SafePlants

Halodule: A Genus of Seagrasses

Halodule is a genus of seagrasses belonging to the family Cymodoceaceae, first described as a genus in 1841. These plants are found in tropical and semi-tropical ocean shores worldwide.

Considerations for Pets

• Halodule species are needle-like seagrass.
• Halodule wrightii seeds have a hard seed-coat.

Taxonomy and Nomenclature

• Scientific Name: Halodule Endlicher
• Family: Cymodoceaceae
• Kingdom: PLANTAE
• Division: ANTHOPHYTA
• Class: MONOCOTYLEDONEAE
• Order: HELOBIAE
• Alternative Genus Name: Diplanthera Thouars (1806), not Gleditsch (1764)

Species within the Halodule Genus

• Halodule uninervis (Forsskl) Ascherson
• Common Name: Narrowleaf seagrass (English)
• Halodule wrightii Ascherson
• Common Name: Shoalweed, Shoalgrass
• Halodule pinifolia (Miki) den Hartog
• Halodule beaudettei den Hartog
• Halodule bermudensis den Hartog

Distribution and Habitat

• Halodule species are widespread on tropical and semi-tropical ocean shores globally.
• Halodule uninervis is native to the western Pacific and Indian Oceans.
• Halodule wrightii is native to seacoasts of warmer oceans, including reports from California and Texas. It also occupies the shallowest waters in the Gulf of Mexico and can be found along the Texas coast.
• Halodule uninervis is distributed in separate patches along the coast of Kuwait.
• Halodule uninervis and Halodule pinifolia are widely distributed throughout the coastlines of Malaysia.
• Halodule spp. are found in Mexico.

Ecological Role

• Halodule wrightii may form carpet-like beds in warm, shallow waters and can act as a pioneer species in ecological succession.

Morphological Characteristics and Growth Habits

• Halodule wrightii is a "seagrass" that may form carpet-like beds in warm, shallow waters.
• Halodule species generally feature rhizomes that are branched and root at the nodes.
• Halodule wrightii is dioecious, having male and female flowers on separate plants.

Interactions with Other Organisms

• Halodule wrightii shoot density influences the composition of the associated algal community in rocky environments.
• Halodule wrightii seagrass beds provide a habitat for various fish species.

Further Information

• ARKive provides seagrass photos and facts.
• The IUCN Red List publishes species range maps, including one for Halodule pinifolia.
• WoRMS (World Register of Marine Species) provides taxonomic details for Halodule uninervis (AphiaID: 208924).
• USDA PLANTS Database includes general information for Halodule wrightii (Symbol: HAWR).
• Wikimedia Commons hosts media, including a file of Halodule uninervis.