Step 1: Understanding the Concept:
Ichthyotaxonomy and commercial pelagic tuna species identification in Indian waters.
Step 2: Detailed Explanation:
Scientific nomenclature of commercial scombrid tuna species:
1. {Euthynnus affinis: Commonly known as the Little Tuna Kawakawa Mackerel Tuna (characterized by 2--5 dark spots on breast between pectoral and pelvic fins, and dark wavy stripes above lateral line).
2. {Katsuwonus pelamis: Skipjack Tuna (characterized by 4--6 longitudinal dark stripes on silvery belly).
3. {Auxis thazard: Frigate Tuna.
4. {Thunnus albacares: Yellowfin Tuna.
Step 3: Final Answer:
Thus, the scientific name of little tuna is Euthynnus affinis, corresponding to option (C).