Species Profile

Mexican Mosquito-fern

Scientific Name: Azolla mexicana
Other/Previous Names: Mexican Mosquito Fern
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: November 2008
Last COSEWIC Designation: Threatened
SARA Status: Schedule 1, Threatened


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Quick Links: | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | National Recovery Program | Documents

Image of Mexican Mosquito-fern

Mexican Mosquito-fern Photo 1

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Description

Mexican Mosquito-fern Azolla mexicana is a tiny floating aquatic fern found in wetlands and small wet areas. Individual plants range in size from 1-2 cm in length. Leaves are tiny and overlap like shingles. Spore-producing structures, borne below the water surface, are present in the Canadian populations. Roots are simple and short. Plants usually have three “floats”. This species forms extensive green or red mats on the water surface. (Updated 2017/01/20)

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Distribution and Population

The natural range of Mexican Mosquito-fern is North, Central and South America (from Peru, northern Bolivia and Brazil north). In Canada, it is restricted in occurrence to British Columbia, where it occurs at the northern tip of its range. The eight extant British Columbia populations occur in three regions: the Little Fort area, the Shuswap Lake area, and Vernon. The extent of occurrence is 5400 km2 and the area of occupancy for the small fragmented water bodies is 11 km2 based on a 1 x 1 km grid and 40 km2 based on a 2 x 2 km grid. (Updated 2017/01/20)

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Habitat

Mexican Mosquito-fern is a wetland species of sheltered still waters and is found in ponds, ditches, oxbow ponds, and lakeshores. It grows best in 50% sunlight, and is tolerant of semi-shade conditions. In BC, it is found in sites with pH ranging from 6.5- 8.1, although it is tolerant of pH ranging from 3.5 to 10. (Updated 2017/01/20)

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Biology

This aquatic fern grows in a symbiotic relationship with a species of bluegreen alga (a cyanobacterium) Anabaena azollae. Primary reproduction is through fragmentation of plants. Secondary reproduction is sexual through spore production. This is a heterosporous fern: two types of spores (of different sizes and appearance) are produced that fall to the bottom of water bodies and eventually germinate, producing new plants. Dispersal is by wind, waterfowl, and accidentally by humans. (Updated 2017/01/20)

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Threats

Mexican Mosquito-fern is naturally limited by factors such as water chemistry and temperature, which restrict its range in British Columbia. Threats to the populations include road repairs and construction, housing / urban development, accidental spills on roads and railways (which can influence water chemistry and could cause complete population die-off), invasive species, and eutrophication of sites. (Updated 2017/01/20)

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Protection

Federal Protection

The Mexican Mosquito-fern is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

Name Recovery Strategy for the Mexican Mosquito-fern (Azolla mexicana) in Canada
Status First posting on SAR registry

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Documents

PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

6 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Update Status Report on the Mexican Mosquito-fern Azolla mexicana in Canada (2009)

    Mexican Mosquito-fern Azolla mexicana is a tiny floating aquatic fern found in wetlands and small wet areas. Individual plants range in size from 1-2 cm in length. Leaves are tiny and overlap like shingles. Spore-producing structures, borne below the water surface, are present in the Canadian populations. Roots are simple and short. Plants usually have three “floats”. This species forms extensive green or red mats on the water surface.

COSEWIC Assessments

  • COSEWIC Assessment - Mexican Mosquito-fern (2009)

    Mexican Mosquito-fern Azolla mexicana is a tiny floating aquatic fern found in wetlands and small wet areas. Individual plants range in size from 1-2 cm in length. Leaves are tiny and overlap like shingles. Spore-producing structures, borne below the water surface, are present in the Canadian populations. Roots are simple and short. Plants usually have three “floats”. This species forms extensive green or red mats on the water surface.

Response Statements

  • Response Statement - Mexican Mosquito-fern (2009)

    This tiny floating aquatic fern of south-central British Columbia is restricted to 8 small water bodies where its populations undergo periodic fluctuations in numbers of individuals. Two populations and their habitat have been lost in recent years due to construction activities with most of the extant populations occurring adjacent to major highways or a railway where they are at potential risk from maintenance activities, including the use of chemicals such as road salt.

Recovery Strategies

  • Recovery Strategy for the Mexican Mosquito-fern (Azolla mexicana) in Canada (2017)

    The Minister of Environment and Climate Change is the competent minister under SARA for the Mexican Mosquito-fern and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of British Columbia as per section 39(1) of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). The Province of British Columbia provided the attached recovery plan for the Mexican Mosquito-fern (Part 2) as science advice to the jurisdictions responsible for managing the species in British Columbia. It was prepared in cooperation with Environment and Climate Change Canada.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2009 (2009)

    2009 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update March 31, 2017