| Report Year: 2009 |
| Arrowhead Lake (Sac), Sac County |
| Zooplankton |
| | 6/1/2009 | 7/6/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Suborder/Genus | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) | Dry Mass (μg/L) |
| Cladocera |
| Bosmina | 3.090 | 0.000 | 1.545 | 3.956 | 1.044 | 2.157 | 19.226 | 39.802 | 1.672 | 0.557 | 0.000 |
| Ceriodaphnia | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 2.001 | 17.060 | 0.000 | 0.000 | 0.000 | 0.000 |
| Daphnia | 106.470 | 198.286 | 152.378 | 74.263 | 102.197 | 47.130 | 31.344 | 17.404 | 110.811 | 26.583 | 23.725 |
| Copepoda |
| Calanoida | 56.175 | 64.046 | 60.110 | 9.412 | 33.847 | 16.776 | 87.184 | 103.232 | 60.069 | 1.375 | 21.499 |
| Cyclopoida | 4.795 | 25.827 | 15.311 | 8.572 | 0.505 | 4.202 | 57.144 | 1.078 | 13.986 | 12.461 | 9.533 |
| Nauplii | 3.119 | 7.339 | 5.229 | 5.589 | 5.235 | 17.583 | 12.230 | 11.366 | 7.718 | 1.363 | 4.781 |
| Nauplii |
| Nauplii | 3.119 | 7.339 | 5.229 | 5.589 | 5.235 | 17.583 | 12.230 | 11.366 | 7.718 | 1.363 | 4.781 |
| Rotifera |
| Ascomorpha | 0.000 | 2.432 | 1.216 | 0.032 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 |
| Asplanchna | 0.000 | 0.000 | 0.000 | 8.313 | 14.816 | 1.113 | 0.000 | 0.000 | 0.020 | 0.306 | 0.000 |
| Brachionus | 0.000 | 0.243 | 0.121 | 0.009 | 0.003 | 0.000 | 0.000 | 0.000 | 0.000 | 0.025 | 0.000 |
| Conochilus | 0.000 | 0.000 | 0.000 | 0.000 | 0.010 | 0.001 | 0.005 | 0.000 | 0.004 | 0.000 | 0.000 |
| Kellicottia | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.063 | 0.000 | 0.000 | 0.000 | 0.028 | 0.000 |
| Keratella cochlearis | 0.088 | 0.712 | 0.400 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 |
| Keratella | 0.000 | 0.000 | 0.000 | 0.324 | 0.370 | 0.221 | 3.207 | 0.965 | 0.562 | 0.084 | 0.140 |
| Lecane | 0.000 | 0.000 | 0.000 | 0.005 | 0.032 | 0.000 | 0.000 | 0.000 | 0.019 | 0.000 | 0.000 |
| Polyarthra | 0.000 | 0.042 | 0.021 | 0.725 | 0.118 | 0.097 | 1.669 | 0.235 | 0.238 | 0.000 | 0.000 |
| Pompholx | 0.000 | 0.000 | 0.000 | 0.156 | 0.004 | 0.129 | 0.042 | 0.000 | 0.000 | 0.000 | 0.000 |
| Trichocerca | 0.000 | 0.000 | 0.000 | 0.026 | 0.000 | 0.012 | 0.023 | 0.015 | 0.052 | 0.000 | 0.000 |
| Total | 173.737 | 298.926 | 236.332 | 111.382 | 158.181 | 91.486 | 229.133 | 174.096 | 195.151 | 42.783 | 59.678 |
| Large Suspension Feeders (%) | 61 | 66 | 64 | 47 | 65 | 38 | 25 | 21 | 51 | 69 | 35 |
| Taxonomic Richness | 6 | 8 | 7 | 8 | 8 | 8 | 10 | 6 | 7 | 6 | 5 |
|