Halophila engelmannii facts for kids

Halophila engelmannii is a type of seagrass often called star grass or Engelmann's seagrass. It belongs to the Hydrocharitaceae plant family. This plant grows underwater on sandy or muddy ocean floors that aren't too deep. You can find it in places like the Bahamas, Cuba, Puerto Rico, and along the Gulf Coast of the United States and Gulf Coast of Mexico.

What Does Star Grass Look Like?

Halophila is a special group of seagrasses. Unlike others, its leaves don't have a protective base (called a sheath) where they connect to the stem. Like many other seagrasses, Halophila engelmannii has special stems called rhizomes. These rhizomes grow sideways, just under the sand or mud.

Small roots grow from these rhizomes to help the plant stay in place. Each leaf stem grows from a spot on the rhizome called a node. On each stem, there are usually 4 to 8 leaf blades. Each blade can be up to 30 millimeters (about 1.2 inches) long and 6 millimeters (about 0.2 inches) wide. The blades are oval-shaped and have small, saw-like edges. They also have 6 to 8 tiny lines, or veins, running through them.

Where Does Star Grass Live?

You can find Halophila engelmannii along the coasts of Florida, Texas, the Bahamas, Cuba, and the West Indies. This seagrass can grow in deeper water than some other seagrass types. It has been found at depths of up to 14.4 meters (about 47 feet) underwater.

In the Indian River Lagoon in Florida, Halophila engelmannii is one of three Halophila species. The others are Halophila decipiens and Halophila johnsonii. These different types of Halophila often grow together. They form mixed seagrass meadows in deeper areas where other seagrasses usually don't grow.

Life Cycle and Friends of Star Grass

Halophila engelmannii starts to flower in the early summer. This happens when the water temperature reaches at least 22 degrees Celsius (about 72 degrees Fahrenheit). Interestingly, if a piece of the plant breaks off, it can often grow into a whole new plant!

These underwater seagrass meadows are very important. They provide a home and food for many different ocean creatures, like small invertebrates and fish. In the Indian River Lagoon, several animals enjoy eating Halophila engelmannii. These include sea turtles, sea urchins, parrotfish, surgeonfish, and possibly pinfish. There's even a type of sea slug called Elysia serca that loves to feed on it by sucking out its sap.