''Halophila engelmannii'' is a species of

seagrass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...

in the Hydrocharitaceae family. It is referred to by the common names star grass and Engelmann's seagrass and grows underwater on shallow sandy or muddy sea floors. It is native to the

Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of its population. ...

, the

Cayman Islands The Cayman Islands () is a self-governing British Overseas Territories, British Overseas Territory, and the largest by population. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Cayman, which are located so ...

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

, the

Gulf Coast of the United States The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The list of U.S. states and territories by coastline, coastal states th ...

, the

Gulf Coast of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

, and

Trinidad and Tobago Trinidad and Tobago, officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean, comprising the main islands of Trinidad and Tobago, along with several List of islands of Trinidad and Tobago, smaller i ...

Description

Halophila is the only genus of seagrass lacking basal sheaths on the leaf stems. Like other seagrasses, ''Halophila engelmannii'' has

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

s that run along near the surface of sand or mud, with roots at the nodes to anchor them in place. Each leaf stem grows from a node and has a pair of scales halfway up and another pair at the base of the leaf blades. There are 4 to 8 blades on each stem, each of which is up to long and wide. Each blade is oval, has 6 to 8 veins and a finely serrated margin.

Distribution

''Halophila engelmannii'' is found on the coasts of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, the

and the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

. It can grow in deeper waters than do some other species of seagrass, at depths down to . It is one of three species of '' Halophila'' found in the

Indian River Lagoon The Indian River Lagoon is a grouping of three lagoons: the Mosquito Lagoon, the Banana River, and the Indian River, on the Atlantic Coast of Florida; one of the most biodiverse estuaries in the Northern Hemisphere and is home to more than 4, ...

, Florida, the others being '' Halophila decipiens'' and '' Halophila ovalis'' in the form of Johnson's seagrass. They often form mixed

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s at greater depths than other seagrasses normally grow.''Halophila engelmannii'' (Star grass)
Smithsonian Marine Station at Fort Pierce. Retrieved 2012-01-28.

Biology

Flowering occurs in the early summer when the water temperature reaches at least 22 °C. Fragments of the plant that become detached are able to grow into new plants. The seagrass meadow acts as habitat and food source for many invertebrates and fish. In the

, animals that feed on ''Halophila engelmannii'' include

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerh ...

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

s, parrotfish,

surgeonfish Acanthuridae are a family (biology), family of ray-finned fish which includes surgeonfishes, tangs, and Naso (fish), unicornfishes. The family includes about 86 Extant taxon, extant species of ocean, marine fish living in tropical seas, usually ...

and possibly pinfish. The sea slug '' Elysia serca'' preferentially feeds on it by sucking sap.''Elysia serca''
Smithsonian Marine Station at Fort Pierce. Retrieved 2012-01-28.

References

{{Taxonbar, from=Q5643432 engelmannii Flora of the Bahamas Flora of the Cayman Islands Flora of Costa Rica Flora of Cuba Flora of the United States Flora of Mexico Flora of Puerto Rico Flora of Trinidad and Tobago Taxa named by Paul Friedrich August Ascherson Flora without expected TNC conservation status