Eggs

Foods, Animal source foods

Consumption area(s): Earth

1. Different types of eggs
1. Different types of eggs

Introduction

Eggs are biological vessels created by an animal to carry an ovum, which may be fertilized and develop into a zygote. It serves as a protective environment for the embryo’s incubation, supporting its gradual transformation into an animal fetus capable of independent survival.

Description of eggs

The most commonly consumed eggs are those of the chicken, with evidence of consumption dating back to at least 1500 BCE in Southeast Asia. Eggs from other birds, such as ducks and ostriches, are also eaten, though less frequently than chicken eggs. Additionally, eggs from reptiles, amphibians, and fish can be consumed. Notably, fish eggs, known as “caviar,” are highly prized in many cuisines.

The laying of eggs is a common trait among most arthropods, vertebrates (except for some mammals), and mollusks, although some animals, like scorpions, do not lay eggs. The largest egg ever recorded belonged to a whale shark, measuring an impressive 30 cm × 14 cm × 9 cm (about 11.8 × 5.5 × 3.5 inches). However, these eggs typically hatch inside the mother’s body. Among living birds, the ostrich egg is the largest, weighing up to 1.5 kg (3.3 lbs) and measuring 17.8 cm × 14 cm (7 × 5.5 inches).

In contrast, the bee hummingbird produces the smallest known egg among birds, measuring between 6.35 and 11.4 mm (0.25 to 0.45 inches) in length and weighing about 0.5 grams (0.018 ounces). Some eggs laid by reptiles, fish, amphibians, insects, and other invertebrates can be even smaller, highlighting a wide variety of sizes and characteristics across species.

Classification of eggs

Eggs are classified based on the class of animals that produce them. These include:

  • Amphibian eggs
  • Mammal eggs
  • Cartilaginous fish eggs
  • Bony fish eggs
  • Reptile eggs
  • Bird eggs

Photo(s):

1. Adolphe Millot, Public domain, via Wikimedia Commons