Vananda Creek Limnetic Threespine Stickleback

Gasterosteus aculeatus

SARA Status
No Status
NS
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

SARA Status

  • No Status NS
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX
COSEWIC Status
Not at Risk
NR
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

COSEWIC Status

  • Not at Risk NR
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX

Description

Vananda Creek Benthic and Limnetic Threespine Sticklebacks (Gasterosteus aculeatus) are one of several unique Stickleback Species Pairs that live in sympatry. Two species are sympatric when they exist in the same area and evolved together from a common ancestor. The two species of Vananda Creek Sticklebacks descended from the marine Threespine Stickleback and evolved into separate species by living in different habitats. The Vananda Creek Stickleback Species Pair consists of a Benthic and a Limnetic form. The Benthic species lives in nearshore areas, and the Limnetic species lives in open water. The divergence from their common ancestor is thought to have occurred because of the limited competition and predation in the habitat. Habitat or environmental changes can disrupt mating barriers within a species pair and lead to a collapse of the pair into a single hybrid population. Hybrids occur naturally at a low rate.

The Vananda Creek Limnetic Stickleback is around 65 millimetres long and usually smaller than the Benthic species. It has a streamlined body, narrow mouth, and many long gill rakers. Both species of Vananda Creek Sticklebacks have delicate fins, spines on their back and sides and plate-like armour to protect them from predators. Body colour varies from silvery to mottled green and brown. Sexually mature males may develop red colouration on the throat, or in some cases turn completely black.

Habitat

The Vananda Creek Stickleback Species Pair is found in three lakes in the Vananda Creek watershed on Texada Island, British Columbia, Canada. These lakes are Spectacle Lake (also known as Balkwill Lake), Priest Lake, and Emily Lake (also known as Turtle Lake). The species pair is also likely to use the streams and marshes connecting the lakes. The Benthic and Limnetic species exist as separate designatable units.

Vananda Creek Limnetic Sticklebacks live primarily in open water. Both the Limnetic and Benthic species nest in nearshore beaches. Vananda Creek Limnetic Stickleback prefer to spawn in more open areas than the Benthic species. Natural light is necessary for the species to recognize their mates. Both Benthic and Limnetic fry use nearshore habitat with aquatic plants to feed and hide. Juvenile Vananda Creek Limnetic Stickleback are common around steep, rocky and open shoreline. They eventually move offshore to open water. Both the Limnetic and Benthic species overwinter in deeper water.

Threats

Primary threats to the Vananda Creek Stickleback Species Pair include invasive species, water management, habitat loss or degradation from land use, collections for research, recreational activities and disease.

Stickleback Species Pairs have specific needs and are very sensitive to changes in habitat and environmental factors. Changes can disrupt the mating barriers between the Stickleback Species Pair and collapse the species pair into a single hybrid population

Invasive species may disrupt the simple fish communities required by the Vananda Creek Stickleback Species Pair. In recent decades, introduced species caused the extinction of at least two Stickleback Species Pairs.

Water management and land use have an impact on the Vananda Creek environment. Water level reductions from water extraction could directly reduce habitat. Land use such as mining, forestry, and development around Vananda Creek could reduce riparian cover, increase pollution, and increase sedimentation. Riparian vegetation is important for regulating water temperature and food availability. Sedimentation and pollution can alter vegetation and water clarity, which could decrease mate recognition and increase hybridization.  

Further Information

The Vananda Creek Limnetic Stickleback was assessed as Endangered by the Committee on the Status of Endangered Wildlife in Canada in May 2000. This status was reconfirmed in April 2010. The species was listed under the Species at Risk Act in June 2003. A Recovery Strategy that addresses the Paxton Lake, Enos Lake and Vananda Creek Stickleback Species Pairs was posted in 2007. The Recovery Strategy identifies threats, population and distribution objectives and broad approaches to recovery for the six species. A proposed Action Plan for the Paxton Lake and Vananda Creek Stickleback Species Pairs was posted in 2016. It describes critical habitat and identifies ways to implement recovery measures.

Government agencies, stewardship groups (e.g. Texada Stickleback Group Association) and universities such as the University of British Columbia and Michigan State University continue to carry out research to fill knowledge gaps on the Vananda Creek Stickleback Species Pair. They also contribute to outreach and education activities, and management activities towards the recovery of Stickleback Species Pairs. In 2013, the British Columbia Ministry of Forests, Lands, and Natural Resource Operations established a Wildlife Habitat Area for Vananda Creek Stickleback Pairs to aid in habitat protection. Scientific collection guidelines for Stickleback Species Pairs were developed in 2008, with the aim to mitigate impacts of research activities.

This species is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available on the Species at Risk Public Registry.

To find out if this species is protected by provincial or territorial laws, consult the provinces' and territories' website.

Vananda Creek Limnetic Threespine Stickleback

Top: Priest Lake Limnetic Stickleback. Bottom: Priest Lake Benthic Stickleback.

Photo credit: Gerrit J. Velema (Gjvphoto.com)

Scientific Name: Gasterosteus aculeatus
SARA Status: Endangered, Schedule 1
COSEWIC Status: Endangered (April 2010)
Region: British Columbia

Region map

Region map, British Columbia

Did You Know?

Stickleback species pairs evolved after the last glaciation. They are some of the youngest species on Earth and are around only 13,000 years old.

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