Elasmobranchs: Introduction and Biodiversity
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Questions and Answers

What percentage of the Humpback Whale carcass was consumed by sharks within 9 days?

  • 50%
  • 70%
  • 90% (correct)
  • 100%

    • The first Canadian Discovery USA Shark Week show occurred in 2024.

    True

    What attack is shown to have caused the death of a man in a 3000-year-old grave site in Japan?

    shark attack

    Shark teeth were historically used in _______ and medicine bundles.

    <p>funerary</p> Signup and view all the answers

    Which feature is NOT characteristic of the order Pristiophoroformes?

    <p>Caudal Palps</p> Signup and view all the answers

    The saw of a sawshark is primarily used for protection.

    <p>False</p> Signup and view all the answers

    What type of diet do sawsharks primarily have?

    <p>Squid, fish, and crustaceans</p> Signup and view all the answers

    The Genus Pliotrema has _____ gill slits.

    <p>6</p> Signup and view all the answers

    Sawsharks belong to which Order?

    <p>Pristiophoroformes</p> Signup and view all the answers

    What is a key characteristic of Gulper Sharks?

    <p>Dorsal fin has spines</p> Signup and view all the answers

    Gulper Sharks primarily inhabit shallow waters close to the shore.

    <p>False</p> Signup and view all the answers

    How many pups are typically produced in a litter by some species of Gulper Sharks?

    <p>2</p> Signup and view all the answers

    Gulper Sharks are considered to be ______ species.

    <p>endangered</p> Signup and view all the answers

    Gulper Sharks belong to which Family?

    <p>Centrophidae</p> Signup and view all the answers

    Which of the following statements about the Rough Sharks is true?

    <p>Rough Sharks have a luminous organ.</p> Signup and view all the answers

    Rough Sharks live in the Atlantic Ocean.

    <p>False</p> Signup and view all the answers

    What is the typical size of Rough Sharks?

    <p>Approximately 150 cm</p> Signup and view all the answers

    Rough Sharks feed on __________ invertebrates.

    <p>benthic</p> Signup and view all the answers

    Rough Sharks belong to which Family?

    <p>Oxynotidae</p> Signup and view all the answers

    Which of the following is NOT a genus of the Squalidae family?

    <p>Sawshark</p> Signup and view all the answers

    The Northeast Atlantic stock of Dogfish is critically endangered due to overfishing.

    <p>True</p> Signup and view all the answers

    At what age do Dogfish typically reach sexual maturity?

    <p>11-26 years</p> Signup and view all the answers

    Dogfish can live for approximately ____ years.

    <p>100</p> Signup and view all the answers

    What is the typical length of a Frilled Shark?

    <p>7 feet</p> Signup and view all the answers

    Frilled Sharks have more than 6 gills.

    <p>False</p> Signup and view all the answers

    What type of reproductive strategy do Frilled Sharks exhibit?

    <p>Aplacental viviparity</p> Signup and view all the answers

    Frilled Sharks primarily feed on ______.

    <p>squid</p> Signup and view all the answers

    Which Order do Frilled Sharks belong to?

    <p>Hexanchiformes</p> Signup and view all the answers

    Which Family do Frilled Sharks belong to?

    <p>Chlamydoselachia</p> Signup and view all the answers

    Which feature is characteristic of Weasel Sharks?

    <p>Large labial furrow</p> Signup and view all the answers

    Weasel Sharks primarily feed on zooplankton.

    <p>False</p> Signup and view all the answers

    What is the typical size of most Weasel Sharks?

    <p>around 1 meter</p> Signup and view all the answers

    Weasel Sharks typically live in the tropics at depths of about _____ meters.

    <p>200</p> Signup and view all the answers

    Which Family do Weasel Sharks belong to?

    Signup and view all the answers

    What is the maximum growth length of Catsharks?

    <p>1.6 m</p> Signup and view all the answers

    Catsharks possess large spiracles.

    <p>True</p> Signup and view all the answers

    What adaptation do Catsharks have for low oxygen environments?

    <p>Enlarged gills</p> Signup and view all the answers

    Catsharks are primarily _______ layers.

    <p>egg</p> Signup and view all the answers

    What is a common habitat depth for Catsharks?

    <p>Down to 2000m</p> Signup and view all the answers

    Catsharks have teeth that can have up to ______ rows.

    <p>111</p> Signup and view all the answers

    Catsharks belong to which Family?

    <p>Scyliorhinidae</p> Signup and view all the answers

    Which family is the largest among the Catsharks?

    <p>Scyliorhinidae</p> Signup and view all the answers

    The Finback Catshark has a total of 10 species.

    <p>False</p> Signup and view all the answers

    How deep can the False Catshark live, in meters?

    <p>1500</p> Signup and view all the answers

    The False Catshark primarily feeds on ______.

    <p>fish</p> Signup and view all the answers

    Which of the following statements is true about Hammerhead Sharks?

    <p>They primarily eat squid and fish.</p> Signup and view all the answers

    Hammerhead Sharks have the ability to see in a full 360 degrees.

    <p>True</p> Signup and view all the answers

    How many species belong to the genus Sphyrna?

    <p>9</p> Signup and view all the answers

    Hammerhead Sharks typically live in ______ during the day.

    <p>schools</p> Signup and view all the answers

    How many species of Houndsharks are there worldwide?

    <p>40</p> Signup and view all the answers

    All Houndsharks live exclusively in cold water.

    <p>False</p> Signup and view all the answers

    What is a common feature of Houndsharks related to their eyes?

    <p>nictitating eyelids</p> Signup and view all the answers

    The largest species of Houndsharks can grow up to ______ cm.

    <p>220</p> Signup and view all the answers

    Match the following genera of Houndsharks with their corresponding species:

    <p>Mustelus = Smooth Hounds and Gummy Sharks Triakis = Leopard Shark Galeorhinus = Soupfin Shark Other Genera = Various other species</p> Signup and view all the answers

    What is the primary diet of a Megamouth shark?

    <p>Planktivorous</p> Signup and view all the answers

    The Megamouth shark was discovered in 1976.

    <p>True</p> Signup and view all the answers

    What is the scientific order to which the Megamouth shark belongs?

    <p>Lamniformes</p> Signup and view all the answers

    The Megamouth shark can grow up to _____ meters in length.

    <p>5</p> Signup and view all the answers

    Which Family does the Megamouth Shark belong to?

    <p>Megachiasmidae</p> Signup and view all the answers

    Which Family do Goblin Sharks belong to?

    <p>Mitsukurinidae</p> Signup and view all the answers

    What is the maximum length that a Goblin Shark can reach?

    <p>4 meters</p> Signup and view all the answers

    The Goblin Shark primarily feeds on jellyfish.

    <p>False</p> Signup and view all the answers

    What unique feature does the Goblin Shark have that aids in its feeding?

