquarium fishes are recommended as responsible practices.

Respecting Sharks and Bony Fish

  • It is crucial that when engaging with sharks or bony fish, one does so with respect and responsibility.
  • To dispel myths and reduce fear, educate yourself about the biology and behavior of these fish species.
  • To protect sharks and bony fish, it is imperative that fishermen practice responsible fishing practices.
  • Support conservation efforts by supporting initiatives designed to mitigate threats, protect habitats, and heighten awareness about their ecological significance.
  • Follow safety protocols and measures when coexisting with sharks to minimize the risks of negative interactions between people and sharks.
  • We can foster harmonious relations between sharks and other bony fish by raising awareness of their ecological role, encouraging responsible practices, and respecting these creatures.

Similarities Between Sharks and Bony Fish

Characteristic Sharks Bony Fish
Vertebrates Yes Yes
Fins Dorsal, pectoral, pelvic, caudal Dorsal, pectoral, pelvic, caudal
Gills Present Present
Swim Bladder Absent Present (in most species)
Vision Well-developed Well-developed
Reproduction Sexual Sexual
Ectothermic Yes Yes
Sensory Systems Olfaction, vision, lateral line Olfaction, vision, lateral line
Biodiversity Diverse Diverse


Although bony fish and sharks may have the same underwater world, however, they differ in regard to anatomy behavior, behavior and ecological roles. Sharks with their skeletons made of cartilaginous and predatory nature are amazing creatures that have captivated the interest of humankind for ages. Bony fish, on the other hand, constitute the largest vertebrate species on Earth and exhibit incredible range and flexibility. Recognizing and understanding these distinctions will allow us to improve our care for our oceans as well as the amazing life they provide.