Biology & Ecologyof large branchiopods

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Carol W. Witham, VernalPools.Org

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Talk OverviewClassification of large branchiopods

Anatomy of a fairy shrimpBiology of a fairy shrimp

Ecology of large branchiopodsDistribution of fairy shrimp

Endangered Species ActSection 10(a) Recovery Permit

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Classification

Phyllum: ArthropodaSubphyllum: Crustacea

Class: BranchipodaSubclass: Phyllopoda

Conchostraca – clam shrimp

Cladocera – water fleas

Notostraca – tadpole shrimp

Anostraca – fairy shrimp

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Branchiopoda subclass Phyllopoda

Clam Shrimp

Water Fleas

Tadpole Shrimp

Fairy Shrimp

Long extinct shelled ancestor to fairy shrimp

Diplostraca

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Tadpole Shrimp - NotostracaName means

“Not” = back“Ostraca” = hard plate or shell

2 genera and 3 speciesin California

Lepidurus* and Triops*Genera with Threatened or Endangered Species

Lepidurus packardi, an Endangered Species, occurs at Mather

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Fairy Shrimp - AnostracaName means

“An” = without“Ostraca” = hard plate or shell

6 genera and 27+ species in CaliforniaArtemia, Branchinecta*, Eubranchipus, Linderiella,

Streptocephalus*, Thamnocephalus*Genera with Threatened or Endangered Species

Branchinecta lynchi, an Threatened Species, and Linderiella occidentalis occur at Mather

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Anatomy of a Fairy Shrimp

Branchinecta lynchi male

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Anatomy of a Fairy Shrimp

Branchinecta lynchi female

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Identification of Fairy Shrimp

Vernal Pool Fairy ShrimpBranchinecta lynchi

California Fairy ShrimpLinderiella occidentalis

Malesface-on

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Biology of Fairy ShrimpCirculatory System

Heart pumps hemolymph through open systemHemoglobin can make shrimp pink

Oxygen RegulationFeet are primary gills, but entire surface can respire

Water, Salts and WasteVery little is known about the osmotic regulation of

most fairy shrimp

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Biology of Fairy ShrimpReproduction

Males constantly in search of femalesFemales use antennae ornamentation to determine a

suitable, mature mateMating behavior actions

Detection, Orientation, Station-taking, Clasping, Copulation, EjaculationDisengagement

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Reproduction of Fairy ShrimpSo what really happens?

DetectionOrientationStation-takingClaspingCopulationEjaculationDisengagement

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Production of Cysts

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Fairy Shrimp Cysts

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Hatching of Fairy Shrimp Cysts

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Immature Fairy Shrimp

Nauplius

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Immature Fairy Shrimp

Metanauplius

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Vernal Pool Tadpole ShrimpGeneral Biology

Contains large amounts of hemoglobinMolts its exoskeleton as it growsGrows more phyllopods with each moltThree sexes

Males, females and hermaphrodites

Females & hermaphrodites have 2 ovisacks

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Maturation Time for ShrimpLinderiella occidentalis – California fairy shrimp

18-31 days, can have multiple hatchings

Branchinecta lynchi – vernal pool fairy shrimp6-16 days, single hatching, temperature sensitive

Lepidurus packardi – vernal pool tadpole shrimp21-41 days, can live 144 days, multiple hatchings

ExtremesBranchinecta mesovallensis, B. conservatio

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Ecology of Large BranchiopodsEphemeral freshwater systems

Vernal pools, potholes, snow melt ponds

Primary consumers in the food chainFilter feeders – phyto & zooplanktonMunch anything that will fit in mandiblesSome are predators of other fairy shrimp

Essential food chain servicesBirds, bugs and beetles

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Worldwide distribution of AnostracaSouthern Africa

45 species (38 endemic)

Western US & Baja~28 species (15 endemic)

Southwestern Australia19 species (12 endemic)

Argentina18 species (14 endemic)

Italy & southwestern France16 species (7 endemic)

Total # species286

Yet to be described~300

Important group of freshwater habitats in temperate zones

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California distribution of Anostraca

Primarily central valley

28 species

15 endemics

5 listed under the federal Endangered Species Act

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Endangered Species Act

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Endangered Species ActThe federal Endangered Species Act of

1973 was enacted to protect animal and plant species from extinction by preserving the ecosystems in which they survive and by providing programs for their conservation

Includes prohibitions against “take”, but allows certain activities

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Endangered Species ActTo “take” a species means to “harass,

harm, pursue, hunt, shoot, would, kill, trap, capture or collect, or to attempt to engage in any such conduct”.

Exceptions are made under the recovery section of the act where some activities are determined beneficial to the species, including increased knowledge

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Section 10(a) Recovery PermitsAllows “take” to occur if it is considered

beneficial to species recoveryEducational permits

Geographically restrictedOnly requires general knowledge of listed species

occurring in that areaRequires collection of data to justify the benefit to

recovery of the species

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Shrimp Fairy

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