Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:A Guide to Invasive Species of the Galveston Bay Area
Zoobotryon verticillatum
| ITIS TSN: | 155576 |
| Presence: | Current Invaders |
| Habitat: | Aquatic |
| Native Range: | Unknown, widely distributed in warm temperate and tropical waters in western Atlantic and Caribbean |
Human Health
This species poses no known human health impacts.Prohibited Lists
As of 2010, this species is not prohibited by the TPWD.Introduction Pathways
This species was most likely introduced through boat hull fouling (ISSG 2009h).Geographic Distribution
Researchers believe that these species have a worldwide distribution in tropical and warm temperate seas (Hill 2001). Z. verticillatum is known to occur in Galveston Bay.Specific Primary Habitats
The spaghetti Bryozoan is an estuarine and marine species, often found in bays and estuaries in seagrass beds, drift algae, and hard substrates such as oyster reefs, boat hulls, dock pilings, and debris. Z. verticillatum is often associated with other fouling species. The growth of Z. verticillatum flourishes under warm temperatures (22°C or above) and high salinity conditions (Hill 2001; ISSG 2009h).Ecological, Economic, or Social Impact
The bushes of Z. verticillatum can entangle in fishing nets and shrimp trawls. The species affects navigation through hull fouling and fouling of submerged structures, and may also foul industrial pipes. It can affect native sessile organisms via displacement of habitat due to overcrowding (ESF). This Bryozoan may also alter ecosystem processes because of its enormous water filtering capacity (Hill 2001).Physical Description
The spaghetti Bryozoan is a colonial species, comprised of individual zooids that give the appearance of an algal species (ESF). These colonies can grow up to 1 meter in length but each individual zooid (reproducing individual) is only 0.4-0.6 mm long (Hill 2001). This colonial species forms white or transparent, erect, irregularly branched stalks that have the appearance of spaghetti (ISSG 2009h).Reproduction Characteristics
Z. verticillatum reproduces both sexually and asexually. Each zooid in a colony is hermaphroditic, and reproduces eggs and sperm which create zooplanktonic larvae. After the larvae have found a suitable surface on which to attach, a new colony will form. New colonies can also form asexually via fragmentation. Existing colonies expand via asexual budding, growing from April through September when water temperatures are suitable for growth (Hill 2001; ISSG 2009h).Feeding
The spaghetti Bryozoan is a suspension feeder which feeds on zooplankton. It can filter from 25,000-344,000 liters per day (ISSG 2009h).Control
Early detection is key to preventing the spread and establishment of this species and regional/local monitoring or surveillance is essential. If found in local waters, note the location and notify the TPWD.Lists
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail. Sauerkraut grass (Zoobotryon verticillatum) seen in Galveston Bay. Photo courtesy of Jan Culbertson, Texas Parks and Wildlife Department. |