Question

Select the correct matching: (a) Petromyzon Hag fish (b) Echinus Brittle star (c) Apis Silkworm \(\begin{array}{ll}\text { (d) Pennatula } & \- & \text { Sea pen }\end{array}\)

Short answer

The correct match is (d) Pennatula Sea pen.

Step-by-step solution

Matching Petromyzon

Petromyzon refers to a genus of jawless fish known as lampreys. It is often confused with Hagfish. So, the first matching (a) Petromyzon Hag fish is incorrect.

Matching Echinus

Echinus refers to a genus of echinoids which include Sea urchins. Brittle stars belong to a different class so, the second choice (b) Echinus Brittle star is incorrect.

Step 3:Matching Apis

Apis refers to a genus of insects which include Honey bees. Silkworms on the other hand belong to a different species. So, the third choice (c) Apis Silkworm is incorrect

Step 4:Matching Pennatula

Pennatula refers to a genus of soft corals also known as Sea Pens. Therefore, the fourth choice (d) Pennatula Sea pen is correct.

Key concepts

Petromyzon (lampreys)

Petromyzon is a fascinating genus of jawless fish commonly called lampreys. Unlike typical fish, they lack jaws and have a round, sucker-like mouth. This unique mouth structure helps them attach to other fish to feed on their blood and bodily fluids. Lampreys are often confused with hagfish due to their similar eel-like appearance, but they are quite different. While hagfish are slime-producing bottom-dwellers, lampreys are adept swimmers and can be parasitic.

Key characteristics of lampreys include:

• A cartilaginous skeleton without true bones
• Lack of paired fins, which differentiates them from most other fish
• A series of gill pouches instead of the conventional gills with slits

The evolutionary significance of lampreys is notable as they provide insights into the early development of vertebrates. They occupy a unique place in the animal kingdom, bridging the gap between more primitive forms like hagfish and more advanced fishes.

Echinus (sea urchins)

Echinus is a genus that includes sea urchins, spiny sea creatures that are members of the class Echinoidea. Sea urchins have a globular shape and are covered in movable spines, which they use for protection and locomotion. They possess a distinctly rigid exoskeleton or "test" and inhabit various ocean environments, from rocky shores to deep sea beds.

Interesting features of sea urchins include:

• A unique water vascular system, which aids in movement and feeding
• Tube feet that help them to grasp surfaces and capture food
• Complex structures called "Aristotle's lantern" used for grazing and chewing food

Sea urchins play a critical role in marine ecosystems as grazers, helping to control the growth of algae on coral reefs and other substrates. This ecological role makes them an integral part of maintaining the balance of marine environments.

Apis (honey bees)

Apis is a genus of insects that includes honey bees, remarkable for their role in production of honey and pollination of plants. Honey bees exhibit complex social structures and live in well-organized colonies comprised of queens, drones, and worker bees. This social behavior is a key factor in their success and efficiency as pollinators.

Key features of honey bees:

• A unique "waggle dance" to communicate the location of food sources to other bees
• Powerful sensory abilities that help in detecting flowers and nectar from long distances
• Production of honey, wax, and propolis, which have various uses for humans

Honey bees are crucial in ecosystems and agriculture due to their pollination services, significantly contributing to biodiversity and food production. Their decline poses a serious threat to global food security, emphasizing the need for conservation efforts.

Pennatula (sea pens)

Pennatula is a genus of soft corals known as sea pens due to their feather-like appearance. These unique marine organisms are related to sea anemones and other corals but differ in habitat and lifestyle. Sea pens anchor into soft substrates such as sand or mud on the sea floor and exhibit a bioluminescent glow when disturbed.

Notable aspects of sea pens include:

• Consisting of colonies of polyps specialized for different functions
• An ability to retract into the sediment for protection
• A remarkable capability to produce light, serving as a deterrent against predators

Sea pens play a vital role in marine ecosystems, providing habitat and protection for various marine species. Their presence indicates healthy benthic environments and their decline can signal changes in the health of marine ecosystems.