    <p>Protrusible jaw</p> Signup and view all the answers

    The Goblin Shark typically inhabits ______ water.

    <p>deep</p> Signup and view all the answers

    What is the typical size of a Crocodile Shark?

    <p>1m</p> Signup and view all the answers

    Crocodile Sharks primarily inhabit shallow coastal waters.

    <p>False</p> Signup and view all the answers

    What type of prey do Crocodile Sharks primarily eat?

    <p>deepwater squid, fish, and crustaceans</p> Signup and view all the answers

    Crocodile Sharks exhibit ______ migration, moving between depths during the day and night.

    <p>diel</p> Signup and view all the answers

    Which Family do Crocodile Sharks belong to?

    <p>Pseudocarcharidae</p> Signup and view all the answers

    Which characteristic is unique to the Whale Shark compared to other species in the order Orectolobiformes?

    <p>Gill slits are large and non-overlapping</p> Signup and view all the answers

    Orectolobiformes primarily inhabit cold, deep ocean waters.

    <p>False</p> Signup and view all the answers

    Name two species included in the Orectolobiformes order.

    <p>Wobbegong and Nurse</p> Signup and view all the answers

    Which of the following characteristics applies to Nurse Sharks?

    <p>They exhibit suctorial feeding.</p> Signup and view all the answers

    Nurse Sharks are known for their viviparous reproduction method.

    <p>True</p> Signup and view all the answers

    What is the typical length of Nurse Sharks?

    <p>3.5 meters</p> Signup and view all the answers

    Nurse Sharks possess __________, which aid in their ability to detect chemicals in the water.

    <p>barbels</p> Signup and view all the answers

    Which Family do Nurse Sharks belong to?

    <p>Ginglymostoma</p> Signup and view all the answers

    What is the maximum depth at which Blind Sharks are typically found?

    <p>110 meters</p> Signup and view all the answers

    Blind Sharks have ovoviviparous reproductive strategies.

    <p>True</p> Signup and view all the answers

    Blind Sharks primarily feed on ______, cuttlefish, sea anemones, and crustaceans.

    <p>small fish</p> Signup and view all the answers

    Blind Sharks belong to which Family?

    <p>Brachaeluridae</p> Signup and view all the answers

    How many species belong to the genus Chiloscyllium?

    <p>7 species</p> Signup and view all the answers

    Epaulette sharks are known for their ability to walk on their pectoral fins.

    <p>True</p> Signup and view all the answers

    What type of tolerance do epaulette sharks exhibit?

    <p>hypoxia tolerance</p> Signup and view all the answers

    Bamboo sharks primarily forage at night in the ______.

    <p>reef</p> Signup and view all the answers

    Bamboo Sharks belong to which Family?

    <p>Hemiscylliidae</p> Signup and view all the answers

    Wobbegong Sharks belong to which Family?

    <p>Orectolobidae</p> Signup and view all the answers

    How many species are there in the Family Orectolobidae?

    <p>12</p> Signup and view all the answers

    Wobbegong sharks are primarily open ocean predators.

    <p>False</p> Signup and view all the answers

    In which region of the world do Wobbegong sharks typically reside?

    <p>Tropical Indopacific</p> Signup and view all the answers

    Collared Carpet Sharks belong to which Family?

    <p>Parascyllidae</p> Signup and view all the answers

    What feature distinguishes Collared Carpet Sharks from other shark families?

    <p>They possess minute spiracles</p> Signup and view all the answers

    Collared Carpet Sharks have spineless dorsal fins.

    <p>True</p> Signup and view all the answers

    How many genera are found in the Family Parascyllidae?

    <p>2</p> Signup and view all the answers

    The mouth of a Collared Carpet Shark is located _______ of the eyes.

    <p>entirely in front</p> Signup and view all the answers

    What is the typical longevity of a Whale Shark?

    <p>70 years</p> Signup and view all the answers

    Whale Sharks typically give birth to 300 offspring at a time.

    <p>True</p> Signup and view all the answers

    What method do Whale Sharks use for feeding?

    <p>cross flow filtration</p> Signup and view all the answers

    The Whale Shark can reach lengths of up to _____ meters.

    <p>12</p> Signup and view all the answers

    Whale Sharks belong to which Family?

    <p>Rhinchodon</p> Signup and view all the answers

    Zebra Sharks belong to which Family?

    <p>Stegostoma</p> Signup and view all the answers

    In which regions can Zebra Sharks primarily be found?

    <p>Indopacific shallow waters</p> Signup and view all the answers

    Zebra Sharks are primarily diurnal in their behavior.

    <p>False</p> Signup and view all the answers

    What is the maximum length that Zebra Sharks can reach?

    <p>2.5 meters</p> Signup and view all the answers

    Zebra Sharks primarily feed on ______ and small fish.

    <p>invertebrates</p> Signup and view all the answers

    Study Notes

    Whale Carcass Consumption

    • A Humpback Whale carcass was found intact in July 2024.
    • Within 9 days, sharks consumed approximately 90% of the carcass showcasing their feeding habits.

    Archaeological Findings

    • A grave site in Japan, dated at 3000 years old, reveals evidence of a shark attack as the cause of death for a man buried there, highlighting historical interactions between humans and sharks.

    Shark Week Milestone

    • The year 2024 marks the airing of 'Great White North,' the first Canadian Discovery USA Shark Week show in 35 years, indicating growing interest in Canadian shark research and culture.

    Cultural Significance of Shark Teeth

    • Shark teeth were utilized in funerary practices and as components in medicine bundles, reflecting their importance in historical cultural rituals.

    Order Pristiophoroformes - Sawsharks

    • Characterized by a distinct pair of long sensory barbels which aid in locating prey.
    • Equipped with two dorsal fins, contributing to their streamlined body structure.
    • The saw-like snout is utilized to stun prey, enhancing hunting efficiency.
    • Typically reach an approximate length of 5.6 feet, making them sizable among related species.
    • The genus Pliotrema includes only one species, notable for having six gill slits, differing from other genera.
    • Members of the genus Pristiophorus primarily consume squid, fish, and crustaceans, showcasing a diverse diet.
    • There are a total of seven recognized species of sawsharks, with the majority located in the Indopacific region, indicating a specific habitat preference.

    Family Centrophidae - Gulper Shark

    • Comprises 2 genera and 16 species, showcasing diversity within the family.
    • Inhabits tropical warm waters, indicating preference for warmer marine environments.
    • Notably long lifespan of around 70 years, contributing to their longevity in the ocean.
    • Reproduces through ovoviviparity, where eggs hatch inside the female, resulting in a low fecundity rate.
    • Some species give birth to only 2 pups per litter, emphasizing their reproductive limitations.
    • Typically found at depths of approximately 2000 meters, representing a deep-water habitat.
    • Exhibits schooling behavior, suggesting social interactions among individuals.
    • Characterized by dorsal fins with spines, distinguishing physical features that may provide advantages in their environment.
    • Diet consists of fish, squid, and crustaceans, reflecting their predatory nature.
    • Classified as endangered species, highlighting conservation concerns and the need for protective measures.

