MANTECA — Kneeling on the bank of the San Joaquin River, groups of Stockton fourth-graders peered through magnifying glasses to investigate how critters collected in little capsules can thrive in their ecosystem.Among the creatures scooped from the water and studied by the John McCandless STEM Charter students were tadpoles, algae and a wide variety of small insects."Its fun, you get to see things with your own eyes," 9-year-old Edgar Zatarian said as the [...]