By using a sticky mucous, the ____ fish group's nests will stay together.

• A. Bubble-nest builders
• B. Egg-layers
• C. Egg-scatterers
• D. Livebearers

Answer: (A)

Nest stability in bubble-nest builders comes from a glue-like mucus that binds the bubbles into a cohesive nest. These fish create a floating nest by blowing bubbles and then coating them with a sticky secretion, often from the mouth or surrounding glands, so the nest stays intact as eggs are laid and incubated. This mucus-based binding is what keeps the nest together in the water, even as conditions change or as the male guards and tends to the eggs. In contrast, egg-layers simply attach eggs to a surface, egg-scatterers release eggs into the water without a nest, and livebearers give birth to free-swimming young with no nest at all.