    Family Oxynotidae - Rough Sharks

    • Comprises 5 species within the genus Oxynotis.
    • Characterized by sluggish swimming behavior, indicating a low-energy lifestyle.
    • Skin is covered in prickly textures, providing protection and a unique sensory experience.
    • Possesses a luminous organ, potentially used for attraction or communication.
    • Body structure includes triangular sections, which aids in identification and classification.
    • Habitat primarily located in the Mediterranean Sea, demonstrating a specific environmental niche.
    • Features giant spiracles located behind the eyes and dorsal fins, important for respiration and stabilization.
    • Diet consists mainly of benthic invertebrates, indicating a feeding strategy that targets organisms living on the sea floor.
    • Average size is relatively small, measuring around 150 cm in length.

    Family Squalidae - Dogfish

    • Comprises two genera: Dogfish and Spurdog.
    • Contains a total of 29 species recognized within the family.
    • Notable for their longevity, with some individuals living up to approximately 100 years.
    • Characterized by low fecundity, indicating a slow reproduction rate.
    • Feature two dorsal fins, each equipped with venomous spines used for defense.
    • The Northeast Atlantic stock faces critical endangerment, primarily due to unsustainable fishing practices.
    • Sexual maturity is reached between the ages of 11 to 26 years, reflecting a delayed reproductive cycle.

    Frilled Sharks Overview

    • Length reaches approximately 7 feet, making them a significant size among deep-sea species.
    • Inhabits deep waters, typically found at depths of up to 600 meters.
    • Possesses an elongated body shape, which aids in its deep-sea lifestyle.

    Feeding and Anatomy

    • Equipped with fine, sharp teeth that are ideal for grasping and consuming squid, their primary diet.
    • Features six gills, unlike most sharks which usually have five, providing a unique respiratory system.
    • Has an open lateral line system with exposed hair cells, allowing for sensitive detection of changes in water pressure and movement.

    Reproduction

    • Reproduces through aplacental viviparity, meaning young develop inside the mother but are not nourished via a placenta.
    • Typical litter consists of around six young, with a gestation period lasting approximately 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Found primarily in tropical waters at a depth of approximately 200 meters.
    • Comprises 2 genera and a total of 8 different species.
    • Exhibit viviparity, wherein the yolk sac supports the young during development before birth.
    • Most species are relatively small, averaging around 1 meter in length, although some individuals can reach up to 2 meters.
    • Characterized by a large labial furrow, which may aid in feeding.
    • Notable for having a significantly large ventral lobe on the tail, which can influence swimming dynamics.
    • Upper teeth are serrated with a saw-like edge, while lower teeth are sharp and pointed for effective grasping of prey.
    • Diet mainly consists of cephalopods and fish, indicating a preference for agile and mobile prey.

    Overview of Family Scyliorhinidae - Catsharks

    • Inhabit warm, benthic regions, some species found at depths of up to 2000 meters.
    • Gill structure is enlarged, providing adaptation for low oxygen environments.
    • Typically small in size, most species are less than 80 cm in length with a maximum growth of 1.6 meters.
    • Exhibit elongated body shape, enhancing their streamlined appearance.

    Physical Characteristics

    • Possess catlike eyes positioned high on the sides of the head, aiding in vision.
    • Equipped with nictitating eyelids, providing an extra layer of protection for the eyes.
    • Features large spiracles, which assist in respiration while at rest or when buried in substrate.
    • Dental structure includes small teeth with multicusped arrangements, with some species having up to 111 rows of teeth.
    • Males, females, and adult males exhibit different teeth shapes, with males generally possessing larger teeth.

    Reproductive and Structural Features

    • Consist of 7 recognized genera within the family.
    • Characterized by two dorsal fins, both lacking spines, indicating a unique fin structure compared to other shark species.
    • The base of the first dorsal fin is positioned opposite or behind the base of the first pelvic fin, which is a distinguishing anatomical feature.
    • Reproductive method is oviparous, meaning they are egg layers.

    Family Scyliorhinidae - Catsharks

    • Found in warm water benthic environments, inhabiting depths up to 2000 meters.
    • Characterized by an elongated body shape that aids in their efficient movement in water.
    • Distinguished by catlike eyes positioned high on the sides of the head, enhancing their visual field.
    • Possess nictitating eyelids, which provide protection and moisture to the eyes.
    • Notable for large spiracles located behind the eyes, facilitating breathing while at rest on the ocean floor.
    • Dental structure includes small teeth organized in multicusped formations, with up to 111 rows observed.
    • Divided into 7 recognized genera, highlighting their biodiversity within the family.
    • Exhibits sexual dimorphism in teeth shape; males have larger teeth compared to females and juvenile males.
    • The first dorsal fin's base is positioned directly opposite or behind the base of the first pelvic fin, a key anatomical feature.
    • Both dorsal fins are present, lacking any spines, which differentiates them from some other shark families.

    Family Scyliorhinidae - Catsharks

    • The largest family of sharks, encompassing a wide variety of species.

    Subfamily Proscylliidae - Finback Catshark

    • Comprises 8 species characterized as small in size.
    • Inhabits small tropical benthic areas, typically near the ocean floor.
    • Reproduces through egg laying, contributing to specific ecological niches.
    • Populations are negatively impacted by shrimping activities.

    Subfamily Pseudotrikidae - False Catshark

    • Contains 1 species that can grow up to 3 meters in length.
    • Prefers deep water habitats, typically found on slopes down to 1500 meters.
    • Diet primarily consists of fish, highlighting its role as a predator in the deep-sea ecosystem.

    Genus Scyliorhinidae - Catsharks

    • Encompasses over 100 species classified into 15 genera.
    • Displays a diverse range of adaptations and ecological roles within marine environments.

    Family Sphyrnidae - Hammerhead Sharks

    • Comprises 9 species within the genus Sphyrna.
    • Contains 1 species classified under the genus Eusphyrna.
    • Social behavior includes living in schools during the day and becoming solitary at night.
    • Average length of hammerhead sharks is approximately 6 meters.
    • Possess a unique 360-degree field of view, enhancing their ability to detect prey.
    • Diet primarily consists of squid and various fish species.
    • Feature a specialized structure called cephalofoil, which is important for electroreception, allowing them to sense electrical signals in the water.

