Question

One of the representatives of phylum Arthropoda is
A. Cuttlefish
B. Silverfish
C. Pufferfish
D. Flying fish

Answer 1

Hint: The literal meaning of Arthropod means ‘jointed foot.’ These are a group of invertebrate animals that have an outer skeleton. Their characteristic feature is a segmented body having paired appendages joined to it. The Arthropod from the given options consists of fish-like movement and is a small primitive insect.

Complete step by step answer: An arthropod is a phylum that comes under kingdom Animalia. The arthropod animals are characterized by jointed limbs to their segmented bodies. Their cuticle consists of chitin. Each segment of the body usually has a pair of appendages attached to it. All arthropods undergo the process of molting periodically so that they can grow by shedding chitin made cuticles that inhibits their growth.
Now, based on the above discussion let us see which of the given species matches to characters of arthropods.
-Cuttlefish belong to the phylum Mollusca. They are related to other cephalopod mollusks like squid, octopuses, and the nautilus. The Cuttlefish is characterized by an internal shell and eight arms with two tentacles having suckers on them to catch prey. So they are not Arthropods.
-Silverfish is a small wingless insect. It is a primitive insect having a segmented body with cuticle covered skin. It is named silverfish due to its silvery light grey body and fish-like movements. The newly born appears to be white but later they develop silvery color. They belong to class Insecta of phylum Arthropoda.
-Pufferfish or blowfish belong to the phylum Chordata. They have thin hidden spines that are visible when the fish puffs up. They are of the family Tetraodontidae. This means that they have four large teeth. Their common preys are crustaceans and mollusks. Their body has no segments or no hard cuticle covering. Thus, they do not belong to the Arthropoda phylum.
-Flying fish belongs to the phylum Chordata. They are a family of marine fishes and also called flying cod. They are characterized by their long wing-like fins. They are thought to leap in water to get safety from predators. They are not Arthropods.
Therefore, the correct answer is option B, Silverfish. It is not a fish but an insect with a segmented body and fish-like movement.

Note: The large versatility of Arthropods has enabled them to become the most species-rich members in almost all environments. They make up around 80 percent of animal species. Due to their hard shells, they are hard to prey on and thus survive more. But it is ironic that most of the predators for Arthropods have beaks or claws made of chitin that enables them to cut through them.