Lacy crust Bryozoan, Membranipora membranacea

Scientific Name:
Membranipora membanacea
Common Name(s): Lacy-Crust Bryozoan


Research Summary : Jacob M.
The research on lacy-crust bryozoan was hard. The reason is is because most of the websites just copied and pasted form one website to their web site so it was difficult to get new info after I got all the info out if one website.  there were a lot of resources but most of them were not reliable, and the ones that were reliable were all copied and pasted from the other reliable web sites.  Something that was surprising was how much the web sites copied and pasted.  I think some of the most important things I discovered are what lacy-crust bryozoan looks like and the various ways both to stop it and to kill it.  

Identifying Characteristics
  • Makes colonies that are often circular and white.
  • Each colony is made up of a lot of little individual organisms called zooids.
  • Zooids are box like structures that sit next to each other to form a colony.  When seen close up the colony look like bricks in a wall.
  • Grows 1 mm tall and grows up and over 100 mm wide.
  • Each zooid is a little bit larger than a pin head.
  • This species can be distinguished from native bryozoans in the following ways: All other Membranipora bryozoans and Electra pilosa have spines;  lacy-crust bryozoan does not, it has small nubs. The Electra pilosa has oval zooids but lacy-crust bryozoan has rectangular zooids


Taxonomy of Species
   Scientific Classification
 What That Classification Means
 Kingdom  Animalia  Animals are many celled.  Most move.  They eat other organisms for
 energy.   Animals have eukaryotic cells (cells with a nucleus).  They can
 be vertebrates or invertebrates.
 Phylum  Ectoprocta  Aquatic animals with a fan of cilia (hair like stuff) around the mouth.
 Class  Gymnolaemata   Typically live under sea water, grow on the surfaces of rocks and kelp.
 Order  Cheilostomata  Exclusively marine organisms that grow together but are independent of
 each other and grow on many surfaces.
 Family  Membraniporidae   Form colonies and have simple internal anatomy. 
 Genus  Membranipora  Invertebrates that live on algae.
 Species  Membranacea   Lacy-crust bryozoan 

Similar species include
: Electra pilosa, Membranipora tuberculata, Membranipora villosa and Conopeum reticulatum

Location and Movement
Origin/ Native Range
  • Native in the waters of Europe and in shallow water from Alaska to Baja, California.  
  • But, some scientists think that it is native to the North Atlantic ocean.  There is some debate on this mater. 
  • First identified in the Isles of Shoals, Maine in 1987 and soon spread through the Gulf of Maine.
  • This was the first time that it had been seen anywhere on the east coast of the United States. 
Spread of Species
  • Spread from place to place by ballast water (sea water that ships suck up after their cargo is removed). When ships take in water, they take in some organisms with it.  But when the ships get to their next port to reload the ships put all the water and organisms back into the ocean.
  • Lacy-crust bryozoan produce eggs in the spring which develop into small triangular larva that are released into the water.  The larva drift as plankton until they land on a surface where they can start to build a new colony. Larva is distributed by ocean currents.
Where is it now invasive?  From the Maritime Provinces of Canada to Maryland

Is this species in Maine?
Where has it been identified?
  • Has been identified in the coastal bays throughout the state of Maine.
How was this species introduced?
  • Lacy-crust bryozoan was introduced by ballast water. 
  • Once introduced it has spread by ocean currents. 
 Maine Impact
  • Displaces native bryozoans and is responsible for the loss of kelp beds. 
  • Partly responsible for the sea urchin crash, which led to the loss of the sea urchin industry in Maine.
  • Disruption of local ecosystems and food webs. 
  • Grows on fishing gear so fishermen have to spend time cleaning their nets, lines, and traps. 

Natural Environment
  • Found in shallow marine habitats and grows best in fast flowing, shallow, subtidal water.
  • Grows on kelp, large seaweeds, and is very common on  brown algae.
  •  Also found on smooth surfaces such as glass and also found on fishing gear and rocks.
Climate and Temperature Range
  • Lives in all the world's temperate zones. 
  • In Maine, it lives in coastal waters with temperatures of up to the mid 60's Fahrenheit in summer and down to the low 30's in winter. 

Ecological Interactions  Lacy-crust bryozoan is an omnivore.
 It is a filter feeder using tentacle like cilia. They eat whatever is drifting by. 
Consumed By
 Periwinkles and sea urchins.

 Ecological Overall ecological impacts:
  • Encrusts kelp fronds, preventing kelp from photosynthesizing. Weakens kelp fronds.
  • Damaged kelp beds encourage the establishment of other invasive species such as Codium fragile.
  • Compete with various shellfish for space and nutrients. 
Impact on sea urchins:
  • In the Pacific, sea urchins are the natural predator of lacy-crust bryozoan, but sea urchins in the Gulf of Maine normally eat other kinds of bryozoan. 
  • Because the lacy-crust bryozoan is replacing the native bryozoan, it is bad for sea urchins and is contributing to killing them off. 
  • Sea urchins are now abourt 1/6 of their population in 1995 partly from lacy-crust bryozoan.
Human  Loss of jobs due to species disruptions. 
Economic Maine's sea urchin industry started in1995 and stayed in business until 2004 when the sea urchin population crashed.  This fishery has gone out of business, partly from lacy-crust bryozoan.

Biological  Periwinkles and sea urchins both eat lacy-crust bryozoan but there are not any new species
 being introduced to control it.
  • If you spray water that is 55 degrees Centigrade (131 degrees Fahrenheit) for five seconds it kills lacy-crust bryozoan
  • If you scrub the lacy-crust bryozoan off what it is encrusting it also kills it. This works to clean fishing gear and docks, but probably does not work to kill it on kelp.
  • Air drying nets and or washing gets lacy-crust bryozoan off fishing nets. 
  • In April, 2011, the U.S. Coast Guard put in place new rules to keep invasive species from spreading in ballast water from ships.  The rules start to take effect in 2012.   
Chemical  Covering lacy-crust bryozoan with copper sulfate kills lacy-crust bryozoan. 

Interesting Facts
  • Lacy-crust bryozoan has an 8 week growing season every year.