    Family Triakidae - Houndsharks

    • Comprises 9 genera and approximately 40 species found globally.
    • Prefers habitats in warm to temperate water environments.
    • Characterized by the presence of two prominent dorsal fins.
    • Contains anal fins which aid in stability while swimming.
    • Features oval-shaped eyes equipped with nictitating eyelids for protection.
    • Size ranges from small to medium, measuring between 37 cm to 220 cm in length.
    • Includes 28 species within the Mustelus genus, commonly referred to as Smooth Hounds and Gummy Sharks.
    • Contains 5 species in the Triakis genus, known as Leopard Sharks.
    • Holds 1 species belonging to the Galeorhinus genus, recognized as the Soupfin Shark.

    Shark Facts and Discoveries

    • July 2024: An intact Humpback Whale carcass is observed, with 90% consumed by sharks in just 9 days.
    • Ancient evidence: A 3000-year-old grave in Japan reveals a man who died from a shark attack.
    • 2024 marks the first Canadian Discovery USA Shark Week show titled 'Great White North' in 35 years.
    • Historical use of shark teeth in funerary and medicinal bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by long sensory barbels and two dorsal fins.
    • Saw-like jaws used to stun prey with an average length of approximately 5.6 ft.
    • Genus Pliotrema includes a single species with 6 gill slits.
    • Genus Pristiophorus primarily preys on squid, fish, and crustaceans with 7 species mostly found in the Indopacific region.

    Family Centrophidae - Gulper Sharks

    • Comprised of 2 genera and 16 species living in warm tropical waters.
    • Long lifespan of around 70 years and ovoviviparous reproductive strategy with low fecundity.
    • Typically gives birth to 2 pups per litter.
    • Prefers deep waters around 2000m and feeds on fish, squid, and crustaceans.
    • Classified as endangered.

    Family Oxynotidae - Rough Sharks

    • Encompasses 5 species within the genus Oxynotis.
    • Noted for sluggish swimming and prickly skin, with a distinctive luminous organ.
    • Triangular body sections and large spiracles characterize their morphology.
    • Found in the Mediterranean and primarily feed on benthic invertebrates, typically measuring around 150 cm.

    Family Squalidae - Dogfish

    • Includes 2 genera and 29 species like Dogfish and Spurdog, known for longevity up to 100 years.
    • Exhibits a low reproductive rate and has 2 dorsal fins equipped with venomous spines.
    • The Northeast Atlantic stock is critically endangered due to fishing activities.
    • Sexual maturity is reached between 11 and 26 years.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Grows to approximately 7 ft in length and inhabits deep waters around 600m.
    • Features an elongated body, fine teeth, and 6 gills.
    • Aplacental viviparous reproduction allows for around 6 young per litter with a gestation of 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Found in tropical waters at depths of about 200m, consisting of 2 genera and 8 species.
    • Yolk sac viviparous species, generally reaching sizes of around 1m, but can grow up to 2m.
    • Notable for large labial furrow and a significant ventral lobe on the tail, primarily consuming cephalopods and fish.

    Family Scyliorhinidae - Catsharks

    • Largest family of sharks with species distributed across global warm waters, including 7 genera.
    • Adaptations include enlarged gills for low oxygen conditions, catlike eyes, and small, multicusped teeth with up to 111 rows.
    • Two dorsal fins are present, and all are oviparous.
    • Males exhibit larger teeth compared to females and adult males differ in tooth shapes.
    • Specific families like Proscylliidae and Pseudotrikidae have unique habitats and sizes ranging from small tropical benthic areas to deep slopes of 1500m.

    Family Triakidae - Houndsharks

    • Comprises 9 genera and 40 species thriving in warm to temperate waters.
    • Notable for 2 prominent dorsal fins and anal fins, with sizes varying from 37 cm to 220 cm.
    • Includes species like Mustelus (Smooth Hounds and Gummy Sharks), Triakis (Leopard Shark), and Galeorhinus (Soupfin Shark).

    Family Sphyrnidae - Hammerhead Sharks

    • Comprises 9 Sphyrna species and 1 Eusphyrna species; known for schooling behavior during daylight.
    • Typically around 6m in length, characterized by a unique cephalofoil for enhanced electroreception.
    • Diet primarily consists of squid and fish.

    Megamouth Shark

    • Belongs to Order Lamniformes and Family Megachiasmidae, first discovered in 1976.
    • A deep-water planktivorous species that reaches lengths of 5m and weighs approximately 1200 kg.

    Introduction to Sharks

    • In July 2024, a Humpback Whale carcass was observed, with sharks consuming 90% of it within 9 days.
    • Archaeological evidence from a 3000-year-old grave in Japan indicates a man died from a shark attack.
    • "Great White North" marks the first Canadian Discovery USA Shark Week show in 35 years, premiering in 2024.
    • Shark teeth have historically been incorporated into funerary and medicinal bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by long sensory barbels and two dorsal fins.
    • The saw-like snout is used to stun and capture prey.
    • Average length is approximately 5.6 feet.
    • The genus Pliotrema has one species with 6 gill slits.
    • The genus Pristiophorus primarily feeds on squid, fish, and crustaceans, with seven species mainly found in the Indopacific region.

    Family Centrophidae - Gulper Shark

    • Comprises 2 genera and 16 species.
    • Inhabits tropical warm waters and lives up to ~70 years.
    • Reproduces ovoviviparously with low fecundity, producing about 2 pups per litter in some species.
    • Found at depths of around 2000m and is a schooling species.
    • Dorsal fins have spines, and the species feeds on fish, squid, and crustaceans.
    • Listed as endangered.

    Family Oxynotidae - Rough Sharks

    • Contains 5 species within the genus Oxynotis.
    • Features include a sluggish swimming style, prickly skin, and body sections that are triangular.
    • Known for a luminous organ and giant spiracles.
    • Primarily found in the Mediterranean and feeds on benthic invertebrates.
    • Average size is small, measuring up to 150 cm.

    Family Squalidae - Dogfish

    • Comprises 2 genera with 29 species, including Dogfish and Spurdog.
    • Long lifespan of approximately 100 years and exhibits low fecundity.
    • Features 2 dorsal fins equipped with venomous spines.
    • The Northeast Atlantic stock is critically endangered due to fishing pressures.
    • Sexual maturity is reached between 11-26 years of age.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Reaches lengths of about 7 feet and inhabits deep waters around 600m.
    • Notable for an elongated body and fine teeth adapted for squid predation.
    • Possesses 6 gills and an open lateral line with exposed hair cells.
    • Aplacental viviparity with a litter size of around 6, gestation lasts approximately 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Occur in tropical waters at depths near 200m.
    • Comprised of 2 genera and 8 species; most species are small, typically around 1m, but can grow up to 2m.
    • Notable for a large labial furrow and sizable ventral tail lobe.
    • Upper teeth have saw edges, while lower teeth are pointed.
    • Prey includes cephalopods and fish.

    Family Scyliorhinidae - Catsharks

    • Habitat includes warm, benthic subtidal waters, with some species residing down to 2000m.
    • Generally small, under 80 cm, with a maximum growth of 1.6m.
    • Features an elongated body and catlike eyes positioned high on the head, possessing nictitating eyelids.
    • Offers an adaptation for low oxygen with enlarged gills and possesses numerous small teeth, up to 111 rows across 7 genera.
    • Males have larger teeth compared to females and adults exhibiting different tooth shapes.

