Biology & Ecology of large branchiopods

Transcription

1 Biology & Ecology of large branchiopods Carol W. Witham, VernalPools.Org

2 Talk Overview Classification of large branchiopods Anatomy of a fairy shrimp Biology of a fairy shrimp Ecology of large branchiopods Distribution of fairy shrimp Endangered Species Act Section 10(a) Recovery Permit

3 Classification Phyllum: Arthropoda Subphyllum: Crustacea Class: Branchipoda Subclass: Phyllopoda Conchostraca clam shrimp Cladocera water fleas Notostraca tadpole shrimp Anostraca fairy shrimp

4 Branchiopoda subclass Phyllopoda Fairy Shrimp Water Fleas Tadpole Shrimp Clam Shrimp Long extinct shelled ancestor to fairy shrimp Diplostraca

5 Tadpole Shrimp - Notostraca Name means Not = back Ostraca = hard plate or shell 2 genera and 3 species in California Lepidurus* and Triops *Genera with Threatened or Endangered Species Lepidurus packardi, an Endangered Species, occurs at Mather

6 Fairy Shrimp - Anostraca Name means An = without Ostraca = hard plate or shell 6 genera and 27+ species in California Artemia, Branchinecta*, Eubranchipus, Linderiella, Streptocephalus*, Thamnocephalus *Genera with Threatened or Endangered Species Branchinecta lynchi, an Threatened Species, and Linderiella occidentalis occur at Mather

7 Anatomy of a Fairy Shrimp Branchinecta lynchi male

8 Anatomy of a Fairy Shrimp Branchinecta lynchi female

9 Identification of Fairy Shrimp Males face-on California Fairy Shrimp Linderiella occidentalis Vernal Pool Fairy Shrimp Branchinecta lynchi

10 Biology of Fairy Shrimp Circulatory System Heart pumps hemolymph through open system Hemoglobin can make shrimp pink Oxygen Regulation Feet are primary gills, but entire surface can respire Water, Salts and Waste Very little is known about the osmotic regulation of most fairy shrimp

11 Biology of Fairy Shrimp Reproduction Males constantly in search of females Females use antennae ornamentation to determine a suitable, mature mate Mating behavior actions Detection, Orientation, Station-taking, Clasping, Copulation, Ejaculation Disengagement

12 Reproduction of Fairy Shrimp So what really happens? Detection Orientation Station-taking Clasping Copulation Ejaculation Disengagement

13 Production of Cysts

14 Fairy Shrimp Cysts

15 Hatching of Fairy Shrimp Cysts

16 Immature Fairy Shrimp Nauplius

17 Immature Fairy Shrimp Metanauplius

18 Vernal Pool Tadpole Shrimp General Biology Contains large amounts of hemoglobin Molts its exoskeleton as it grows Grows more phyllopods with each molt Three sexes Males, females and hermaphrodites Females & hermaphrodites have 2 ovisacks

19 Maturation Time for Shrimp Linderiella occidentalis California fairy shrimp days, can have multiple hatchings Branchinecta lynchi vernal pool fairy shrimp 6-16 days, single hatching, temperature sensitive Lepidurus packardi vernal pool tadpole shrimp days, can live 144 days, multiple hatchings Extremes Branchinecta mesovallensis, B. conservatio

20 Ecology of Large Branchiopods Ephemeral freshwater systems Vernal pools, potholes, snow melt ponds Primary consumers in the food chain Filter feeders phyto & zooplankton Munch anything that will fit in mandibles Some are predators of other fairy shrimp Essential food chain services Birds, bugs and beetles

21 Worldwide distribution of Anostraca Southern Africa 45 species (38 endemic) Western US & Baja ~28 species (15 endemic) Southwestern Australia 19 species (12 endemic) Argentina 18 species (14 endemic) Italy & southwestern France 16 species (7 endemic) Total # species 286 Yet to be described ~300 Important group of freshwater habitats in temperate zones

22 California distribution of Anostraca Primarily central valley 28 species 15 endemics 5 listed under the federal Endangered Species Act

23 Endangered Species Act

24 Endangered 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

25 Endangered 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

26 Section 10(a) Recovery Permits Allows take to occur if it is considered beneficial to species recovery Educational permits Geographically 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

27 Shrimp Fairy

28 VernalPools.Org dedicated to saving California s vernal pool landscapes