Always industrious, jawfish keep their burrows shaped up. They line the entrance with rocky rubble so it won't cave in, and they're forever shoveling out mouthfuls of sand. They sometimes raid a neighbor's burrow for choice pebbles and shells.

Coral reefs around the world are in danger. Silt (fine soil) smothers coral when it washes off the land from farm fields, roads and building sites. More towns and resorts near shore mean more sewage, oil and chemicals in the water. Global warming and changes in weather patterns create conditions that corals can't survive.

• The Spanish name for jawfishes is "bocas grandes," meaning "big mouths." Jawfishes use their big mouths like scoops as they move sand and rocks while digging their burrows.
• Besides serving as scoops, jawfishes' big mouths come in handy at mating time. The males carry their eggs inside their mouths until they hatch. Males can be territorial; they may use their mouths to "joust" with other jawfishes.