    Family Triakidae - Houndsharks

    • Contains 9 genera and 40 species found in warm to temperate waters.
    • Distinguished by two prominent dorsal fins and an anal fin.
    • Size ranges from 37cm to 220cm; includes species such as Mustelus (Smooth Hounds), Triakis (Leopard Shark), and Galeorhinus (Soupfin Shark).

    Family Sphyrnidae - Hammerhead Sharks

    • Comprises 9 species under Sphyrna and 1 species in Eusphyrna.
    • Known for schooling behavior during the day and solitary habits at night.
    • Typically around 6m long, equipped with a unique 360-degree field of view and cephalofoil for electroreception.
    • Diet primarily consists of squid and fish.

    Megamouth Shark

    • Falls under Order Lamniformes, Family Megachiasmidae.
    • Discovered in 1976, it's a deep-water species with a planktivorous diet.
    • Typically measures 5m in length and weighs approximately 1200kg.

    Goblin Shark

    • Rarer deep-water species, measuring about 4m in length.
    • Features a unique protrusible jaw extending to the end of its snout.
    • Consumes fish, cephalopods, and crustaceans.

    Humpback Whale and Sharks

    • In July 2024, an intact Humpback Whale carcass is found; sharks consume 90% within 9 days.
    • A 3000-year-old grave in Japan reveals a man died from a shark attack.
    • 2024 marks the first Canadian Discovery USA Shark Week show 'Great White North' in 35 years.
    • Shark teeth have historical significance, used in funerary and medicinal bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by long sensory barbels and two dorsal fins.
    • Saw-like snouts are employed to stun prey, generally measuring ~5.6ft.
    • Genus Pliotrema features 6 gill slits, with only one species.
    • Genus Pristiophorus consumes squid, fish, and crustaceans; comprises seven species primarily in the Indopacific region.

    Family Centrophidae - Gulper Shark

    • Contains two genera with 16 species, inhabiting warm tropical waters.
    • Notable for longevity, living around 70 years and exhibiting low fecundity.
    • Ovoviviparous reproduction results in only two pups per litter in some species.
    • Found at deep depths ~2000m, these schooling sharks feed on fish, squid, and crustaceans, and are classified as endangered.

    Family Oxynotidae - Rough Sharks

    • Comprises five species under the genus Oxynotis, recognized for sluggish swimming and prickly skin.
    • Features a luminous organ and triangular body sections, residing mainly in the Mediterranean.
    • They possess giant spiracles and dorsal fins, preying on benthic invertebrates, reaching sizes up to ~150 cm.

    Family Squalidae - Dogfish

    • Encompasses two genera: Dogfish and Spurdog, with 29 species overall.
    • Can live up to 100 years, showing low reproductive rates.
    • Possess two dorsal fins, both containing venomous spines, making them critical for survival.
    • The Northeast Atlantic stock is critically endangered due to fishery activities, with sexual maturity occurring between 11-26 years.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Measure approximately 7ft in length and live at depths of around 600m.
    • Characterized by an elongated body with fine teeth, primarily feeding on squid.
    • Possess six gills and exhibit a unique open lateral line system with exposed hair cells.
    • Aplacental viviparous reproduction results in about six juveniles per litter with a gestation period of 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Inhabit tropical regions around ~200m depth with two genera and eight species.
    • Characterized by viviparous yolk sac development.
    • Generally small, most species averaging ~1m and maxing out at 2m.
    • Equipped with large labial furrows and a prominent ventral tail lobe, feeding mainly on cephalopods and fish.

    Family Scyliorhinidae - Catsharks

    • The largest shark family, living in warm subtidal waters and sometimes down to 2000m.
    • Range in size, typically under 80cm, with some reaching up to 1.6m.
    • Features an elongated body and catlike eyes positioned high on their heads, equipped with nictitating eyelids and large spiracles.
    • Have multicusped small teeth in up to 111 rows, with varied shapes among males, females, and adult males.
    • Noted for two dorsal fins without spines and egg-laying reproduction.

    Family Triakidae - Houndsharks

    • Comprises 40 species across nine genera found in warm to temperate waters.
    • Distinguished by two prominent dorsal fins and anal fins, alongside oval eyes with nictitating eyelids.
    • Size ranges from 37cm to 220cm, including species such as Mustelus (Smooth Hounds) and Triakis (Leopard Shark).

    Family Sphyrnidae - Hammerhead Sharks

    • Contains nine species in Sphyrna and one in Eusphyrna, known for their schooling behavior during the day and solitary behavior at night.
    • Typically reach lengths of ~6m with a unique cephalofoil structure providing a 360-degree field of vision.
    • Predominantly feed on squid and fish, utilizing electroreception for hunting.

    Megamouth Shark

    • Belongs to the order Lamniformes and family Megachiasmidae, first discovered in 1976.
    • A deep-water, planktivorous species that can reach lengths of 5m and weights of 1200kg.

    Goblin Shark

    • A rare deep-water shark species, maxing out at 4m in length.
    • Known for its protrusible jaw and dietary habits that include fish, cephalopods, and crustaceans.

    Crocodile Shark

    • Resides in mesopelagic zones down to 600m, growing to about 1m in size.
    • Characterized by large eyes and small fins, with a circumtropical distribution.
    • Feeds on deepwater squid, fish, and crustaceans, exhibiting diel migratory behavior.

    Overview of Order Orectolobiformes

    • Comprises 7 families, 13 genera, and 43 species.
    • Notable members include the Whale Shark, Wobbegong, Nurse Shark, Bamboo Shark, Collared Carpet Shark, Zebra Shark, and Blind Shark.

    Habitat and Distribution

    • Found in tropical to temperate zones.
    • Inhabit shallow to deep waters across the Atlantic, Indopacific, and Indian Oceans.

    Reproductive Characteristics

    • Includes both oviparous (egg-laying) and ovoviviparous (live-bearing) species.

    Physical Features

    • Characterized by two spineless dorsal fins.
    • Features a short, transverse mouth positioned anterior to the eyes.
    • Possesses specialized nostrils and prominent barbels for sensory perception.
    • Nasoral grooves present, aiding in sensory functions.
    • Spiracles vary in size, typically located below the eye; Whale Shark's spiracles are situated behind the eye.
    • Small gill slits that overlap, with the fourth slit's positioning overlapping the fifth, except for the Whale Shark which has large, non-overlapping gill slits.
    • Caudal fin features an upper lobe aligned with the main body.

