Biology & EcologyBiology & Ecology of large branchiopods

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Carol W. Witham, VernalPools.Org

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Talk OverviewTalk Overview

Classification of large branchiopodsAnatomy of a fairy shrimp

Biology of a fairy shrimp

Ecology of large branchiopodsDistribution of fairy shrimp

Endangered Species ActSection 10(a) Recovery Permit

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ClassificationClassification

Phyllum: Arthropoda

Subphyllum: Crustacea

Class: Branchipoda

Subclass: Phyllopoda

Conchostraca – clam shrimp

Cladocera – water fleas

Notostraca – tadpole shrimp

Anostraca – fairy shrimp

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Branchiopoda Branchiopoda subclass Phyllopodasubclass Phyllopoda

Clam Shrimp

Water Fleas

Tadpole Shrimp

Fairy Shrimp

Long extinct shelled ancestor to fairy shrimp

Diplostraca

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Tadpole Shrimp - NotostracaTadpole Shrimp - Notostraca

Name 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 - AnostracaFairy Shrimp - Anostraca

Name 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 ShrimpAnatomy of a Fairy Shrimp

Branchinecta lynchi male

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Anatomy of a Fairy ShrimpAnatomy of a Fairy Shrimp

Branchinecta lynchi female

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Identification of Fairy ShrimpIdentification of Fairy Shrimp

Vernal Pool Fairy ShrimpBranchinecta lynchi

California Fairy ShrimpLinderiella occidentalis

Malesface-on

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Biology of Fairy ShrimpBiology of Fairy Shrimp

Circulatory SystemHeart pumps hemolymph through open system

Hemoglobin 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 ShrimpBiology of Fairy Shrimp

ReproductionMales constantly in search of females

Females use antennae ornamentation to determine a suitable, mature mate

Mating behavior actionsDetection, Orientation,

Station-taking, Clasping,

Copulation, Ejaculation

Disengagement

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Reproduction of Fairy ShrimpReproduction of Fairy Shrimp

So what really happens?Detection

Orientation

Station-taking

Clasping

Copulation

Ejaculation

Disengagement

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Production of CystsProduction of Cysts

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Fairy Shrimp CystsFairy Shrimp Cysts

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Hatching of Fairy Shrimp CystsHatching of Fairy Shrimp Cysts

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Immature Fairy ShrimpImmature Fairy Shrimp

Nauplius

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Immature Fairy ShrimpImmature Fairy Shrimp

Metanauplius

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Vernal Pool Tadpole ShrimpVernal Pool Tadpole Shrimp

General BiologyContains large amounts of hemoglobin

Molts its exoskeleton as it grows

Grows more phyllopods with each molt

Three sexesMales, females and

hermaphrodites

Females & hermaphrodites have 2 ovisacks

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Maturation Time for ShrimpMaturation Time for Shrimp

Linderiella occidentalis – California fairy shrimp

18-31 days, can have multiple hatchings

Branchinecta lynchi – vernal pool fairy shrimp

6-16 days, single hatching, temperature sensitive

Lepidurus packardi – vernal pool tadpole shrimp

21-41 days, can live 144 days, multiple hatchings

ExtremesBranchinecta mesovallensis, B. conservatio

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Ecology of Large BranchiopodsEcology of Large Branchiopods

Ephemeral freshwater systemsVernal pools, potholes, snow melt ponds

Primary consumers in the food chainFilter feeders – phyto & zooplankton

Munch anything that will fit in mandibles

Some are predators of other fairy shrimp

Essential food chain servicesBirds, bugs and beetles

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Worldwide distribution of AnostracaWorldwide distribution of Anostraca

Southern Africa45 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 AnostracaCalifornia distribution of Anostraca

Primarily central valley

28 species

15 endemics

5 listed under the federal Endangered Species Act

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Endangered Species ActEndangered Species Act

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Endangered Species ActEndangered Species Act

The 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 ActEndangered Species Act

To “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 PermitsSection 10(a) Recovery Permits

Allows “take” to occur if it is considered beneficial to species recovery

Educational permitsGeographically restricted

Only requires general knowledge of listed species occurring in that area

Requires collection of data to justify the benefit to recovery of the species

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Shrimp FairyShrimp Fairy

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