What is the largest animal phylum in terms of number of species?Group of answer choicesArthropodsMollusksAnnelidsVertebratesRoundworms

Break Down the Problem

1. Identify the phyla listed in the answer choices.
2. Research the number of species in each phylum to determine which phylum has the highest count.

Relevant Concepts

• Animal Phyla: The classification of animals into groups based on shared characteristics.
• Species Count: The total number of identified species within a given phylum.

Analysis and Detail

1. Arthropods: This phylum includes insects, arachnids, crustaceans, and others, with estimates of over 1 million described species. It is known to be the largest phylum in terms of species diversity.
2. Mollusks: This group includes snails, clams, and cephalopods. They have around 85,000 described species.
3. Annelids: This phylum includes segmented worms such as earthworms and leeches, with approximately 22,000 recognized species.
4. Vertebrates: This subgroup of the phylum Chordata includes fish, birds, mammals, reptiles, and amphibians. They have around 66,000 species.
5. Roundworms: Known scientifically as Nematodes, they consist of around 25,000 described species, although many more may be undiscovered.

Verify and Summarize

After researching the respective species counts:

• Arthropods: > 1,000,000 species.
• Mollusks: ~ 85,000 species.
• Annelids: ~ 22,000 species.
• Vertebrates: ~ 66,000 species.
• Roundworms: ~ 25,000 species.

The comparison clearly indicates that Arthropods have a significantly higher number of species than any other listed phylum.

Final Answer

The largest animal phylum in terms of number of species is Arthropods.