    Humpback Whale and Shark Interactions

    • In July 2024, an intact Humpback Whale carcass was found; within 9 days, 90% was consumed by sharks.
    • A 3000-year-old grave in Japan revealed a man who died from a shark attack.
    • The first-ever Canadian Discovery USA Shark Week show, "Great White North," aired in 2024 after 35 years.

    Sharks' Historical and Cultural Significance

    • Shark teeth have been utilized in funerary practices and traditional medicine bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by long sensory barbels, two dorsal fins, and a notable saw for stunning prey.
    • Typically reach lengths of approximately 5.6 feet.
    • The genus Pliotrema has one species with six gill slits.
    • The genus Pristiophorus feeds on squid, fish, and crustaceans; most species reside in the Indo-Pacific region.

    Family Centrophidae - Gulper Shark

    • Comprised of 2 genera and 16 species; inhabits warm tropical waters.
    • Known for longevity, with lifespans around 70 years.
    • Reproduces ovoviviparously with low fecundity, yielding two pups in some species.
    • Lives at depths of around 2000 meters and displays schooling behavior.
    • Has spiny dorsal fins and preys on fish, squid, and crustaceans; currently classified as endangered.

    Family Oxynotidae - Rough Sharks

    • Consists of five species in the genus Oxynotis; known for sluggish swimming and prickly skin.
    • Features include a luminous organ and distinctive triangular body sections, typically located in the Mediterranean.
    • Large spiracles facilitate breathing while feeding on benthic invertebrates.

    Family Squalidae - Dogfish

    • Comprises two genera and 29 species, including Dogfish and Spurdog.
    • Known for achieving extensive lifespans of approximately 100 years with low reproductive rates.
    • Features two dorsal fins equipped with venomous spines; the Northeast Atlantic stock is critically endangered due to overfishing.
    • Sexual maturity is reached between 11-26 years.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Typically grows to about 7 feet in length; inhabits deep waters at around 600 meters.
    • Possesses an elongated body, fine teeth, and six gill slits.
    • Exclusively feeds on squid and has an open lateral line system exposed to the environment.
    • Exhibits aplacental viviparity with a low litter size and a gestation period of approximately 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Prefers tropical habitats around 200 meters depths; comprises 2 genera with 8 species.
    • Exhibits viviparous reproduction with yolk sac reliance.
    • Typically small, most species around 1 meter but can reach up to 2 meters; characterized by large labial furrows.

    Family Scyliorhinidae - Catsharks

    • Found in warm, benthic subtidal zones, some residing down to 2000 meters.
    • Recognized for elongated bodies and catlike eyes positioned high on the head with nictitating eyelids.
    • Small in size, typically less than 80 cm, with some reaching 1.6 meters.
    • Features distinctive multicusped teeth, with males presenting different shapes and larger size teeth compared to females.

    Catsharks Family Overview

    • Largest family of sharks, categorized into three significant families:
      • Proscylliidae (Finback Catshark) features 8 species that are small, tropical egg layers affected by shrimping.
      • Pseudotrikidae (False Catshark) has a single species that reaches 3 meters in deep environments.
      • Scyliorhinidae includes over 100 species across 15 genera.

    Family Triakidae - Houndsharks

    • Comprises 9 genera and 40 species found in warm to temperate waters.
    • Distinguished by two prominent dorsal fins and anal fins; oval eyes with nictitating eyelids.
    • Size ranges from small to medium, typically measuring 37 cm to 220 cm.

    Family Sphyrnidae - Hammerhead Sharks

    • Consists of 9 species within the genus Sphyrna and one in Eusphyrna.
    • Social during the day and solitary at night; can grow to approximately 6 meters.
    • Possesses a unique cephalofoil structure, providing a 360-degree field of view for detecting prey.

    Megamouth Shark

    • Falls under the Order Lamniformes and Family Megachiasmidae.
    • Discovered in 1976; distinguishes itself as a deep-water planktivorous shark.
    • Can grow up to 5 meters and weigh around 1200 kg.

    Goblin Shark

    • Considered a rare deep-water single species that reaches approximately 4 meters in length.
    • Features a protrusible jaw and primarily consumes fish, cephalopods, and crustaceans.

    Crocodile Shark

    • Lives in mesopelagic zones down to 600 meters; typically grows to about 1 meter.
    • Recognizable for its large eyes and small fins; consumes deepwater squid, fish, and crustaceans.

    Order Orectolobiformes Overview

    • Encompasses 7 families, 13 genera, and 43 species, including notable species like the Whale Shark and Nurse Shark.
    • Distributed in tropical and temperate waters with oviparous and ovoviviparous reproduction methods.
    • Characterized by two spineless dorsal fins, specialized nostrils, prominent barbels, and diverse gill slit structures.

    Family Ginglymostoma - Nurse Sharks

    • Comprises 4 species; known for benthic lifestyle and features such as barbels for chemosensory feeding.
    • This live-bearing family can reach lengths of approximately 3.5 meters.

    Family Brachaeluridae - Blind Sharks

    • Comprises two species specifically found in shallow coastal waters up to approximately 110 meters deep along the eastern coast of Australia.
    • Characterized by long barbels and large spiracles, which aid in sensing their environment.
    • Features two dorsal fins and a short tail, distinguishable traits among sharks.
    • Diet primarily consists of small fish, cuttlefish, sea anemones, and various crustaceans, demonstrating a diverse feeding habit.
    • Reproduction occurs through ovoviviparity, where embryos develop inside eggs that hatch within the female's body.
    • Named for their unique behavior of closing their eyes when removed from water, a notable adaptation for protecting their eyes during stress.

    Family Hemiscylliidae - Bamboo Sharks

    • Includes 7 species categorized under the genus Chiloscyllium, known for their long snouts.
    • Commonly kept in aquariums due to their manageable size and peaceful nature.
    • Contains 10 species within the genus Hemiscyllium, characterized by shorter snouts.
    • Notable species includes the Epaulette shark, recognized for its ability to tolerate low oxygen environments, or hypoxia.
    • Unique locomotion feature: can walk on their pectoral fins, allowing them to navigate shallow waters effectively.
    • Primarily foraging occurs at night on reefs, making them nocturnal hunters.
    • Reproduce by laying eggs, contributing to the species' life cycle and population dynamics.

    Family Hemiscylliidae - Bamboo Sharks

    • Includes 7 species in the genus Chiloscyllium (Long Snout) and 10 species in Hemiscyllium (Short Snout).
    • Commonly found in aquariums; the Epaulette shark is hypoxia tolerant and can walk on pectoral fins.
    • Active nighttime foragers in reefs; reproduce by laying eggs.

    Introduction

    • A Humpback Whale carcass was observed intact in July 2024; 90% consumed by sharks within 9 days.
    • Archaeological evidence from Japan indicates a 3000-year-old grave of a man who died from a shark attack.
    • In 2024, 'Great White North' became the first Canadian Discovery USA Shark Week feature in 35 years.
    • Historical use of shark teeth in funerary practices and medicinal bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by a pair of long sensory barbels and two dorsal fins.
    • Uses saw-like snouts to stun prey; generally grows to 5.6ft.
    • The genus Pliotrema contains one species with six gill slits, while Pristiophorus genus preys on squid, fish, and crustaceans.
    • Majority of the 7 species inhabit the Indopacific region.

