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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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