    Family Centrophidae - Gulper Shark

    • Comprises 2 genera and 16 species; typically inhabits tropical warm waters.
    • Known for longevity, living approximately 70 years and exhibiting ovoviviparous reproduction.
    • Produces low fecundity with as few as 2 pups per litter, residing in deep waters around 2000m.
    • Diet includes fish, squid, and crustaceans; species are considered endangered.

    Family Oxynotidae - Rough Sharks

    • Contains 5 species within the genus Oxynotis; known for sluggish swimming and prickly skin.
    • Unique features include a luminous organ, triangular body sections, and giant spiracles.
    • Primarily found in the Mediterranean, feeding on benthic invertebrates; specimen size averages around 150 cm.

    Family Orectolobidae - Wobbegong Sharks

    • Comprises 12 species; commonly inhabit shallow waters of the tropical Indopacific.
    • Large body size and ambush hunting strategy characterize these sharks.

    Family Squalidae - Dogfish

    • Includes 2 genera with a total of 29 species, such as Dogfish and Spurdog.
    • Known for their longevity of around 100 years and low fecundity.
    • Distinguished by two dorsal fins equipped with venomous spines; critically endangered in the Northeast Atlantic due to overfishing.
    • Sexual maturity occurs between 11 to 26 years.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Average length of about 7ft; thrive in deep water at depths around 600m.
    • Notable for an elongated body, fine teeth, and a diet primarily consisting of squid.
    • Possess six gills and an open lateral line, exhibiting aplacental viviparity with ~6 young per litter, gestation lasting approximately 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Tropical species generally found at depths around 200m; comprises 2 genera and 8 species.
    • Viviparous with a yolk sac, most species reach sizes around 1m but can grow up to 2m.
    • Characterized by a large labial furrow and distinctive upper and lower teeth structures.

    Family Scyliorhinidae - Catsharks

    • Represents the largest shark family, with various genera including Proscylliidae and Pseudotrikidae.
    • Adapted to warm, benthic environments, some extending down to 2000m.
    • Features small, multi-cusped teeth in up to 111 rows, and display sexual dimorphism in tooth shape.
    • Species specialize in egg-laying; marked by elongated bodies with catlike eyes and notable spiracles.

    Family Triakidae - Houndsharks

    • Comprises 9 genera and 40 species, inhabiting warm to temperate waters.
    • Recognizable by two prominent dorsal fins and distinct anal fins; sizes range from 37cm to 220cm.
    • Includes notable species like Mustelus (Smooth Hounds), Triakis (Leopard Shark), and Galeorhinus (Soupfin Shark).

    Family Sphyrnidae - Hammerhead Sharks

    • Contains 9 species in Sphyrna and 1 in Eusphyrna; observed in schools during the day, solitary at night.
    • Grows up to ~6m; features a unique 360-degree field of view and a diet of squid and fish.
    • Equipped with a cephalofoil for enhanced electroreception abilities.

    Megamouth Shark

    • Falls under Order Lamniformes, Family Megachiasmidae; discovered in 1976.
    • Deep water species known for its planktivorous diet, generally reaching 5m in length and weighing up to 1200kg.

    Goblin Shark

    • A rare deep-water species, typically measuring 4m in length.
    • Notable for its protrusible jaw extending forward from the snout; diet consists of fish, cephalopods, and crustaceans.

    Crocodile Shark

    • Resides in mesopelagic regions down to 600m, reaching sizes around 1m.
    • Features large eyes and small fins, with a circumpolar distribution; primarily preys on deepwater squid, fish, and crustaceans.
    • Exhibits diel migration behavior and a unique 'fiberoptic' feeding strategy.

    Order Orectolobiformes

    • Comprises 7 families, 13 genera, and 43 species, including Whale Shark and various carpet sharks.
    • Adapted to tropical and temperate waters, exhibiting both oviparous and ovoviviparous reproductive strategies.
    • Characterized by two spineless dorsal fins and specialized adaptations such as prominent barbels and spiracles.

    Family Ginglymostoma - Nurse Sharks

    • Composed of 4 species; primarily benthic with chemosensory barbels.
    • Known for suctorial feeding; capable of reaching lengths of 3.5m and give live birth.

    Family Brachaeluridae - Blind Sharks

    • Consists of 2 species prevalent in shallow coastal waters, ~110m deep off Australia's eastern coast.
    • Distinguished by long barbels and large spiracles, exhibiting ovoviviparity and a diet of small fish and crustaceans.
    • Named for their distinct behavior of closing eyes when removed from water.

    Family Parascyllidae - Collared Carpet Sharks

    • Comprises 2 distinct genera within the family.
    • Share superficial similarities with Catsharks, particularly cat-like eyes and the presence of subocular pockets.
    • Mouth structure differs significantly; positioned entirely in front of the eyes, contrasting with other shark families.
    • Characterized by having two dorsal fins that lack spines.
    • The origin of the anal fin is located well ahead of the second dorsal fin, a distinguishing feature.
    • Minute spiracles serve as a unique identifier, setting them apart from other shark species.

    Whale Sharks Overview

    • Largest fish species, measuring up to 12 meters in length and weighing around 20 tons.
    • Remarkable longevity, with a lifespan of up to 70 years.

    Habitat and Distribution

    • Found in warm, tropical oceans, typically within 30 degrees of latitude from the equator.
    • Prefers areas with abundant plankton for feeding.

    Feeding Mechanism

    • Utilizes a unique cross-flow filtration system to filter feed on plankton.
    • Can consume small fish and other marine organisms while swimming.

    Reproduction

    • Capable of producing a high number of offspring, with approximately 300 live young per litter.
    • Births occur in a process called ovoviviparity, where eggs hatch inside the female’s body.

    Anatomy

    • Notable for having a spiracle located just behind each eye, aiding in respiration while feeding.

    Family Hemiscylliidae - Bamboo Sharks

    • Comprises 7 species in the genus Chiloscyllium (Long Snout).
    • Commonly kept in aquariums.
    • 10 species in the genus Hemiscyllium (Short Snout), notable for the epaulette shark's ability to tolerate hypoxia.
    • Unique locomotion via pectoral fins, enabling walking movements.
    • Active nighttime foragers along reefs.
    • Reproduce through egg-laying.

    Significant Events

    • July 2024, a Humpback Whale carcass fully consumed by sharks within 9 days.
    • Discovery of a 3000-year-old grave site in Japan reveals evidence of a fatal shark attack.
    • In 2024, "Great White North" became the first Canadian Shark Week show in 35 years.
    • Historical use of shark teeth in funerary practices and medicine bundles.

    Order Pristiophoroformes - Sawsharks

    • Characterized by a pair of long sensory barbels and two dorsal fins.
    • Employ their saw-like snouts to stun prey.
    • Typically measure around 5.6 feet in length.
    • Genus Pliotrema features a single species with 6 gill slits.
    • Genus Pristiophorus primarily feeds on squid, fish, and crustaceans.
    • Contains 7 species, most prevalent in the Indopacific.

    Family Centrophidae - Gulper Shark

    • Encompasses 2 genera and 16 species, residing in tropical warm waters.
    • Notably long-lived, with lifespans reaching around 70 years.
    • Exhibits ovoviviparity, producing low fecundity with typically two pups per litter.
    • Found in deep waters, approximately 2000 meters deep, often schooling.
    • Dorsal fin features spines; diet consists of fish, squid, and crustaceans.
    • Classified as an endangered species.

    Family Oxynotidae - Rough Sharks

    • Contains 5 species within the genus Oxynotis.
    • Identified as sluggish swimmers with prickly skin and triangular body sections.
    • Possess luminous organs and live primarily in the Mediterranean.
    • Characterized by giant spiracles and dorsal fins.
    • Feed on benthic invertebrates and typically measure around 150 cm.

    Family Orectolobidae - Wobbegong Sharks

    • Comprises 12 species, often found in shallow waters of the tropical Indopacific.
    • Notable for their large body size; known as ambush predators.

    Family Parascyllidae - Collared Carpet Sharks

    • Consists of 2 genera; resembles catsharks due to cat-like eyes and subocular pockets.
    • Distinguished by mouth positioning entirely in front of the eyes and spineless dorsal fins.
    • Anal fin origin is located ahead of the second dorsal fin, equipped with minute spiracles.

    Family Squalidae - Dogfish

    • Includes 2 genera with 29 species, known as dogfish and spurdog.
    • Renowned for longevity, reaching up to 100 years, and low fecundity.
    • Features two dorsal fins equipped with venomous spines; Northeast Atlantic stock critically endangered due to overfishing.
    • Sexual maturity occurs between 11-26 years.

    Order Hexanchiformes, Family Chlamydoselachia - Frilled Sharks

    • Can grow up to approximately 7 feet and inhabit deep waters around 600 meters.
    • Exhibits an elongated body with fine teeth, primarily preying on squid.
    • Characterized by 6 gills and open lateral lines with exposed hair cells.
    • Aplacental viviparity observed with litters around 6 young and a gestation period of 3.5 years.

    Family Hemigaleidae - Weasel Sharks

    • Found at tropical depths around 200 meters; contains 2 genera and 8 species.
    • Exhibits yolk sac viviparity; most species are around 1 meter, though some can grow up to 2 meters.
    • Notable features include large labial furrows and a prominent ventral lobe of the tail.
    • Upper teeth are saw-edged while lower teeth are pointed. Diet consists mainly of cephalopods and fish.

    Family Scyliorhinidae - Catsharks

    • The largest family among sharks, consisting of multiple genera and over 100 species.
    • Adapted to warm water benthic environments, some found at depths down to 2000 meters.
    • Characterized by elongated bodies, high-set cat-like eyes, and nictitating eyelids.
    • Possess large spiracles and specialized teeth with multiple rows; sexual dimorphism in teeth shapes.
    • Includes Proscylliidae (Finback Catshark), Pseudotrikidae (False Catshark), and Scyliorhinidae (True Catsharks).

    Family Rhinchodon - Whale Sharks

    • The largest shark species, reaching around 12 meters and weighing up to 20 tons with a lifespan of about 70 years.
    • Found in circumtropical regions, prefer warm waters to 30 degrees latitude.
    • Filter feeds on plankton via cross-flow filtration, with up to 300 live young per litter.
    • Notable spiracle located behind the eye.

    Family Stegostomae - Zebra Sharks

    • Monotypic family reaching lengths of 2.5 meters.
    • Inhabit shallow waters of the Indopacific, exhibiting nocturnal and benthic behavior.
    • Feeds primarily on small fish and invertebrates, reproducing through egg-laying.

    Family Triakidae - Houndsharks

    • Comprises 9 genera and 40 species available across warm to temperate waters.
    • Characterized by two prominent dorsal fins and anal fins; oval eyes with nictitating eyelids.
    • Sizes range from small (37 cm) to medium (220 cm), with various species including Mustelus (Smooth Hounds) and Triakis (Leopard Sharks).

    Family Sphyrnidae - Hammerhead Sharks

    • Contains 9 species in the genus Sphyrna and 1 in Eusphyrna.
    • Social fish that school during the day but are solitary at night.
    • Approximate length of 6 meters; unique cephalofoil structure assists in 360-degree vision.
    • Diet includes squid and fish, utilizing electroreception.

    Megamouth Shark

    • Order Lamniformes, family Megachiasmidae; discovered in 1976.
    • Deep-water species measuring around 5 meters and weighing 1200 kg.
    • Primarily planktivorous.

    Goblin Shark

    • A rare deep-water shark species characterized by a length of 4 meters.
    • Features a protrusible jaw extending to the end of its snout, preying on fish, cephalopods, and crustaceans.

    Crocodile Shark

    • Mesopelagic shark found in waters down to 600 meters and typically around 1 meter in length.
    • Notable for large eyes and small fins; exhibits a circumpolar distribution.
    • Feeds on deep-water squid, fish, and crustaceans, demonstrating diel migration patterns.

    Order Orectolobiformes

    • Comprises 7 families, 13 genera, and 43 species, including Whale Shark, Wobbegong, Nurse, Bamboo, Collared Carpet, Zebra, and Blind Sharks.
    • Occupies tropical to temperate regions, exhibiting oviparous and ovoviviparous reproductive modes.
    • Characterized by two spineless dorsal fins, anterior short transverse mouth, specialized nostrils, and variable spiracle sizes.

    Family Ginglymostoma - Nurse Sharks

    • Encompasses 4 species; known for their benthic lifestyle and chemosensory abilities.
    • Engage in suctorial feeding; typically grow to about 3.5 meters with live-bearing reproduction.

    Family Brachaeluridae - Blind Sharks

    • Consists of 2 species found in shallow coastal waters (~110 meters) off Australia.
    • Characterized by long barbels, large spiracles, and two dorsal fins; short tails.
    • Diet comprises small fish, cuttlefish, sea anemones, and crustaceans.
    • Exhibits ovoviviparity and gets its name from its behavior of closing its eyes when out of water.

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    Description

    Explore fascinating facts about sharks, including their interactions with whale carcasses and archaeological evidence of shark attacks on humans. Learn about the cultural importance of shark teeth in ancient rituals and the significance of recent milestones in shark research, particularly in Canada.

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